GNU Gnulib

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GNU Gnulib

This manual is for GNU Gnulib (updated 2024-07-01 14:48:34), which is a library of common routines intended to be shared at the source level.

Copyright © 2004–2024 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License”.

Table of Contents

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1 Brief Overview

Gnulib is a source code library that provides basic functionality to programs and libraries. Many software packages make use of Gnulib to avoid reinventing the portability wheel.

Resources:

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1.1 Gnulib Basics

While portability across operating systems is not one of GNU’s primary goals, it has helped introduce many people to the GNU system, and is worthwhile when it can be achieved at a low cost. This collection helps lower that cost.

Gnulib is intended to be the canonical source for most of the important “portability” and/or common files for GNU projects. These are files intended to be shared at the source level; Gnulib is not a typical library meant to be installed and linked against. Thus, unlike most projects, Gnulib does not normally generate a source tarball distribution; instead, developers grab modules directly from the source repository.

The easiest, and recommended, way to do this is to use the gnulib-tool script. Since there is no installation procedure for Gnulib, gnulib-tool needs to be run directly in the directory that contains the Gnulib source code. You can do this either by specifying the absolute filename of gnulib-tool, or by using a symbolic link from a place inside your PATH to the gnulib-tool file of your preferred Gnulib checkout. For example: 

$ ln -s $HOME/gnu/src/gnulib.git/gnulib-tool $HOME/bin/gnulib-tool

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1.2 Git Checkout

Gnulib is available for anonymous checkout. In any Bourne-shell the following should work: 

$ git clone https://git.savannah.gnu.org/git/gnulib.git

For a read-write checkout you need to have a login on ‘savannah.gnu.org’ and be a member of the Gnulib project at https://savannah.gnu.org/projects/gnulib. Then, instead of the URL https://git.savannah.gnu.org/git/gnulib.git, use the URL ‘ssh://user@git.savannah.gnu.org/srv/git/gnulib’ where user is your login name on savannah.gnu.org.

git resources:

Overview:

https://en.wikipedia.org/wiki/Git_(software)

Homepage:

https://git-scm.com/

When you use git annotate or git blame with Gnulib, it’s recommended that you use the -w option, in order to ignore massive whitespace changes that happened in 2009.

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1.3 Keeping Up-to-date

The best way to work with Gnulib is to check it out of git. To synchronize, you can use git pull.

Subscribing to the bug-gnulib@gnu.org mailing list will help you to plan when to update your local copy of Gnulib (which you use to maintain your software) from git. You can review the archives, subscribe, etc., via https://lists.gnu.org/mailman/listinfo/bug-gnulib.

Sometimes, using an updated version of Gnulib will require you to use newer versions of GNU Automake or Autoconf. You may find it helpful to join the autotools-announce mailing list to be advised of such changes.

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1.4 Contributing to Gnulib

All software here is copyrighted by the Free Software Foundation—you need to have filled out an assignment form for a project that uses the module for that contribution to be accepted here.

If you have a piece of code that you would like to contribute, please email bug-gnulib@gnu.org.

Generally we are looking for files that fulfill at least one of the following requirements:

  • If your .c and .h files define functions that are broken or missing on some other system, we should be able to include it.
  • If your functions remove arbitrary limits from existing functions (either under the same name, or as a slightly different name), we should be able to include it.

If your functions define completely new but rarely used functionality, you should probably consider packaging it as a separate library.

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1.4.1 Gnulib licensing

Gnulib contains code both under GPL and LGPL. Because several packages that use Gnulib are GPL, the files state they are licensed under GPL. However, to support LGPL projects as well, you may use some of the files under LGPL. The “License:” information in the files under modules/ clarifies the real license that applies to the module source.

Keep in mind that if you submit patches to files in Gnulib, you should license them under a compatible license, which means that sometimes the contribution will have to be LGPL, if the original file is available under LGPL via a “License: LGPL” information in the projects’ modules/ file.

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1.4.2 Indent with spaces not TABs

We use space-only indentation in nearly all files. This includes all *.h, *.c, *.y files, except for the regex module. Makefile and ChangeLog files are excluded, since TAB characters are part of their format.

In order to tell your editor to produce space-only indentation, you can use these instructions.

  • For Emacs: Add these lines to your Emacs initialization file ($HOME/.emacs or similar): 
    ;; In Gnulib, indent with spaces everywhere (not TABs).
;; Exceptions: Makefile and ChangeLog modes.
(add-hook 'find-file-hook '(lambda ()
  (if (and buffer-file-name
           (string-match "/gnulib\\>" (buffer-file-name))
           (not (string-equal mode-name "Change Log"))
           (not (string-equal mode-name "Makefile")))
      (setq indent-tabs-mode nil))))
  • For vi (vim): Add these lines to your $HOME/.vimrc file: 
    " Don't use tabs for indentation. Spaces are nicer to work with.
set expandtab

    For Makefile and ChangeLog files, compensate for this by adding this to your $HOME/.vim/after/indent/make.vim file, and similarly for your $HOME/.vim/after/indent/changelog.vim file: 

    " Use tabs for indentation, regardless of the global setting.
set noexpandtab
  • For Eclipse: In the “Window|Preferences” dialog (or “Eclipse|Preferences” dialog on Mac OS),
    1. Under “General|Editors|Text Editors”, select the “Insert spaces for tabs” checkbox.
    2. Under “C/C++|Code Style”, select a code style profile that has the “Indentation|Tab policy” combobox set to “Spaces only”, such as the “GNU [built-in]” policy.

    If you use the GNU indent program, pass it the option --no-tabs.

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1.4.3 How to add a new module

  • Add the header files and source files to lib/.
  • If the module needs configure-time checks, write an Autoconf macro for it in m4/module.m4. See m4/README for details.
  • Write a module description modules/module, based on modules/TEMPLATE.
  • If the module contributes a section to the end-user documentation, put this documentation in doc/module.texi and add it to the “Files” section of modules/module. Most modules don’t do this; they have only documentation for the programmer (= Gnulib user). Such documentation usually goes into the lib/ source files. It may also go into doc/; but don’t add it to the module description in this case.
  • Add the module to the list in MODULES.html.sh.

You can test that a module builds correctly with: 

$ ./gnulib-tool --create-testdir --dir=/tmp/testdir module1 ... moduleN
$ cd /tmp/testdir
$ ./configure && make

Other things:

  • Check the license and copyright year of headers.
  • Check that the source code follows the GNU coding standards; see https://www.gnu.org/prep/standards.
  • Add source files to config/srclist* if they are identical to upstream and should be upgraded in Gnulib whenever the upstream source changes.
  • Include header files in source files to verify the function prototypes.
  • Make sure a replacement function doesn’t cause warnings or clashes on systems that have the function.
  • Autoconf functions can use ‘gl_*’ prefix. The ‘AC_*’ prefix is for autoconf internal functions.
  • Build files only if they are needed on a platform. Look at the alloca and fnmatch modules for how to achieve this. If for some reason you cannot do this, and you have a .c file that leads to an empty .o file on some platforms (through some big #if around all the code), then ensure that the compilation unit is not empty after preprocessing. One way to do this is to #include <stddef.h> or <stdio.h> before the big #if.

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1.5 Portability guidelines

Gnulib code is intended to be portable to a wide variety of platforms, not just GNU platforms. Gnulib typically attempts to support a platform as long as it is still supported by its provider, even if the platform is not the latest version. See Target Platforms.

Many Gnulib modules exist so that applications need not worry about undesirable variability in implementations. For example, an application that uses the malloc module need not worry about malloc (0) returning a null pointer on some Standard C platforms; and glob users need not worry about glob silently omitting symbolic links to nonexistent files on some platforms that do not conform to POSIX.

Gnulib code is intended to port without problem to new hosts, e.g., hosts conforming to recent C and POSIX standards. Hence Gnulib code should avoid using constructs that these newer standards no longer require, without first testing for the presence of these constructs. For example, because C11 made variable length arrays optional, Gnulib code should avoid them unless it first uses the vararrays module to check whether they are supported.

The following subsections discuss some exceptions and caveats to the general Gnulib portability guidelines.

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1.5.1 C language versions

Currently Gnulib assumes at least a freestanding C99 compiler, possibly operating with a C library that predates C99; with time this assumption will likely be strengthened to later versions of the C standard. Old platforms currently supported include AIX 6.1, HP-UX 11i v1 and Solaris 10, though these platforms are rarely tested. Gnulib itself is so old that it contains many fixes for obsolete platforms, fixes that may be removed in the future.

Because of the freestanding C99 assumption, Gnulib code can include <float.h>, <limits.h>, <stdarg.h>, <stddef.h>, and <stdint.h> unconditionally; <stdbool.h> is also in the C99 freestanding list but is obsolescent as of C23. Gnulib code can also assume the existence of <ctype.h>, <errno.h>, <fcntl.h>, <locale.h>, <signal.h>, <stdio.h>, <stdlib.h>, <string.h>, and <time.h>. Similarly, many modules include <sys/types.h> even though it’s not even in C11; that’s OK since <sys/types.h> has been around nearly forever.

Even if the include files exist, they may not conform to the C standard. However, GCC has a fixincludes script that attempts to fix most conformance problems. Gnulib currently assumes include files largely conform to C99 or better. People still using ancient hosts should use fixincludes or fix their include files manually.

Even if the include files conform, the library itself may not. For example, strtod and mktime have some bugs on some platforms. You can work around some of these problems by requiring the relevant modules, e.g., the Gnulib mktime module supplies a working and conforming mktime.

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1.5.2 C99 features assumed by Gnulib

Although the C99 standard specifies many features, Gnulib code is conservative about using them, partly because Gnulib predates the widespread adoption of C99, and partly because many C99 features are not well-supported in practice. C99 features that are reasonably portable nowadays include:

  • A declaration after a statement, or as the first clause in a for statement.
  • long long int.
  • <stdbool.h>, although Gnulib code no longer uses it directly, preferring plain bool via the stdbool module instead. See stdbool.h.
  • <stdint.h>, assuming the stdint module is used. See stdint.h.
  • Compound literals and designated initializers.
  • Variadic macros.
    Note: The handling of __VA_ARGS__ in MSVC differs from the one in ISO C 99, see https://stackoverflow.com/questions/5134523/. But usually this matters only for macros that decompose __VA_ARGS__.
  • static inline functions.
  • __func__, assuming the func module is used. See func.
  • The restrict qualifier, assuming AC_REQUIRE([AC_C_RESTRICT]) is used. This qualifier is sometimes implemented via a macro, so C++ code that uses Gnulib should avoid using restrict as an identifier.
  • Flexible array members (however, see the flexmember module).

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1.5.3 C99 features avoided by Gnulib

Gnulib avoids some features even though they are standardized by C99, as they have portability problems in practice. Here is a partial list of avoided C99 features. Many other C99 features are portable only if their corresponding modules are used; Gnulib code that uses such a feature should require the corresponding module.

  • Variable length arrays (VLAs) or variably modified types, without checking whether __STDC_NO_VLA__ is defined. See the vararrays and vla modules.
  • Block-scope variable length arrays, without checking whether either GNULIB_NO_VLA or __STDC_NO_VLA__ is defined. This lets you define GNULIB_NO_VLA to pacify GCC when using its -Wvla-larger-than warnings option, and to avoid large stack usage that may have security implications. GNULIB_NO_VLA does not affect Gnulib’s other uses of VLAs and variably modified types, such as array declarations in function prototype scope.
  • Converting to pointers via integer types other than intptr_t or uintptr_t. Although the C standard says that values of these integer types, if they exist, should be convertible to and from intmax_t and uintmax_t without loss of information, on CHERI platforms such conversions result in integers that, if converted back to a pointer, cannot be dereferenced.
  • extern inline functions, without checking whether they are supported. See Extern inline functions.
  • Type-generic math functions.
  • Universal character names in source code.
  • <iso646.h>, since GNU programs need not worry about deficient source-code encodings.
  • Comments beginning with ‘//’. This is mostly for style reasons.

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1.5.4 Other portability assumptions made by Gnulib

Gnulib code makes the following assumptions that go beyond what C and POSIX require:

  • Standard internal types like ptrdiff_t and size_t are no wider than long. The GNU coding standards allow code to make this assumption, POSIX requires implementations to support at least one programming environment where this is true, and such environments are recommended for Gnulib-using applications. When it is easy to port to non-POSIX platforms like MinGW where these types are wider than long, new Gnulib code should do so, e.g., by using ptrdiff_t instead of long. However, it is not always that easy, and no effort has been made to check that all Gnulib modules work on MinGW-like environments.
  • int and unsigned int are at least 32 bits wide. POSIX and the GNU coding standards both require this.
  • Signed integer arithmetic is two’s complement.

    Previously, Gnulib code sometimes also assumed that signed integer arithmetic wraps around, but modern compiler optimizations sometimes do not guarantee this, and Gnulib code with this assumption is now considered to be questionable. See Integer Properties.

    Although some Gnulib modules contain explicit support for ones’ complement and signed magnitude integer representations, which are allowed by C17 and earlier, these modules are the exception rather than the rule. All practical Gnulib targets use two’s complement, which is required by C23.

  • There are no “holes” in integer values: all the bits of an integer contribute to its value in the usual way. In particular, an unsigned type and its signed counterpart have the same number of bits when you count the latter’s sign bit. (As an exception, Gnulib code is portable to CHERI platforms even though this assumption is false for CHERI.)
  • Objects with all bits zero are treated as zero or as null pointers. For example, memset (A, 0, sizeof A) initializes an array A of pointers to null pointers.
  • The types intptr_t and uintptr_t exist, and pointers can be converted to and from these types without loss of information.
  • Addresses and sizes behave as if objects reside in a flat address space. In particular:
    • If two nonoverlapping objects have sizes S and T represented as ptrdiff_t or size_t values, then S + T cannot overflow.
    • A pointer P points within an object O if and only if (char *) &O <= (char *) P && (char *) P < (char *) (&O + 1).
    • Arithmetic on a valid pointer is equivalent to the same arithmetic on the pointer converted to uintptr_t, except that offsets are multiplied by the size of the pointed-to objects. For example, if P + I is a valid expression involving a pointer P and an integer I, then (uintptr_t) (P + I) == (uintptr_t) ((uintptr_t) P + I * sizeof *P). Similar arithmetic can be done with intptr_t, although more care must be taken in case of integer overflow or negative integers.
    • A pointer P has alignment A if and only if (uintptr_t) P % A is zero, and similarly for intptr_t.
    • If an existing object has size S, and if T is sufficiently small (e.g., 8 KiB), then S + T cannot overflow. Overflow in this case would mean that the rest of your program fits into T bytes, which can’t happen in realistic flat-address-space hosts.
    • Adding zero to a null pointer does not change the pointer. For example, 0 + (char *) NULL == (char *) NULL.

Some system platforms violate these assumptions and are therefore not Gnulib porting targets. See Unsupported Platforms.

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1.6 High Quality

We develop and maintain a testsuite for Gnulib. The goal is to have a 100% firm interface so that maintainers can feel free to update to the code in git at any time and know that their application will not break. This means that before any change can be committed to the repository, a test suite program must be produced that exposes the bug for regression testing.

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1.6.1 Stable Branches

In Gnulib, we don’t use topic branches for experimental work. Therefore, occasionally a broken commit may be pushed in Gnulib. It does not happen often, but it does happen.

To compensate for this, Gnulib offers “stable branches”. These are branches of the Gnulib code that are maintained over some longer period (a year, for example) and include

  • bug fixes,
  • portability enhancements (to existing as well as to new platforms),
  • updates to config.guess and config.sub.

Not included in the stable branches are:

  • new features, such as new modules,
  • optimizations,
  • refactorings,
  • complex or risky changes in general,
  • updates to texinfo.tex,
  • documentation updates.

So far, we have six stable branches:

stable-202407

A stable branch that starts at the beginning of July 2024.

stable-202401

A stable branch that starts at the beginning of January 2024.

stable-202307

A stable branch that starts at the beginning of July 2023. It is no longer updated.

stable-202301

A stable branch that starts at the beginning of January 2023. It is no longer updated.

stable-202207

A stable branch that starts at the beginning of July 2022. It is no longer updated.

stable-202201

A stable branch that starts at the beginning of January 2022. It is no longer updated.

The two use-cases of stable branches are thus:

  • You want to protect yourself from occasional breakage in Gnulib.
  • When making a bug-fix release of your code, you can incorporate bug fixes in Gnulib, by pulling in the newest commits from the same stable branch that you were already using for the previous release.

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1.6.2 Writing reliable code

When compiling and testing Gnulib and Gnulib-using programs, certain compiler options can help improve reliability. First of all, make it a habit to use ‘-Wall’ in all compilation commands. Beyond that, the manywarnings module enables several forms of static checking in GCC and related compilers (see manywarnings).

For dynamic checking, you can run configure with CFLAGS options appropriate for your compiler. For example: 

./configure \
 CPPFLAGS='-Wall'\
 CFLAGS='-g3 -O2'\
' -D_FORTIFY_SOURCE=2'\
' -fsanitize=undefined'\
' -fsanitize-undefined-trap-on-error'

Here:

  • -D_FORTIFY_SOURCE=2 enables extra security hardening checks in the GNU C library.
  • -fsanitize=undefined enables GCC’s undefined behavior sanitizer (ubsan), and
  • -fsanitize-undefined-trap-on-error causes ubsan to abort the program (through an “illegal instruction” signal). This measure stops exploit attempts and also allows you to debug the issue.

Without the -fsanitize-undefined-trap-on-error option, -fsanitize=undefined causes messages to be printed, and execution continues after an undefined behavior situation. The message printing causes GCC-like compilers to arrange for the program to dynamically link to libraries it might not otherwise need. With GCC, instead of -fsanitize-undefined-trap-on-error you can use the -static-libubsan option to arrange for two of the extra libraries (libstdc++ and libubsan) to be linked statically rather than dynamically, though this typically bloats the executable and the remaining extra libraries are still linked dynamically.

It is also good to occasionally run the programs under valgrind (see Running self-tests under valgrind).

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1.7 Join the GNU Project

GNU Gnulib is part of the GNU Operating System, developed by the GNU Project.

If you are the author of an awesome program and want to join us in writing Free (libre) Software, please consider making it an official GNU program and become a GNU Maintainer. Instructions on how to do this are here. We are looking forward to hacking with you!

Don’t have a program to contribute? Look at all the other ways to help.

And to learn more about Free (libre) Software in general, please read and share this page.

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2 Philosophy

Gnulib’s design and development philosophy is organized around steady, collaborative, and open development of reusable modules that are suitable for a reasonably wide variety of platforms.

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2.1 Benefits of using Gnulib

Gnulib is useful to enhance various aspects of a package:

  • Portability: With Gnulib, a package maintainer can program against the POSIX and GNU libc APIs and nevertheless expect good portability to platforms that don’t implement POSIX.
  • Maintainability: When a package uses modules from Gnulib instead of code written specifically for that package, the maintainer has less code to maintain.
  • Security: Gnulib provides functions that are immune against vulnerabilities that plague the uses of the corresponding commonplace functions. For example, asprintf, canonicalize_file_name are not affected by buffer sizing problems that affect sprintf, realpath. openat does not have the race conditions that open has. Etc.
  • Reliability: Gnulib provides functions that combine a call to a system function with a check of the result. Examples are xalloc, xprintf, xstrtod, xgetcwd.
  • Structure: Gnulib offers a way to structure code into modules, typically one include file, one source code file, and one autoconf macro for each functionality. Modularity helps maintainability.

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2.2 Library vs. Reusable Code

Classical libraries are installed as binary object code. Gnulib is different: It is used as a source code library. Each package that uses Gnulib thus ships with part of the Gnulib source code. The used portion of Gnulib is tailored to the package: A build tool, called gnulib-tool, is provided that copies a tailored subset of Gnulib into the package.

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2.3 Portability and Application Code

One of the goals of Gnulib is to make portable programming easy, on the basis of the standards relevant for GNU (and Unix). The objective behind that is to avoid a fragmentation of the user community into disjoint user communities according to the operating system, and instead allow synergies between users on different operating systems.

Another goal of Gnulib is to provide application code that can be shared between several applications. Some people wonder: "What? glibc doesn’t have a function to copy a file?" Indeed, the scope of a system’s libc is to implement the relevant standards (ISO C, POSIX) and to provide access functions to the kernel’s system calls, and little more.

There is no clear borderline between both areas.

For example, Gnulib has a facility for generating the name of backup files. While this task is entirely at the application level—no standard specifies an API for it—the naïve code has some portability problems because on some platforms the length of file name components is limited to 30 characters or so. Gnulib handles that.

Similarly, Gnulib has a facility for executing a command in a subprocess. It is at the same time a portability enhancement (it works on GNU, Unix, and Windows, compared to the classical fork/exec idiom which is not portable to Windows), as well as an application aid: it takes care of redirecting stdin and/or stdout if desired, and emits an error message if the subprocess failed.

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2.4 Target Platforms

Gnulib supports a number of platforms that we call the “reasonable portability targets”. This class consists of widespread operating systems, for three years after their last availability, or—for proprietary operating systems—as long as the vendor provides commercial support for it. Already existing Gnulib code for older operating systems is usually left in place for longer than these three years. So it comes that programs that use Gnulib run pretty well also on these older operating systems.

Some operating systems are not very widespread, but are Free Software and are actively developed. Such platforms are also supported by Gnulib, if that OS’s developers community keeps in touch with the Gnulib developers, by providing bug reports, analyses, or patches. For such platforms, Gnulib supports only the versions of the last year or the last few months, depending on the maturity of said OS project, the number of its users, and how often these users upgrade.

Niche operating systems are generally unsupported by Gnulib, unless some of their developers or users contribute support to Gnulib.

The degree of support Gnulib guarantees for a platform depends on the amount of testing it gets from volunteers. Platforms on which Gnulib is frequently tested are the best supported. Then come platforms with occasional testing, then platforms which are rarely tested. Usually, we fix bugs when they are reported. Except that some rarely tested platforms are also low priority; bug fixes for these platforms can take longer.

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2.4.1 Supported Platforms

As of 2024, the list of supported platforms is the following:

  • glibc systems. With glibc 2.19 or newer, they are frequently tested. About the kernels:
    • glibc on Linux is frequently tested.
    • glibc on kFreeBSD is rarely tested.
    • musl libc on Linux is occasionally tested.
  • macOS. In versions 12.5, it’s occasionally tested. In version 10.5, it’s rarely tested.
  • FreeBSD 14.0 or newer is occasionally tested.
  • OpenBSD 7.0 or newer is occasionally tested.
  • NetBSD 10.0 or newer is occasionally tested.
  • AIX 7.1 and 7.3 are occasionally tested.
  • Solaris 10 and 11.4 are occasionally tested. Solaris 9 is rarely tested and low priority.
  • Android is occasionally tested, through the Termux app on Android 11.
  • Cygwin 2.9 and 3.4 are occasionally tested. Cygwin 1.7.x no longer tested.
  • Native Windows:
    • mingw is occasionally tested. Only the latest version of mingw is tested; older versions are not supported.
    • MSVC 14 (Microsoft Visual Studio 2015 14.0) is occasionally tested. Only “release” builds (compiler option ‘-MD’) are supported, not “debug” builds (compiler option ‘-MDd’).

    Note that some modules are currently unsupported on native Windows: mgetgroups, getugroups, idcache, userspec, openpty, login_tty, forkpty, pt_chown, grantpt, pty, savewd, mkancesdirs, mkdir-p, euidaccess, faccessat. The versions of Windows that are supported are Windows 10 and newer.

  • GNU Hurd 0.9 is rarely tested.
  • Minix 3.3.0 is no longer tested.
  • Haiku is no longer tested.
  • uClibc on Linux is no longer tested.
  • QNX is no longer tested.

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2.4.2 Formerly Supported Platforms

The following platforms were supported in the past, but are no longer supported:

  • glibc versions 2.1.x and older.
  • Mac OS X 10.4 and older.
  • AIX 6 and older.
  • HP-UX 11.31.
  • IRIX 6.5 and older.
  • OSF/1 5.1.
  • Solaris 8 and older.
  • Interix.
  • BeOS.

Gnulib supports these operating systems only in an unvirtualized environment. When you run an OS inside a virtual machine, you have to be aware that the virtual machine can bring in bugs of its own. For example, floating-point operations on Solaris can behave slightly differently in QEMU than on real hardware. And Haiku’s bash program misbehaves in VirtualBox 3, whereas it behaves fine in VirtualBox 4.

Similarly, running native Windows binaries on GNU/Linux under WINE is rarely tested and low priority: WINE has a set of behaviours and bugs that is slightly different from native Windows.

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2.4.3 Unsupported Platforms

Some platforms with C compilers are not supported by Gnulib because the platforms violate Gnulib’s C portability assumptions. See Other portability assumptions made by Gnulib.

These assumptions are not required by the C or POSIX standards but hold on almost all practical porting targets. If you need to port Gnulib code to a platform where these assumptions are not true, we would appreciate hearing of any fixes. We need fixes that do not increase runtime overhead on standard hosts and that are relatively easy to maintain.

These platforms are listed below to illustrate problems that Gnulib and Gnulib-using code would have if it were intended to be portable to all practical POSIX or C platforms.

  • Clang’s -fsanitize=undefined option causes the program to crash if it adds zero to a null pointer – behavior that is undefined in strict C, but which yields a null pointer on all practical porting targets and which the Gnulib portability guidelines allow.

    If you use Clang with -fsanitize=undefined, you can work around the problem by also using ‘-fno-sanitize=pointer-overflow’, although this may also disable some unrelated and useful pointer checks. Perhaps someday the Clang developers will fix the infelicity.

  • The IBM i’s pointers are 128 bits wide and it lacks the two types intptr_t and uintptr_t, which are optional in the C and POSIX standards. However, these two types are required for the XSI extension to POSIX, and many Gnulib modules use them. To work around this compatibility problem, Gnulib-using applications can be run on the IBM i’s PASE emulation environment. The IBM i’s architecture descends from the System/38 (1978).
  • The Unisys ClearPath Dorado’s machine word is 36 bits. Its signed integers use a ones’-complement representation. On these machines, CHAR_BIT == 9 and INT_MIN == -INT_MAX. By default UINT_MAX is 2^{36} - 2, which does not conform to the C requirement that it be one less than a power of two. Although compiler options can raise UINT_MAX to be 2^{36} - 1, this can break system code that uses -0 as a flag value. This platform’s architecture descends from the UNIVAC 1103 (1953).
  • The Unisys ClearPath Libra’s machine word is 48 bits with a 4-bit tag and a 4-bit data extension. Its unsigned int uses the low-order 40 bits of the word, and int uses the low-order 41 bits of the word with a signed-magnitude representation. On these machines, INT_MAX == UINT_MAX, INT_MIN == -INT_MAX, and sizeof (int) == 6. This platform’s architecture descends from the Burroughs B5000 (1961).

The following platforms are not supported by Gnulib. The cost of supporting them would exceed the benefit because they are rarely used, or poorly documented, or have been supplanted by other platforms, or diverge too much from POSIX, or some combination of these and other factors. Please don’t bother sending us patches for them.

  • Windows 95/98/ME.
  • DJGPP and EMX (the 32-bit operating systems running in DOS).
  • MSDOS (the 16-bit operating system).
  • Windows Mobile, Symbian OS, iOS.

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2.5 Modules

Gnulib is divided into modules. Every module implements a single facility. Modules can depend on other modules.

A module consists of a number of files and a module description. The files are copied by gnulib-tool into the package that will use it, usually verbatim, without changes. Source code files (.h, .c files) reside in the lib/ subdirectory. Autoconf macro files reside in the m4/ subdirectory. Build scripts reside in the build-aux/ subdirectory.

The module description contains the list of files; gnulib-tool copies these files. It contains the module’s dependencies; gnulib-tool installs them as well. It also contains the autoconf macro invocation (usually a single line or nothing at all); gnulib-tool ensures this is invoked from the package’s configure.ac file. And also a Makefile.am snippet; gnulib-tool collects these into a Makefile.am for the tailored Gnulib part. The module description and include file specification are for documentation purposes; they are combined into MODULES.html.

The module system serves two purposes:

  1. It ensures consistency of the used autoconf macros and Makefile.am rules with the source code. For example, source code which uses the getopt_long function—this is a common way to implement parsing of command line options in a way that complies with the GNU standards—needs the source code (lib/getopt.c and others), the autoconf macro which detects whether the system’s libc already has this function (in m4/getopt.m4), and a few Makefile.am lines that create the substitute getopt.h if not. These three pieces belong together. They cannot be used without each other. The module description and gnulib-tool ensure that they are copied altogether into the destination package.
  2. It allows for scalability. It is well-known since the inception of the MODULA-2 language around 1978 that dissection into modules with dependencies allows for building large sets of code in a maintainable way. The maintainability comes from the facts that:
    • Every module has a single purpose; you don’t worry about other parts of the program while creating, reading or modifying the code of a module.
    • The code you have to read in order to understand a module is limited to the source of the module and the .h files of the modules listed as dependencies. It is for this reason also that we recommend to put the comments describing the functions exported by a module into its .h file.

    In other words, the module is the elementary unit of code in Gnulib, comparable to a class in object-oriented languages like Java or C#.

The module system is the basis of gnulib-tool. When gnulib-tool copies a part of Gnulib into a package, it first compiles a module list, starting with the requested modules and adding all the dependencies, and then collects the files, configure.ac snippets and Makefile.am snippets.

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2.6 Various Kinds of Modules

There are modules of various kinds in Gnulib. For a complete list of the modules, see in MODULES.html.

2.6.1 Support for ISO C or POSIX functions.

When a function is not implemented by a system, the Gnulib module provides an implementation under the same name. Examples are the ‘snprintf’ and ‘readlink’ modules.

Similarly, when a function is not correctly implemented by a system, Gnulib provides a replacement. For functions, we use the pattern 

#if !HAVE_WORKING_FOO
# define foo rpl_foo
#endif

and implement the foo function under the name rpl_foo. This renaming is needed to avoid conflicts at compile time (in case the system header files declare foo) and at link/run time (because the code making use of foo could end up residing in a shared library, and the executable program using this library could be defining foo itself).

For header files, such as stdint.h, we provide the substitute only if the system doesn’t provide a correct one. The template of this replacement is distributed in a slightly different name, with ‘.in’ inserted before the ‘.h’ extension, so that on systems which do provide a correct header file the system’s one is used.

The modules in this category are supported in C++ mode as well. This means, while the autoconfiguration uses the C compiler, the resulting header files and function substitutes can be used with a matching C++ compiler as well.

2.6.2 Enhancements of ISO C or POSIX functions

These are sometimes POSIX functions with GNU extensions also found in glibc—examples: ‘getopt’, ‘fnmatch’—and often new APIs—for example, for all functions that allocate memory in one way or the other, we have variants which also include the error checking against the out-of-memory condition.

2.6.3 Portable general use facilities

Examples are a module for copying a file—the portability problems relate to the copying of the file’s modification time, access rights, and extended attributes—or a module for extracting the tail component of a file name—here the portability to native Windows requires a different API than the classical POSIX basename function.

2.6.4 Reusable application code

Examples are an error reporting function, a module that allows output of numbers with K/M/G suffixes, or cryptographic facilities.

2.6.5 Object oriented classes

Examples are data structures like ‘list’, or abstract output stream classes that work around the fact that an application cannot implement an stdio FILE with its logic. Here, while staying in C, we use implementation techniques like tables of function pointers, known from the C++ language or from the Linux kernel.

2.6.6 Interfaces to external libraries

Examples are the ‘iconv’ module, which interfaces to the iconv facility, regardless whether it is contained in libc or in an external libiconv. Or the ‘readline’ module, which interfaces to the GNU readline library.

2.6.7 Build / maintenance infrastructure

An example is the ‘maintainer-makefile’ module, which provides extra Makefile tags for maintaining a package.

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2.7 Collaborative Development

Gnulib is maintained collaboratively. The mailing list is <bug-gnulib at gnu dot org>. Be warned that some people on the list may be very active at some times and unresponsive at other times.

Every module has one or more maintainers. While issues are discussed collaboratively on the list, the maintainer of a module nevertheless has a veto right regarding changes in his module.

All patches should be posted to the list, regardless whether they are proposed patches or whether they are committed immediately by the maintainer of the particular module. The purpose is not only to inform the other users of the module, but mainly to allow peer review. It is not uncommon that several people contribute comments or spot bugs after a patch was proposed.

Conversely, if you are using Gnulib, and a patch is posted that affects one of the modules that your package uses, you have an interest in proofreading the patch.

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2.9 Steady Development

Gnulib modules are continually adapted, to match new practices, to be consistent with newly added modules, or simply as a response to build failure reports.

If you are willing to report an occasional regression, we recommend to use the newest version from git always, except in periods of major changes. Most Gnulib users do this.

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2.10 Openness

Gnulib is open in the sense that we gladly accept contributions if they are generally useful, well engineered, and if the contributors have signed the obligatory papers with the FSF.

The module system is open in the sense that a package using Gnulib can

  1. locally patch or override files in Gnulib,
  2. locally add modules that are treated like Gnulib modules by gnulib-tool.

This is achieved by the ‘--local-dir’ option of gnulib-tool (see Extending Gnulib).

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3 Invoking gnulib-tool

The gnulib-tool command is the recommended way to import Gnulib modules. It is possible to borrow Gnulib modules in a package without using gnulib-tool, relying only on the meta-information stored in the modules/* files, but with a growing number of modules this becomes tedious. gnulib-tool simplifies the management of source files, Makefile.ams and configure.ac in packages incorporating Gnulib modules.

gnulib-tool is not installed in a standard directory that is contained in the PATH variable. It needs to be run directly in the directory that contains the Gnulib source code. You can do this either by specifying the absolute filename of gnulib-tool, or you can also use a symbolic link from a place inside your PATH to the gnulib-tool file of your preferred and most up-to-date Gnulib checkout, like this: 

$ ln -s $HOME/gnu/src/gnulib.git/gnulib-tool $HOME/bin/gnulib-tool

Run ‘gnulib-tool --help’ for information. To get familiar with gnulib-tool without affecting your sources, you can also try some commands with the option ‘--dry-run’; then gnulib-tool will only report which actions it would perform in a real run without changing anything.

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3.1 Finding modules

There are four ways of finding the names of Gnulib modules that you can use in your package:

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3.2 Initial import

Gnulib assumes that your project uses Autoconf. When using Gnulib, you will need to have Autoconf among your build tools.

Gnulib also assumes that your project’s configure.ac contains the line 

AC_CONFIG_HEADERS([config.h])

The config.h file gets generated with platform dependent C macro definitions, and the source files include it (see Changing your sources for use with Gnulib).

Unless you use gnulib-tool’s --gnu-make option, Gnulib also assumes that your project uses Automake at least in a subdirectory of your project. While the use of Automake in your project’s top level directory is an easy way to fulfil the Makefile conventions of the GNU coding standards, Gnulib does not require it.

Invoking ‘gnulib-tool --import’ will copy source files, create a Makefile.am to build them, generate a file gnulib-comp.m4 with Autoconf M4 macro declarations used by configure.ac, and generate a file gnulib-cache.m4 containing the cached specification of how Gnulib is used.

Our example will be a library that uses Autoconf, Automake and Libtool. It calls strdup, and you wish to use gnulib to make the package portable to C99 and C11 (which don’t have strdup). 

~/src/libfoo$ gnulib-tool --import strdup
Module list with included dependencies:
  absolute-header
  extensions
  strdup
  string
File list:
  lib/dummy.c
  lib/strdup.c
  lib/string.in.h
  m4/absolute-header.m4
  m4/extensions.m4
  m4/gnulib-common.m4
  m4/strdup.m4
  m4/string_h.m4
Creating directory ./lib
Creating directory ./m4
Copying file lib/dummy.c
Copying file lib/strdup.c
Copying file lib/string.in.h
Copying file m4/absolute-header.m4
Copying file m4/extensions.m4
Copying file m4/gnulib-common.m4
Copying file m4/gnulib-tool.m4
Copying file m4/strdup.m4
Copying file m4/string_h.m4
Creating lib/Makefile.am
Creating m4/gnulib-cache.m4
Creating m4/gnulib-comp.m4
Finished.

You may need to add #include directives for the following .h files.
  #include <string.h>

Don't forget to
  - add "lib/Makefile" to AC_CONFIG_FILES in ./configure.ac,
  - mention "lib" in SUBDIRS in Makefile.am,
  - mention "-I m4" in ACLOCAL_AMFLAGS in Makefile.am,
    or add an AC_CONFIG_MACRO_DIRS([m4]) invocation in ./configure.ac,
  - invoke gl_EARLY in ./configure.ac, right after AC_PROG_CC,
  - invoke gl_INIT in ./configure.ac.
~/src/libfoo$

By default, the source code is copied into lib/ and the M4 macros in m4/. You can override these paths by using --source-base=DIRECTORY and --m4-base=DIRECTORY. Some modules also provide other files necessary for building. These files are copied into the directory specified by ‘AC_CONFIG_AUX_DIR’ in configure.ac or by the --aux-dir=DIRECTORY option. If neither is specified, the current directory is assumed.

gnulib-tool can make symbolic links instead of copying the source files. The option to specify for this is ‘--symlink’, or ‘-s’ for short. This can be useful to save a few kilobytes of disk space. But it is likely to introduce bugs when gnulib is updated; it is more reliable to use ‘gnulib-tool --update’ (see below) to update to newer versions of gnulib. Furthermore it requires extra effort to create self-contained tarballs, and it may disturb some mechanism the maintainer applies to the sources. For these reasons, this option is generally discouraged.

gnulib-tool will overwrite any preexisting files, in particular Makefile.am. It is also possible to separate the generated Makefile.am content (for building the gnulib library) into a separate file, say gnulib.mk, that can be included by your handwritten Makefile.am, but this is a more advanced use of gnulib-tool.

Consequently, it is a good idea to choose directories that are not already used by your projects, to separate gnulib imported files from your own files. This approach is also useful if you want to avoid conflicts between other tools (e.g., gettextize that also copy M4 files into your package. Simon Josefsson successfully uses a source base of gl/, and a M4 base of gl/m4/, in several packages.

After the ‘--import’ option on the command line comes the list of Gnulib modules that you want to incorporate in your package. The names of the modules coincide with the filenames in Gnulib’s modules/ directory.

Some Gnulib modules depend on other Gnulib modules. gnulib-tool will automatically add the needed modules as well; you need not list them explicitly. gnulib-tool will also memorize which dependent modules it has added, so that when someday a dependency is dropped, the implicitly added module is dropped as well (unless you have explicitly requested that module).

If you want to cut a dependency, i.e., not add a module although one of your requested modules depends on it, you may use the option ‘--avoid=module’ to do so. Multiple uses of this option are possible. Of course, you will then need to implement the same interface as the removed module.

A few manual steps are required to finish the initial import. gnulib-tool printed a summary of these steps.

First, you must ensure Autoconf can find the macro definitions in gnulib-comp.m4. Use the ACLOCAL_AMFLAGS specifier in your top-level Makefile.am file, as in: 

ACLOCAL_AMFLAGS = -I m4

Alternatively, add an AC_CONFIG_MACRO_DIRS invocation in your configure.ac file, as in: 

AC_CONFIG_MACRO_DIRS([m4])

You are now ready to call the M4 macros in gnulib-comp.m4 from configure.ac. The macro gl_EARLY must be called as soon as possible after verifying that the C compiler is working. Typically, this is immediately after AC_PROG_CC, as in: 

...
AC_PROG_CC
gl_EARLY
...

The core part of the gnulib checks are done by the macro gl_INIT. Place it further down in the file, typically where you normally check for header files or functions. It must come after other checks which may affect the compiler invocation, such as AC_MINIX. For example: 

...
# For gnulib.
gl_INIT
...

gl_INIT will in turn call the macros related with the gnulib functions, be it specific gnulib macros, like gl_FUNC_ALLOCA or Autoconf or Automake macros like AC_FUNC_ALLOCA or AM_FUNC_GETLINE. So there is no need to call those macros yourself when you use the corresponding gnulib modules.

You must also make sure that the gnulib library is built. Add the Makefile in the gnulib source base directory to AC_CONFIG_FILES, as in: 

AC_CONFIG_FILES(... lib/Makefile ...)

You must also make sure that make will recurse into the gnulib directory. To achieve this, add the gnulib source base directory to a SUBDIRS Makefile.am statement, as in: 

SUBDIRS = lib

or if you, more likely, already have a few entries in SUBDIRS, you can add something like: 

SUBDIRS += lib

Finally, you have to add compiler and linker flags in the appropriate source directories, so that you can make use of the gnulib library. Since some modules (‘getopt’, for example) may copy files into the build directory, top_builddir/lib is needed as well as top_srcdir/lib. For example: 

...
AM_CPPFLAGS = -I$(top_builddir)/lib -I$(top_srcdir)/lib
...
LDADD = lib/libgnu.a
...

Don’t forget to #include the various header files. In this example, you would need to make sure that ‘#include <string.h>’ is evaluated when compiling all source code files, that want to make use of strdup.

In the usual case where Autoconf is creating a config.h file, you should include config.h first, before any other include file. That way, for example, if config.h defines ‘restrict’ to be the empty string on a non-C99 host, or a macro like ‘_FILE_OFFSET_BITS’ that affects the layout of data structures, the definition is consistent for all include files. Also, on some platforms macros like ‘_FILE_OFFSET_BITS’ and ‘_GNU_SOURCE’ may be ineffective, or may have only a limited effect, if defined after the first system header file is included.

Finally, note that you cannot use AC_LIBOBJ or AC_REPLACE_FUNCS in your configure.ac and expect the resulting object files to be automatically added to lib/libgnu.a. This is because your AC_LIBOBJ and AC_REPLACE_FUNCS invocations from configure.ac augment a variable @LIBOBJS@ (and/or @LTLIBOBJS@ if using Libtool), whereas lib/libgnu.a is built from the contents of a different variable, usually @gl_LIBOBJS@ (or @gl_LTLIBOBJS@ if using Libtool).

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3.3 Modified imports

You can at any moment decide to use Gnulib differently than the last time.

There are two ways to change how Gnulib is used. Which one you’ll use, depends on where you keep track of options and module names that you pass to gnulib-tool.

  • If you store the options and module names in a file under your own control, such as autogen.sh, bootstrap, bootstrap.conf, or similar, simply invoke gnulib-tool again, with modified options and more or fewer module names.
  • gnulib-tool remembers which modules were used last time. If you want to rely on gnulib-tool’s own memory of the last used options and module names, you can use the commands gnulib-tool --add-import and gnulib-tool --remove-import.

    So, if you only want to use more Gnulib modules, simply invoke gnulib-tool --add-import new-modules. The list of modules that you pass after ‘--add-import’ is added to the previous list of modules.

    Similarly, if you want to use fewer Gnulib modules, simply invoke gnulib-tool --remove-import unneeded-modules. The list of modules that you pass after ‘--remove-import’ is removed from the previous list of modules. Note that if a module is then still needed as dependency of other modules, it will be used nevertheless. If you want to really not use a module any more, regardless of whether other modules may need it, you need to use the ‘--avoid’ option.

    For other changes, such as different choices of ‘--lib’, ‘--source-base’ or ‘--aux-dir’, the normal way is to modify manually the file gnulib-cache.m4 in the M4 macros directory, then launch ‘gnulib-tool --add-import’.

    The only change for which this doesn’t work is a change of the ‘--m4-base’ directory. Because, when you pass a different value of ‘--m4-base’, gnulib-tool will not find the previous gnulib-cache.m4 file any more. A possible solution is to manually copy the gnulib-cache.m4 into the new M4 macro directory.

    In the gnulib-cache.m4 file, the macros have the following meaning:

    gl_LOCAL_DIR

    The argument is a colon separated list of local directories where gnulib-tool will search before looking at gnulib’s directory. Corresponds to the ‘--local-dir’ command line argument.

    gl_MODULES

    The argument is a space separated list of the requested modules, not including dependencies.

    gl_WITH_OBSOLETE

    The presence of this macro corresponds to the ‘--with-obsolete’ command line argument. It takes no arguments.

    gl_WITH_CXX_TESTS

    The presence of this macro corresponds to the ‘--with-c++-tests’ command line argument and to the absence of the ‘--without-c++-tests’ command line argument. It takes no arguments.

    gl_WITH_LONGRUNNING_TESTS

    The presence of this macro corresponds to the ‘--with-longrunning-tests’ command line argument and to the absence of the ‘--without-longrunning-tests’ command line argument. It takes no arguments.

    gl_WITH_PRIVILEGED_TESTS

    The presence of this macro corresponds to the ‘--with-longrunning-tests’ command line argument and to the absence of the ‘--without-longrunning-tests’ command line argument. It takes no arguments.

    gl_WITH_UNPORTABLE_TESTS

    The presence of this macro corresponds to the ‘--with-unportable-tests’ command line argument and to the absence of the ‘--without-unportable-tests’ command line argument. It takes no arguments.

    gl_WITH_ALL_TESTS

    The presence of this macro corresponds to the ‘--with-all-tests’ command line argument. It takes no arguments.

    gl_AVOID

    The argument is a space separated list of modules that should not be used, even if they occur as dependencies. Corresponds to the ‘--avoid’ command line argument.

    gl_SOURCE_BASE

    The argument is the relative file name of the directory containing the gnulib source files (mostly *.c and *.h files). Corresponds to the ‘--source-base’ command line argument.

    gl_M4_BASE

    The argument is the relative file name of the directory containing the gnulib M4 macros (*.m4 files). Corresponds to the ‘--m4-base’ command line argument.

    gl_PO_BASE

    The argument is the relative file name of the directory containing *.po files. Corresponds to the ‘--po-base’ command line argument.

    gl_DOC_BASE

    The argument is the relative file name of the directory containing documentation files. Corresponds to the ‘--doc-base’ command line argument.

    gl_TESTS_BASE

    The argument is the relative file name of the directory containing the gnulib unit test files. Corresponds to the ‘--tests-base’ command line argument.

    gl_WITH_TESTS

    The presence of this macro corresponds to the ‘--with-tests’ command line argument. It takes no arguments.

    gl_LIB

    The argument is the name of the library to be created. Corresponds to the ‘--lib’ command line argument.

    gl_LGPL

    The presence of this macro without arguments corresponds to the ‘--lgpl’ command line argument. The presence of this macro with an argument (whose value must be 2 or 3) corresponds to the ‘--lgpl=arg’ command line argument.

    gl_MAKEFILE_NAME

    The argument is the name of the makefile in the source-base and tests-base directories. Corresponds to the ‘--makefile-name’ command line argument.

    gl_TESTS_MAKEFILE_NAME

    The argument is the name of the makefile in the tests-base directory. Corresponds to the ‘--tests-makefile-name’ command line argument.

    gl_AUTOMAKE_SUBDIR

    The presence of this macro corresponds to the ‘--automake-subdir’ command line argument. It takes no arguments.

    gl_CONDITIONAL_DEPENDENCIES

    The presence of this macro corresponds to the ‘--conditional-dependencies’ command line argument and to the absence of the ‘--no-conditional-dependencies’ command line argument. It takes no arguments.

    gl_LIBTOOL

    The presence of this macro corresponds to the ‘--libtool’ command line argument and to the absence of the ‘--no-libtool’ command line argument. It takes no arguments.

    gl_MACRO_PREFIX

    The argument is the prefix to use for macros in the gnulib-comp.m4 file. Corresponds to the ‘--macro-prefix’ command line argument.

    gl_PO_DOMAIN

    The argument is the prefix of the i18n domain, typically matching the package name. Corresponds to the ‘--po-domain’ command line argument.

    gl_WITNESS_C_MACRO

    The argument is the C macro that is defined when the sources in this directory are compiled or used. Corresponds to the ‘--witness-c-macro’ command line argument.

    gl_VC_FILES

    The argument to this macro is true or false. The former corresponds to the ‘--vc-files’ command line argument and the latter corresponds to the ‘--no-vc-files’ command line argument.

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3.4 Simple update

When you want to update to a more recent version of Gnulib, without changing the list of modules or other parameters, a simple call does it: 

$ gnulib-tool --add-import

This will create, update or remove files, as needed.

Note: From time to time, changes are made in Gnulib that are not backward compatible. When updating to a more recent Gnulib, you should consult Gnulib’s NEWS file to check whether the incompatible changes affect your project.

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3.5 Changing your sources for use with Gnulib

When you use Gnulib, you need to make some small changes to your source code base.

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3.5.1 -I options

Gnulib contains some header file overrides. This means that when building on systems with deficient header files in /usr/include/, it may create files named string.h, stdlib.h, stdint.h or similar in the build directory. In the other source directories of your package you will usually pass ‘-I’ options to the compiler, so that these Gnulib substitutes are visible and take precedence over the files in /usr/include/.

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3.5.2 Include <config.h>

These Gnulib substitute header files rely on <config.h> being already included. Furthermore <config.h> must be the first include in every compilation unit. This means that to all your source files and likely also to all your tests source files you need to add an ‘#include <config.h>’ at the top. Which source files are affected? Exactly those whose compilation includes a ‘-I’ option that refers to the Gnulib library directory.

This is annoying, but inevitable: On many systems, <config.h> is used to set system dependent flags (such as _GNU_SOURCE on GNU systems), and these flags have no effect after any system header file has been included.

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3.5.3 Style of #include statements

When including including specific header files, you need to use the ‘#include <...>’ syntax, not the ‘#include "..."’ syntax. This is true for the following POSIX or ISO C standardized header files:

  • arpa/inet.h
  • assert.h
  • ctype.h
  • dirent.h
  • endian.h
  • errno.h
  • fcntl.h
  • fenv.h
  • float.h
  • fnmatch.h
  • glob.h
  • iconv.h
  • inttypes.h
  • langinfo.h
  • limits.h
  • locale.h
  • math.h
  • monetary.h
  • netdb.h
  • net/if.h
  • netinet/in.h
  • poll.h
  • pthread.h
  • sched.h
  • search.h
  • signal.h
  • spawn.h
  • stdalign.h
  • stdarg.h
  • stdbit.h
  • stddef.h
  • stdint.h
  • stdio.h
  • stdlib.h
  • string.h
  • strings.h
  • sys/msg.h
  • sys/resource.h
  • sys/select.h
  • sys/sem.h
  • sys/shm.h
  • sys/socket.h
  • sys/stat.h
  • sys/time.h
  • sys/times.h
  • sys/types.h
  • sys/uio.h
  • sys/utsname.h
  • sys/wait.h
  • termios.h
  • threads.h
  • time.h
  • uchar.h
  • unistd.h
  • utime.h
  • wchar.h
  • wctype.h

as well as for the following header files that exist in the GNU C library but are not standardized:

  • alloca.h
  • byteswap.h
  • error.h
  • getopt.h
  • malloc.h
  • omp.h
  • pty.h
  • selinux/selinux.h
  • sys/file.h
  • sys/ioctl.h
  • sys/random.h
  • sysexits.h
  • utmp.h

The reason for this requirement is that for these header files, the Gnulib override uses #include_next to include the system-provided header of the same name, and #include_next may not work right with the ‘#include "..."’ syntax.

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3.7 Finding recommended ISO C and POSIX function substitutes

Gnulib contains a wealth of portability workarounds for ISO C and POSIX functions. They are listed in detail in the chapter ISO C and POSIX Function Substitutes. If you want to know which function substitutes are recommended for your package, you can search your source code for ISO C and POSIX functions that it uses and read the corresponding sections of said documentation chapter. But this is a tedious task. Here is an alternative approach that makes this task easier.

  1. Add the Gnulib module ‘posixcheck’ to the Gnulib imports of your package, as described earlier in this chapter.
  2. Do a make distclean if you previously built in the top-level directory. Then regenerate the Autotools-generated parts of the package.
  3. On a glibc system, build your package. Pay attention to the compiler warnings. Warnings are generated for uses of ISO C and POSIX functions that have portability problems or other important pitfalls and for which you have not yet imported the corresponding Gnulib module. If you get, say, a warning “warning: call to ’close’ declared with attribute warning: close does not portably work on sockets - use gnulib module close for portability”, put ‘close’ on your list of modules to import.
  4. Add the modules you noted to the Gnulib imports of your package.
  5. Optionally, you can do the same steps again, and make sure that there are no warnings left except those that you want to intentionally ignore.
  6. Finally, remove the Gnulib module ‘posixcheck’ from the Gnulib imports, and run make distclean.

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3.8 Modifying the build rules of a Gnulib import directory

In some cases, you may want to set additional compiler options for use within the Gnulib import directory. For example, the ‘relocatable’ module operates better if you define the C macros ENABLE_COSTLY_RELOCATABLE and INSTALLDIR during its compilation.

There are two ways to do so: Use of the gnulib-tool option --makefile-name, and a kitchen-sink module.

With the gnulib-tool option --makefile-name, you are telling gnulib-tool to generate an includable Makefile.am portion, rather than a self-contained Makefile.am. For example, when you use --makefile-name=Makefile.gnulib, gnulib-tool will generate Makefile.gnulib, and you will provide a hand-written Makefile.am that includes Makefile.gnulib through a line such as 

include Makefile.gnulib

Before this include, you need to initialize this set of Makefile.am variables:

  • AUTOMAKE_OPTIONS
  • SUBDIRS
  • noinst_HEADERS
  • noinst_LIBRARIES
  • noinst_LTLIBRARIES
  • pkgdata_DATA (only with Automake ≥ 1.11.4)
  • EXTRA_DIST
  • BUILT_SOURCES
  • SUFFIXES
  • MOSTLYCLEANFILES
  • MOSTLYCLEANDIRS
  • CLEANFILES
  • DISTCLEANFILES
  • MAINTAINERCLEANFILES
  • AM_CPPFLAGS
  • AM_CFLAGS

AUTOMAKE_OPTIONS should be initialized as described in Changing Automake’s Behavior in GNU Automake. The other variables can be initialized to empty. However, you will most likely want to initialize some of them with non-empty values, in order to achieve the desired customization.

The other approach, the kitchen-sink module, is more advanced. See chapter Extending Gnulib.

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3.9 Building directly from the top-level directory

By default, the Gnulib import directory will contain a generated Makefile.am file. After configuring, this produces a generated Makefile in this directory. As a consequence, the build from the top-level directory will use a recursive make invocation for this directory.

Some people prefer a build system where the Makefile in the top-level directory directly builds the artifacts in the subdirectories, without an intermediate make invocation. This is called “non-recursive make” and is supported by Automake. For more details, see https://autotools.io/automake/nonrecursive.html.

Gnulib supports this flavour of build system too. To use it, pass two options to gnulib-tool: ‘--makefile-name’ and ‘--automake-subdir’.

With the gnulib-tool option ‘--makefile-name’, you are telling gnulib-tool to generate an includable Makefile.am portion in the Gnulib import directory, rather than a self-contained Makefile.am. For example, when you use ‘--makefile-name=Makefile.gnulib’, gnulib-tool will generate Makefile.gnulib.

With the option ‘--automake-subdir’, you are telling gnulib-tool that you will include the generated file from the Makefile.am in the top-level directory, rather than from a Makefile.am in the same directory. For example, the top-level Makefile.am might contain this directive: 

include lib/Makefile.gnulib

The option ‘--automake-subdir’ is also supported in combination with ‘--with-tests’ (see Bundling the unit tests of the Gnulib modules). Note that in this case, however, the generated unit tests directory will contains a Makefile.am and thus use a recursive make invocation. This is not a problem, since the built artifacts of your package have no dependencies towards the Gnulib unit tests, nor vice versa.

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3.10 Using Gnulib for both a library and a program

Your project might build both a library and some accompanying programs in the same source tree. In that case you might want to use different modules for the library than for the programs. Typically the programs might want to make use of getopt-posix or version-etc, while the library wants to stay clear of these modules for technical or licensing reasons.

Let’s assume that your project contains a lib directory where the source of the library resides and a src directory for the sources of the programs as follows. 

.
|-- configure.ac
|-- lib
|   |-- foo.c
|   `-- Makefile.am
|-- Makefile.am
`-- src
    |-- bar.c
    `-- Makefile.am

You can now add two instances of Gnulib to your project in separate source trees: 

~/src/libfoo$ gnulib-tool --import --lib=libgnu --source-base=gnulib \
              --m4-base=gnulib/m4 --macro-prefix=gl strndup
~/src/libfoo$ gnulib-tool --import --lib=libgnutools \
              --source-base=src/gnulib --m4-base=src/gnulib/m4 \
              --macro-prefix=gl_tools getopt-gnu

The first one will import the module strndup in gnulib and the second one will import getopt-gnu in src/gnulib and you will end up with the following source tree (many files omitted in the interest of brevity): 

.
|-- configure.ac
|-- gnulib
|   |-- m4
|   |-- strndup.c
|-- lib
|   |-- foo.c
|   `-- Makefile.am
|-- Makefile.am
`-- src
    |-- bar.c
    |-- gnulib
    |   |-- getopt.c
    |   |-- getopt.in.h
    |   |-- m4
    `-- Makefile.am

As discussed in Bundling the unit tests of the Gnulib modules, you may not use ‘--with-tests’ for this project since the configure.ac is shared.

Integration with your code is basically the same as outlined in Initial import with the one exception that you have to add both the macro gl_EARLY and the macro gl_tools_EARLY to your configure.ac (and of course also both macros gl_INIT and gl_tools_INIT). Obviously the name of the second macro is dependent on the value of the --macro-prefix option in your gnulib-tool invocation. 

...
AC_PROG_CC
gl_EARLY
gl_tools_EARLY
...
# For gnulib.
gl_INIT
gl_tools_INIT
...

Also as outlined in Initial import you will have to add compiler and linker flags. For the library you might have to add something along the line of the following to your Makefile.am: 

...
AM_CPPFLAGS = -I$(top_srcdir)/gnulib -I$(top_builddir)/gnulib
...
libfoo_la_LIBADD = $(top_builddir)/gnulib/libgnu.la
...

Correspondingly for the programs you will have to add something like this: 

...
AM_CPPFLAGS = -I$(top_srcdir)/src/gnulib -I$(top_builddir)/src/gnulib
...
LDADD = $(top_builddir)/src/gnulib/libgnutools.la
...

The name of the library that you have pass in the linker option depends on the --lib option in gnulib-tool invocation.

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3.11 Caveat: gettextize and autopoint users

The programs gettextize and autopoint, part of GNU gettext, import or update the internationalization infrastructure. Some of this infrastructure, namely ca. 20 Autoconf macro files and the config.rpath file, is also contained in Gnulib and may be imported by gnulib-tool. The use of gettextize or autopoint will therefore overwrite some of the files that gnulib-tool has imported, and vice versa.

Avoiding to use gettextize (manually, as package maintainer) or autopoint (as part of a script like autoreconf or autogen.sh) is not the solution: These programs also import the infrastructure in the po/ and optionally in the intl/ directory.

The copies of the conflicting files in Gnulib are more up-to-date than the copies brought in by gettextize and autopoint. When a new gettext release is made, the copies of the files in Gnulib will be updated immediately.

The choice of which version of gettext to require depends on the needs of your package. For a package that wants to comply to GNU Coding Standards, the steps are:

  1. When you run gettextize, always use the gettextize from the matching GNU gettext release. For the most recent Gnulib checkout, this is the newest release found on https://ftp.gnu.org/gnu/gettext/. For an older Gnulib snapshot, it is the release that was the most recent release at the time the Gnulib snapshot was taken.
  2. After running gettextize, invoke gnulib-tool and import the gettext module. Also, copy the latest version of gnulib’s build-aux/po/Makefile.in.in to your po/ directory (this is done for you if you use gnulib’s autogen.sh script).
  3. If you get an error message like *** error: gettext infrastructure mismatch: using a Makefile.in.in from gettext version ... but the Autoconf macros are from gettext version ..., it means that a new GNU gettext release was made, and its Autoconf macros were integrated into Gnulib and now mismatch the po/ infrastructure. In this case, fetch and install the new GNU gettext release and run gettextize followed by gnulib-tool.

On the other hand, if your package is not as concerned with compliance to the latest standards, but instead favors development on stable environments, the steps are:

  1. Determine the oldest version of gettext that you intend to support during development (at this time, gnulib recommends going no older than version 0.17). Run autopoint (not gettextize) to copy infrastructure into place (newer versions of gettext will install the older infrastructure that you requested).
  2. Invoke gnulib-tool, and import the gettext-h module.

Regardless of which approach you used to get the infrastructure in place, the following steps must then be used to preserve that infrastructure (gnulib’s autogen.sh script follows these rules):

  1. When a script of yours run autopoint, invoke gnulib-tool afterwards.
  2. When you invoke autoreconf after gnulib-tool, make sure to not invoke autopoint a second time, by setting the AUTOPOINT environment variable, like this: 
    $ env AUTOPOINT=true autoreconf --install

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3.12 Handling Gnulib’s own message translations

Gnulib provides some functions that emit translatable messages using GNU gettext. The ‘gnulib’ domain at the Translation Project collects translations of these messages, which you should incorporate into your own programs.

There are two basic ways to achieve this. The first, and older, method is to list all the source files you use from Gnulib in your own po/POTFILES.in file. This will cause all the relevant translatable strings to be included in your POT file. When you send this POT file to the Translation Project, translators will normally fill in the translations of the Gnulib strings from their “translation memory”, and send you back updated PO files.

However, this process is error-prone: you might forget to list some source files, or the translator might not be using a translation memory and provide a different translation than another translator, or the translation might not be kept in sync between Gnulib and your package. It is also slow and causes substantial extra work, because a human translator must be in the loop for each language and you will need to incorporate their work on request.

For these reasons, a new method was designed and is now recommended. If you pass the --po-base=directory and --po-domain=domain options to gnulib-tool, then gnulib-tool will create a separate directory with its own POTFILES.in, and fetch current translations directly from the Translation Project (using rsync or wget, whichever is available). The POT file in this directory will be called domain-gnulib.pot, depending on the domain you gave to the --po-domain option (typically the same as the package name). This causes these translations to reside in a separate message domain, so that they do not clash either with the translations for the main part of your package nor with those of other packages on the system that use possibly different versions of Gnulib. When you use these options, the functions in Gnulib are built in such a way that they will always use this domain regardless of the default domain set by textdomain.

In order to use this method, you must—in each program that might use Gnulib code—add an extra line to the part of the program that initializes locale-dependent behavior. Where you would normally write something like: 

  setlocale (LC_ALL, "");
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);

you should add an additional bindtextdomain call to inform gettext of where the MO files for the extra message domain may be found: 

  bindtextdomain (PACKAGE "-gnulib", LOCALEDIR);

(This example assumes that the domain that you specified to gnulib-tool is the same as the value of the PACKAGE preprocessor macro.)

Since you do not change the textdomain call, the default message domain for your program remains the same and your own use of gettext functions will not be affected.

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3.13 Integration with Version Control Systems

If a project stores its source files in a version control system (VCS), such as CVS, Subversion, or Git, one needs to decide which files to commit.

In principle, all files created by gnulib-tool, except gnulib-cache.m4, can be treated like generated source files, like for example a parser.c file generated from parser.y. Alternatively, they can be considered source files and updated manually.

Here are the three different approaches in common use. Each has its place, and you should use whichever best suits your particular project and development methods.

  1. In projects which commit all source files, whether generated or not, into their VCS, the gnulib-tool generated files should all be committed. In this case, you should pass the option ‘--no-vc-files’ to gnulib-tool, which avoids alteration of VCS-related files such as .gitignore.

    Gnulib also contains files generated by make (and removed by make clean), using information determined by configure. For a Gnulib source file of the form lib/foo.in.h, the corresponding lib/foo.h is such a make-generated file. These should not be checked into the VCS, but instead added to .gitignore or equivalent.

  2. In projects which customarily omit from their VCS all files that are generated from other source files, none of these files and directories are added into the VCS. As described in Modified imports, there are two ways to keep track of options and module names that are passed to gnulib-tool. The command for restoring the omitted files depends on it:
    • If they are stored in a file other than gnulib-cache.m4, such as autogen.sh, bootstrap, bootstrap.conf, or similar, the restoration command is the entire gnulib-tool ... --import ... invocation with all options and module names.
    • If the project relies on gnulib-tool’s memory of the last used options and module names, then the file gnulib-cache.m4 in the M4 macros directory must be added to the VCS, and the restoration command is: 
      $ gnulib-tool --update

      The ‘--update’ option operates much like the ‘--add-import’ option, but it does not offer the possibility to change the way Gnulib is used. Also it does not report in the ChangeLogs the files that it had to add because they were missing.

    Most packages nowadays use the first among these two approaches. Over time, three ways of handling version control have evolved.

    In the cases (A) and (B), a “git submodule” is used to reference the precise commit of the gnulib repository, so that each developer running ‘./bootstrap --pull’ or autopull.sh will get the same version of all gnulib-provided files.

    The alternative is to always follow the newest Gnulib automatically. Note that this can cause breakages at unexpected moments, namely when a broken commit is pushed in Gnulib. It does not happen often, but it does happen.

    • (A) In this approach, the developers use a git submodule manually.

      The location of the submodule can be chosen to fit the package’s needs; here’s how to initially create the submodule in the directory gnulib: 

      $ git submodule add -- https://git.savannah.gnu.org/git/gnulib.git gnulib

      Thereafter, the developer will run this command to update the submodule to the recorded checkout level: 

      $ git submodule update --init gnulib

      Use this sequence to update to a newer version of gnulib: 

      $ git submodule update --remote gnulib
$ git add gnulib
$ ./bootstrap --bootstrap-sync

      If multiple submodules are used, the following may be useful: 

      $ git config alias.syncsub "submodule foreach git pull origin master"
$ git syncsub
    • (B) In this approach, the build-aux/bootstrap or autopull.sh program (see Programs for developing in Git checkouts) is used to aid a developer in using this setup. You copy this program (and if it’s autopull.sh, its companion files) into your package and place the copy or copies under version control. The program can be customized using bootstrap.conf which you also put under version control.
    • (C) In this approach, you write the autopull.sh and autogen.sh files by hand.

      autopull.sh is most easily written as a script that invokes 

      ./gitsub.sh pull || exit 1

      where gitsub.sh is described in Programs for developing in Git checkouts.

      autogen.sh typically contains an explicit gnulib-tool invocation, followed by 

      aclocal -I m4 \
  && autoconf \
  && autoheader && touch config.h.in \
  && automake --add-missing --copy \
  && rm -rf autom4te.cache \
  || exit $?
  3. Some projects take a “middle road”: they do commit Gnulib source files as in the first approach, but they do not commit other derived files, such as a Makefile.in generated by Automake. This increases the size and complexity of the repository, but can help occasional contributors by not requiring them to have a full Gnulib checkout to do a build, and all developers by ensuring that all developers are working with the same version of Gnulib in the repository. It also supports multiple Gnulib instances within a project. It remains important not to commit the make-generated files, as described above.

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3.14 Bundling the unit tests of the Gnulib modules

You can bundle the unit tests of the Gnulib modules together with your package, through the ‘--with-tests’ option. Together with ‘--with-tests’, you also specify the directory for these tests through the ‘--tests-base’ option. Of course, you need to add this directory to the SUBDIRS variable in the Makefile.am of the parent directory.

The advantage of having the unit tests bundled is that when your program has a problem on a particular platform, running the unit tests may help determine quickly if the problem is on Gnulib’s side or on your package’s side. Also, it helps verifying Gnulib’s portability, of course.

The unit tests will be compiled and run when the user runs ‘make check’. When the user runs only ‘make’, the unit tests will not be compiled.

In the SUBDIRS variable, it is useful to put the Gnulib tests directory after the directory containing the other tests, not before: 

SUBDIRS = gnulib-lib src man tests gnulib-tests

This will ensure that on platforms where there are test failures in either directory, users will see and report the failures from the tests of your program.

Note: In packages which use more than one invocation of gnulib-tool in the scope of the same configure.ac, you cannot use ‘--with-tests’. You will have to use a separate configure.ac in this case.

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3.15 Avoiding unnecessary checks and compilations

In some cases, a module is needed by another module only on specific platforms. But when a module is present, its Autoconf checks are always executed, and its Makefile.am additions are always enabled. So it can happen that some Autoconf checks are executed and some source files are compiled, although no other module needs them on this particular platform, just in case some other module would need them.

The option ‘--conditional-dependencies’ enables an optimization of configure checks and Makefile.am snippets that avoids this. With this option, whether a module is considered “present” is no longer decided when gnulib-tool is invoked, but later, when configure is run. This applies to modules that were added as dependencies while gnulib-tool was run; modules that were passed on the command line explicitly are always “present”.

For example, the timegm module needs, on platforms where the system’s timegm function is missing or buggy, a replacement that is based on a function mktime_internal. The module mktime-internal that provides this function provides it on all platforms. So, by default, the file mktime-internal.c will be compiled on all platforms, even on glibc and BSD systems which have a working timegm function. When the option ‘--conditional-dependencies’ is given, on the other hand, and if mktime-internal was not explicitly required on the command line, the file mktime-internal.c will only be compiled on the platforms where the timegm needs them.

Conditional dependencies are specified in the module description by putting the condition on the same line as the dependent module, enclosed in brackets. The condition is a boolean shell expression that can assume that the configure.ac snippet from the module description has already been executed. In the example above, the dependency from timegm to mktime-internal is written like this: 

Depends-on:
...
mktime-internal [test $HAVE_TIMEGM = 0 || test $REPLACE_TIMEGM = 1]
...

Note: The option ‘--conditional-dependencies’ cannot be used together with the option ‘--with-tests’. It also cannot be used when a package uses gnulib-tool for several subdirectories, with different values of ‘--source-base’, in the scope of a single configure.ac file.

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4 Writing modules

This chapter explains how to write modules of your own, either to extend Gnulib for your own package (see Extending Gnulib), or for inclusion in gnulib proper.

The guidelines in this chapter do not necessarily need to be followed for using gnulib-tool. They merely represent a set of good practices. Following them will result in a good structure of your modules and in consistency with gnulib.

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4.1 Source code files

Every API (C functions or variables) provided should be declared in a header file (.h file) and implemented in one or more implementation files (.c files). The separation has the effect that users of your module need to read only the contents of the .h file and the module description in order to understand what the module is about and how to use it—not the entire implementation. Furthermore, users of your module don’t need to repeat the declarations of the functions in their code, and are likely to receive notification through compiler errors if you make incompatible changes to the API (like, adding a parameter or changing the return type of a function).

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4.2 Header files

The .h file should declare the C functions and variables that the module provides.

The .h file should be stand-alone. That is, it does not require other .h files to be included before. Rather, it includes all necessary .h files by itself.

It is a tradition to use CPP tricks to avoid parsing the same header file more than once, which might cause warnings. The trick is to wrap the content of the header file (say, foo.h) in a block, as in: 

#ifndef FOO_H
# define FOO_H
...
body of header file goes here
...
#endif /* FOO_H */

Whether to use FOO_H or _FOO_H is a matter of taste and style. The C99 and C11 standards reserve all identifiers that begin with an underscore and either an uppercase letter or another underscore, for any use. Thus, in theory, an application might not safely assume that _FOO_H has not already been defined by a library. On the other hand, using FOO_H will likely lead the higher risk of collisions with other symbols (e.g., KEY_H, XK_H, BPF_H, which are CPP macro constants, or COFF_LONG_H, which is a CPP macro function). Your preference may depend on whether you consider the header file under discussion as part of the application (which has its own namespace for CPP symbols) or a supporting library (that shouldn’t interfere with the application’s CPP symbol namespace).

Adapting C header files for use in C++ applications can use another CPP trick, as in: 

# ifdef __cplusplus
extern "C"
{
# endif
...
body of header file goes here
...
# ifdef __cplusplus
}
# endif

The idea here is that __cplusplus is defined only by C++ implementations, which will wrap the header file in an ‘extern "C"’ block. Again, whether to use this trick is a matter of taste and style. While the above can be seen as harmless, it could be argued that the header file is written in C, and any C++ application using it should explicitly use the ‘extern "C"’ block itself. Your preference might depend on whether you consider the API exported by your header file as something available for C programs only, or for C and C++ programs alike.

Note that putting a #include in an extern "C" { ... } block yields a syntax error in C++ mode on some platforms (e.g., glibc systems with g++ v3.3 to v4.2, AIX, IRIX). For this reason, it is recommended to place the #include before the extern "C" block.

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4.3 Implementation files

The .c file or files implement the functions and variables declared in the .h file.

Include ordering

Every implementation file must start with ‘#include <config.h>’. This is necessary for activating the preprocessor macros that are defined on behalf of the Autoconf macros. Some of these preprocessor macros, such as _GNU_SOURCE, would have no effect if defined after a system header file has already been included.

Then comes the ‘#include "..."’ specifying the header file that is being implemented. Putting this right after ‘#include <config.h>’ has the effect that it verifies that the header file is self-contained.

Then come the system and application headers. It is customary to put all the system headers before all application headers, so as to minimize the risk that a preprocessor macro defined in an application header confuses the system headers on some platforms.

In summary:

  • First comes #include <config.h>.
  • Second comes the #include "..." specifying the module being implemented.
  • Then come all the #include <...> of system or system-replacement headers, in arbitrary order.
  • Then come all the #include "..." of gnulib and application headers, in arbitrary order.

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4.4 Specification

The specification of a function should answer at least the following questions:

  • What is the purpose of the function?
  • What are the arguments?
  • What is the return value?
  • What happens in case of failure? (Exit? A specific return value? Errno set?)
  • Memory allocation policy: If pointers to memory are returned, are they freshly allocated and supposed to be freed by the caller?

Where to put the specification describing exported functions? Three practices are used in gnulib:

  • The specification can be as comments in the header file, just above the function declaration.
  • The specification can be as comments in the implementation file, just above the function definition.
  • The specification can be in texinfo format, so that it gets included in the gnulib manual.

In any case, the specification should appear in just one place, unless you can ensure that the multiple copies will always remain identical.

The advantage of putting it in the header file is that the user only has to read the include file normally never needs to peek into the implementation file(s).

The advantage of putting it in the implementation file is that when reviewing or changing the implementation, you have both elements side by side.

The advantage of texinfo formatted documentation is that it is easily published in HTML or Info format.

Currently (as of 2020), 70% of gnulib uses the first practice, 25% of gnulib uses the second practice, and a small minority uses the texinfo practice.

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4.5 Module description

For the module description, you can start from an existing module’s description, or from a blank one: module/TEMPLATE for a normal module, or module/TEMPLATE-TESTS for a unit test module. Some more fields are possible but rarely used. Use module/TEMPLATE-EXTENDED if you want to use one of them.

Module descriptions have the following fields. Absent fields are equivalent to fields with empty contents.

Description

This field should contain a concise description of the module’s functionality. One sentence is enough. For example, if it defines a single function ‘frob’, the description can be ‘frob() function: frobnication.’ Gnulib’s documentation generator will automatically convert the first part to a hyperlink when it has this form.

Status

This field is either empty/absent, or contains the word ‘obsolete’. In the latter case, gnulib-tool will, unless the option --with-obsolete is given, omit it when it used as a dependency. It is good practice to also notify the user about an obsolete module. This is done by putting into the ‘Notice’ section (see below) text like ‘This module is obsolete.’

Notice

This field contains text that gnulib-tool will show to the user when the module is used. This can be a status indicator like ‘This module is obsolete.’ or additional advice. Do not abuse this field.

Applicability

This field is either empty/absent, or contains the word ‘all’. It describes to which Makefile.am the module is applied. By default, a normal module is applied to source_base/Makefile.am (normally lib/Makefile.am), whereas a module ending in -tests is applied to tests_base/Makefile.am (normally tests/Makefile.am). If this field is ‘all’, it is applied to both Makefile.ams. This is useful for modules which provide Makefile.am macros rather than compiled source code.

Files

This field contains a newline separated list of the files that are part of the module. gnulib-tool copies these files into the package that uses the module.

This list is typically ordered by importance: First comes the header file, then the implementation files, then other files.

It is possible to have the same file mentioned in multiple modules. That is, if the maintainers of that module agree on the purpose and future of said file.

Depends-on

This field contains a newline separated list of the modules that are required for the proper working of this module. gnulib-tool includes each required module automatically, unless it is specified with option --avoid or it is marked as obsolete and the option --with-obsolete is not given.

A test modules foo-tests implicitly depends on the corresponding non-test module foo. foo implicitly depends on foo-tests if the latter exists and if the option --with-tests has been given.

Tests modules can depend on non-tests modules. Non-tests modules should not depend on tests modules. (Recall that tests modules are built in a separate directory.)

Each listed required module may be declared a conditional dependency. This is indicated by placing the condition for the dependency on the same line, enclosed in brackets, after the name of the required module. The condition is a shell expression that is run after the module’s configure.ac statements. For example: 

strtoull   [test $ac_cv_func_strtoumax = no]

Lines starting with # are recognized as comments and are ignored.

configure.ac-early

This field contains configure.ac stuff (Autoconf macro invocations and shell statements) that are logically placed early in the configure.ac file: right after the AC_PROG_CC invocation. This section is adequate for statements that modify CPPFLAGS, as these can affect the results of other Autoconf macros.

configure.ac

This field contains configure.ac stuff (Autoconf macro invocations and shell statements).

It is forbidden to add items to the CPPFLAGS variable here, other than temporarily, as these could affect the results of other Autoconf macros.

We avoid adding items to the LIBS variable, other than temporarily. Instead, the module can export an Autoconf-substituted variable that contains link options. The user of the module can then decide to which executables to apply which link options. Recall that a package can build executables of different kinds and purposes; having all executables link against all libraries is inappropriate.

If the statements in this section grow larger than a couple of lines, we recommend moving them to a .m4 file of their own.

Makefile.am

This field contains Makefile.am statements. Variables like lib_SOURCES are transformed to match the name of the library being built in that directory. For example, lib_SOURCES may become libgnu_a_SOURCES (for a plain library) or libgnu_la_SOURCES (for a libtool library). Therefore, the normal way of having an implementation file lib/foo.c compiled unconditionally is to write 

lib_SOURCES += foo.c
Include

This field contains the preprocessor statements that users of the module need to add to their source code files. Typically it’s a single include statement. A shorthand is allowed: You don’t need to write the word “#include”, just the name of the include file in the way it will appear in an include statement. Example: 

"foo.h"
Link

This field contains the set of libraries that are needed when linking libraries or executables that use this module. Often this will be written as a reference to a Makefile variable. Please write them one per line, so that gnulib-tool can remove duplicates when presenting a summary to the user. Example: 

$(POW_LIBM)
$(LTLIBICONV) when linking with libtool, $(LIBICONV) otherwise

When this field is omitted, it defaults to the union of the Link field of the dependencies.

License

This field specifies the license that governs the source code parts of this module. See Copyright for details. Be sure to place, in every source code file, a copyright notice and the appropriate license notice, taken from the etc/license-notices/ directory.

Maintainer

This field specifies the persons who have a definitive say about proposed changes to this module. You don’t need to mention email addresses here: they can be inferred from the ChangeLog file.

Please put at least one person here. We don’t like unmaintained modules.

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4.6 Autoconf macros

For a module foo, an Autoconf macro file m4/foo.m4 is typically created when the Autoconf macro invocations for the module are longer than one or two lines.

The name of the main entry point into this Autoconf macro file is typically gl_FOO. For modules outside Gnulib that are not likely to be moved into Gnulib, please use a prefix specific to your package: gt_ for GNU gettext, cu_ for GNU coreutils, etc.

For modules that define a function foo, the entry point is called gl_FUNC_FOO instead of gl_FOO. For modules that provide a header file with multiple functions, say foo.h, the entry point is called gl_FOO_H or gl_HEADER_FOO_H. This convention is useful because sometimes a header and a function name coincide (for example, fcntl and fcntl.h).

For modules that provide a replacement, it is useful to split the Autoconf macro into two macro definitions: one that detects whether the replacement is needed and requests the replacement by setting a HAVE_FOO variable to 0 or a REPLACE_FOO variable to 1 (this is the entry point, say gl_FUNC_FOO), and one that arranges for the macros needed by the replacement code lib/foo.c (typically called gl_PREREQ_FOO). The reason of this separation is

  1. to make it easy to update the Autoconf macros when you have modified the source code file: after changing lib/foo.c, all you have to review is the Depends-on section of the module description and the gl_PREREQ_FOO macro in the Autoconf macro file.
  2. The Autoconf macros are often large enough that splitting them eases maintenance.

Autoconf macro files in Gnulib all start with a header consisting of

  1. A comment line with the file name. This is useful because in some cases the generated aclocal.m4 file does not contain a reference to the .m4 file but its entire contents. The comment makes it clear which .m4 file is where in the aclocal.m4 file.
  2. A comment line with a serial number. This is useful when people use the ‘aclocal --install’ command. aclocal will then refrain from copying a file with a smaller serial number onto a file with a larger serial number. The serial number should be a positive integer on the main branch, or a positive fractional number on a stable branch.
  3. The copyright and license header, as usual.

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4.7 Making proper use of AC_LIBOBJ

Source files that provide a replacement should be only compiled on the platforms that need this replacement. While it is actually possible to compile a .c file whose contents is entirely #ifdef’ed out on the platforms that don’t need the replacement, this practice is discouraged because

  • It makes the build time longer than needed, by invoking the compiler for nothing.
  • It produces a .o file that suggests that a replacement was needed.
  • Empty object files produce a linker warning on some platforms: MSVC.

The typical idiom for invoking AC_LIBOBJ is thus the following, in the module description: 

if test $HAVE_FOO = 0 || test $REPLACE_FOO = 1; then
  AC_LIBOBJ([foo])
  gl_PREREQ_FOO
fi

Important: Do not place AC_LIBOBJ invocations in the Autoconf macros in the m4/ directory. The purpose of the Autoconf macros is to determine what features or bugs the platform has, and to make decisions about which replacements are needed. The purpose of the configure.ac and Makefile.am sections of the module descriptions is to arrange for the replacements to be compiled. Source file names do not belong in the m4/ directory.

When an AC_LIBOBJ invocation is unconditional, it is simpler to just have the source file compiled through an Automake variable augmentation: In the Makefile.am section write 

lib_SOURCES += foo.c

When a module description contains an AC_LIBOBJ([foo]) invocation, you must list the source file lib/foo.c in the Files section. This is needed even if the module depends on another module that already lists lib/foo.c in its Files section – because your module might be used among the test modules (in the directory specified through ‘--tests-base’) and the other module among the main modules (in the directory specified through ‘--source-base’), and in this situation, the AC_LIBOBJ([foo]) of your module can only be satisfied by having foo.c be present in the tests source directory as well.

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4.8 Unit test modules

A unit test that is a simple C program usually has a module description as simple as this: 

Files:
tests/test-foo.c
tests/macros.h

Depends-on:

configure.ac:

Makefile.am:
TESTS += test-foo
check_PROGRAMS += test-foo

The test program tests/test-foo.c often has the following structure:

  • First comes the obligatory ‘#include <config.h>’.
  • Second comes the include of the header file that declares the API being tested. Including it here verifies that said header file is self-contained.
  • Then come other includes. In particular, the file macros.h is often used here. It contains a convenient ASSERT macro.

The body of the test, then, contains many ASSERT invocations. When a test fails, the ASSERT macro prints the line number of the failing statement, thus giving you, the developer, an idea of which part of the test failed, even when you don’t have access to the machine where the test failed and the reporting user cannot run a debugger.

Sometimes it is convenient to write part of the test as a shell script. (For example, in areas related to process control or interprocess communication, or when different locales should be tried.) In these cases, the typical module description is like this: 

Files:
tests/test-foo.sh
tests/test-foo.c
tests/macros.h

Depends-on:

configure.ac:

Makefile.am:
TESTS += test-foo.sh
TESTS_ENVIRONMENT += FOO_BAR='@FOO_BAR@'
check_PROGRAMS += test-foo

Here, the TESTS_ENVIRONMENT variable can be used to pass values determined by configure or by the Makefile to the shell script, as environment variables. The Autoconf values EXEEXT and srcdir are already provided as environment variables, through an initial value of TESTS_ENVIRONMENT that gnulib-tool puts in place.

Regardless of the specific form of the unit test, the following guidelines should be respected:

  • A test indicates success by exiting with exit code 0. It should normally not produce output in this case. (Output to temporary files that are cleaned up at the end of the test are possible, of course.)
  • A test indicates failure by exiting with an exit code different from 0 and 77, typically 1. It is useful to print a message about the failure in this case. The ASSERT macro already does so.
  • A test indicates "skip", that is, that most of its interesting functionality could not be performed, through a return code of 77. A test should also print a message to stdout or stderr about the reason for skipping. For example: 
      fputs ("Skipping test: multithreading not enabled\n", stderr);
  return 77;

    Such a message helps detecting bugs in the autoconf macros: A simple message ‘SKIP: test-foo’ does not sufficiently catch the attention of the user.

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4.9 Incompatible changes

Incompatible changes to Gnulib modules should be mentioned in Gnulib’s NEWS file. Incompatible changes here mean that existing source code may not compile or work any more.

We don’t mean changes in the binary interface (ABI), since

  1. Gnulib code is used in source-code form.
  2. The user who distributes libraries that contain Gnulib code is supposed to bump the version number in the way described in the Libtool documentation before every release.

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5 Extending Gnulib

Gnulib modules are intended to be suitable for widespread use. Most problems with Gnulib can and should be fixed in a generic way, so that all of Gnulib’s users can benefit from the change. But occasionally a problem arises that is difficult or undesirable to fix generically, or a project that uses Gnulib may need to work around an issue before the Gnulib maintainers commit a final fix. Maintainers may also want to add their own pools of modules to projects as Gnulib “staging areas.”

The obvious way to make local changes to Gnulib modules is to use gnulib-tool to check out pristine modules, then to modify the results in-place. This works well enough for short-lived experiments. It is harder to keep modified versions of Gnulib modules for a long time, even though Git (or another distributed version control systems) can help out a lot with this during the development process.

Git, however, doesn’t address the distribution issue. When a package “foobar” needs a modified version of, say, stdint.in.h, it either has to put a comment into foobar/autogen.sh saying “Attention! This doesn’t work with a pristine Gnulib, you need this and that patch after checking out Gnulib,” or it has to use the ‘--avoid=stdint’ option and provide the modified stdint module in a different directory.

The --local-dir option to gnulib-tool solves this problem. It allows the package to override or augment Gnulib. This means:

In a release tarball, you can distribute the contents of this --local-dir directory that will be combinable with newer versions of Gnulib, barring incompatible changes to Gnulib.

If the --local-dir=directory option is specified, then gnulib-tool looks in directory whenever it reads a file from the Gnulib directory. Suppose gnulib-tool is looking for file. Then:

You can specify the --local-dir multiple times. In this case, the first specified directory has the highest precedence. That is, a file found in one directory will shadow any file and file.diff in the later directories and in the Gnulib directory. And a file file.diff found in one directory will be applied on top of the combination of file and file.diff files found in the later directories and in the Gnulib directory.

Please make wise use of this option. It also allows you to easily hold back modifications you make to Gnulib macros in cases it may be better to share them.

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6 Miscellaneous Notes

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6.1 Out of memory handling

The gnulib API does not have a standard error code for the out of memory error condition. Instead of adding a non-standard error code, gnulib has chosen to adopt a different strategy. Out of memory handling happens in rare situations, but performing the out of memory error handling after almost all API function invocations pollute your source code and might make it harder to spot more serious problems. The strategy chosen improves code readability and robustness.

For most applications, aborting the application with an error message when the out of memory situation occurs is the best that can be wished for. This is how the library behaves by default (using the ‘xalloc-die’ module).

However, we realize that some applications may not want to abort execution in any situation. Gnulib supports a hook to let the application regain control and perform its own cleanups when an out of memory situation has occurred. The application can define a function (having a void prototype, i.e., no return value and no parameters) and set the library variable xalloc_die to that function. The variable should be declared as follows. 

extern void (*xalloc_die) (void);

Gnulib will invoke this function if an out of memory error occurs. Note that the function should not return. Of course, care must be taken to not allocate more memory, as that will likely also fail.

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6.2 Obsolete modules

Modules can be marked obsolete. This means that the problems they fix don’t occur any more on the platforms that are reasonable porting targets now. gnulib-tool warns when obsolete modules are mentioned on the command line, and by default ignores dependencies from modules to obsolete modules. When you pass the option --with-obsolete to gnulib-tool, dependencies to obsolete modules will be included, however, unless blocked through an --avoid option. This option is useful if your package should be portable even to very old platforms.

In order to mark a module obsolete, you need to add this to the module description: 

Status:
obsolete

Notice:
This module is obsolete.

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6.3 Extra tests modules

Test modules can be marked with some special status attributes. When a test module has such an attribute, gnulib-tool --import will not include it by default.

The supported status attributes are:

c++-test

Indicates that the test is testing C++ interoperability. Such a test is useful in a C++ or mixed C/C++ package, but is useless in a C package.

longrunning-test

Indicates that the test takes a long time to compile or execute (more than five minutes or so). Such a test is better avoided in a release that is made for the general public.

privileged-test

Indicates that the test will request special privileges, for example, ask for the superuser password. Such a test may hang when run non-interactively and is therefore better avoided in a release that is made for the general public.

unportable-test

Indicates that the test is known to fail on some systems, and that there is no workaround about it. Such a test is better avoided in a release that is made for the general public.

gnulib-tool --import --with-tests will not include tests marked with these attributes by default. When gnulib-tool is invoked with one of the options --with-c++-tests, --with-longrunning-tests, --with-privileged-tests, --with-unportable-tests, it will include tests despite the corresponding special status attribute. When gnulib-tool receives the option --with-all-tests, it will include all tests regardless of their status attributes.

gnulib-tool --create-testdir --with-tests and gnulib-tool --create-megatestdir --with-tests by default include all tests of modules specified on the command line, regardless of their status attributes. Tests of modules occurring as dependencies are not included by default if they have one of these status attributes. The options --with-c++-tests, --with-longrunning-tests, --with-privileged-tests, --with-unportable-tests are recognized here as well. Additionally, gnulib-tool also understands the options --without-c++-tests, --without-longrunning-tests, --without-privileged-tests, --without-unportable-tests.

In order to mark a module with a status attribute, you need to add it to the module description, like this: 

Status:
longrunning-test

If only a part of a test deserves a particular status attribute, you can split the module into a primary and a secondary test module, say foo-tests and foo-extra-tests. Then add a dependency from foo-tests to foo-extra-tests, and mark the foo-extra-tests with the particular status attribute.

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6.4 Modules that modify the way other modules work

The normal way to design modules is that each module has its own code, and the module dependencies provide the facilities on which this code can rely. But sometimes it is necessary to use more advanced techniques. For example:

  • You may want to have optional module dependencies: Let module A use facilities provided by module B, if module B is present, but without requiring that module B is present.
  • A module can indicate support for particular behaviours. For example, Gnulib has a module ‘sigpipe’ that requests POSIX compatible SIGPIPE behaviour from all other modules – something that is not enabled by default. Or consider the ‘nonblocking’ module, that is an indicator that all I/O functions should handle non-blocking file descriptors – something that, equally, is not enabled by default.
  • A module can indicate to other modules that they can rely on certain guarantees, and thus omit specific code. For example, when Gnulib’s ‘malloc-gnu’ module is present, you can omit code that test n against zero when you call malloc (n).

Be aware that these advanced techniques likely cause breakage in the situation of multiple gnulib-tool invocations in the scope of a single configure file. This is because the question “is module B present?” does not have a unique answer in such situations. gnulib-tool has support for these techniques in the situation of --create-testdir --single-configure, which basically has two gnulib-tool invocations, one for a set of modules that end up in gllib, and one for the set of modules that end up in gltests. But you should be aware that this does not cover the general situation.

Which technique to use, depends on the answer to the question: “If my module occurs among the modules of gltests, should it have an effect on the modules in gllib?”

If the answer is “no”, your module description should invoke the Autoconf macro gl_MODULE_INDICATOR. This Autoconf macro takes one argument: the name of your module. The effect of gl_MODULE_INDICATOR([my-module]) is to define, in config.h, a C macro GNULIB_MY_MODULE that indicates whether your macro is considered to be present. This works even when your macro is used in gltests: GNULIB_MY_MODULE will then evaluate to 1 in gltests but to 0 in gllib.

If the answer is “yes”, you have two techniques available. The first one is to invoke a similar Autoconf macro, named gl_MODULE_INDICATOR_FOR_TESTS. It works similarly. However, when your macro is used in gltests, GNULIB_MY_MODULE will evaluate to 1 both in gltests and in gllib.

The second one is to define a shell variable in the configure file that tells whether your module is present, through use of m4_divert_text. The Autoconf macros of a dependency module will initialize this shell variable, through ‘m4_divert_text([DEFAULTS], [my_shell_var=no])’. The Autoconf macros of your module will override this value, through ‘m4_divert_text([INIT_PREPARE], [my_shell_var=yes])’. Then you can use my_shell_var in the Autoconf macros of both modules. You can find more details about this technique in the Gnulib module getopt-gnu.

Reminder: These techniques are advanced. They have the potential to cause lots of headaches if you apply them incorrectly.

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6.5 A C++ namespace for gnulib

The function definitions provided by Gnulib (.c code) are meant to be compiled by a C compiler. The header files (.h files), on the other hand, can be used in either C or C++.

By default, when used in a C++ compilation unit, the .h files declare the same symbols and overrides as in C mode, except that functions defined by Gnulib or by the system are declared as ‘extern "C"’.

It is also possible to indicate to Gnulib to provide many of its symbols in a dedicated C++ namespace. If you define the macro GNULIB_NAMESPACE to an identifier, many functions will be defined in the namespace specified by the identifier instead of the global namespace. For example, after you have defined 

#define GNULIB_NAMESPACE gnulib

at the beginning of a compilation unit, Gnulib’s <fcntl.h> header file will make available the open function as gnulib::open. The symbol open will still refer to the system’s open function, with its platform specific bugs and limitations.

The symbols provided in the Gnulib namespace are those for which the corresponding header file contains a _GL_CXXALIAS_RPL or _GL_CXXALIAS_SYS macro invocation.

The benefits of this namespace mode are:

  • Gnulib defines fewer symbols as preprocessor macros. For example, on a platform where open has to be overridden, Gnulib normally does #define open rpl_open. If your package has a class with a member open, for example a class foo with a method foo::open, then if you define this member in a compilation unit that includes <fcntl.h> and use it in a compilation unit that does not include <fcntl.h>, or vice versa, you will get a link error. Worse: You will not notice this problem on the platform where the system’s open function works fine. This problem goes away in namespace mode.
  • It provides a safety check whether the set of modules your package requests from Gnulib is sufficient. For example, if you use the function gnulib::open in your code, and you forgot to request the module ‘open’ from Gnulib, you will get a compilation error (regardless of the platform).

The drawback of this namespace mode is that the system provided symbols in the global namespace are still present, even when they contain bugs that Gnulib fixes. For example, if you call open (...) in your code, it will invoke the possibly buggy system function, even if you have requested the module ‘open’ from gnulib-tool.

You can turn on the namespace mode in some compilation units and keep it turned off in others. This can be useful if your package consists of an application layer that does not need to invoke POSIX functions and an operating system interface layer that contains all the OS function calls. In such a situation, you will want to turn on the namespace mode for the application layer—to avoid many preprocessor macro definitions—and turn it off for the OS interface layer—to avoid the drawback of the namespace mode, mentioned above.

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6.6 License Texinfo sources

Gnulib provides copies of the GNU GPL, GNU LGPL, GNU Affero GPL, and GNU FDL licenses in Texinfo form. (The master location is https://www.gnu.org/licenses/). These Texinfo documents do not have any node names and structures built into them; for your manual, you should @include them in an appropriate @node.

The conventional name for the GPL node is ‘Copying’ and for the FDL ‘GNU Free Documentation License’. The LGPL doesn’t seem to have a conventional node name.

Of course the license texts themselves should not be changed at all.

The recommended way to make use of these license files, consistently with current practice, is as follows:

  • The code license (GNU GPL, GNU LGPL, or GNU Affero GPL) is usually present as a file in the top-level directory. This is true not only for the release tarballs, but also in the VCS repository. The file is typically named ‘COPYING’ for the GNU GPL, or ‘COPYING.LIB’ or ‘COPYING.LESSER’ for the GNU LGPL. The presence of this file fulfills a legal obligation; see https://www.gnu.org/licenses/gpl-faq.html#WhyMustIInclude.

    To make use of the code license in your documentation, you may request one of the modules gpl-3.0, gpl-2.0, lgpl-3.0, lgpl-2.1, agpl-3.0, through a gnulib-tool invocation. Or you may copy the relevant Texinfo file directly into your VCS repository. Both approaches are equally good. The Texinfo file changes very rarely.

  • The documentation license file (GNU FDL) is usually not present as a file in the top-level directory, because that would be ambiguous: When you use the GNU FDL, you need to specify the Invariant Sections, the Front-Cover Texts, and the Back-Cover Texts.

    To make use of this documentation license, copy the relevant Texinfo file (doc/fdl-1.3.texi) into your VCS repository. This makes sure that anyone who receives a copy of your VCS repository has also received a copy of the documentation license. In the documentation, also state what are the Invariant Sections, the Front-Cover Texts, and the Back-Cover Texts.

We recommend to place the licenses as appendices at the end of the manual, right before any indices. For the FDL, we suggest the following @menu entry: 

* GNU Free Documentation License::  License for copying this manual

For any @detailmenu entries, we suggest the following: 

Copying This Manual

* GNU Free Documentation License::     Copying and sharing this manual

And for actual inclusion of the FDL itself, we suggest the following: 

@node GNU Free Documentation License
@appendix GNU Free Documentation License

@include fdl.texi

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6.7 Building gnulib

If you wish to help the gnulib development effort with build logs for your favorite platform, you may perform these steps:

  1. Prerequisites tools

    Install the proper development tools. To build and test all of Gnulib, you will need development tools for the programming languages C, C++, Java, and Perl, along with standard POSIX utilities such as awk, make and sh. You will also need development tools that include Autoconf, Automake, Bison, Gettext, Git, GNU M4, Gperf, Libtool, and Texinfo. Some of these tools are needed only by some modules. More details can be found in Gnulib’s DEPENDENCIES file.

  2. Obtain Gnulib

    See https://www.gnu.org/software/gnulib/ for how to get the current Gnulib sources via Git.

  3. Create gnulib directory

    On a machine with GNU development tools installed and with a gnulib git checkout, use 

    gnulib-tool --create-testdir --with-tests --dir=...

    Alternatively, pick a small set of modules and run 

    gnulib-tool --create-megatestdir --with-tests --dir=... autobuild MODULES

    (You can’t do this with all of Gnulib at once: gnulib-tool would run for a week and produce a directory that takes more than 100 GB, maybe even 1 TB, of disk space.)

  4. Transfer gnulib directory

    Transfer this directory to a build machine (HP-UX, Cygwin, or whatever). Often it is easier to transfer one file, and this can be achieved by running, inside the directory the following commands: 

    ./configure
make dist

    And then transferring the dummy-0.tar.gz file.

  5. Build modules

    On the build machine, run ./do-autobuild (or "nohup ./do-autobuild"). It creates a directory logs/ with a log file for each module.

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7 Building the ISO C and POSIX Substitutes

This section shows a radically different way to use Gnulib.

You can extract the ISO C / POSIX substitutes part of gnulib by running the command 

gnulib-tool --create-testdir --source-base=lib \
            --dir=/tmp/posixlib `posix-modules`

The command ‘posix-modules’ is found in the same directory as gnulib-tool.

The resulting directory can be built on a particular platform, independently of the program being ported. Then you can configure and build any program, by setting CPPFLAGS and LDFLAGS at configure time accordingly: set CPPFLAGS="-I.../posixlib/lib", plus any essential type definitions and flags that you find in .../posixlib/config.h, and set LDFLAGS=".../posixlib/lib/libgnu.a".

This way of using Gnulib is useful when you don’t want to modify the program’s source code, or when the program uses a mix between C and C++ sources (requiring separate builds of the posixlib for the C compiler and for the C++ compiler).

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8 ISO C Keyword Substitutes

This chapter describes which keywords specified by ISO C are substituted by Gnulib.

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8.1 alignof and alignas

Gnulib module: alignasof

The alignasof module arranges for alignas and alignof to be more like standard C.

Portability problems fixed by Gnulib:

  • Pre-C11 platforms lack alignas and alignof.
  • On pre-C23 platforms, <stdalign.h> must be included before using alignas or alignof. See stdalign.h.

Portability problems not fixed by Gnulib:

  • On pre-C23 platforms, alignas and alignof are macros.

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8.2 bool

Gnulib module: stdbool

Portability problems fixed by Gnulib:

  • The keywords bool, true, and false are not available: gcc 12 and other compilers predating C23.

Portability problems not fixed by Gnulib:

  • On pre-C23 platforms, the keyword substitutes are macros.
  • On pre-C23 platforms, the keyword substitutes assume C99 or later.

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8.3 nullptr

Gnulib module: nullptr

The nullptr module arranges for nullptr to act like standard C and C++.

The nullptr keyword yields a null pointer. It differs from the NULL macro, in that NULL might be an integer whereas nullptr is of a special nullptr_t type with only one value, namely nullptr itself. Using nullptr can help some compilers emit more sensible warnings, can avoid the need to cast a null pointer passed to a function prototyped with an ellipsis, and removes the need to include <stddef.h> merely to define NULL.

Portability problems fixed by Gnulib:

  • Some platforms lack nullptr: For C: GCC 12, Clang 15, and other pre-2023 C compilers. For C++: pre-2011 C++ compilers.
  • Some platforms incorrectly warn when nullptr is a sentinel argument: GCC 13.2 and 14.0.

Portability problems not fixed by Gnulib:

  • On older platforms, nullptr is a macro instead of a keyword.
  • On older platforms, nullptr does not have the type nullptr_t. In C, it has type void *; in C++ it has an integer type.
  • On older platforms Gnulib cannot easily emulate nullptr_t, so null pointer type checking is more error prone. In C, _Generic expressions cannot reliably distinguish the type of nullptr from integer or void * types. C++ overloading has similar limitations.

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8.4 static_assert

Gnulib module: assert-h

The assert-h module arranges for both static_assert and <assert.h> to be like standard C. See assert.h.

Portability problems fixed by Gnulib:

  • Pre-C11 platforms lack static_assert.
  • On pre-C23 platforms, <assert.h> must be included before using static_assert.

Portability problems not fixed by Gnulib:

  • On pre-C23 platforms, static_assert is a macro.

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9 ISO C and POSIX Header File Substitutes

This chapter describes which header files specified by ISO C or POSIX are substituted by Gnulib, which portability pitfalls are fixed by Gnulib, and which (known) portability problems are not worked around by Gnulib.

The notation “Gnulib module: —” means that Gnulib does not provide a module providing a substitute for the header file. When the list “Portability problems not fixed by Gnulib” is empty, such a module is not needed: No portability problems are known. Otherwise, it indicates that such a module would be useful but is not available: No one so far found this header file important enough to contribute a substitute for it. If you need this particular header file, you may write to <bug-gnulib at gnu dot org>.

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9.1 aio.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/aio.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, Cygwin, mingw, MSVC 14, Haiku, Android 9.0.
  • The type off64_t is not defined on some platforms: macOS 14, FreeBSD 10.4, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.

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9.2 arpa/inet.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/arpa_inet.h.html

Gnulib module: arpa_inet

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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9.3 assert.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/assert.h.html

Gnulib module: assert-h

See also the Gnulib modules assert and verify.

Portability problems fixed by Gnulib:

  • On older C platforms <assert.h> must be included before using static_assert. For example, GCC versions before 13 do not support the static_assert keyword that was standardized by C23.
  • On older platforms static_assert does not allow the second string-literal argument to be omitted. For example, GCC versions before 9.1 do not support the single-argument static_assert that was standardized by C23 and C++17.
  • Even-older platforms do not support static_assert at all. For example, GCC versions before 4.6 and G++ versions before 4.3 do not support the two-argument form, which was standardized by C11 and C++11.
  • Older C platforms might not support the obsolescent _Static_assert keyword or macro. This portability problem should not matter with code using this module, as such code should use static_assert instead.

Portability problems not fixed by Gnulib:

  • A static_assert can also be used within a struct or union specifier, in place of an ordinary declaration of a member of the struct or union. The Gnulib substitute can be used only as an ordinary declaration in code intended to be portable to C99 or earlier.
  • In C23 and C++11 and later, static_assert is a keyword. In C11 and C17 it is a macro. Any Gnulib substitute is also a macro.
  • In C99 and later, assert can be applied to any scalar expression. In C89, the argument to assert is of type int.

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9.4 complex.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/complex.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.7.7, mingw, MSVC 9.

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9.5 cpio.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/cpio.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: Minix 3.1.8, Cygwin 2.4.x, mingw, MSVC 14.

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9.6 ctype.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/ctype.h.html

Gnulib module: ctype

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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9.7 dirent.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/dirent.h.html

Gnulib module: dirent

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: MSVC 14.
  • The type ino_t is missing on some platforms: glibc 2.23 and others.

Portability problems not fixed by Gnulib:

  • Although many systems define a struct dirent member named d_type and directory entry type macros like DT_DIR and DT_LNK, some do not: Minix 3.1.8, AIX 7.2, HP-UX 11, Solaris 11.4, mingw.
  • On systems with d_type, not every filesystem supports d_type, and those lacking support will set it to DT_UNKNOWN.
  • Some systems define a struct dirent member named d_namlen containing the string length of d_name, but others do not: glibc 2.23 on Linux, Minix 3.1.8, Solaris 11.4, Cygwin. All of these, except Cygwin, have a member d_reclen instead, that has a different semantics.
  • Some systems define a struct dirent member named d_off containing a magic cookie suitable as an argument to seekdir, but others do not: glibc 2.23 on Hurd, macOS 11.1, FreeBSD 11.0, NetBSD 10.0, OpenBSD 6.7, AIX 5.1, HP-UX 11, Cygwin, mingw.
  • Some systems define a struct dirent member named d_reclen containing the number of bytes in the directory entry record, but others do not. This member has limited utility, as it is an implementation detail.

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9.8 dlfcn.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/dlfcn.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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9.9 errno.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/errno.h.html

Gnulib module: errno

Portability problems fixed by Gnulib:

  • The macro EOVERFLOW is not defined on some platforms: OpenBSD 4.0, mingw, MSVC 9.
  • The macro ENOLINK is not defined on some platforms: OpenBSD 6.7, mingw, MSVC 9.
  • The macro EMULTIHOP is not defined on some platforms: OpenBSD 6.7, mingw, MSVC 14.
  • The macro ECANCELED is not defined on some platforms: OpenBSD 4.0, Cygwin, mingw, MSVC 9.
  • The macros ENOMSG, EIDRM, EPROTO, EBADMSG, ENOTSUP are not defined on some platforms: OpenBSD 4.0, mingw, MSVC 9.
  • The macro ESTALE is not defined on some platforms: mingw, MSVC 14.
  • The macro EDQUOT is not defined on some platforms: NonStop Kernel, mingw, MSVC 14.
  • The macros ENETRESET, ECONNABORTED are not defined on some platforms: Minix 3.1.8, mingw, MSVC 9.
  • The macros EWOULDBLOCK, ETXTBSY, ELOOP, ENOTSOCK, EDESTADDRREQ, EMSGSIZE, EPROTOTYPE, ENOPROTOOPT, EPROTONOSUPPORT, EOPNOTSUPP, EAFNOSUPPORT, EADDRINUSE, EADDRNOTAVAIL, ENETDOWN, ENETUNREACH, ECONNRESET, ENOBUFS, EISCONN, ENOTCONN, ETIMEDOUT, ECONNREFUSED, EHOSTUNREACH, EALREADY, EINPROGRESS are not defined on some platforms: mingw, MSVC 9.
  • The macros EOWNERDEAD, ENOTRECOVERABLE are not defined on some platforms: glibc/Linux 2.3.6, glibc/Hurd 2.15, glibc/kFreeBSD 2.15, Mac OS X 10.5, FreeBSD 6.0, NetBSD 9.3, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin, mingw without pthreads-win32, MSVC 9.
  • The macro EILSEQ is not defined on some platforms: LynxOS 178 2.2.2.

Portability problems not fixed by Gnulib:

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9.10 fcntl.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/fcntl.h.html

Gnulib module: fcntl-h

Portability problems fixed by Gnulib:

  • The type pid_t is not defined on some platforms: MSVC 14.
  • The type mode_t is not defined on some platforms: MSVC 14.
  • The type off64_t is not defined on some platforms: macOS 14, FreeBSD 10.4, NetBSD 10.0, OpenBSD 7.5, MSVC 14, Cygwin, Haiku, Minix 3.3.
  • ‘O_CLOEXEC’ is not defined on some platforms: Mac OS X 10.6, FreeBSD 8.4, NetBSD 5.1, OpenBSD 4.9, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 10, Cygwin 1.7.1, mingw, MSVC 14.
  • ‘O_DIRECTORY’, ‘O_DSYNC’, ‘O_NOCTTY’, ‘O_NOFOLLOW’, ‘O_RSYNC’, ‘O_SYNC’, and ‘O_TTY_INIT’ are not defined on some platforms. When not otherwise defined, Gnulib defines these macros to 0, which is generally safe.
  • ‘O_NONBLOCK’ is not defined on some platforms. If the ‘nonblocking’ module is in use, gnulib guarantees a working non-zero value; otherwise, the gnulib replacement is 0.
  • ‘O_EXEC’ and ‘O_SEARCH’ are not defined on some platforms. Gnulib defines these macros to ‘O_RDONLY’, which is typically 0. The ‘O_PATH’ macro of GNU/Linux is not a suitable substitute, as fchmod fails with ‘errno==EBADF’ when invoked on a file descriptor that was opened with ‘O_PATH’.
  • ‘O_ACCMODE’ is not defined on some platforms: MSVC 14.
  • The ‘O_ACCMODE’ mask mistakenly omits ‘O_SEARCH’ and ‘O_EXEC’ on some platforms: Cygwin.
  • ‘O_BINARY’, ‘O_TEXT’ (not specified by POSIX, but essential for portability to native Windows platforms) are defined on some platforms but not on others. Gnulib defines these macros to 0 on GNU and other platforms that do not distinguish between text and binary I/O.
  • ‘O_CLOEXEC’, ‘O_NOFOLLOW’, and ‘O_TTY_INIT’ are defined to values that are too large for an int on some platforms: AIX 7.1 with XL C 12.1.
  • ‘O_DIRECT’, ‘O_IGNORE_CTTY’, ‘O_NDELAY’, ‘O_NOATIME’, ‘O_NOLINK’, ‘O_NOLINKS’, and ‘O_NOTRANS’ (not specified by POSIX) are defined on some platforms but not on others. When not otherwise defined, Gnulib defines these macros to 0, which is generally safe.
  • ‘FD_CLOEXEC’, ‘F_DUPFD’, and ‘F_GETFD’ are not defined on some platforms: mingw, MSVC 14.
  • ‘F_DUPFD_CLOEXEC’ is not defined on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, AIX 5.1, HP-UX 11, Solaris 11 2010-11, Cygwin 1.7.1, mingw, MSVC 14.
  • ‘AT_FDCWD’, ‘AT_EACCESS’, ‘AT_SYMLINK_NOFOLLOW’, ‘AT_SYMLINK_FOLLOW’, and ‘AT_REMOVEDIR’ are not defined on many platforms: glibc 2.3.6, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, AIX 5.1, HP-UX 11, Cygwin 1.5.x, mingw, MSVC 14.
  • ‘AT_FDCWD’ is defined with a value too large for an int on some platforms: Solaris 11.3.

Portability problems not fixed by Gnulib:

  • ‘O_PATH’ is not defined on some platforms: glibc 2.13, macOS 13, FreeBSD 13.0, NetBSD 9.2, OpenBSD 7.1, Minix 3.3.0, AIX 7.3, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.
  • ‘F_SETFD’, ‘F_GETFL’, ‘F_SETFL’, ‘F_GETLK’, ‘F_SETLK’, ‘F_SETLKW’, ‘F_GETOWN’, and ‘F_SETOWN’ are not defined on some platforms: mingw, MSVC 14.
  • ‘POSIX_FADV_DONTNEED’, ‘POSIX_FADV_NOREUSE’, ‘POSIX_FADV_NORMAL’, ‘POSIX_FADV_RANDOM’, ‘POSIX_FADV_SEQUENTIAL’, and ‘POSIX_FADV_WILLNEED’ are not defined on some platforms.

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9.11 fenv.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/fenv.h.html

Gnulib module: fenv

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, AIX 5.1, Cygwin 1.7.7, MSVC 9.

Portability problems not fixed by Gnulib:

  • On MSVC, the values of the rounding direction macros have changed: In MSVC 14, FE_UPWARD is 0x100 and FE_DOWNWARD is 0x200, whereas in MSVC 14.30, it’s the opposite.

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9.12 float.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/float.h.html

Gnulib module: float

Portability problems fixed by Gnulib:

  • The conversion from int to long double in incorrect on some platforms: glibc 2.7 on Linux/SPARC64.
  • The values of LDBL_* macros are incorrect on some platforms: On OpenBSD 4.0 and MirBSD 10, they are the same as the values of the DBL_* macros, although ‘long double’ is a larger type than ‘double’. On FreeBSD/x86 6.4, they represent the incorrect 53-bit precision assumptions in the compiler, not the real 64-bit precision at runtime. On Linux/PowerPC with GCC 4.4, and on AIX 7.1 with GCC 4.2, they don’t reflect the “double double” representation of long double correctly.

Portability problems not fixed by Gnulib:

  • The macro FLT_ROUNDS is a constant expression and does not represent the current rounding mode on some platforms: glibc 2.11, HP-UX 11, mingw.

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9.13 fmtmsg.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/fmtmsg.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, Cygwin, mingw, MSVC 14, Android 9.0.

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9.14 fnmatch.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/fnmatch.h.html

Gnulib module: fnmatch-h, fnmatch-gnu

Portability problems fixed by Gnulib module fnmatch-h:

  • This header file is missing on some platforms: mingw, MSVC 14.

Portability problems fixed by Gnulib module fnmatch-gnu, together with module fnmatch-h:

  • The macros FNM_LEADING_DIR and FNM_CASEFOLD are not defined on some platforms: AIX 7.2, HP-UX 11.31, Solaris 10.
  • The macro FNM_EXTMATCH is not defined on all non-glibc platforms: musl libc, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.2, Minix 3.3, AIX 7.2, HP-UX 11.31, Solaris 11.4, Cygwin 3.4.6, Android 13.
  • The macro FNM_FILE_NAME is not defined on some platforms: NetBSD 10.0, AIX 7.2, HP-UX 11.31, Solaris 10.

Portability problems not fixed by Gnulib:

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9.15 ftw.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/ftw.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: FreeBSD 5.2.1, NetBSD 3.0, Minix 3.1.8, mingw, MSVC 14.

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9.16 glob.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/glob.h.html

Gnulib module: glob-h

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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9.17 grp.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/grp.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.

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9.18 iconv.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/iconv.h.html

Gnulib module: iconv

Portability problems fixed by Gnulib:

  • The <iconv.h> from GNU libiconv is not found if installed in $PREFIX/include.

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: FreeBSD 6.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14, when GNU libiconv is not installed.

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9.19 inttypes.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/inttypes.h.html

Gnulib module: inttypes

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: MSVC 9.
  • This header file is very incomplete on some platforms.
  • The declarations of imaxabs and imaxdiv are missing on some platforms: NetBSD 3.0, OpenBSD 6.7, AIX 5.1, HP-UX 11.
  • The declarations of strtoimax and strtoumax are missing on some platforms: OpenBSD 6.7, AIX 5.1 (missing only strtoumax).
  • On some hosts that predate C++11, when using C++ one must define __STDC_FORMAT_MACROS to make visible the declarations of format macros such as PRIdMAX.

Portability problems not fixed by Gnulib:

  • The PRIb*, PRIB*, SCNb* macros, that were added in ISO C 23, are missing on many platforms: glibc 2.37 and many others.

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9.20 iso646.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/iso646.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: Minix 3.1.8, HP-UX 11.00, Cygwin, mingw.

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9.21 langinfo.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/langinfo.h.html

Gnulib module: langinfo

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.
  • The constant CODESET is not defined on some platforms: OpenBSD 6.7.
  • The constants ALTMON_1 to ALTMON_12 are not defined on some platforms: glibc 2.26, musl libc, macOS 11.1, NetBSD 8.0, OpenBSD 6.5, AIX 7.2, HP-UX 11.31, Solaris 11.4, Haiku, Cygwin 2.9.
  • The constants ERA, ERA_D_FMT, ERA_D_T_FMT, ERA_T_FMT, ALT_DIGITS are not defined on some platforms: OpenBSD 6.7.

Portability problems not fixed by Gnulib:

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9.22 libgen.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/libgen.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.

The Gnulib module dirname provides similar API, with functions base_name and dir_name that also work with Windows file names.

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9.23 limits.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/limits.h.html

Gnulib module: limits-h or gethostname

Portability problems fixed by Gnulib module limits-h:

  • The macros LLONG_MIN, LLONG_MAX, ULLONG_MAX are not defined on some platforms: older glibc systems (e.g. Fedora 1), AIX 5.1, HP-UX 11, OpenVMS.
  • The macro MB_LEN_MAX is not defined on some platforms: pcc 1.2.0.DEVEL 20220331.
  • The macros WORD_BIT, LONG_BIT are not defined on some platforms: glibc 2.11 without -D_GNU_SOURCE, Cygwin, mingw, MSVC 14.
  • Macros like CHAR_WIDTH are not defined on some platforms: glibc 2.24, NetBSD 10.0, many others.
  • The macros BOOL_MAX and BOOL_WIDTH are not defined on some platforms: glibc 2.32, many others.
  • The macro BOOL_MAX is not defined with some compilers: clang 15.0.6.
  • The macro SSIZE_MAX is not defined on some platforms: MSVC 14.

Portability problems fixed by Gnulib module gethostname:

  • The HOST_NAME_MAX macro is not defined on some platforms: macOS 11.1, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • The macro SSIZE_MAX has the wrong type, albeit with the correct value: 32-bit glibc 2.24 (on some architectures), Cygwin 2.5.2.

For PATH_MAX, Gnulib provides a module pathmax with a header file "pathmax.h". It defines PATH_MAX to a constant on platforms with a file name length limit.

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9.24 locale.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/locale.h.html

Gnulib module: locale

Portability problems fixed by Gnulib:

  • The definition of ‘LC_MESSAGES’ is missing on some platforms: mingw, MSVC 14.
  • The locale_t type is not defined on some platforms: glibc 2.11, macOS 11.1.
  • The struct lconv type does not contain any members on some platforms: Android up to 2014.
  • The struct lconv type does not contain the members int_p_cs_precedes, int_p_sign_posn, int_p_sep_by_space, int_n_cs_precedes, int_n_sign_posn, int_n_sep_by_space on some platforms: glibc, OpenBSD 4.9, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.
  • Some platforms provide a NULL macro that cannot be used in arbitrary expressions: NetBSD 5.0

Portability problems not fixed by Gnulib:

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9.25 math.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/math.h.html

Gnulib module: math

Portability problems fixed by Gnulib:

  • The conversion from int to long double in incorrect on some platforms: glibc 2.7 on Linux/SPARC64.
  • The macro NAN is not defined on some platforms: OpenBSD 4.0, AIX 5.1.
  • The macro NAN is not exposed outside of C99 compilation on some platforms: glibc.
  • The macros NAN and HUGE_VAL expand to a function address rather than a floating point constant on some platforms: Solaris 10.
  • The macros HUGE_VALF and HUGE_VALL are not defined on some platforms: glibc/HPPA, glibc/SPARC, AIX 5.1, Solaris 9, MSVC 9.
  • The macros FP_ILOGB0 and FP_ILOGBNAN are not defined on some platforms: NetBSD 5.1, AIX 5.1, Solaris 9, MSVC 9.
  • The macros FP_ILOGB0 and FP_ILOGBNAN have wrong values on some platforms: Haiku 2022.
  • The macros NAN, HUGE_VALL, and INFINITY are not defined on some platforms: OpenVMS.

Portability problems not fixed by Gnulib:

  • NAN is not a compile time constant with some compilers: OpenVMS.
  • The macro or variable math_errhandling is not defined on some platforms: glibc 2.11, OpenBSD 4.9, NetBSD 5.1, UP-UX 11, Cygwin 1.7.9, mingw, MSVC 9.

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9.26 monetary.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/monetary.h.html

Gnulib module: monetary

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 1.7.1, mingw, MSVC 14, Android 9.0.
  • This header file has a syntax error in C++ mode on some platforms: NetBSD 8.0.

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9.27 mqueue.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/mqueue.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

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9.28 ndbm.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/ndbm.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14, Android 9.0.

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9.29 net/if.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/net_if.h.html

Gnulib module: net_if

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.
  • This header file is not self-contained on some platforms (needing <sys/socket.h> to be included first): Mac OS X 10.5, FreeBSD 8.2, OpenBSD 5.2.

Portability problems not fixed by Gnulib:

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9.30 netdb.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/netdb.h.html

Gnulib module: netdb

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.
  • This header file is incomplete on some platforms: Cygwin 1.5.x, Haiku.
  • This header file does not define AI_ALL, AI_V4MAPPED on some platforms: NetBSD 10.0.
  • This header file does not define AI_ADDRCONFIG on some platforms: NetBSD 5.0.
  • This header file incorrectly defines NI_MAXHOST on some platforms: musl libc 1.2.4, OpenBSD 7.5.

Portability problems not fixed by Gnulib:

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9.31 netinet/in.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/netinet_in.h.html

Gnulib module: netinet_in

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.
  • This header file is not self-contained on some platforms (it requires <sys/types.h> to be included first): OpenBSD 4.6.

Portability problems not fixed by Gnulib:

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9.32 netinet/tcp.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/netinet_tcp.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.

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9.33 nl_types.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/nl_types.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: Minix 3.1.8, Cygwin, mingw, MSVC 14, Android 9.0.

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9.34 poll.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/poll.h.html

Gnulib module: poll-h

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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9.35 pthread.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/pthread.h.html

Gnulib module: pthread-h

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms. Minix 3.1.8, mingw 2.x, MSVC 14. But the provided replacement covers only the essential POSIX threads API. Furthermore it is just a dummy on some of these platforms: Minix 3.1.8.
  • This header pollutes the namespace with some broken macro implementations for various functions such as strtok_r and gmtime_r: mingw 3.0.

Portability problems not fixed by Gnulib:

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9.36 pwd.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/pwd.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.

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9.37 regex.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/regex.h.html

Gnulib module: regex

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • This header file is not self-contained on some platforms: it requires <sys/types.h> to be included first.

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9.38 sched.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sched.h.html

Gnulib module: sched

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.
  • This header file does not define the type pid_t on some platforms: glibc 2.11, macOS 11.1.
  • struct sched_param is not defined on some platforms: Haiku.
  • SCHED_FIFO, SCHED_RR, SCHED_OTHER are not defined on some platforms: Haiku.

Portability problems not fixed by Gnulib:

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9.39 search.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/search.h.html

Gnulib module: search

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: Minix 3.1.8.

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9.40 semaphore.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/semaphore.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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9.41 setjmp.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/setjmp.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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9.42 signal.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/signal.h.html

Gnulib module: signal-h

Portability problems fixed by Gnulib:

  • volatile sig_atomic_t is rejected by older compilers on some platforms: AIX.
  • sigset_t is missing on some platforms: MSVC 14.
  • sigset_t is only declared in <sys/types.h> on some platforms: mingw.
  • struct sigaction and siginfo_t are missing on some platforms: mingw, MSVC 14.
  • The type pid_t is not defined on some platforms: MSVC 14.
  • The signal SIGPIPE is not defined on some platforms: mingw, MSVC 14.
  • The macros SA_RESETHAND and SA_RESTART are not defined on some platforms: NonStop.
  • The type sighandler_t (a GNU extension) is not defined on most non-glibc platforms: macOS 11.1, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • Many signals are not defined on some platforms: mingw, MSVC 14.
  • The macro SIGBUS is set to the same value as SIGSEGV, rather than being a distinct signal, on some platforms: Haiku.

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9.43 spawn.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/spawn.h.html

Gnulib module: spawn

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.7.25, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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9.44 stdalign.h

POSIX specification:
Not in POSIX yet, but we expect it will be, at least temporarily until it becomes obsolete due to its phasing out starting in C23. ISO C23 (latest free draft http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf) sections 6.5.3.4, 6.7.5, 7.15. C++11 (latest free draft http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2011/n3242.pdf) section 18.10.

Gnulib module: alignasof

Portability problems fixed by Gnulib:

  • On older C platforms <stdalign.h> must be included before using alignas or alignof. For example, GCC versions before 13 do not support these keywords, which were standardized by C23. On C23 and later platforms, <stdalign.h> has no effect and need not be included. (Gnulib-using code should not include <stdalign.h> without also employing Gnulib’s now-deprecated stdalign module.)
  • This header file is missing on many platforms: FreeBSD 6.4, NetBSD 7.1, OpenBSD 6.7, Minix 3.3.0, AIX 7.1, HP-UX 11.31, Solaris 11.3, mingw, MSVC 14, Android 9.0.
  • Clang 3.0’s <stdalign.h> does not define alignof.
  • The alignof macro returns too large values for the types double and long long in GCC 4.7.0.
  • Older C platforms might not support the obsolescent _Alignas and _Alignof keywords or macros. This portability problem should not matter with code using this module, as such code should use alignas and alignof instead.
  • In C11 and C17, <stdalign.h> defines the macros __alignas_is_defined and __alignof_is_defined to 1. In C23, these macros are not defined. This portability problem should not matter with code using Gnulib’s alignasof module, as such code should use alignas and alignof without checking these two macros. (Gnulib’s now-deprecated stdalign module defines these two macros.)
  • Clang 17 does not support an alignas attribute in the specifier-qualifier position of a member declaration.

Portability problems not fixed by Gnulib:

  • In C11 and later, the operand of alignof must be a parenthesized type. Recent versions of GCC support an extension in which the operand can also be a unary expression, as with sizeof. The Gnulib substitute does not support this extension.
  • On most pre-C11 platforms, the operand of alignof cannot be a structure type containing a flexible array member.
  • The alignas keyword or macro is not always supported. Supported compilers include any compiler supporting C11 or later, which includes GCC, IBM C, Sun C 5.9 and later, and MSVC 7.0 and later.
  • Some compilers do not support alignment via alignas of auto variables (i.e., variables on the stack). They diagnose and ignore the alignment: Sun C 5.11.
  • Some linkers do not support operands of alignas that are greater than 8: mingw.
  • Some compilers require the operand of alignas to be a single integer constant, not an expression: MSVC 7.0 through at least 10.0.
  • The Sun C 5.13 (2014) compiler sometimes mishandles the alignment of multiple external variables that are declared close together with alignas. The bug is fixed in Sun C 5.15, also known as Oracle Developer Studio 12.6 (2017).
  • You cannot assume that alignas and alignof are reserved words; they might be macros.

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9.45 stdarg.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stdarg.h.html

Gnulib module: stdarg

Portability problems fixed by Gnulib:

  • Some compilers (e.g., AIX 5.3 cc) need to be in c99 mode for the builtin va_copy to work.

Portability problems not fixed by Gnulib:

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9.46 stdatomic.h

POSIX specification:
Not in POSIX yet, but we expect it will be. ISO C11 (latest free draft http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1570.pdf) section 7.17.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on many platforms: glibc with GCC 4.8.x or clang 2.8, FreeBSD 6.4, NetBSD 7.0, OpenBSD 6.5, OpenBSD 6.9 with gcc, Minix 3.3.0, AIX 7.2 with xlc or xlclang, HP-UX 11.31, Solaris 11.3 with Oracle Studio 12.4 (Sun C 5.13), Cygwin 1.5.19, mingw, MSVC 14.
  • Linus Torvalds believes that “no compiler writer will get the C/C++ memory model right”; see https://lkml.org/lkml/2018/6/7/761.

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9.47 stdbit.h

POSIX :
Not in POSIX yet, but we expect it will be. ISO C23 (latest free draft http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf) section 7.18.

Gnulib module: stdbit

Portability problems fixed by Gnulib:

  • This header file is missing on many non-C23 platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 17, Android 15.

Portability problems not fixed by Gnulib:

  • On older non-C23 platforms lacking typeof or equivalent, a call to stdc_bit_floor and stdc_bit_ceil may yield a type that is wider than its argument. Although C23 seems to allow this, it differs from GNU behavior.
  • On non-C23 platforms, type-generic functions apply portably only to the standard unsigned integer types specified by C17 or earlier.

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9.48 stdbool.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stdbool.h.html

Gnulib module: stdbool-c99

The stdbool-c99 module is present only for programs that formerly used the old stdbool module for C99 compatibility, and that for some reason cannot use the current stdbool module for C23 compatibility.

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: AIX 5.1, HP-UX 11.
  • This header file is not usable in C++ mode with the vendor compiler on Solaris 10.
  • Some compilers have bugs relating to ‘bool’.
  • This header file defines true incorrectly on some platforms: OpenBSD 4.7 with gcc 2.95.

Portability problems not fixed by Gnulib:

  • ‘_Bool’ cannot be used before <stdbool.h> is included, or if the program is intended to be compiled by a C++ compiler. (With the advent of C23, ‘_Bool’ is obsolescent anyway.)
  • You cannot assume that _Bool is a typedef; it might be a macro. For example, C23 allows _Bool to be a macro.
  • Bit-fields of type ‘bool’ are not supported. Portable code should use ‘unsigned int foo : 1;’ rather than ‘bool foo : 1;’.
  • Casts and automatic conversions to ‘bool’ don’t test against the zero value or the null pointer, as they should. Such casts should only be used if the value is known to be equal to 0 or 1.
  • You cannot assume that casting a floating point literal to ‘bool’ will result in a constant expression.

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9.49 stdckdint.h

POSIX specification:
Not in POSIX yet, but we expect it will be. ISO draft C23 (https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf) section 7.20.

Gnulib module: stdckdint

Portability problems fixed by Gnulib:

  • This header file is missing on many platforms: glibc 2.29, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 6.7, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

  • In draft C23, arguments of stdckdint.h macros can have side effects.

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9.50 stddef.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stddef.h.html

Gnulib module: stddef

Portability problems fixed by Gnulib:

  • Some platforms fail to provide unreachable, which was added in C23: GCC 13, clang 15, AIX with xlc 12.1, Solaris with Sun C 5.15, and others.
  • Some platforms fail to provide max_align_t, which was added in C11: NetBSD 8.0, Solaris 11.0, and others.
  • max_align_t does not have the expected alignment on some platforms: NetBSD 8.0/x86, AIX 7.2 with xlc in 64-bit mode.
  • Some platforms provide a NULL macro that cannot be used in arbitrary expressions: NetBSD 5.0
  • Some platforms provide a NULL macro whose value does not have the size of a pointer: AIX 7.2 with xlc in 64-bit mode.
  • When this header file is provided by TinyCC 0.9.27 on glibc or macOS systems, it does not fulfil the expectations of other system header files.

Portability problems not fixed by Gnulib:

  • Some platforms fail to provide nullptr_t, which Gnulib cannot usefully emulate: GCC 12, Clang 15, and other pre-2023 C compilers.
  • Some platforms define nullptr_t even when <stddef.h> is not included: GCC 14.0.1 20240411 (Red Hat 14.0.1-0).
  • Some platforms provide an offsetof macro that cannot be used in arbitrary expressions: Solaris 11.4 This problem can be worked around by parenthesizing the offsetof expression in the unlikely case you use it with sizeof or ‘[]’.

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9.51 stdint.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stdint.h.html

Gnulib module: stdint

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: OpenBSD 3.8, AIX 5.1, HP-UX 11.11, MSVC 9.
  • This header file is very incomplete on some platforms.
  • The values of SIG_ATOMIC_MIN and SIG_ATOMIC_MAX are incorrect on some platforms: FreeBSD 6.2/ia64, FreeBSD 13.0/arm64.
  • The value of WINT_MAX is incorrect on some platforms: mingw.
  • The values of INT8_MAX, UINT8_MAX etc. are not usable in preprocessor expressions on some platforms: HP-UX 11.23.
  • The values of INTPTR_MAX and UINTPTR_MAX, although correctly defined in <stdint.h>, are replaced by empty values when <limits.h> or <inttypes.h> gets included later on some platforms: Solaris 9 with GCC 4.5 or newer.
  • The macros WCHAR_MIN and WCHAR_MAX are not defined in <stdint.h> (only in <wchar.h>) on some platforms: Dragonfly.
  • On some hosts that predate C++11, when using C++ one must define __STDC_CONSTANT_MACROS to make visible the definitions of constant macros such as INTMAX_C, and one must define __STDC_LIMIT_MACROS to make visible the definitions of limit macros such as INTMAX_MAX.
  • The macro SIZE_MAX has the wrong type, albeit with the correct value: 32-bit glibc 2.24 (on s390 architecture), Mac OS X 10.7.
  • Macros like INTMAX_WIDTH are not defined on some platforms: glibc 2.24, NetBSD 10.0, many others.

Portability problems not fixed by Gnulib:

  • {uint,int}_fast{8,16,32,64}_t may not correspond to the fastest types available on the system. Other <stdint.h> substitutes may define these types differently, so public header files should avoid these types.
  • Macros are used instead of typedefs.
  • Some C preprocessors mishandle constants that do not fit in long int. For example, as of 2007, Sun C mishandled #if LLONG_MIN < 0 on a platform with 32-bit long int and 64-bit long long int; this bug was fixed on or before Oracle Developer Studio 12.6 (Sun C 5.15 SunOS_sparc 2017/05/30). Some older preprocessors mishandle constants ending in LL. To work around these problems, compute the value of expressions like LONG_MAX < LLONG_MAX at configure-time rather than at #if-time.

The stdint module uses #include_next. If you wish to install the generated stdint.h file under another name, typically in order to be able to use some of the types defined by stdint.h in your public header file, you could use the following Makefile.am-snippet: 


BUILT_SOURCES += idn-int.h
DISTCLEANFILES += idn-int.h
nodist_include_HEADERS += idn-int.h

idn-int.h:
	if test -n "$(STDINT_H)"; then \
		sed -e s/include_next/include/ gl/stdint.h > idn-int.h; \
	else \
		echo '#include <stdint.h>' > idn-int.h; \
	fi

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9.52 stdio.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stdio.h.html

Gnulib module: stdio

Portability problems fixed by Gnulib:

  • The type off_t is not defined on some platforms: glibc 2.8, eglibc 2.11.2 and others.
  • The type ssize_t is not defined on some platforms: glibc 2.8, Mac OS X 10.5, Solaris 10, MSVC 14, and others.
  • The type va_list is not defined on some platforms: glibc 2.8, OpenBSD 4.0, Solaris 11.4, and others.
  • The type off64_t is not defined on some platforms: macOS 14, FreeBSD 10.4, NetBSD 10.0, OpenBSD 7.5, MSVC 14, Cygwin, Haiku, Minix 3.3.
  • Some platforms provide a NULL macro that cannot be used in arbitrary expressions: NetBSD 5.0

Portability problems not fixed by Gnulib:

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9.53 stdlib.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stdlib.h.html

Gnulib module: stdlib, system-posix

Portability problems fixed by the Gnulib module stdlib:

  • The macros EXIT_SUCCESS and EXIT_FAILURE are not defined on some platforms.
  • Some platforms provide a NULL macro that cannot be used in arbitrary expressions: NetBSD 5.0
  • The value of MB_CUR_MAX is too small (3 instead of 4) in UTF-8 locales on some platforms: Solaris 10.

Portability problems fixed by the Gnulib module system-posix:

  • The macros WIFSIGNALED, WIFEXITED, WIFSTOPPED, WTERMSIG, WEXITSTATUS, WNOHANG, WUNTRACED, WSTOPSIG are not defined in this header file (only in <sys/wait.h>) on some platforms: MirBSD 10.

Portability problems not fixed by Gnulib:

  • The definition of the type once_flag, of the macro ONCE_FLAG_INIT, and the declaration of the function call_once, that are required by ISO C 23, are not provided. To get them, import Gnulib module call_once and include <threads.h> rather than <stdlib.h>.
  • System status macros such as WEXITSTATUS require an lvalue argument on some platforms. macOS 11.1.

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9.54 stdnoreturn.h

POSIX specification:
Not in POSIX yet, but we expect it will be. ISO C11 (latest free draft http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1570.pdf) sections 7.23.

Gnulib module: stdnoreturn

Portability problems fixed by Gnulib:

  • This header file is missing on many platforms: FreeBSD 6.4, NetBSD 7.1, OpenBSD 6.7, Minix 3.3.0, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9.0, mingw, MSVC 14, Android 9.0.
  • This file conflicts with some system header files, such as <stdlib.h> and <process.h>, on some platforms: MSVC/clang.

Portability problems not fixed by Gnulib:

  • <stdnoreturn.h> and the noreturn macro are obsolescent in C23.
  • <stdnoreturn.h> cannot be #included in C++ mode on some platforms: FreeBSD 13.1.
  • <stdnoreturn.h> should be #included before ‘_Noreturn’ is used.
  • You cannot assume that _Noreturn is a reserved word; it might be a macro.
  • When the macro lint is defined, standard headers define _Noreturn (and therefore noreturn) to be a macro that expands to the empty token sequence on some platforms: Cygwin 2.5.1, FreeBSD 10.3.
  • On Cygwin 1.7.30 and MSVC 14, noreturn expands to the empty token sequence, to avoid problems with standard headers that use noreturn in combination with __attribute__ or __declspec. Although the resulting code operates correctly, the compiler is not informed whether noreturn functions do not return, so it may generate incorrect warnings at compile-time, or code that is slightly less optimized. This problem does not occur with _Noreturn.
  • Circa 2012 bleeding-edge GCC with -Werror=old-style-declaration requires _Noreturn or noreturn before the returned type in a declaration, and therefore rejects valid but unusually-worded declarations such as void _Noreturn foo (void);.

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9.55 string.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/string.h.html

Gnulib module: string

Portability problems fixed by Gnulib:

  • Some platforms provide a NULL macro that cannot be used in arbitrary expressions: NetBSD 5.0

Portability problems not fixed by Gnulib:

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9.56 strings.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/strings.h.html

Gnulib module: strings

Portability problems fixed by Gnulib:

  • This header file is not self-contained on some platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: MSVC 14.
  • This header file defines symbols, such as ‘index’, often used for variables, making debugging harder.

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9.57 stropts.h

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/stropts.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin, mingw, MSVC 14, Android 9.0.
  • This header is removed in POSIX.1-2024.

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9.58 sys/ipc.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_ipc.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.

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9.59 sys/mman.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_mman.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.

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9.60 sys/msg.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_msg.h.html

Gnulib module: sys_msg

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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9.61 sys/resource.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_resource.h.html

Gnulib module: sys_resource

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.
  • On some platforms, this header file requires that <sys/types.h> and <sys/time.h> already be included: FreeBSD 5.0.
  • On some platforms, this header file does not define the RUSAGE_SELF and RUSAGE_CHILDREN constants: OpenVMS.

Portability problems not fixed by Gnulib:

  • On some platforms, this header does not define some or all of the symbolic constants required by POSIX. For example, OpenVMS and Android do not define RLIM_SAVED_CUR or RLIM_SAVED_MAX.

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9.62 sys/select.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_select.h.html

Gnulib module: sys_select

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: HP-UX 11.11, NonStop Kernel, mingw, MSVC 14.
  • This header file is not self-contained on some platforms: it requires <sys/types.h> to be included first.
  • This header file is not self-contained—it requires <string.h> before FD_ZERO can be used—on some platforms: AIX 7.1, Solaris 11.4.

Portability problems not fixed by Gnulib:

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9.63 sys/sem.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_sem.h.html

Gnulib module: sys_sem

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.

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9.64 sys/shm.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_shm.h.html

Gnulib module: sys_shm

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.

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9.65 sys/socket.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_socket.h.html

Gnulib module: sys_socket

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.
  • This header file is not self-contained on some platforms: it requires <sys/types.h> to be included first.
  • This header file does not define the type struct iovec on some platforms: OpenBSD 4.4.
  • This header file is lacking the SHUT_RD, SHUT_WR, SHUT_RDWR macros on some platforms, despite having the shutdown functions: emx+gcc.
  • The struct sockaddr_storage type does not have a member ss_family on some platforms: AIX 7.1.
  • The CMSG_SPACE and CMSG_LEN macros are not provided on some platforms: OpenVMS.
  • This header file does not define the SO_REUSEPORT macro on some platforms: Minix 3.1.8, Solaris 10, Cygwin, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • This header file does not declare the msg_control and msg_controllen members of struct msghdr on some platforms. This can be detected by the absence of the CMSG_FIRSTHDR macro: gnulib replacement header, old BSD

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9.66 sys/stat.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_stat.h.html

Gnulib module: sys_stat

Portability problems fixed by Gnulib module sys_stat:

  • The type mode_t is not defined on some platforms: MSVC 14.
  • Some macros, such as S_IFMT or S_IFIFO, are missing on some platforms.
  • The macros S_ISBLK, S_ISCHR, S_ISDIR, S_ISFIFO, S_ISLNK, S_ISREG, S_ISSOCK are broken on some platforms.
  • Some platforms define macros, such as S_ISDOOR, that are not defined on other platforms.
  • The functions lstat and mkdir are not declared on some platforms: mingw, MSVC 14.
  • The macros UTIME_NOW and UTIME_OMIT are missing on some platforms.
  • On some platforms, struct stat does not include st_atim, st_mtim, or st_ctim members. Use the gnulib module ‘stat-time’ for accessors to portably get at subsecond resolution.

Portability problems fixed by Gnulib module sys_stat, together with module windows-stat-inodes:

  • On Windows platforms (excluding Cygwin), st_ino is always 0.

On platforms where off_t is a 32-bit type, struct stat cannot represent the size of files or block devices 2 GiB or lager and may not work correctly on directories 2 GiB or larger. Also, on platforms where ino_t is a 32-bit type, struct stat cannot represent larger inode numbers. See Large File Support, for how to address these problems.

See Avoiding the year 2038 problem, for portability issues with the time_t components of struct stat.

Portability problems not fixed by Gnulib:

  • The macro S_IFBLK is missing on some platforms: MSVC 14.
  • On OpenVMS, st_ino is an array of three ino_t values, not a single value. b are known to represent the same file.
  • On some platforms, two different files may have the same st_dev and st_ino values, even when st_ino is nonzero:
    • GNU/Linux NFS servers that export all local file systems as a single NFS file system, if a local st_dev exceeds 255, or if a local st_ino exceeds 16777215.
    • Network Appliance NFS servers in snapshot directories; see Network Appliance bug #195.
    • ClearCase MVFS; see bug id ATRia04618.
  • On some file systems, st_size contains bogus information for symlinks; use the Gnulib module areadlink-with-size for a better way to get symlink contents.

To partially work around porting problems with Microsoft Windows and OpenVMS, you can use the Gnulib same-inode module to test whether two struct stat objects are known to represent the same file. For example, psame_inode (&a, &b) is true if the struct stat objects a and b are known to represent the same file.

Another partial workaround is to compare other file metadata such as st_mode and st_mtime on platforms where st_dev and st_ino not uniquely identify a file. However, this does not work reliably on files whose metadata are being changed by other programs, or where the metadata happen to be equal.

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9.67 sys/statvfs.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_statvfs.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: OpenBSD 3.8, mingw, MSVC 14.

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9.68 sys/time.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_time.h.html

Gnulib module: sys_time

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: MSVC 14.
  • ‘struct timeval’ is not defined on some platforms.
  • ‘struct timeval’ is defined with a tv_sec type that is narrower than time_t on some native Windows platforms: mingw64 in 64-bit mode, mingw64 in 32-bit mode when __MINGW_USE_VC2005_COMPAT is defined, MSVC 14 in 64-bit mode, MSVC 14 in 32-bit mode when _USE_32BIT_TIME_T is not defined.

See Avoiding the year 2038 problem, for portability issues with time_t and the time_t component of struct timeval.

Portability problems not fixed by Gnulib:

  • ‘struct timeval’ is defined with a tv_sec type that is wider than time_t: OpenBSD 5.1 in 64-bit mode.

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9.69 sys/timeb.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/009695399/basedefs/sys/timeb.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: OpenBSD 6.7, Android 9.0.

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9.70 sys/times.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_times.h.html

Gnulib module: sys_times

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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9.71 sys/types.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_types.h.html

Gnulib module: sys_types

Portability problems fixed by Gnulib:

  • The type pid_t is not defined on some platforms: MSVC 14.
  • The type size_t is not defined in this file on some platforms: MSVC 14.
  • The type ssize_t is not defined on some platforms: MSVC 14.
  • The type mode_t is not defined on some platforms: MSVC 14.
  • The type off64_t is not defined on some platforms: macOS 14, FreeBSD 10.4, NetBSD 10.0, OpenBSD 7.5, MSVC 14, Cygwin, Haiku, Minix 3.3.
  • Some systems leak definitions of major, minor, and makedev through this header; however, when sys/sysmacros.h exists, that file should also be included to avoid deprecation warnings from the versions in this header: glibc 2.25.

See Avoiding the year 2038 problem, for portability issues with time_t.

Portability problems not fixed by Gnulib:

  • On some platforms the types blksize_t and suseconds_t are signed integer types that are wider than long: glibc x32

This module, together with the module largefile, also defines the type off_t to a 64-bit integer type on some platforms: mingw, MSVC 14.

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9.72 sys/uio.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_uio.h.html

Gnulib module: sys_uio

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.
  • This header file is not self-contained (it requires <sys/types.h> to be included first) on some platforms: OpenBSD 4.4.

Portability problems not fixed by Gnulib:

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9.73 sys/un.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_un.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.
  • This header requires <code>sys/socket.h</code> to be included first on some platforms: Cygwin 1.7.18.

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9.74 sys/utsname.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_utsname.h.html

Gnulib module: sys_utsname

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.
  • This header file is not self-contained on some platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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9.75 sys/wait.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_wait.h.html

Gnulib module: sys_wait

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • System status macros such as WEXITSTATUS require an lvalue argument on some platforms. macOS 11.1.

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9.76 syslog.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/syslog.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.

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9.77 tar.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/tar.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: Cygwin 1.5.x, mingw, MSVC 14.

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9.78 termios.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/termios.h.html

Gnulib module: termios

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.
  • This header does not declare pid_t on all platforms: glibc on some architectures, FreeBSD 6.4, OpenBSD 4.9, Cygwin 1.7.11.

Portability problems not fixed by Gnulib:

  • The types struct termios, cc_t, speed_t, tcflag_t are not defined on some platforms: mingw, MSVC 14.

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9.79 tgmath.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/tgmath.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: Mac OS X 10.5, FreeBSD 5.2.1, NetBSD 10.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.7.9, mingw, MSVC 14, Android 9.0.

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9.80 threads.h

Defines the multithreading facility of ISO C11.

Gnulib module: threads-h

Portability problems fixed by Gnulib:

  • This header file is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.2.x, mingw, MSVC 14, Android 9.0.
  • This header file defines thrd_start_t incorrectly on some platforms: AIX 7.2.
  • This header file does not define TSS_DTOR_ITERATIONS on some platforms: AIX 7.2.

Portability problems not fixed by Gnulib:

  • There is no way to define a working thread_local macro on some platforms:
    • Mac OS X 10.5,
    • OpenBSD 6.5,
    • AIX 7.1 with gcc (but it works with ‘xlc -qthreaded -qtls’),
    • HP-UX 11.31 with cc (but it works with gcc),
    • Android 4.3.

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9.81 time.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/time.h.html

Gnulib module: time-h

Portability problems fixed by Gnulib:

  • ‘struct timespec’ is not defined on some platforms.
  • The macro TIME_UTC is not defined on many platforms: glibc 2.15, macOS 10.13, FreeBSD 11.0, NetBSD 7.1, OpenBSD 6.0, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • Some platforms provide a NULL macro that cannot be used in arbitrary expressions: NetBSD 5.0.

Portability problems fixed by the Gnulib module year2038:

  • On some platforms where time_t defaults to 32-bit but can be changed to 64-bit, functions like stat can fail with errno == EOVERFLOW when a 32-bit timestamp is out of range, such as with a file timestamp in the far future or past: glibc 2.34+ atop 32-bit x86 or ARM Linux. See Avoiding the year 2038 problem.

Portability problems not fixed by Gnulib:

  • On some platforms struct tm lacks the the tm_gmtoff and tm_zone members: AIX 7.3, HP-UX 11, Solaris 11.4, mingw, MSVC 14.
  • On some platforms the global state variables daylight, timezone and tzname are not available. Even on platforms where they are available, their contents are often unreliable, even in single-threaded programs. Portable code can instead use struct tm’s tm_gmtoff and tm_zone members when available, and the strftime function with %z or %Z conversion specifiers otherwise.
  • On platforms where time_t is always 32-bit, functions like stat can fail with errno == EOVERFLOW when a timestamp is out of range, such as with a file timestamp in the far future or past; on other such platforms, the functions silently return the low-order 32 bits of the correct timestamp. These platforms will be obsolete when 32-bit time_t rolls around, which will occur in 2038 for the typical case when time_t is signed. See Avoiding the year 2038 problem.
  • On some platforms the tv_nsec member of struct timespec is not of type long, but is of type long long instead: glibc x32

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9.82 trace.h

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/trace.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin, mingw, MSVC 14, Android 9.0.
  • This header is removed in POSIX.1-2024.

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9.83 uchar.h

Defines the types char16_t, char32_t and declares the functions mbrtoc16, c16rtomb, mbrtoc32, c32rtomb.

Gnulib module: uchar or uchar-c23

Portability problems fixed by either Gnulib module uchar or uchar-c23:

  • This header file is missing on many non-glibc platforms: glibc 2.15, macOS 14, FreeBSD 6.4, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin, mingw, MSVC 9.
  • This file is not self-contained on some platforms: Haiku.
  • This file produces compilation errors in C++ mode on some platforms: AIX 7.2 with xlclang++.

Portability problems fixed by Gnulib module uchar-c23:

  • char32_t values may not be Unicode code points. This is the case in ISO C 11 compliant but not ISO C 23 compliant implementations.

Portability problems not fixed by Gnulib:

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9.84 ucontext.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/009695399/basedefs/ucontext.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: OpenBSD 6.7, Cygwin 1.7.35, mingw, MSVC 14.

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9.85 ulimit.h

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/ulimit.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, Cygwin, mingw, MSVC 14, Android 9.0.
  • This header is removed in POSIX.1-2024.

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9.86 unistd.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/unistd.h.html

Gnulib module: unistd

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: MSVC 14.
  • The type off64_t is not defined on some platforms: macOS 14, FreeBSD 10.4, NetBSD 10.0, OpenBSD 7.5, MSVC 14, Cygwin, Haiku, Minix 3.3.
  • The SEEK_* macros are not defined in this file on some platforms: mingw.
  • The *_FILENO macros are not defined in this file on some platforms: OS/2 EMX, mingw.
  • The _exit function is not declared in this file on some platforms: mingw.
  • Some platforms provide a NULL macro that cannot be used in arbitrary expressions: NetBSD 5.0

Portability problems not fixed by Gnulib:

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9.87 utime.h

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/utime.h.html

Gnulib module: utime-h

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

  • This header is removed in POSIX.1-2024.

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9.88 utmpx.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/utmpx.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: FreeBSD 8.4, OpenBSD 7.2, Minix 3.1.8, mingw, MSVC 14, Android 13.0.
  • While some platforms have the struct utmpx field ut_user, older platforms have the field ut_name.
  • The struct utmpx field ut_exit does not exist on some platforms: macOS, FreeBSD, AIX, Cygwin.
  • The struct utmpx field ut_session does not exist on some platforms: macOS, FreeBSD, AIX, HP-UX, Cygwin.
  • The struct utmpx field ut_addr or ut_addr_v6 or ut_ss does not exist on some platforms: macOS, FreeBSD, AIX, Solaris.
  • On some platforms, the struct utmpx field ut_tv is not of type struct timeval. Instead, it is a different struct with tv_sec and tv_usec members that may have different types than the members of struct timeval: glibc 2.39 on platforms where time_t was historically 32 bits and where log file formats were not changed when 64-bit time_t was introduced.
  • On some platforms, this API does not support timestamps past the year 2038: glibc 2.39 on 32-bit platforms like x86 and ARM where time_t was historically 32 bits; however, glibc 2.40 is planned to support timestamps up to the year 2106, by changing ut_tv.tv_sec’s type to be a 32-bit unsigned integer.
  • On some platforms, this header misbehaves if the year2038 or year2038-recommended modules are used and the program is configured without the --disable-year2038 option. The readutmp module works around this problem: glibc 2.38 on 32-bit platforms like x86 and ARM where time_t was historically 32 bits. See Avoiding the year 2038 problem.

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9.89 wchar.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/wchar.h.html

Gnulib module: wchar

Portability problems fixed by Gnulib:

  • This header file cannot be included on some platforms: Linux uClibc built without wide character support.
  • The type wint_t is incorrect on some platforms: mingw, MSVC 14.
  • Some platforms provide a NULL macro that cannot be used in arbitrary expressions: NetBSD 5.0

Portability problems not fixed by Gnulib:

  • This header file leads to link errors and endless recursions or endless loops on some platforms: glibc version 2.5 or older, together with gcc version 4.3 or newer and the option ‘-std=c99’ or ‘-std=gnu99’.

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9.90 wctype.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/wctype.h.html

Gnulib module: wctype-h

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: HP-UX 11.00.
  • The type wint_t is incorrect on some platforms: mingw, MSVC 14.
  • The functions isw* are missing on some platforms: FreeBSD 4.11.

Portability problems not fixed by Gnulib:

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9.91 wordexp.h

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/wordexp.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

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10 ISO C and POSIX Function Substitutes

This chapter describes which functions and function-like macros specified by ISO C (including ISO TS 18661-1) or POSIX are substituted by Gnulib, which portability pitfalls are fixed by Gnulib, and which (known) portability problems are not worked around by Gnulib.

The notation “Gnulib module: —” means that Gnulib does not provide a module providing a substitute for the function. When the list “Portability problems not fixed by Gnulib” is empty, such a module is not needed: No portability problems are known. Otherwise, it indicates that such a module would be useful but is not available: No one so far found this function important enough to contribute a substitute for it. If you need this particular function, you may write to <bug-gnulib at gnu dot org>.

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10.1 FD_CLR

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/FD_CLR.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.2 FD_ISSET

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/FD_ISSET.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.3 FD_SET

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/FD_SET.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.4 FD_ZERO

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/FD_ZERO.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.5 _Exit

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/_Exit.html

Gnulib module: _Exit

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.5.x, Android 4.4.

Portability problems not fixed by Gnulib:

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10.6 _exit

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/_exit.html

Gnulib module: unistd

Portability problems fixed by Gnulib:

  • This function is declared in a different header file (namely, <stdlib.h>) on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.7 _longjmp

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/_longjmp.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • This function is removed in POSIX.1-2024.

Note: Despite its being removed from POSIX, in 2024 on all systems which have _setjmp, it is the fastest way to save the registers but not the signal mask (up to 30 times faster than setjmp on some systems).

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10.8 _setjmp

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/_setjmp.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is removed in POSIX.1-2024.

Note: Despite its being removed from POSIX, in 2024 on all systems which have _setjmp, it is the fastest way to save the registers but not the signal mask (up to 30 times faster than setjmp on some systems).

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10.9 _tolower

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/_tolower.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, Minix 3.1.8, Android 4.4.
  • This function is removed in POSIX.1-2024. Use the function tolower instead.

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10.10 _toupper

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/_toupper.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, Minix 3.1.8, Android 4.4.
  • This function is removed in POSIX.1-2024. Use the function toupper instead.

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10.11 a64l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/a64l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, Minix 3.1.8, mingw, MSVC 14, Android 9.0.
  • This function was not correctly implemented in glibc versions before 2.2.5.

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10.12 abort

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/abort.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • Some platforms mistakenly close all stdio streams prior to raising SIGABRT: Cygwin 1.5.x.
  • Some platforms always print a message to stderr, even if a SIGABRT handler uses longjmp to resume execution at a safe point: mingw, MSVC 14.

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10.13 abs

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/abs.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Android 4.3.

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10.14 accept

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/accept.html

Gnulib module: accept

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), the descriptors returned by the accept function cannot be used in calls to read, write, and close; you have to use recv, send, closesocket in these cases instead.
  • On Windows platforms (excluding Cygwin), error codes from this function are not placed in errno, and WSAGetLastError must be used instead.
  • On HP-UX 11, in 64-bit mode, when the macro _HPUX_ALT_XOPEN_SOCKET_API is not defined, this function behaves incorrectly because it is declared to take a pointer to a 64-bit wide socklen_t entity but in fact considers it as a pointer to a 32-bit wide unsigned int entity.

Portability problems not fixed by Gnulib:

  • Some platforms don’t have a socklen_t type; in this case this function’s third argument type is ‘int *’.
  • On some platforms, this function’s third argument type is ‘void *’, not ‘socklen_t *’: Solaris 10.

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10.15 access

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/access.html

Gnulib module: access

Portability problems fixed by Gnulib:

  • This function does not support the X_OK mode on some platforms: MSVC 14.
  • This function does not reject trailing slashes on symlinks to non-directories on some platforms: Mac OS X 10.5.

Portability problems not fixed by Gnulib:

  • This function uses the effective id instead of the real id on some platforms: Cygwin 1.5.x.

Other problems of this function:

  • There is an inherent race between calling this function and performing some action based on the results; you should think twice before trusting this function, especially in a set-uid or set-gid program.
  • This function does not have an option for not following symbolic links (like stat versus lstat). If you need this option, use the Gnulib module faccessat with the AT_EACCESS flag.
  • On Solaris, for the root user, any file is X_OK even if the file does not have the x permission bit set.
  • On native Windows, files whose basename does not contain a ‘.’ cannot be executed through execlp or execvp. Nevertheless, this function may return true for such files.
  • On Windows, different facilities for executing a program have different ways of finding an executable file, by trying various suffixes. For example, execlp and execvp search for files with the suffixes .com, .exe, .bat, .cmd, when the file with the given file name does not exist. Whereas cmd.exe searches according to the PATHEXT environment variable. This function does not perform any search; it merely looks at the file with the given file name.

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10.16 acos

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/acos.html

Gnulib module: acos

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.17 acosf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/acosf.html

Gnulib module: acosf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.18 acosh

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/acosh.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 9.

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10.19 acoshf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/acoshf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, mingw, MSVC 9.

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10.20 acoshl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/acoshl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 4.4.
  • This function produces results which are accurate to only 16 digits on some platforms: NetBSD 10.0.

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10.21 acosl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/acosl.html

Gnulib module: acosl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, Android 4.4.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

  • This function produces results which are accurate to only 16 digits on some platforms: NetBSD 10.0.

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10.22 aio_cancel

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_cancel.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, this function may not work correctly on files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.23 aio_error

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_error.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, this function may not work correctly on files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.24 aio_fsync

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_fsync.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, this function may not work correctly on files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.25 aio_read

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_read.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, this function may not work correctly on files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.26 aio_return

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_return.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, this function may not work correctly on files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.27 aio_suspend

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_suspend.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, this function may not work correctly on files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.28 aio_write

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/aio_write.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, this function may not work correctly on files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.29 alarm

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/alarm.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function has no impact if <code>SIGALRM</code> is inherited as ignored; programs should use <code>signal (SIGALRM, SIG_DFL)</code> if it is important to ensure the alarm will fire.
  • Use of this function in multi-threaded applications is not advised.
  • This function is missing on some platforms: mingw (2011), MSVC 14.
  • This function is conditionally declared in the non-standard <io.h> header on some platforms: mingw (2012 or newer).

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10.30 aligned_alloc

Documentation:
man aligned_alloc

Gnulib module: aligned_alloc

Portability problems fixed by Gnulib:

  • This function fails if the alignment argument is smaller than sizeof (void *) on some platforms: macOS 14, AIX 7.3.1.

Portability problems not fixed by Gnulib:

  • On some platforms, aligned_alloc crashes if the requested size is not a multiple of the alignment: AddressSanitizer (gcc 11.2 or clang 13).
  • This function is missing on many older platforms: glibc 2.15, macOS 10.14, FreeBSD 6.4, NetBSD 7.1, OpenBSD 6.0, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

Gnulib has partial substitutes for aligned_alloc that do not crash even if the AddressSanitizer bug is present:

  • The Gnulib module alignalloc provides a portable function alignalloc that is a near-substitute for glibc aligned_alloc, except that the result must be freed with alignfree rather than plain free.
  • The Gnulib module aligned-malloc provides functions for allocating and freeing blocks of suitably aligned memory.
  • The Gnulib module pagealign_alloc provides a similar API for allocating and freeing blocks of memory aligned on a system page boundary.

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10.31 alphasort

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/alphasort.html

Gnulib module: alphasort

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Solaris 9, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • The parameters of this function are declared as const void * on some platforms: glibc 2.3.6, macOS 10.7, FreeBSD 6.0, NetBSD 7.1, OpenBSD 6.7.
  • The parameters of this function are declared as void * on some platforms: AIX 5.1.

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10.32 asctime

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/asctime.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is deprecated in C23. Likewise, POSIX says this function is obsolescent and it is planned to be removed in a future version. Portable applications can use strftime (or even sprintf) instead. However, strftime is locale dependent.
  • This function may overflow its internal buffer if its argument specifies a year before 1000 or after 9999. See ctime.
  • Although it is tempting to call this function on the value that functions like localtime return, this is typically a mistake. On most current platforms, these functions return a null pointer for timestamps out of range, and this function has undefined behavior in that case.

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10.33 asctime_r

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/asctime_r.html

Gnulib module: extensions

Portability problems fixed by Gnulib:

  • This function has an incompatible declaration on some platforms: Solaris 11.4 (when _POSIX_PTHREAD_SEMANTICS is not defined).

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • This function is removed in POSIX.1-2024. Use the function strftime (or even sprintf) instead. However, strftime is locale dependent.
  • This function may overflow its output buffer if its argument specifies a year before 1000 or after 9999. See ctime.
  • Although it is tempting to call this function on the value that functions like localtime return, this is typically a mistake. On most current platforms, these functions return a null pointer for timestamps out of range, and this function has undefined behavior in that case.

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10.34 asin

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/asin.html

Gnulib module: asin

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.35 asinf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/asinf.html

Gnulib module: asinf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.36 asinh

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/asinh.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 9.

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10.37 asinhf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/asinhf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, mingw, MSVC 9.

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10.38 asinhl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/asinhl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 4.4.
  • This function produces results which are accurate to only 16 digits on some platforms: NetBSD 10.0.

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10.39 asinl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/asinl.html

Gnulib module: asinl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, Android 4.4.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

  • This function produces results which are accurate to only 16 digits on some platforms: NetBSD 10.0.

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10.40 assert

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/assert.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

Extension: Gnulib offers a module ‘assert’ that allows the installer to disable assertions through a ‘configure’ option: ‘--disable-assert’.

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10.41 atan

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atan.html

Gnulib module: atan

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.42 atan2

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atan2.html

Gnulib module: atan2

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.43 atan2f

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atan2f.html

Gnulib module: atan2f

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.44 atan2l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atan2l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, Android 4.4.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.
  • This function produces results which are accurate to only 16 digits on some platforms: NetBSD 10.0.

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10.45 atanf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atanf.html

Gnulib module: atanf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.46 atanh

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atanh.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 9.

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10.47 atanhf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atanhf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, mingw, MSVC 9.

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10.48 atanhl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atanhl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 4.4.
  • This function produces results which are accurate to only 16 digits on some platforms: NetBSD 10.0.

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10.49 atanl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atanl.html

Gnulib module: atanl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, Android 4.4.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

  • This function produces results which are accurate to only 16 digits on some platforms: NetBSD 10.0.

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10.50 atexit

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atexit.html

Gnulib module: atexit

Portability problems fixed by Gnulib:

  • This function is missing on some old platforms.

Portability problems not fixed by Gnulib:

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10.51 atof

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atof.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Android 4.4.
  • This function mis-parses strings with leading ‘+’ on some old platforms: Old versions of Linux.
  • This function returns a positive value for negative underflow on some platforms: glibc 2.4, Mingw, Cygwin.
  • This function fails to do a valid parse of ‘-0x’ on some platforms: glibc 2.4, Cygwin < 1.5.25-11.
  • This function fails to parse Infinities and plain NaNs on some platforms: Mingw, OpenBSD 4.0.
  • This function fails to parse NaN() on some platforms: Mingw, OpenBSD 4.0, Cygwin < 1.5.25-11.
  • This function fails to parse NaN(n-char-sequence) on some platforms: Mingw, OpenBSD 4.0.
  • This function fails to parse C99 hexadecimal floating point on some platforms: Mingw, OpenBSD 4.0.
  • This function fails to correctly parse very long strings on some platforms: Mingw, Cygwin.

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10.52 atoi

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atoi.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.53 atol

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atol.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.54 atoll

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/atoll.html

Gnulib module: atoll

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11.23, MSVC 9.

Portability problems not fixed by Gnulib:

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10.55 basename

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/basename.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-basename-3.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • glibc and Android have two different functions basename: the POSIX version and the GNU version.
  • basename assumes file names in POSIX syntax; it does not work with file names in Windows syntax.

The Gnulib module basename-lgpl provides similar API, with a function last_component, that also works with Windows file names.

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10.56 bind

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/bind.html

Gnulib module: bind

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), error codes from this function are not placed in errno, and WSAGetLastError must be used instead.

Portability problems not fixed by Gnulib:

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10.57 bsearch

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/bsearch.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.58 btowc

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/btowc.html

Gnulib module: btowc

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.00, mingw.
  • This function returns WEOF for a NUL argument on some platforms: Cygwin 1.7.2.
  • In the C or POSIX locales, this function is not consistent with Gnulib’s mbrtowc and can return WEOF: glibc 2.35, MirOS BSD #10.
  • In the C or POSIX locales, this function is not consistent with mbrtowc on some platforms: mingw.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function btoc32, provided by Gnulib module btoc32, operates on 32-bit wide characters and therefore does not have this limitation.

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10.59 c8rtomb

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on most platforms: glibc 2.35, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.3.0, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.4.6, mingw, MSVC 14, Android 9.0.

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10.60 c16rtomb

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on most non-glibc platforms: glibc 2.15, macOS 14, FreeBSD 6.4, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 3.4.6, mingw, MSVC 9, Android 4.4.

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10.61 c32rtomb

Gnulib module: c32rtomb

Portability problems fixed by Gnulib:

  • This function is missing on most non-glibc platforms: glibc 2.15, macOS 14, FreeBSD 6.4, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 3.4.6, mingw, MSVC 9, Android 4.4.
  • This function returns 0 when the first argument is NULL in some locales on some platforms: AIX 7.2.

Portability problems not fixed by Gnulib:

  • This function is only defined as an inline function on some platforms: Haiku 2020.

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10.62 cabs

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cabs.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11, Solaris 9.

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10.63 cabsf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cabsf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, mingw, MSVC 9.

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10.64 cabsl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cabsl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 10.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 5.1.

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10.65 cacos

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cacos.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9, Android 5.1.

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10.66 cacosf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cacosf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9, Android 5.1.

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10.67 cacosh

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cacosh.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9, Android 5.1.

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10.68 cacoshf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cacoshf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9, Android 5.1.

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10.69 cacoshl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cacoshl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 11.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 7.1.

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10.70 cacosl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cacosl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 11.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 7.1.

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10.71 calloc

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/calloc.html

Gnulib module: calloc-posix

Portability problems fixed by Gnulib:

  • Upon failure, the function does not set errno to ENOMEM on some platforms: mingw, MSVC 14.
  • On some platforms, calloc (n, s) can succeed even if multiplying n by s would exceed PTRDIFF_MAX or SIZE_MAX. Although failing to check for exceeding PTRDIFF_MAX is arguably allowed by POSIX it can lead to undefined behavior later, so calloc-posix does not allow going over the limit.

Extension: Gnulib provides a module ‘calloc-gnu’ that substitutes a calloc implementation that behaves more like the glibc implementation. It fixes this portability problem:

  • calloc (0, s) and calloc (n, 0) return NULL on success on some platforms: AIX 7.2.

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10.72 call_once

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Call-Once.html.

Gnulib module: call_once

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

  • This function makes applications hang forever on some platforms: Cygwin 3.5.3.
  • This function does not work on some platforms: Haiku.

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10.73 canonicalize

Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.74 canonicalizef

Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.75 canonicalizel

Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.76 carg

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/carg.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.77 cargf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cargf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.78 cargl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cargl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 5.1.

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10.79 casin

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/casin.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9, Android 5.1.

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10.80 casinf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/casinf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9, Android 5.1.

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10.81 casinh

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/casinh.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9, Android 5.1.

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10.82 casinhf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/casinhf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9, Android 5.1.

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10.83 casinhl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/casinhl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 11.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 7.1.

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10.84 casinl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/casinl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 11.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 7.1.

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10.85 catan

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/catan.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9, Android 5.1.

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10.86 catanf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/catanf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9, Android 5.1.

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10.87 catanh

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/catanh.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9, Android 5.1.

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10.88 catanhf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/catanhf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9, Android 5.1.

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10.89 catanhl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/catanhl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 11.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 7.1.

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10.90 catanl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/catanl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 11.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 7.1.

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10.91 catclose

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/catclose.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 7.1.

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10.92 catgets

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/catgets.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 7.1.

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10.93 catopen

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/catopen.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 7.1.

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10.94 cbrt

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cbrt.html

Gnulib module: cbrt

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, MSVC 9.

Portability problems not fixed by Gnulib:

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10.95 cbrtf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cbrtf.html

Gnulib module: cbrtf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9, MSVC 9.

Portability problems not fixed by Gnulib:

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10.96 cbrtl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cbrtl.html

Gnulib module: cbrtl or cbrtl-ieee

Portability problems fixed by either Gnulib module cbrtl or cbrtl-ieee

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9, Android 4.4.
  • This function produces grossly wrong results on some platforms: OpenBSD 5.1/SPARC.

Portability problems fixed by Gnulib module cbrtl-ieee:

Portability problems not fixed by Gnulib:

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10.97 ccos

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ccos.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.98 ccosf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ccosf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.99 ccosh

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ccosh.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.100 ccoshf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ccoshf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.101 ccoshl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ccoshl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 14.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 7.1.

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10.102 ccosl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ccosl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 14.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 7.1.

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10.103 ceil

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ceil.html

Gnulib module: ceil or ceil-ieee

Portability problems fixed by either Gnulib module ceil or ceil-ieee:

Portability problems fixed by Gnulib module ceil-ieee:

  • This function returns a positive zero for an argument between -1 and 0 on some platforms: AIX 7.1.

Portability problems not fixed by Gnulib:

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10.104 ceilf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ceilf.html

Gnulib module: ceilf or ceilf-ieee

Portability problems fixed by either Gnulib module ceilf or ceilf-ieee:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems fixed by Gnulib module ceilf-ieee:

  • This function returns a positive zero for an argument between -1 and 0 on some platforms: macOS 10.5, AIX 7.1.

Portability problems not fixed by Gnulib:

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10.105 ceill

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ceill.html

Gnulib module: ceill or ceill-ieee

Portability problems fixed by either Gnulib module ceill or ceill-ieee:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.
  • This function returns a wrong result for small arguments on some platforms: OpenBSD 5.6.

Portability problems fixed by Gnulib module ceill-ieee:

Portability problems not fixed by Gnulib:

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10.106 cexp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cexp.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.107 cexpf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cexpf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.108 cexpl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cexpl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 13.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 7.1.

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10.109 cfgetispeed

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cfgetispeed.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4.

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10.110 cfgetospeed

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cfgetospeed.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4.

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10.111 cfsetispeed

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cfsetispeed.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4.

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10.112 cfsetospeed

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cfsetospeed.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4.

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10.113 chdir

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/chdir.html

Gnulib module: chdir

Portability problems fixed by Gnulib:

  • This function is declared in different header files (namely, <io.h> or <direct.h>) on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.114 chmod

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/chmod.html

Gnulib module: chmod

Portability problems fixed by Gnulib:

  • This function does not fail when the file name argument ends in a slash and (without the slash) names a non-directory, on some platforms: AIX 7.2.
  • This function fails with a wrong error code (EINVAL instead of ENOTDIR) when the file name argument ends in a slash and (without the slash) names a non-directory, on some platforms: mingw, MSVC.

Portability problems not fixed by Gnulib:

  • This function sometimes fails with EACCES when the failure is due to lack of appropriate privileges (EPERM), not to search permission denied on the file name prefix (EACCES): Linux kernel 5.15 with glibc 2.35 and a CIFS v1 file system (see https://bugs.gnu.org/65599).

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10.115 chown

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/chown.html

Gnulib module: chown

Portability problems fixed by Gnulib:

  • Some platforms fail to detect trailing slash on non-directories, as in chown("link-to-file/",uid,gid): macOS 14, FreeBSD 7.2, AIX 7.3.1, Solaris 9.
  • Some platforms fail to update the change time when at least one argument was not -1, but no ownership changes resulted: OpenBSD 7.2.
  • When passed an argument of -1, some implementations really set the owner user/group id of the file to this value, rather than leaving that id of the file alone: some very old platforms.
  • When applied to a symbolic link, some implementations don’t dereference the symlink, i.e. they behave like lchown: some very old platforms.
  • This function is missing on some platforms; however, the replacement always fails with ENOSYS: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • This function sometimes fails with EACCES when the failure is due to lack of appropriate privileges (EPERM), not to search permission denied on the file name prefix (EACCES): Linux kernel 5.15 with glibc 2.35 and a CIFS v1 file system (see https://bugs.gnu.org/65599).

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10.116 cimag

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cimag.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.117 cimagf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cimagf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.118 cimagl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cimagl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 5.1.

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10.119 clearerr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clearerr.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.120 clock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clock.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.121 clock_getcpuclockid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clock_getcpuclockid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.11, FreeBSD 6.0, NetBSD 7.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.9, mingw, MSVC 14, Android 5.1.

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10.122 clock_getres

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clock_getres.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.11, Minix 3.1.8, mingw, MSVC 14.
  • On many platforms, this function returns a value other than the clock resolution of clock_gettime, i.e., the minimum distance between differing timestamps. For example, on AIX 7.2 it returns 10 milliseconds even though the clock resolution is 1 microsecond. Conversely, on GNU/Linux it typically returns 1 nanosecond even though the clock resolution may be greater.

The Gnulib module gettime-res is a partial substitute; it implements the CLOCK_REALTIME functionality of clock_getres, and fixes the too-high resolution bug of platforms like AIX 7.2.

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10.123 clock_gettime

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clock_gettime.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.11, Minix 3.1.8, mingw, MSVC 14.
  • This function leaves the upper 32 bits of the tv_sec field of the result uninitialized on some platforms: mingw in 32-bit mode.

The Gnulib modules gettime and timespec_get are partial substitutes; they implement the CLOCK_REALTIME functionality of clock_gettime.

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10.124 clock_nanosleep

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clock_nanosleep.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.11, FreeBSD 11.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.9, mingw, MSVC 14.

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10.125 clock_settime

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clock_settime.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.11, Minix 3.1.8, Cygwin 1.7.9, mingw, MSVC 14.

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10.126 clog

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clog.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 11.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9, Android 7.1.

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10.127 clogf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clogf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 11.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9, Android 7.1.

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10.128 clogl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/clogl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 11.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 7.1.

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10.129 close

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/close.html

Gnulib module: close

Portability problems fixed by Gnulib:

  • This function is declared in a different header file (namely, <io.h>) on some platforms: MSVC 14.
  • This function crashes when invoked with invalid arguments on some platforms: MSVC 14.
  • On Windows platforms (excluding Cygwin), socket and accept do not return file descriptors that can be closed by close. Instead, closesocket must be used.

Portability problems not fixed by Gnulib:

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10.130 closedir

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/closedir.html

Gnulib module: closedir

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.131 closelog

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/closelog.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.132 cnd_broadcast

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Condition-Variables.html.

Gnulib module: cnd

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.133 cnd_destroy

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Condition-Variables.html.

Gnulib module: cnd

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.134 cnd_init

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Condition-Variables.html.

Gnulib module: cnd

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.135 cnd_signal

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Condition-Variables.html.

Gnulib module: cnd

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.136 cnd_timedwait

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Condition-Variables.html.

Gnulib module: cnd

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

  • This function sometimes waits indefinitely instead of up to the specified time point, on some platforms (glibc/Linux, musl libc) in some hypervisors: VirtualBox 6.1.50_Ubuntu with paravirtualization set to "Default" or "KVM".

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10.137 cnd_wait

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Condition-Variables.html.

Gnulib module: cnd

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.138 confstr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/confstr.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

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10.139 conj

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/conj.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.140 conjf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/conjf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.141 conjl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/conjl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 5.1.

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10.142 connect

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/connect.html

Gnulib module: connect

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), error codes from this function are not placed in errno, and WSAGetLastError must be used instead.

Portability problems not fixed by Gnulib:

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10.143 copysign

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/copysign.html

Gnulib module: copysign

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, MSVC 9.

Portability problems not fixed by Gnulib:

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10.144 copysignf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/copysignf.html

Gnulib module: copysignf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9, MSVC 9.

Portability problems not fixed by Gnulib:

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10.145 copysignl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/copysignl.html

Gnulib module: copysignl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9.

Portability problems not fixed by Gnulib:

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10.146 cos

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cos.html

Gnulib module: cos

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.147 cosf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cosf.html

Gnulib module: cosf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.148 cosh

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cosh.html

Gnulib module: cosh

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.149 coshf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/coshf.html

Gnulib module: coshf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.150 coshl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/coshl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, Android 4.4.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.
  • This function produces results which are accurate to only 16 digits on some platforms: NetBSD 10.0.

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10.151 cosl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cosl.html

Gnulib module: cosl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, Android 4.4.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

  • This function produces results which are accurate to only 16 digits on some platforms: NetBSD 10.0.

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10.152 cpow

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cpow.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 11.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9, Android 7.1.

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10.153 cpowf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cpowf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 11.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9, Android 7.1.

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10.154 cpowl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cpowl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 11.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 7.1.

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10.155 cproj

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cproj.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.
  • The glibc implementation is or was broken.

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10.156 cprojf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cprojf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.
  • The glibc implementation is or was broken.

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10.157 cprojl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/cprojl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 5.1.
  • The glibc implementation is or was broken.

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10.158 creal

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/creal.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.159 crealf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/crealf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.160 creall

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/creall.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 5.1.

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10.161 creat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/creat.html

Gnulib module: creat

Portability problems fixed by Gnulib:

  • This function does not support modes with execution bits (such as 0700) on some platforms: MSVC 14.
  • On platforms where off_t is a 32-bit type, creat may not work correctly with files 2 GiB and larger. See Large File Support.
  • This function does not fail when the file name argument ends in a slash and (without the slash) names a nonexistent file, on some platforms: FreeBSD 7.2, AIX 7.1, HP-UX 11.31, Solaris 9.

Portability problems not fixed by Gnulib:

  • On Windows, this function returns a file handle in O_TEXT mode. If you need a file handle in O_BINARY mode, you need to use the function open instead.

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10.162 crypt

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/crypt.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.34, FreeBSD 6.0, NetBSD 5.0, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function is not declared in <unistd.h> (without -D_GNU_SOURCE) on some platforms: glibc (at least 2.11–2.13).

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10.163 csin

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/csin.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.164 csinf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/csinf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.165 csinh

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/csinh.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.166 csinhf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/csinhf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.167 csinhl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/csinhl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 14.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 7.1.

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10.168 csinl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/csinl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 14.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 7.1.

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10.169 csqrt

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/csqrt.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.170 csqrtf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/csqrtf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.171 csqrtl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/csqrtl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 5.1.

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10.172 ctan

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctan.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.173 ctanf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctanf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.174 ctanh

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctanh.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.175 ctanhf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctanhf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, mingw, MSVC 9.

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10.176 ctanhl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctanhl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 14.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 7.1.

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10.177 ctanl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctanl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 14.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 7.1.

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10.178 ctermid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctermid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 7.1.

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10.179 ctime

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctime.html

Gnulib module: ctime

Portability problems fixed by Gnulib:

  • On native Windows platforms (mingw, MSVC), this function works incorrectly when the environment variable TZ has been set by Cygwin.

Portability problems not fixed by Gnulib:

  • This function is deprecated in C23. Likewise, POSIX says this function is obsolescent and it is planned to be removed in a future version. Portable applications can use localtime_r and strftime (or even sprintf) instead. However, localtime_r can fail and strftime is locale dependent.
  • This function may overflow its internal buffer if its argument specifies a time before the year 1000 or after the year 9999.
  • This function may dereference an internal null pointer if its argument specifies a time before the year INT_MIN+1900 or after the year INT_MAX+1900.
  • The ctime function need not be reentrant, and consequently is not required to be thread safe. Implementations of ctime typically write the timestamp into static buffer. If two threads call ctime at roughly the same time, you might end up with the wrong date in one of the threads, or some undefined string.
  • Native Windows platforms (mingw, MSVC) support only a subset of time zones supported by GNU or specified by POSIX. See tzset.

Although ctime and related functions asctime, asctime_r and ctime_r formerly were plausible to use, they are now unsafe in general, and should be avoided.

Decades ago when time_t was narrow and there was no strftime or internationalization, code could call these functions and then select the parts needed. For example, in Unix 7th Edition /usr/src/cmd/ls.c (1979): 

cp = ctime(&p->lmtime);
if(p->lmtime < year)
        printf(" %-7.7s %-4.4s ", cp+4, cp+20); else
        printf(" %-12.12s ", cp+4);

This had well-defined behavior when time_t was only 32 bits and so was OK for circa 1979 platforms.

However, today’s platforms have a time_t so wide that the year might not be in the range [1000, 9999]. In this case the behavior of ctime is undefined and some platforms behave badly, overrunning a buffer or dereferencing an internal null pointer; and even on platforms where no undefined behavior occurs, the 7th Edition code generates wrong output for out-of-range years, because it incorrectly assumes that every year is represented by exactly four digits.

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10.180 ctime_r

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ctime_r.html

Gnulib module: extensions

Portability problems fixed by Gnulib:

  • This function has an incompatible declaration on some platforms: Solaris 11.4 (when _POSIX_PTHREAD_SEMANTICS is not defined).

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • This function is removed in POSIX.1-2024. Use the functions localtime_r and strftime (or even sprintf) instead. However, localtime_r can fail and strftime is locale dependent.
  • This function may overflow its output buffer if its argument specifies a time before the year 1000 or after the year 9999. See ctime.
  • This function may dereference an internal null pointer if its argument specifies a time before the year INT_MIN+1900 or after the year INT_MAX+1900.

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10.181 daddl

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.27, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.182 daylight

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/daylight.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable’s contents are unreliable if you use a geographical TZ setting like TZ="America/Los_Angeles".
  • This variable is missing on some platforms: FreeBSD 14.0, OpenBSD 5.7.
  • This variable is called _daylight on some platforms: mingw with -DNO_OLDNAMES, MSVC.
  • The address of this variable is not a compile-time constant on some platforms: mingw, MSVC.
  • Native Windows platforms (mingw, MSVC) support only a subset of time zones supported by GNU or specified by POSIX. See tzset.

This variable is vestigial: it is not needed and does not suffice in general. It is planned to be removed from a future version of POSIX. A more portable way of getting the UTC offset is to use strftime with the %z format. See strftime.

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10.183 dbm_clearerr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_clearerr.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, HP-UX 11.11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.184 dbm_close

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_close.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.185 dbm_delete

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_delete.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.186 dbm_error

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_error.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, HP-UX 11.11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.187 dbm_fetch

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_fetch.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.188 dbm_firstkey

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_firstkey.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.189 dbm_nextkey

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_nextkey.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.190 dbm_open

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_open.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.191 dbm_store

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dbm_store.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.192 ddivl

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.27, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.193 dfmal

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.14.5

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.194 difftime

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/difftime.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.195 dirfd

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dirfd.html

Gnulib module: dirfd

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 7.1, HP-UX 11, Solaris 10, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • This function always fails on some platforms: mingw.
  • There is a dirfd macro but no function, and the macro does not work with an argument of type void *, as a function would: NetBSD 9.2.

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10.196 dirname

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dirname.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • dirname assumes file names in POSIX syntax; it does not work with file names in Windows syntax.

The Gnulib module dirname provides similar API, with functions dir_name and mdir_name, that also works with Windows file names.

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10.197 div

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/div.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.198 dlclose

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dlclose.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.199 dlerror

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dlerror.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.200 dlopen

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dlopen.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dlopen-1.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.
  • If the file name argument is not absolute, the file is searched for. The search algorithm is system specific.

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10.201 dlsym

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dlsym.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dlsym-1.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.
  • The visibility of symbols loaded in dependent shared libraries or present in the main executable is system dependent.

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10.202 dmull

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.27, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.203 dprintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dprintf.html

Gnulib module: dprintf or dprintf-posix or dprintf-gnu

Portability problems fixed by either Gnulib module dprintf or dprintf-posix or dprintf-gnu:

  • This function is missing on many non-glibc platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.5.x, mingw, MSVC 14.

Portability problems fixed by either Gnulib module dprintf-posix or dprintf-gnu:

  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • printf "%f", "%e", "%g" of Infinity and NaN yields an incorrect result on some platforms: AIX 7.3, Solaris 11.4.
  • This function does not support the ‘a’ and ‘A’ directives on some platforms: Solaris 11.4.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support precisions in the ‘ls’ directive correctly on some platforms: Solaris 11.4.
  • This function does not round the argument of the ‘a’ directive correctly on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4.
  • printf "%010f" of NaN and Infinity yields an incorrect result (padded with zeroes, or wrong capitalization) on some platforms: AIX 7.3, Solaris 11.4.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • This function does not support precisions larger than 512 or 1024 in integer, floating-point and pointer output on some platforms: AIX 7.1.
  • This function produces wrong output for the ‘lc’ directive with a NUL wide character argument on some platforms: musl libc 1.2.4.

Portability problems fixed by Gnulib module dprintf-gnu:

  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.

Portability problems fixed by either Gnulib module dprintf-posix or dprintf-gnu and additionally the Gnulib module printf-with-n-directive:

  • This function does not support the ‘n’ directive on some platforms: glibc when used with _FORTIFY_SOURCE >= 2 (set by default on Ubuntu), macOS 14, OpenBSD, Android.

Portability problems not fixed by Gnulib:

  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.
  • Formatting noncanonical ‘long double’ numbers produces nonmeaningful results on some platforms: glibc and others, on x86, x86_64, IA-64 CPUs.
  • When formatting an integer with grouping flag, this function inserts thousands separators even in the "C" locale on some platforms: NetBSD 5.1.
  • On some platforms, this function does not set errno or the stream error indicator on attempts to write to a read-only stream: Cygwin 1.7.9.

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10.204 drand48

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/drand48.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.205 dsqrtl

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.14.6

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.206 dsubl

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.27, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.207 dup

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dup.html

Gnulib module: dup

Portability problems fixed by Gnulib:

  • This function is declared in a different header file (namely, <io.h>) on some platforms: MSVC 14.
  • This function crashes when invoked with invalid arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.208 dup2

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/dup2.html

Gnulib module: dup2

Portability problems fixed by Gnulib:

  • This function is declared in a different header file (namely, <io.h>) on some platforms: MSVC 14.
  • This function always returns 0 for success on some platforms: mingw, MSVC 14.
  • This function can hang when duplicating an fd to itself on some platforms: mingw, MSVC 14.
  • This function crashes when invoked with invalid arguments on some platforms: Cygwin 1.7.17, MSVC 14.
  • This function crashes when invoked with valid arguments on some platforms: Cygwin 1.7.25.
  • This function fails with EINVAL when duplicating an fd to itself: Android.
  • This function resets the FD_CLOEXEC flag when duplicating an fd to itself on some platforms: Haiku.
  • This function returns 0 for dup2 (1, 1) on some platforms: Cygwin 1.5.x.
  • This function may return -EBADF instead of -1 on some platforms: Linux releases between July 2008 and May 2009 (versions 2.6.27 to 2.6.29).
  • This function returns EMFILE instead of EBADF for large targets, which interferes with using dup2(fd,fd)==fd) as the minimal EBADF filter: AIX 7.1, FreeBSD 6.1, Cygwin 1.5.

Portability problems not fixed by Gnulib:

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10.209 duplocale

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/duplocale.html

Gnulib module: duplocale

Portability problems fixed by Gnulib:

  • The argument LC_GLOBAL_LOCALE is not supported on some platforms: glibc 2.11, AIX 7.1.
  • With the argument LC_GLOBAL_LOCALE, this function returns a wrong result on some platforms: NetBSD 7.1.

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 9.0, NetBSD 5.0, OpenBSD 6.1, Minix 3.1.8, AIX 6.1, HP-UX 11, Solaris 11.3, Cygwin 2.5.x, mingw, MSVC 14, Android 4.4.
  • This function is useless because the locale_t type is not defined on some platforms: z/OS.
  • With the argument LC_GLOBAL_LOCALE, this function returns a wrong result on some platforms: Haiku.

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10.210 encrypt

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/encrypt.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function is not declared in <unistd.h> (without -D_GNU_SOURCE) on some platforms: glibc (at least 2.11–2.13).
  • POSIX.1-2024 says this function is obsolescent and it is planned to be removed in a future version.

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10.211 endgrent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/endgrent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 7.1.

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10.212 endhostent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/endhostent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 8.1.

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10.213 endnetent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/endnetent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Cygwin 2.9, mingw, MSVC 14, Android 8.1.

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10.214 endprotoent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/endprotoent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 8.1.

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10.215 endpwent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/endpwent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.216 endservent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/endservent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.217 endutxent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/endutxent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14, Android 9.0.

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10.218 environ

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/environ.html

Gnulib module: environ

Portability problems fixed by Gnulib:

  • POSIX does not require this variable to be declared, and it is indeed not declared on some platforms: macOS 14, FreeBSD 14.0, NetBSD 5.0, OpenBSD 3.8, Solaris 11.4.
  • On macOS, this variable is not declared. Up to Mac OS X 10.4, one can use 
    extern char **environ;

    to get the variable declared. This does not work any more, however, in shared libraries on macOS 10.5. Here is a workaround: Instead, one can use 

    #include <crt_externs.h>
#define environ (*_NSGetEnviron())

    This works at all versions of macOS.

  • On Cygwin in 64-bit mode, references to this variable cause a link error when the option -Wl,--disable-auto-import is in use.

Portability problems not fixed by Gnulib:

  • The address of this variable is not a compile-time constant on some platforms: mingw.
  • Assigning NULL to environ to clear all variables is not portable; better is to assign environ to one-element array containing a NULL pointer. That said, an empty environment is not portable either, as some systems may require particular environment variables (such as PATH) to be present in order to operate consistently.

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10.219 erand48

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/erand48.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.220 erf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/erf.html

Gnulib module: erf

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, MSVC 9.

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10.221 erfc

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/erfc.html

Gnulib module: erfc

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, MSVC 9.

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10.222 erfcf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/erfcf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.

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10.223 erfcl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/erfcl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 7.1, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 4.4.
  • This function produces results which are accurate to only 16 digits on some platforms: NetBSD 10.0.

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10.224 erff

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/erff.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.

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10.225 erfl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/erfl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 7.1, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 4.4.
  • This function produces results which are accurate to only 16 digits on some platforms: NetBSD 10.0.

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10.226 errno

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/errno.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • On Windows, the socket functions don’t set errno; their error code is available through WSAGetLastError() instead.

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10.227 execl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/execl.html

Gnulib module: execl

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not pass command-line arguments correctly if they contain space, tab, backslash, or double-quote characters.
  • On Windows platforms (excluding Cygwin), this function spawns an asynchronous child process and then exits the current process immediately. As a consequence, the parent of the current process 1. may incorrectly proceed as if its child had exited, and 2. will never see the child’s exit status.
  • On Windows platforms (excluding Cygwin), the return type of this function is intptr_t, not int.

Note: The Gnulib replacement for this function is not async-safe, that is, it must not be invoked from a signal handler.

Portability problems not fixed by Gnulib:

  • On some platforms, a script without executable permission is still run: Cygwin 1.5.x.

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10.228 execle

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/execle.html

Gnulib module: execle

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not pass command-line arguments correctly if they contain space, tab, backslash, or double-quote characters.
  • On Windows platforms (excluding Cygwin), this function spawns an asynchronous child process and then exits the current process immediately. As a consequence, the parent of the current process 1. may incorrectly proceed as if its child had exited, and 2. will never see the child’s exit status.
  • On Windows platforms (excluding Cygwin), the return type of this function is intptr_t, not int.

Note: The Gnulib replacement for this function is not async-safe, that is, it must not be invoked from a signal handler.

Portability problems not fixed by Gnulib:

  • On some platforms, a script without executable permission is still run: Cygwin 1.5.x.

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10.229 execlp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/execlp.html

Gnulib module: execlp

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not pass command-line arguments correctly if they contain space, tab, backslash, or double-quote characters.
  • On Windows platforms (excluding Cygwin), this function spawns an asynchronous child process and then exits the current process immediately. As a consequence, the parent of the current process 1. may incorrectly proceed as if its child had exited, and 2. will never see the child’s exit status.
  • On Windows platforms (excluding Cygwin), the return type of this function is intptr_t, not int.

Portability problems not fixed by Gnulib:

  • On some platforms, a script without executable permission is still run: Cygwin 1.5.x.

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10.230 execv

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/execv.html

Gnulib module: execv

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not pass command-line arguments correctly if they contain space, tab, backslash, or double-quote characters.
  • On Windows platforms (excluding Cygwin), this function spawns an asynchronous child process and then exits the current process immediately. As a consequence, the parent of the current process 1. may incorrectly proceed as if its child had exited, and 2. will never see the child’s exit status.
  • On Windows platforms (excluding Cygwin), the return type of this function is intptr_t, not int.

Note: The Gnulib replacement for this function is not async-safe, that is, it must not be invoked from a signal handler.

Portability problems not fixed by Gnulib:

  • On some platforms, a script without executable permission is still run: Cygwin 1.5.x.

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10.231 execve

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/execve.html

Gnulib module: execve

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not pass command-line arguments correctly if they contain space, tab, backslash, or double-quote characters.
  • On Windows platforms (excluding Cygwin), this function spawns an asynchronous child process and then exits the current process immediately. As a consequence, the parent of the current process 1. may incorrectly proceed as if its child had exited, and 2. will never see the child’s exit status.
  • On Windows platforms (excluding Cygwin), the return type of this function is intptr_t, not int.

Note: The Gnulib replacement for this function is not async-safe, that is, it must not be invoked from a signal handler.

Portability problems not fixed by Gnulib:

  • On some platforms, a script without executable permission is still run: Cygwin 1.5.x.

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10.232 execvp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/execvp.html

Gnulib module: execvp

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not pass command-line arguments correctly if they contain space, tab, backslash, or double-quote characters.
  • On Windows platforms (excluding Cygwin), this function spawns an asynchronous child process and then exits the current process immediately. As a consequence, the parent of the current process 1. may incorrectly proceed as if its child had exited, and 2. will never see the child’s exit status.
  • On Windows platforms (excluding Cygwin), the return type of this function is intptr_t, not int.

Portability problems not fixed by Gnulib:

  • On some platforms, a script without executable permission is still run: Cygwin 1.5.x.

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10.233 exit

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/exit.html

Gnulib module: stdlib

Portability problems fixed by Gnulib:

  • Some problems with the macros EXIT_SUCCESS and EXIT_FAILURE, see stdlib.h.

Portability problems not fixed by Gnulib:

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10.234 exp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/exp.html

Gnulib module: exp

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.235 exp2

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/exp2.html

Gnulib module: exp2

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, MSVC 9.
  • This function returns grossly wrong results on some platforms: OpenBSD 4.9.

Portability problems not fixed by Gnulib:

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10.236 exp2f

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/exp2f.html

Gnulib module: exp2f

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.

Portability problems not fixed by Gnulib:

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10.237 exp2l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/exp2l.html

Gnulib module: exp2l or exp2l-ieee

Portability problems fixed by either Gnulib module exp2l or exp2l-ieee:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9, Android 4.4.
  • This function returns Infinity instead of large finite values on some platforms: NetBSD 10.0/i386.
  • This function produces results which are accurate to only 16 digits on some platforms: NetBSD 10.0/x86_64.

Portability problems fixed by Gnulib module exp2l-ieee:

  • This function returns a wrong value for a NaN argument on some platforms: OpenBSD 4.9.

Portability problems not fixed by Gnulib:

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10.238 expf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/expf.html

Gnulib module: expf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.239 expl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/expl.html

Gnulib module: expl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, Android 4.4.
  • This function returns 0.0 for all arguments on some platforms: Haiku 2017.
  • This function returns NaN for small operands on some platforms: OpenBSD 5.4.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.
  • This function produces results which are accurate to only 16 digits on some platforms: musl libc 1.2.2/arm64, musl libc 1.2.2/s390x, NetBSD 10.0.

Portability problems not fixed by Gnulib:

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10.240 expm1

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/expm1.html

Gnulib module: expm1 or expm1-ieee

Portability problems fixed by either Gnulib module expm1 or expm1-ieee:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 9.

Portability problems fixed by Gnulib module expm1-ieee:

  • This function has problems when the argument is minus zero on some platforms: AIX 7.1.

Portability problems not fixed by Gnulib:

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10.241 expm1f

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/expm1f.html

Gnulib module: expm1f or expm1f-ieee

Portability problems fixed by either Gnulib module expm1f or expm1f-ieee:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, mingw, MSVC 9.

Portability problems fixed by Gnulib module expm1f-ieee:

  • This function returns a positive zero for a minus zero argument on some platforms: AIX 7.2.

Portability problems not fixed by Gnulib:

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10.242 expm1l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/expm1l.html

Gnulib module: expm1l

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 9.3, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 4.4.
  • This function returns 0 instead of small positive values on some platforms: NetBSD 10.0/i386.
  • This function produces results which are accurate to only 16 digits on some platforms: musl libc 1.2.2/arm64, musl libc 1.2.2/s390x, Mac OS X 10.5, NetBSD 10.0/x86_64.

Portability problems not fixed by Gnulib:

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10.243 fabs

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fabs.html

Gnulib module: fabs

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.244 fabsf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fabsf.html

Gnulib module: fabsf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.245 fabsl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fabsl.html

Gnulib module: fabsl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.246 faccessat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/faccessat.html

Gnulib module: faccessat

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 10.9, FreeBSD 7.4, NetBSD 6.1.5, OpenBSD 4.9, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 4.0.4.
  • On some platforms, faccessat (dfd, "file/", amode, flag) succeeds instead of failing when file is not a directory. macOS 14.

Portability problems not fixed by Gnulib:

  • The replacement does not always take ACLs into account.
  • The replacement is not safe to be used in libraries.
  • The replacement is not multithread-safe.
  • The replacement does not support the AT_SYMLINK_NOFOLLOW flag, which is supported by GNU faccessat.
  • On some platforms, faccessat can mishandle AT_EACCESS after a process starts as root and then becomes non-root: GNU/Linux with glibc 2.32.

Other problems of this function:

  • There is an inherent race between calling this function and performing some action based on the results; you should think twice before trusting this function, especially in a set-uid or set-gid program.

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10.247 fadd

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.27, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.248 faddl

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.27, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.249 fattach

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fattach.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.250 fchdir

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fchdir.html

Gnulib module: fchdir

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14. But the replacement function is not safe to be used in libraries and is not multithread-safe.

Portability problems not fixed by Gnulib:

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10.251 fchmod

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fchmod.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • This function sometimes fails with EACCES when the failure is due to lack of appropriate privileges (EPERM), not to search permission denied on the file name prefix (EACCES): Linux kernel 5.15 with glibc 2.35 and a CIFS v1 file system (see https://bugs.gnu.org/65599).

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10.252 fchmodat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fchmodat.html

Gnulib module: fchmodat

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14. But the replacement function is not safe to be used in libraries and is not multithread-safe.
  • This function does not fail when the file name argument ends in a slash and (without the slash) names a non-directory, on some platforms: AIX 7.2.
  • When given the AT_SYMLINK_NOFOLLOW flag, this function fails with errno set to ENOTSUP, even when the file is not a symbolic link: GNU/Linux with glibc 2.31, Cygwin 2.9.

Portability problems not fixed by Gnulib:

  • Some platforms do not allow changing the access bits on symbolic links.
  • If the AT_SYMLINK_NOFOLLOW flag is specified, this function can fail with errno set to EMFILE or ENFILE, and it fails with errno set to EOPNOTSUPP if the /proc file system is not mounted: GNU/Linux with glibc 2.34.
  • This function sometimes fails with EACCES when the failure is due to lack of appropriate privileges (EPERM), not to search permission denied on the file name prefix (EACCES): Linux kernel 5.15 with glibc 2.35 and a CIFS v1 file system (see https://bugs.gnu.org/65599).

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10.253 fchown

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fchown.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • This function sometimes fails with EACCES when the failure is due to lack of appropriate privileges (EPERM), not to search permission denied on the file name prefix (EACCES): Linux kernel 5.15 with glibc 2.35 and a CIFS v1 file system (see https://bugs.gnu.org/65599).

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10.254 fchownat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fchownat.html

Gnulib module: fchownat

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.5.x, mingw, MSVC 14. But the replacement function is not safe to be used in libraries and is not multithread-safe. Also, the replacement may fail to change symlinks if lchown is unsupported, or fail altogether if chown is unsupported.
  • This function is declared in <sys/stat.h>, not in <unistd.h>, on some platforms: Android 4.3.
  • Some platforms fail to detect trailing slash on non-directories, as in fchown(dir,"link-to-file/",uid,gid,flag): Solaris 9.
  • Some platforms mistakenly dereference symlinks when using AT_SYMLINK_NOFOLLOW: Linux kernel 2.6.17.
  • This function does not fail for an empty filename on some platforms: Linux with glibc < 2.11.

Portability problems not fixed by Gnulib:

  • This function sometimes fails with EACCES when the failure is due to lack of appropriate privileges (EPERM), not to search permission denied on the file name prefix (EACCES): Linux kernel 5.15 with glibc 2.35 and a CIFS v1 file system (see https://bugs.gnu.org/65599).

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10.255 fclose

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fclose.html

Gnulib module: fclose

Portability problems fixed by Gnulib:

  • On some platforms, this function fails to set the file position of a seekable input stream to the byte after the last one actually read: glibc 2.34, FreeBSD, AIX 7.2.
  • This function crashes if the stream’s file descriptor has already been closed on some platforms: MSVC 14.
  • On Windows platforms (excluding Cygwin), socket and accept followed by fdopen do not return streams that can be closed by fclose.

Portability problems not fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.

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10.256 fcntl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fcntl.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fcntl-3.html

Gnulib module: fcntl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • This function does not support F_DUPFD_CLOEXEC on some platforms: glibc with Linux kernels before 2.6.24, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, AIX 7.1, HP-UX 11, Solaris 11 2010-11, Cygwin 1.7.1. Note that the gnulib replacement code is functional but not atomic.
  • The F_DUPFD_CLOEXEC action of this function does not set the FD_CLOEXEC flag on some platforms: NetBSD 10.0.
  • The F_DUPFD_CLOEXEC action of this function sets the FD_CLOEXEC flag on the wrong file descriptor on some platforms: Haiku.
  • The F_DUPFD action of this function does not reject out-of-range targets properly on some platforms: AIX 7.1, Cygwin 1.5.x, Haiku.
  • The F_DUPFD action of this function mistakenly clears FD_CLOEXEC on the source descriptor on some platforms: Haiku.

Portability problems not fixed by Gnulib:

  • The replacement function does not support F_SETFD, F_GETFL, F_SETFL, F_GETOWN, F_SETOWN, F_GETLK, F_SETLK, and F_SETLKW on some platforms: mingw, MSVC 14.
  • When a file does not support locking (such as on an NFS file system that does not support file locking), calls with F_SETLK and F_SETLKW fail with errno set to different values on different systems: EINVAL on OpenIndiana (as suggested by the POSIX 1003.1-2017 fcntl specification), ENOLCK on GNU/Linux, and EOPNOTSUPP on FreeBSD.

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10.257 fdatasync

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fdatasync.html

Gnulib module: fdatasync

Portability problems fixed by Gnulib:

  • This function is present but not declared on some platforms: Mac OS X 10.7.
  • This function is missing on some platforms: Mac OS X 10.5, FreeBSD 11.0, OpenBSD 3.8, Minix 3.1.8, mingw, MSVC 14, Android 2.2.

Portability problems not fixed by Gnulib:

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10.258 fdetach

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fdetach.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.259 fdim

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fdim.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, MSVC 9.

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10.260 fdimf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fdimf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.

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10.261 fdiml

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fdiml.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9.

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10.262 fdiv

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.27, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.263 fdivl

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.27, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.264 fdopen

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fdopen.html

Gnulib module: fdopen

Portability problems fixed by Gnulib:

  • This function crashes when invoked with invalid arguments on some platforms: MSVC 14.
  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.

Portability problems not fixed by Gnulib:

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10.265 fdopendir

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fdopendir.html

Gnulib module: fdopendir

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.5.x, mingw, MSVC 14. But the replacement function is not safe to be used in libraries and is not multithread-safe. Also, the replacement does not guarantee that ‘dirfd(fdopendir(n))==n’ (dirfd might fail, or return a different file descriptor than n).
  • This function exists but is not declared on some platforms: FreeBSD 7.3.
  • This function does not reject non-directory file descriptors on some platforms: GNU/Hurd.
  • This function mistakenly closes non-directory file descriptors on some platforms: FreeBSD 8.1.

Portability problems not fixed by Gnulib:

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10.266 feclearexcept

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/feclearexcept.html

Gnulib module: fenv-exceptions-tracking-c99

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, Cygwin 1.7.7, MSVC 9, Android 4.4.
  • This function is broken on some platforms: OpenBSD 7.4/mips64, Minix 3.3/i386.

Portability problems not fixed by Gnulib:

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10.267 fegetenv

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fegetenv.html

Gnulib module: fenv-environment

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, Cygwin 1.7.7, MSVC 9, Android 4.4.
  • This function clears all exception trap bits on some platforms: glibc 2.19/x86_64, Mac OS X 10.5/i386, Mac OS X 10.5/x86_64.
  • This function does not save the exception trap bits on some platforms: AIX 7.3.

Portability problems not fixed by Gnulib:

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10.268 fegetexceptflag

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fegetexceptflag.html

Gnulib module: fenv-exceptions-state-c99

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, Cygwin 1.7.7, MSVC 9, Android 4.4.

Portability problems not fixed by Gnulib:

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10.269 fegetmode

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Control-Functions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.270 fegetround

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fegetround.html

Gnulib module: fenv-rounding

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, AIX 5.1, Solaris 9, Cygwin 1.7.7, MSVC 9, Android 4.4.

Portability problems not fixed by Gnulib:

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10.271 feholdexcept

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/feholdexcept.html

Gnulib module: fenv-environment

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, AIX 5.1, Solaris 9, Cygwin 1.7.7, MSVC 9, Android 4.4.
  • This function does not work on some platforms: glibc 2.5, FreeBSD 12.2/arm64.
  • This function does not save the exception trap bits on some platforms: AIX 7.3.
  • This function does not clear the exception trap bits on some platforms: musl libc, mingw.
  • This function may fail on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.272 feof

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/feof.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.273 feraiseexcept

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/feraiseexcept.html

Gnulib module: fenv-exceptions-tracking-c99

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, Cygwin 1.7.7, MSVC 9, Android 4.4.
  • This function does not detect failures on glibc 2.19/arm.
  • This function does not trigger traps on Cygwin 3.4.9/x86_64.

Portability problems not fixed by Gnulib:

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10.274 ferror

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ferror.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.275 fesetenv

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fesetenv.html

Gnulib module: fenv-environment

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, Cygwin 1.7.7, MSVC 9, Android 4.4.
  • This function does not work on some platforms: FreeBSD 12.2/arm64.
  • This function does not restore the floating-point exception trap bits on some platforms: musl libc/i386, musl libc/x86_64, AIX 7.3, Solaris 10 and 11, MSVC 14.
  • The macro FE_DFL_ENV cannot be used because it leads to a link error on some platforms: NetBSD 10.0/hppa, NetBSD 10.0/sparc, Cygwin 2.9.0.
  • This function, when called with FE_DFL_ENV argument, has no effect on the x86 mxcsr register and thus on floating-point operations performed in the SSE unit on some platforms: mingw 10.

Portability problems not fixed by Gnulib:

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10.276 fesetexcept

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Status-bit-operations.html.

Gnulib module: fenv-exceptions-tracking-c23

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function triggers floating-point exception traps although it shouldn’t, on glibc 2.37/i386, glibc 2.37/powerpc.

Portability problems not fixed by Gnulib:

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10.277 fesetexceptflag

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fesetexceptflag.html

Gnulib module: fenv-exceptions-state-c99

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, Cygwin 1.7.7, MSVC 9, Android 4.4.
  • This function triggers floating-point exception traps although it shouldn’t, on glibc 2.37/i386, glibc 2.37/x86_64, glibc 2.37/powerpc, musl libc, Mac OS X 10.5, Minix 3.3, mingw, Haiku.
  • This function clears too many floating-point exception flags on glibc 2.37/alpha.
  • This function loses the FE_INVALID flag on FreeBSD 14.0/powerpc64, NetBSD 9.3/powerpc.
  • This function is also buggy on AIX 7.3.1.

Portability problems not fixed by Gnulib:

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10.278 fesetmode

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Control-Functions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.279 fesetround

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fesetround.html

Gnulib module: fenv-rounding

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, AIX 5.1, Solaris 9, Cygwin 1.7.7, MSVC 9, Android 4.4.
  • This function does not work on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

  • The rounding mode has no effect on long double operations on some platforms: FreeBSD/arm64, NetBSD/sparc64, OpenBSD/arm64, OpenBSD/mips64.

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10.280 fetestexcept

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fetestexcept.html

Gnulib module: fenv-exceptions-tracking-c99

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, Cygwin 1.7.7, MSVC 9, Android 4.4.
  • This function clears the floating-point exception trap bits on some platforms: NetBSD 9.3/x86_64.
  • This function is broken on some platforms: Minix 3.3/i386.

Portability problems not fixed by Gnulib:

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10.281 fetestexceptflag

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Status-bit-operations.html.

Gnulib module: fenv-exceptions-state-c23

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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10.282 feupdateenv

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/feupdateenv.html

Gnulib module: fenv-environment

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, Cygwin 1.7.7, MSVC 14, Android 4.4.
  • This function crashes when given the argument FE_DFL_ENV on some platforms: glibc 2.37/riscv64.
  • This function does not work on some platforms: glibc 2.5/ia64, FreeBSD 12.2/arm64.
  • This function forgets about the currently set floating-point exception flags on some platforms: Mac OS X 10.5/i386, Mac OS X 10.5/x86_64.
  • This function does not restore the floating-point exception trap bits on some platforms: musl libc/i386, musl libc/x86_64, AIX 7.3, Solaris 10 and 11, mingw 10.
  • This function does not trigger traps on glibc 2.37/hppa, musl libc/s390x, NetBSD 10.0/powerpc.
  • This function may fail on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.283 fexecve

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fexecve.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11 2010-11, Cygwin 1.5.x, mingw, MSVC 14, Android 8.1.

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10.284 fflush

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fflush.html

Gnulib module: fflush

Portability problems fixed by Gnulib:

  • fflush followed by fseek or fseeko, applied to an input stream, should have the effect of positioning the underlying file descriptor. It doesn’t do this on some platforms: glibc 2.34, FreeBSD 14.0, and others.
  • fflush on an input stream changes the position of the stream to the end of the previous buffer, on some platforms: mingw, MSVC 14.
  • fflush on an input stream right after ungetc does not discard the ungetc buffer, on some platforms: macOS 14, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Cygwin 1.5.25-10.

Portability problems not fixed by Gnulib:

  • fflush, ftell, ftello, fgetpos behave incorrectly on input streams that are opened in O_TEXT mode and whose contents contains Unix line terminators (LF), on some platforms: mingw, MSVC 14.
  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • This function crashes if the stream’s file descriptor has already been closed, if MSVC_INVALID_PARAMETER_HANDLING is HAIRY_LIBRARY_HANDLING or SANE_LIBRARY_HANDLING, on some platforms: MSVC 14.
  • fflush on an input stream right after ungetc does not discard the ungetc buffer, on some platforms: AIX 5.1, HP-UX 11, Solaris 11 2010-11, mingw, MSVC 14.

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10.285 ffma

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.14.5

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.286 ffmal

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.14.5

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.287 ffs

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ffs.html

Gnulib module: ffs

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • This function is only defined as an inline function on some platforms: Android 13.

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10.288 fgetc

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fgetc.html

Gnulib module: stdio, nonblocking

Portability problems fixed by Gnulib module stdio, together with module nonblocking:

  • When reading from a non-blocking pipe whose buffer is empty, this function fails with errno being set to EINVAL instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • C99 and POSIX.1-2001 and later require end-of-file to be sticky, that is, they require this function to act as if it reads end-of-file if feof would return nonzero. However, on some systems this function attempts to read from the underlying file descriptor even if the stream’s end-of-file indicator is set. These systems include glibc and default Solaris.
  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • This function crashes if the stream’s file descriptor has already been closed, if MSVC_INVALID_PARAMETER_HANDLING is HAIRY_LIBRARY_HANDLING or SANE_LIBRARY_HANDLING, on some platforms: MSVC 14.

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10.289 fgetpos

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fgetpos.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, this function may not work correctly on files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • fflush, ftell, ftello, fgetpos behave incorrectly on input streams that are opened in O_TEXT mode and whose contents contains Unix line terminators (LF), on some platforms: mingw, MSVC 14.
  • This function mistakenly succeeds on pipes on some platforms: mingw 10.

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10.290 fgets

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fgets.html

Gnulib module: stdio, nonblocking

Portability problems fixed by Gnulib module stdio, together with module nonblocking:

  • When reading from a non-blocking pipe whose buffer is empty, this function fails with errno being set to EINVAL instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • C99 and POSIX.1-2001 and later require end-of-file to be sticky, that is, they require this function to act as if it reads end-of-file if feof would return nonzero. However, on some systems this function attempts to read from the underlying file descriptor even if the stream’s end-of-file indicator is set. These systems include glibc and default Solaris.
  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.

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10.291 fgetwc

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fgetwc.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.5.x.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.292 fgetws

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fgetws.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.5.x.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.293 fileno

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fileno.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.294 flockfile

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/flockfile.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.295 floor

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/floor.html

Gnulib module: floor or floor-ieee

Portability problems fixed by either Gnulib module floor or floor-ieee:

Portability problems fixed by Gnulib module floor-ieee:

Portability problems not fixed by Gnulib:

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10.296 floorf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/floorf.html

Gnulib module: floorf or floorf-ieee

Portability problems fixed by either Gnulib module floorf or floorf-ieee:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems fixed by Gnulib module floorf-ieee:

Portability problems not fixed by Gnulib:

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10.297 floorl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/floorl.html

Gnulib module: floorl or floorl-ieee

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.298 fma

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fma.html

Gnulib module: fma

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.
  • This function produces wrong results on some platforms: glibc 2.11, Mac OS X 10.5, FreeBSD 6.4/x86, NetBSD 8.0, OpenBSD 7.4/arm64, Cygwin 1.5, mingw.

Portability problems not fixed by Gnulib:

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10.299 fmaf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmaf.html

Gnulib module: fmaf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.
  • This function produces wrong results on some platforms: glibc 2.11, Mac OS X 10.5, FreeBSD 6.4/x86, FreeBSD 12.2/arm, OpenBSD 7.4/arm64, Cygwin 1.5, mingw.

Portability problems not fixed by Gnulib:

  • This function produces wrong results on some platforms: musl libc/powerpc64le when emulated by QEMU 5.0.0.

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10.300 fmal

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmal.html

Gnulib module: fmal

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9, Android 4.4.
  • This function produces wrong results on some platforms: glibc 2.17, macOS 13/x86_64, FreeBSD 6.4/x86, OpenBSD 7.4/arm64, mingw.

Portability problems not fixed by Gnulib:

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10.301 fmax

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmax.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, MSVC 9.

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10.302 fmaxf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmaxf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.

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10.303 fmaximum

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.4

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.304 fmaximumf

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.4

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.305 fmaximuml

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.4

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.306 fmaximum_mag

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.6

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.307 fmaximum_magf

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.6

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.308 fmaximum_magl

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.6

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.309 fmaximum_mag_num

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.10

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.310 fmaximum_mag_numf

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.10

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.311 fmaximum_mag_numl

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.10

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.312 fmaximum_num

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.8

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.313 fmaximum_numf

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.8

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.314 fmaximum_numl

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.8

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.315 fmaxl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmaxl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9.

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10.316 fmaxmag

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.317 fmaxmagf

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.318 fmaxmagl

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.319 fmemopen

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmemopen.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.5.x, mingw, MSVC 14, Android 5.1.

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10.320 fmin

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmin.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, MSVC 9.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.321 fminf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fminf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.

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10.322 fminimum

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.5

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.323 fminimumf

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.5

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.324 fminimuml

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.5

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.325 fminimum_mag

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.7

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.326 fminimum_magf

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.7

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.327 fminimum_magl

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.7

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.328 fminimum_mag_num

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.11

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.329 fminimum_mag_numf

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.11

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.330 fminimum_mag_numl

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.11

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.331 fminimum_num

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.9

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.332 fminimum_numf

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.9

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.333 fminimum_numl

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.12.9

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.334 fminl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fminl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9.

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10.335 fminmag

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.336 fminmagf

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.337 fminmagl

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.338 fmod

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmod.html

Gnulib module: fmod or fmod-ieee

Portability problems fixed by either Gnulib module fmod or fmod-ieee:

Portability problems fixed by Gnulib module fmod-ieee:

  • This function has problems when the first argument is minus zero on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.339 fmodf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmodf.html

Gnulib module: fmodf or fmodf-ieee

Portability problems fixed by either Gnulib module fmodf or fmodf-ieee:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems fixed by Gnulib module fmodf-ieee:

  • This function has problems when the first argument is minus zero on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.340 fmodl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmodl.html

Gnulib module: fmodl or fmodl-ieee

Portability problems fixed by either Gnulib module fmodl or fmodl-ieee:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, Android 4.4.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.
  • This function is not declared and does not work on some platforms: AIX 5.1.

Portability problems fixed by Gnulib module fmodl-ieee:

  • This function has problems when the first argument is minus zero on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.341 fmtmsg

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fmtmsg.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.342 fmul

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.27, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.343 fmull

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.27, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.344 fnmatch

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fnmatch.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fnmatch-3.html

Documentation:

Gnulib module: fnmatch or fnmatch-gnu

Portability problems fixed by either Gnulib module fnmatch or fnmatch-gnu:

  • This function is missing on some platforms: mingw, MSVC 14.
  • The "?" pattern character fails to match characters outside the single-byte range on some platforms: NetBSD 10.0, Android 13.
  • The "?" pattern character fails to match characters outside the Unicode BMP on some platforms: Solaris 10, Cygwin 3.4.6, MSVC, 32-bit AIX.
  • In the pattern, negated character ranges (such as [!a-z]) are not supported on some platforms: Solaris 11.4.
  • In the pattern, character classes (such as [:alnum:]) inside bracket expressions are not supported on some platforms: FreeBSD 13.2, NetBSD 10.0, Solaris 11 OpenIndiana, Cygwin 3.4.6.
  • In the pattern, character classes (such as [:alnum:]) inside bracket expressions fail to match characters outside the single-byte range on some platforms: Android 13.
  • The character class [:cntrl:] matches the empty string on some platforms: Solaris 11.4.
  • Ranges that start or end with a backslash don’t work right on some platforms: glibc 2.3.3.
  • In the pattern, an opening bracket without closing bracket does not match a literal '[' on some platforms: glibc 2.12, macOS 12.5, NetBSD 10.0.

Portability problems fixed by Gnulib module fnmatch-gnu:

  • This function does not support the flags FNM_LEADING_DIR and FNM_CASEFOLD on some platforms: AIX 7.2, HP-UX 11.31, Solaris 10.
  • The flag FNM_CASEFOLD does not work in many situations on some platforms: NetBSD 10.0.
  • The flag FNM_CASEFOLD does not work for multibyte characters consisting of more than one byte on some platforms: Android 13.
  • This function does not support the flag FNM_EXTMATCH on all non-glibc platforms: musl libc, macOS 12.5, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.2, Minix 3.3, AIX 7.2, HP-UX 11.31, Solaris 11.4, Cygwin 3.4.6, Android 13.
  • This function does not support the flag FNM_FILE_NAME as an alias of FNM_PATHNAME on some platforms: NetBSD 10.0, AIX 7.2, HP-UX 11.31, Solaris 10.

Portability problems not fixed by Gnulib:

Note: Gnulib’s replacement function has some limitations:

  • It does not implement patterns with collating elements (such as "[[.ch.]]") or equivalence classes (such as "[[=a=]]").

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10.345 fopen

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fopen.html

Gnulib module: fopen or fopen-gnu

Portability problems fixed by either Gnulib module fopen or fopen-gnu:

  • This function does not fail when the file name argument ends in a slash and (without the slash) names a nonexistent file or a file that is not a directory, on some platforms: HP-UX 11.00, AIX 7.1, Solaris 9.
  • On platforms where off_t is a 32-bit type, fopen may not work correctly with files 2 GiB and larger. See Large File Support.
  • On Windows platforms (excluding Cygwin), this function does usually not recognize the /dev/null filename.

Portability problems fixed by Gnulib module fopen-gnu:

  • This function does not support the mode character ‘x’ (corresponding to O_EXCL), introduced in ISO C11, on some platforms: FreeBSD 8.2, NetBSD 6.1, OpenBSD 5.6, Minix 3.2, AIX 6.1, HP-UX 11.31, Solaris 11.3, Cygwin 1.7.16 (2012), mingw, MSVC 14.
  • This function does not support the mode character ‘e’ (corresponding to O_CLOEXEC), introduced into a future POSIX revision through https://www.austingroupbugs.net/view.php?id=411, on some platforms: glibc 2.6, macOS 14, FreeBSD 9.0, NetBSD 5.1, OpenBSD 5.6, Minix 3.2, AIX 7.2, HP-UX 11.31, Solaris 11.3, Cygwin 1.7.16 (2012), mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • On Windows, this function returns a file stream in “text” mode by default; this means that it translates '\n' to CR/LF by default. Use the "b" flag if you need reliable binary I/O.
  • On Windows platforms (excluding Cygwin), this function fails to open directories for reading. Such streams have implementation-defined semantics on other platforms. To avoid directory streams with a consistent error message, use fstat after open and fdopen, rather than fopen and fileno.

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10.346 fork

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fork.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • On some platforms, fork followed by a call of the exec family (execl, execlp, execle, execv, execvp, or execve) is less efficient than vfork followed by the same call. vfork is a variant of fork that has been introduced to optimize the fork/exec pattern.
  • On Windows platforms (excluding Cygwin), this function is not implemented; use _spawnvp instead.

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10.347 fpathconf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fpathconf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.348 fpclassify

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fpclassify.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, OpenBSD 6.7, AIX 5.1, Solaris 11.4, Android 9.0.

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10.349 fprintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fprintf.html

Gnulib module: fprintf-posix or fprintf-gnu or stdio, nonblocking, sigpipe

Portability problems fixed by either Gnulib module fprintf-posix or fprintf-gnu:

  • This function does not support size specifiers as in C99 (hh, ll, j, t, z) on some platforms: AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • printf of ‘long double’ numbers is unsupported on some platforms: mingw, MSVC 14.
  • printf "%f", "%e", "%g" of Infinity and NaN yields an incorrect result on some platforms: AIX 7.3, Solaris 11.4, mingw, MSVC 14.
  • This function does not support the ‘a’ and ‘A’ directives on some platforms: FreeBSD 5.2.1, OpenBSD 4.0, AIX 5.2, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support the ‘F’ directive on some platforms: NetBSD 3.0, AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘ls’ directive on some platforms: OpenBSD 4.0, Cygwin 1.5.x, Haiku.
  • This function does not support precisions in the ‘ls’ directive correctly on some platforms: Solaris 11.4.
  • This function does not support format directives that access arguments in an arbitrary order, such as "%2$s", on some platforms: NetBSD 3.0, mingw, MSVC 14.
  • This function doesn’t support the ' flag on some platforms: NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
  • This function does not round the argument of the ‘a’ directive correctly on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4.
  • printf "%010f" of NaN and Infinity yields an incorrect result (padded with zeroes, or wrong capitalization) on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 7.3, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC/clang.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • This function does not support precisions larger than 512 or 1024 in integer, floating-point and pointer output on some platforms: AIX 7.1, Solaris 10/x86, mingw, MSVC/clang.
  • This function mishandles large floating point precisions (for example, formatting 1.0 with ‘"%.511f"’) on some platforms: Solaris 10.
  • This function produces wrong output for the ‘lc’ directive with a NUL wide character argument on some platforms: musl libc 1.2.4.
  • This function can crash in out-of-memory conditions on some platforms: FreeBSD 14.0, NetBSD 5.0.

Portability problems fixed by Gnulib module fprintf-gnu:

  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.

Portability problems fixed by either Gnulib module fprintf-posix or fprintf-gnu and additionally the Gnulib module printf-with-n-directive:

  • This function does not support the ‘n’ directive on some platforms: glibc when used with _FORTIFY_SOURCE >= 2 (set by default on Ubuntu), macOS 14, OpenBSD, MSVC 14, Android.

Portability problems fixed by Gnulib module stdio or fprintf-posix or fprintf-gnu, together with module nonblocking:

  • When writing to a non-blocking pipe whose buffer is full, this function fails with errno being set to ENOSPC instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems fixed by Gnulib module stdio or fprintf-posix or fprintf-gnu, together with module sigpipe:

  • When writing to a pipe with no readers, this function fails, instead of obeying the current SIGPIPE handler, on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.
  • Formatting noncanonical ‘long double’ numbers produces nonmeaningful results on some platforms: glibc and others, on x86, x86_64, IA-64 CPUs.
  • When formatting an integer with grouping flag, this function inserts thousands separators even in the "C" locale on some platforms: NetBSD 5.1.
  • Attempting to write to a read-only stream fails with EOF but does not set the error flag for ferror on some platforms: glibc 2.13, cygwin 1.7.9.

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10.350 fputc

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fputc.html

Gnulib module: stdio, nonblocking, sigpipe

Portability problems fixed by Gnulib module stdio, together with module nonblocking:

  • When writing to a non-blocking pipe whose buffer is full, this function fails with errno being set to ENOSPC instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems fixed by Gnulib module stdio, together with module sigpipe:

  • When writing to a pipe with no readers, this function fails, instead of obeying the current SIGPIPE handler, on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • On some platforms, this function does not set errno or the stream error indicator on attempts to write to a read-only stream: Cygwin 1.7.9.
  • This function crashes if the stream’s file descriptor has already been closed, if MSVC_INVALID_PARAMETER_HANDLING is HAIRY_LIBRARY_HANDLING or SANE_LIBRARY_HANDLING, on some platforms: MSVC 14.

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10.351 fputs

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fputs.html

Gnulib module: stdio, nonblocking, sigpipe

Portability problems fixed by Gnulib module stdio, together with module nonblocking:

  • When writing to a non-blocking pipe whose buffer is full, this function fails with errno being set to ENOSPC instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems fixed by Gnulib module stdio, together with module sigpipe:

  • When writing to a pipe with no readers, this function fails, instead of obeying the current SIGPIPE handler, on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • On some platforms, this function does not set errno or the stream error indicator on attempts to write to a read-only stream: Cygwin 1.7.9.

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10.352 fputwc

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fputwc.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.5.x.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.353 fputws

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fputws.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.5.x.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.
  • On some platforms, this function does not set errno or the stream error indicator on attempts to write to a read-only stream: Cygwin 1.7.9.

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10.354 fread

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fread.html

Gnulib module: stdio, nonblocking

Portability problems fixed by Gnulib module stdio, together with module nonblocking:

  • When reading from a non-blocking pipe whose buffer is empty, this function fails with errno being set to EINVAL instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • C99 and POSIX.1-2001 and later require end-of-file to be sticky, that is, they require this function to act as if it reads end-of-file if feof would return nonzero. However, on some systems this function attempts to read from the underlying file descriptor even if the stream’s end-of-file indicator is set. These systems include glibc and default Solaris.
  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • This function crashes if the stream’s file descriptor has already been closed, if MSVC_INVALID_PARAMETER_HANDLING is HAIRY_LIBRARY_HANDLING or SANE_LIBRARY_HANDLING, on some platforms: MSVC 14.

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10.355 free

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/free.html

Gnulib module: free-posix

Portability problems fixed by Gnulib:

  • This function may clobber errno on many platforms: glibc 2.32, Mac OS X, FreeBSD, NetBSD, OpenBSD 4.4, Minix, AIX, HP-UX, Cygwin, mingw, MSVC.

Portability problems not fixed by Gnulib:

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10.356 freeaddrinfo

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/freeaddrinfo.html

Gnulib module: getaddrinfo

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11.11, Cygwin 1.5.x, mingw, MSVC 14.
  • On Windows, this function is declared in <ws2tcpip.h> rather than in <netdb.h>.
  • On Windows, in 32-bit mode, this function is defined with a calling convention that is different from cdecl.

Portability problems not fixed by Gnulib:

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10.357 freelocale

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/freelocale.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 9.0, NetBSD 5.0, OpenBSD 6.1, Minix 3.1.8, AIX 6.1, HP-UX 11, Solaris 11.3, Cygwin 2.5.x, mingw, MSVC 14, Android 4.4.
  • This function is useless because the locale_t type is not defined on some platforms: z/OS.
  • This function may cause crashes in subsequent newlocale invocations on some platforms: Haiku.

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10.358 freopen

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/freopen.html

Gnulib module: freopen

Portability problems fixed by Gnulib:

  • On some platforms, if stream does not already have an open file descriptor, freopen returns the stream without opening the file: glibc 2.24.
  • On platforms where off_t is a 32-bit type, freopen may not work correctly with files 2 GiB and larger. See Large File Support.
  • On Windows platforms (excluding Cygwin), this function does usually not recognize the /dev/null filename.

Portability problems not fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • This function does not support a NULL file name argument on some platforms: OpenBSD 4.9, AIX 7.1, HP-UX 11.23, Solaris 10, mingw, MSVC 14.
  • This function does not fail when the file name argument ends in a slash and (without the slash) names a nonexistent file or a file that is not a directory, on some platforms: HP-UX 11.00, Solaris 9.
  • Applications should not assume that fileno(f) will be the same before and after a call to freopen(name,mode,f). However, the module freopen-safer can at least protect stdin, stdout, and stderr.

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10.359 frexp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/frexp.html

Gnulib module: frexp

Portability problems fixed by Gnulib:

  • This function does not work on denormalized numbers on some platforms: NetBSD 3.0.
  • This function does not work on negative zero on some platforms: NetBSD 4.99, MSVC 14.
  • This function does not work on infinite numbers on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.360 frexpf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/frexpf.html

Gnulib module: frexpf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.
  • This function does not work on negative zero on some platforms: mingw.
  • This function does not work on infinite numbers on some platforms: mingw.

Portability problems not fixed by Gnulib:

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10.361 frexpl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/frexpl.html

Gnulib module: frexpl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, Android 4.4.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.
  • This function does not work on finite numbers on some platforms: AIX 5.1, MSVC 14.
  • This function does not work on denormalized numbers on some platforms: macOS 10.13/i386.
  • This function does not work on infinite numbers on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.362 fromfp

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.363 fromfpf

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.364 fromfpl

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.365 fromfpx

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.366 fromfpxf

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.367 fromfpxl

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.368 fscanf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fscanf.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fscanf.html

Gnulib module: stdio, nonblocking

Portability problems fixed by Gnulib module stdio, together with module nonblocking:

  • When reading from a non-blocking pipe whose buffer is empty, this function fails with errno being set to EINVAL instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • C99 and POSIX.1-2001 and later require end-of-file to be sticky, that is, they require this function to act as if it reads end-of-file if feof would return nonzero. However, on some systems this function attempts to read from the underlying file descriptor even if the stream’s end-of-file indicator is set. These systems include glibc and default Solaris.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.38, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.2, AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • On Windows, this function doesn’t support the hh, ll, j, t, z size specifiers.

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10.369 fseek

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fseek.html

Gnulib module: fseek

Portability problems fixed by Gnulib:

  • This function mistakenly succeeds on pipes on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • On platforms where long is a 32-bit type, fseek does not work correctly with files 2 GiB and larger, even when the AC_SYS_LARGEFILE macro is used. The fix is to use fseeko instead.

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10.370 fseeko

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fseeko.html

Gnulib module: fseeko

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • The declaration of fseeko in <stdio.h> is not enabled by default on some platforms: glibc 2.3.6.
  • This function fails on seekable stdin, stdout, and stderr: cygwin <= 1.5.24.
  • On platforms where off_t is a 32-bit type, fseeko does not work correctly with files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

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10.371 fsetpos

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fsetpos.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, this function may not work correctly on files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

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10.372 fsqrt

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.14.6

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.373 fsqrtl

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.12.14.6

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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10.374 fstat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fstat.html

Gnulib module: fstat

Portability problems fixed by Gnulib:

  • This function crashes when invoked with invalid arguments on some platforms: MSVC 14.
  • On platforms where off_t is a 32-bit type, fstat may not correctly report the size of files or block devices 2 GiB and larger.. See Large File Support.
  • On Linux/x86 and Linux/x86_64, applications compiled in 32-bit mode cannot access files that happen to have a 64-bit inode number. This can occur with file systems such as XFS (typically on large disks) and NFS. See Large File Support.
  • On macOS 12.6, when this function yields a timestamp with a nonpositive tv_sec value, tv_nsec might be in the range -999999999..-1, representing a negative nanoseconds offset from tv_sec. Solaris 11.4 is similar, except that tv_sec might also be -1000000000.
  • The st_atime, st_ctime, st_mtime fields are affected by the current time zone and by the DST flag of the current time zone on some platforms: mingw, MSVC 14 (when the environment variable TZ is set).

Portability problems not fixed by Gnulib:

  • See sys/stat.h, for general portability problems with struct stat.
  • On Cygwin, fstat applied to the file descriptors 0 and 1, returns different st_ino values, even if standard input and standard output are not redirected and refer to the same terminal.

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10.375 fstatat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fstatat.html

Gnulib module: fstatat

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.5.x, mingw, MSVC 14. But the replacement function is not safe to be used in libraries and is not multithread-safe.
  • On platforms where off_t is a 32-bit type, fstatat may not correctly report the size of files or block devices larger than 2 GB. See Large File Support.
  • On some platforms, fstatat(fd,"file/",buf,flag) succeeds instead of failing with ENOTDIR. Solaris 9.
  • For symlinks, when the argument ends in a slash, some platforms don’t dereference the argument: Solaris 9.
  • On macOS 12.6, when this function yields a timestamp with a nonpositive tv_sec value, tv_nsec might be in the range -999999999..-1, representing a negative nanoseconds offset from tv_sec. Solaris 11.4 is similar, except that tv_sec might also be -1000000000.

Portability problems not fixed by Gnulib:

  • This function does not fail when the second argument is an empty string on some platforms, even when AT_EMPTY_PATH is not used: glibc 2.7, Linux 2.6.38.
  • This function sets st_ino only to the low-order 32 bits of the inode number of a socket or pipe, which thus can disagree with the st_ino obtained by fstat: macOS 14.
  • See sys/stat.h, for general portability problems with struct stat.

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10.376 fstatvfs

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fstatvfs.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where f_blocks in ‘struct statvfs’ is a 32-bit value, this function may not work correctly on files systems larger than 4 TiB. See Large File Support. This affects glibc/Hurd, HP-UX 11, Solaris.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, mingw, MSVC 14, Android 4.3.

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10.377 fsub

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.27, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.378 fsubl

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Misc-FP-Arithmetic.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.27, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.379 fsync

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fsync.html

Gnulib module: fsync

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • If the argument is a read-only file descriptor, this function fails with EBADF on some platforms: AIX 7.2, Cygwin 2.9.

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10.380 ftell

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ftell.html

Gnulib module: ftell

Portability problems fixed by Gnulib:

  • This function mistakenly succeeds on pipes on some platforms: mingw, MSVC 14.
  • This function produces incorrect results after putc that followed a getc call that reached EOF on some platforms: Solaris 11 2010-11.
  • This function, when invoked after ungetc, throws away the ungetc buffer, changes the stream’s file position, and returns the wrong position on some platforms: macOS 10.15, 11, 12.
  • This function mistakenly succeeds on pipes on some platforms: mingw 10.

Portability problems not fixed by Gnulib:

  • This function produces incorrect results immediately after fseek on some platforms: HP-UX 11.
  • fflush, ftell, ftello, fgetpos behave incorrectly on input streams that are opened in O_TEXT mode and whose contents contains Unix line terminators (LF), on some platforms: mingw, MSVC 14.
  • On platforms where long is a 32-bit type, ftell does not work correctly with files 2 GiB and larger, even when the AC_SYS_LARGEFILE macro is used. The fix is to use ftello instead.

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10.381 ftello

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ftello.html

Gnulib module: ftello

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • The declaration of ftello in <stdio.h> is not enabled by default on some platforms: glibc 2.3.6.
  • This function produces incorrect results after putc that followed a getc call that reached EOF on some platforms: Solaris 11 2010-11.
  • This function, when invoked after ungetc, throws away the ungetc buffer, changes the stream’s file position, and returns the wrong position on some platforms: macOS 10.15, 11, 12.
  • This function fails on seekable stdin, stdout, and stderr: cygwin <= 1.5.24.
  • This function mistakenly succeeds on pipes on some platforms: mingw 10.
  • On platforms where off_t is a 32-bit type, ftello does not work correctly with files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function produces incorrect results immediately after fseek on some platforms: HP-UX 11.
  • fflush, ftell, ftello, fgetpos behave incorrectly on input streams that are opened in O_TEXT mode and whose contents contains Unix line terminators (LF), on some platforms: mingw, MSVC 14.

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10.382 ftok

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ftok.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.383 ftruncate

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ftruncate.html

Gnulib module: ftruncate

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: MSVC 14.
  • On platforms where off_t is a 32-bit type, this function may not work correctly on files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

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10.384 ftrylockfile

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ftrylockfile.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.385 ftw

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ftw.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, this function may not work correctly on files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 3.0, Minix 3.1.8, mingw, MSVC 14, Android 4.1.
  • This function is removed in POSIX.1-2024. Use the Gnulib module fts instead.

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10.386 funlockfile

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/funlockfile.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.387 futimens

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/futimens.html

Gnulib module: futimens

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.5, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 4.3. However, the replacement function may end up truncating timestamps to worse resolution than supported by the file system.
  • This function returns a bogus value instead of failing with ENOSYS on some platforms: Linux kernel 2.6.21.
  • When using UTIME_OMIT or UTIME_NOW, some systems require the tv_sec argument to be 0, and don’t necessarily handle all file permissions in the manner required by POSIX: Linux kernel 2.6.25.
  • When using UTIME_OMIT for the modification time, but specifying an access time, some systems fail to update the change time: Linux kernel 2.6.32, macOS 14, NetBSD 10.0, Solaris 11.1.
  • Passing AT_FDCWD as the fd argument does not properly fail with EBADF on some systems: glibc 2.11, musl libc, Solaris 11.

Portability problems not fixed by Gnulib:

  • Some platforms lack the ability to change the timestamps of a file descriptor, so the replacement can fail with ENOSYS; the gnulib module ‘utimens’ provides a more reliable interface fdutimens.
  • The mere act of using stat modifies the access time of directories on some platforms, so utimensat can only effectively change directory modification time: Cygwin 1.5.x.

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10.388 fwide

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fwide.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.00, Cygwin 1.5.x, MSVC 14.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.
  • fwide is not guaranteed to be able to change a file stream’s mode to a different mode than the current one.

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10.389 fwprintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fwprintf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11.00, Cygwin 1.5.x.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.
  • In the C or POSIX locales, the %c and %s conversions may fail on some platforms: glibc 2.35.
  • When formatting an integer with grouping flag, this function inserts thousands separators even in the "C" locale on some platforms: NetBSD 5.1.
  • On some platforms, this function does not set errno or the stream error indicator on attempts to write to a read-only stream: Cygwin 1.7.9.

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10.390 fwrite

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fwrite.html

Gnulib module: stdio, nonblocking, sigpipe

Portability problems fixed by Gnulib module stdio, together with module nonblocking:

  • When writing to a non-blocking pipe whose buffer is full, this function fails with errno being set to ENOSPC instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems fixed by Gnulib module stdio, together with module sigpipe:

  • When writing to a pipe with no readers, this function fails, instead of obeying the current SIGPIPE handler, on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • On some platforms, this function does not set errno or the stream error indicator on attempts to write to a read-only stream: Cygwin 1.7.9.
  • This function crashes if the stream’s file descriptor has already been closed, if MSVC_INVALID_PARAMETER_HANDLING is HAIRY_LIBRARY_HANDLING or SANE_LIBRARY_HANDLING, on some platforms: MSVC 14.

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10.391 fwscanf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/fwscanf.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fwscanf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11.00, Cygwin 1.5.x.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.38, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.2, AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.392 gai_strerror

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/gai_strerror.html

Gnulib module: getaddrinfo

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11.11, Cygwin 1.5.x.
  • This function is only available in <ws2tcpip.h> on some platforms: mingw, MSVC 14.
  • This function’s return type is char * instead of const char * on some platforms: AIX 7.1, HP-UX 11, Solaris 9, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.393 getaddrinfo

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getaddrinfo.html

Gnulib module: getaddrinfo

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11.11, Cygwin 1.5.x, mingw, MSVC 14.
  • On Windows, this function is declared in <ws2tcpip.h> rather than in <netdb.h>.
  • On Windows, in 32-bit mode, this function is defined with a calling convention that is different from cdecl.

Portability problems not fixed by Gnulib:

  • Unlike glibc’s implementation, gnulib’s replacement does not support internationalized domain names (IDN) encoding.

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10.394 getc

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getc.html

Gnulib module: stdio, nonblocking

Portability problems fixed by Gnulib module stdio, together with module nonblocking:

  • When reading from a non-blocking pipe whose buffer is empty, this function fails with errno being set to EINVAL instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • C99 and POSIX.1-2001 and later require end-of-file to be sticky, that is, they require this function to act as if it reads end-of-file if feof would return nonzero. However, on some systems this function attempts to read from the underlying file descriptor even if the stream’s end-of-file indicator is set. These systems include glibc and default Solaris.
  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.

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10.395 getc_unlocked

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getc_unlocked.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.396 getchar

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getchar.html

Gnulib module: stdio, nonblocking

Portability problems fixed by Gnulib module stdio, together with module nonblocking:

  • When reading from a non-blocking pipe whose buffer is empty, this function fails with errno being set to EINVAL instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • C99 and POSIX.1-2001 and later require end-of-file to be sticky, that is, they require this function to act as if it reads end-of-file if feof would return nonzero. However, on some systems this function attempts to read from the underlying file descriptor even if the stream’s end-of-file indicator is set. These systems include glibc and default Solaris.
  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.

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10.397 getchar_unlocked

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getchar_unlocked.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.398 getcwd

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getcwd.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getcwd.html

Gnulib module: getcwd or getcwd-lgpl

Portability problems fixed by either Gnulib module getcwd or getcwd-lgpl:

  • This function is declared in different header files (namely, <io.h> or <direct.h>) on some platforms: mingw, MSVC 14.
  • On glibc and Solaris 11.4 platforms, getcwd (NULL, n) allocates memory for the result. On some other platforms, this call is not allowed.
  • On some platforms, the prototype for getcwd uses int instead of size_t for the size argument when using non-standard headers, and the declaration is missing from <unistd.h>: mingw, MSVC 14.
  • On some platforms, getcwd (buf, 0) crashes: MSVC 14.
  • On some platforms, getcwd (buf, 0) fails with ERANGE instead of the required EINVAL: mingw.

Portability problems fixed by Gnulib module getcwd:

  • This function does not handle long file names (greater than PATH_MAX) correctly on some platforms: glibc on Linux 2.4.20, musl libc 1.2.2/powerpc64le, macOS 13, FreeBSD 6.4, NetBSD 10.0, OpenBSD 6.7, AIX 7.1.

Portability problems not fixed by Gnulib:

  • When using getcwd(NULL, nonzero), some platforms, such as glibc or cygwin, allocate exactly nonzero bytes and fail with ERANGE if it was not big enough, while other platforms, such as FreeBSD, mingw, or MSVC 14, ignore the size argument and allocate whatever size is necessary. If this call succeeds, an application cannot portably access beyond the string length of the result.

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10.399 getdate

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getdate.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Gnulib provides a module parse-datetime that contains a function parse_datetime that has similar functionality as the getdate function.

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10.400 getdate_err

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getdate_err.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on some platforms: FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.401 getdelim

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getdelim.html

Gnulib module: getdelim

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, mingw, MSVC 14, Android 4.2.
  • This function makes out-of-bounds reads on some platforms: macOS 10.13.
  • This function crashes when passed a pointer to a NULL buffer together with a pointer to a non-zero buffer size on some platforms: FreeBSD 8.0.

Portability problems not fixed by Gnulib:

  • This function has quadratic running time for long lines on some platforms: uClibc 0.9.31.

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10.402 getegid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getegid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.403 getenv

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getenv.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.404 geteuid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/geteuid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.405 getgid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getgid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.406 getgrent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getgrent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 7.1.

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10.407 getgrgid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getgrgid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.408 getgrgid_r

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getgrgid_r.html

Gnulib module: extensions

Portability problems fixed by Gnulib:

  • This function has an incompatible declaration on some platforms: Solaris 11.3 (when _POSIX_PTHREAD_SEMANTICS is not defined).

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 6.0.

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10.409 getgrnam

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getgrnam.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.410 getgrnam_r

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getgrnam_r.html

Gnulib module: extensions

Portability problems fixed by Gnulib:

  • This function has an incompatible declaration on some platforms: Solaris 11.3 (when _POSIX_PTHREAD_SEMANTICS is not defined).

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 6.0.

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10.411 getgroups

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getgroups.html

Gnulib module: getgroups

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • On some platforms, this function fails to reject a negative count, even though that is less than the size that would be returned: macOS 14, FreeBSD 13.0.
  • On NeXTstep 3.2, getgroups (0, NULL) always fails. See macro ‘AC_FUNC_GETGROUPS’.
  • On very old systems, this function operated on an array of ‘int’, even though that was a different size than an array of ‘gid_t’.

Portability problems not fixed by Gnulib:

  • This function is unsafe to call between fork and exec if the parent process is multi-threaded.
  • It is unspecified whether the effective group id will be included in the returned list, nor whether the list will be sorted in any particular order. For that matter, some platforms include the effective group id twice, if it is also a member of the current supplemental group ids.

The Gnulib module mgetgroups provides a similar API.

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10.412 gethostent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/gethostent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14.

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10.413 gethostid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/gethostid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 9.0.

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10.414 gethostname

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/gethostname.html

Gnulib module: gethostname

Portability problems fixed by Gnulib:

  • This function is declared in a different header file (namely, <winsock2.h>) on some platforms: MSVC 14.
  • On mingw and MSVC 14, this function has a prototype that differs from that specified by POSIX, and it is defined only in the ws2_32 library.

Portability problems not fixed by Gnulib:

  • This function’s second argument type is int instead of size_t on some platforms: Solaris 10.
  • If the given buffer is too small for the host name, some implementations fail with EINVAL, instead of returning a truncated host name.

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10.415 getitimer

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getitimer.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • This function is removed in POSIX.1-2024. Use the function timer_gettime instead.

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10.416 getline

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getline.html

Gnulib module: getline

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, mingw, MSVC 14, Android 4.2.
  • This function is missing a declaration on some platforms: AIX 7.1.
  • Some platforms provide a function by this name but with the wrong signature, for example in -linet.
  • This function crashes when passed a pointer to a NULL buffer together with a pointer to a non-zero buffer size on some platforms: FreeBSD 8.0.

Portability problems not fixed by Gnulib:

  • This function has quadratic running time for long lines on some platforms: uClibc 0.9.31.

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10.417 getlogin

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getlogin.html

Gnulib module: getlogin

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: older mingw, MSVC 14.
  • This function is not declared unless _POSIX is defined on some platforms: mingw.

Portability problems not fixed by Gnulib:

  • This function returns an empty string even when standard input is a tty on some platforms: HP-UX 11.11.

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10.418 getlogin_r

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getlogin_r.html

Gnulib module: getlogin_r

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, Minix 3.1.8, mingw, MSVC 14, Android 8.1.
  • This function is not declared unless _REENTRANT is defined, on some platforms: HP-UX 11.
  • This function returns a truncated result, instead of failing with error code ERANGE, when the buffer is not large enough, on some platforms: macOS 14.

Portability problems not fixed by Gnulib:

  • This function has an incompatible declaration on some platforms: FreeBSD 12.0, MidnightBSD 2.0, Solaris 11.4 (when _POSIX_PTHREAD_SEMANTICS is not defined).
  • This function fails even when standard input is a tty on some platforms: HP-UX 11.11.
  • This function fails with error code EINVAL instead of ERANGE when the second argument is zero on some platforms: HP-UX 11.31.
  • This function fails with error code ENOMEM instead of ERANGE on some platforms: Haiku.

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10.419 getmsg

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getmsg.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.420 getnameinfo

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getnameinfo.html

Gnulib module: getaddrinfo

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11.11, Cygwin 1.5.x, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.421 getnetbyaddr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getnetbyaddr.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Cygwin 2.9, mingw, MSVC 14.

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10.422 getnetbyname

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getnetbyname.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Cygwin 2.9, mingw, MSVC 14.

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10.423 getnetent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getnetent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Cygwin 2.9, mingw, MSVC 14, Android 8.1.

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10.424 getopt

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getopt.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/libutil-getopt-3.html

Gnulib module: getopt-posix or getopt-gnu

The module getopt-gnu has support for “long options” and for “options that take optional arguments”. Compared to the API defined by POSIX, it adds a header file <getopt.h> and a function getopt_long.

Portability problems fixed by either Gnulib module getopt-posix or getopt-gnu:

  • This function is missing on some platforms: MSVC 14.
  • The value of optind after a missing required argument is wrong on some platforms: macOS 14, AIX 7.1, mingw.

Portability problems fixed by Gnulib module getopt-gnu:

  • The function getopt does not support the ‘+’ flag in the options string on some platforms: macOS 14, AIX 5.2, HP-UX 11, Solaris 11 2010-11.
  • The function getopt does not obey the combination of ‘+’ and ‘:’ flags in the options string on some platforms: glibc 2.11.
  • The function getopt does not obey the ‘-’ flag in the options string when POSIXLY_CORRECT is set on some platforms: Cygwin 1.7.0.
  • The function getopt does not support options with optional arguments on some platforms: macOS 14, OpenBSD 4.0, AIX 5.2, HP-UX 11, Solaris 11 2010-11, Cygwin 1.5.x.
  • The function getopt_long is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 9, MSVC 14.
  • The function getopt_long does not support abbreviated long options where all disambiguations are equivalent on some platforms: OpenBSD 5.0.
  • The function getopt_long_only is missing on some platforms: FreeBSD 5.2.1, NetBSD 10.0, AIX 5.1, HP-UX 11, Solaris 9, mingw, MSVC 14.
  • This function crashes if the option string includes W; on some platforms: glibc 2.14.

Portability problems not fixed by Gnulib:

  • The default behavior of the glibc implementation of getopt allows mixing option and non-option arguments on the command line in any order. Other implementations, such as the one in Cygwin, enforce strict POSIX compliance: they require that the option arguments precede the non-option arguments. This is something to watch out in your program’s testsuite.
  • The glibc implementation allows a complete reset of the environment, including re-checking for POSIXLY_CORRECT, by setting optind to 0. Several BSD implementations provide optreset, causing a reset by setting it non-zero, although it does not necessarily re-read POSIXLY_CORRECT. Solaris getopt does not support either reset method, but does not maintain state that needs the extra level of reset.
  • On some platforms, this function does not set the stream error indicator on attempts to write to a read-only stream: glibc 2.13, Cygwin 1.7.9.

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10.425 getpayload

Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.

Gnulib module: getpayload

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function returns a wrong result for non-NaN arguments on some platforms: glibc 2.31.

Portability problems not fixed by Gnulib:

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10.426 getpayloadf

Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.

Gnulib module: getpayloadf

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function returns a wrong result for non-NaN arguments on some platforms: glibc 2.31.

Portability problems not fixed by Gnulib:

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10.427 getpayloadl

Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.

Gnulib module: getpayloadl

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function returns a wrong result for non-NaN arguments on some platforms: glibc 2.31.

Portability problems not fixed by Gnulib:

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10.428 getpeername

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpeername.html

Gnulib module: getpeername

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), error codes from this function are not placed in errno, and WSAGetLastError must be used instead.
  • On HP-UX 11, in 64-bit mode, when the macro _HPUX_ALT_XOPEN_SOCKET_API is not defined, this function behaves incorrectly because it is declared to take a pointer to a 64-bit wide socklen_t entity but in fact considers it as a pointer to a 32-bit wide unsigned int entity.

Portability problems not fixed by Gnulib:

  • Some platforms don’t have a socklen_t type; in this case this function’s third argument type is ‘int *’.

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10.429 getpgid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpgid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.430 getpgrp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpgrp.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.431 getpid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.432 getpmsg

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpmsg.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.433 getppid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getppid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.434 getpriority

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpriority.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.435 getprotobyname

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getprotobyname.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.436 getprotobynumber

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getprotobynumber.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.437 getprotoent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getprotoent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 8.1.

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10.438 getpwent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpwent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 7.1.

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10.439 getpwnam

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpwnam.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.440 getpwnam_r

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpwnam_r.html

Gnulib module: extensions

Portability problems fixed by Gnulib:

  • This function has an incompatible declaration on some platforms: Solaris 11.3 (when _POSIX_PTHREAD_SEMANTICS is not defined).

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, mingw, MSVC 14, Android 3.0.

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10.441 getpwuid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpwuid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is unsafe to call between fork and exec if the parent process is multi-threaded. Instead, use getpwuid_r prior to forking.
  • This function is missing on some platforms: mingw, MSVC 14.

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10.442 getpwuid_r

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getpwuid_r.html

Gnulib module: extensions

Portability problems fixed by Gnulib:

  • This function has an incompatible declaration on some platforms: Solaris 11.3 (when _POSIX_PTHREAD_SEMANTICS is not defined).

Portability problems not fixed by Gnulib:

  • This function is unsafe to call between fork and exec if the parent process is multi-threaded. Use it prior to forking.
  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, mingw, MSVC 14, Android 3.0.

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10.443 getrlimit

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getrlimit.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getrlimit-1.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where rlim_t is a 32-bit type, this function does not allow to retrieve limits larger than 4 GiB and larger, such as for RLIMIT_FSIZE. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.444 getrusage

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getrusage.html

Gnulib module: getrusage

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • Many platforms don’t fill in all the fields of struct rusage with meaningful values.

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10.445 gets

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/gets.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is removed in POSIX.1-2024. Use the function fgets instead.
  • This function should never be used, because it can overflow any given buffer.
  • This function is missing on some platforms: OpenBSD 6.7, Solaris 11.4.
  • When reading from a non-blocking pipe whose buffer is empty, this function fails with errno being set to EINVAL instead of EAGAIN on some platforms: mingw, MSVC 14.
  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.

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10.446 getservbyname

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getservbyname.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.447 getservbyport

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getservbyport.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.448 getservent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getservent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.449 getsid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getsid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 4.1.

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10.450 getsockname

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getsockname.html

Gnulib module: getsockname

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), error codes from this function are not placed in errno, and WSAGetLastError must be used instead.
  • On HP-UX 11, in 64-bit mode, when the macro _HPUX_ALT_XOPEN_SOCKET_API is not defined, this function behaves incorrectly because it is declared to take a pointer to a 64-bit wide socklen_t entity but in fact considers it as a pointer to a 32-bit wide unsigned int entity.

Portability problems not fixed by Gnulib:

  • Some platforms don’t have a socklen_t type; in this case this function’s third argument type is ‘int *’.

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10.451 getsockopt

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getsockopt.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getsockopt-1.html

Gnulib module: getsockopt

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), error codes from this function are not placed in errno, and WSAGetLastError must be used instead.
  • On HP-UX 11, in 64-bit mode, when the macro _HPUX_ALT_XOPEN_SOCKET_API is not defined, this function behaves incorrectly because it is declared to take a pointer to a 64-bit wide socklen_t entity but in fact considers it as a pointer to a 32-bit wide unsigned int entity.

Portability problems not fixed by Gnulib:

  • Some platforms don’t have a socklen_t type; in this case this function’s fifth argument type is ‘int *’.
  • Many socket options are not available on all platforms.

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10.452 getsubopt

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getsubopt.html

Gnulib module: getsubopt

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 7.1.
  • This function is declared in unistd.h instead of stdlib.h on some platforms: Cygwin 1.7.1.

Portability problems not fixed by Gnulib:

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10.453 gettimeofday

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/gettimeofday.html

Gnulib module: gettimeofday

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: MSVC 14.
  • This function is declared with a nonstandard function prototype (only one argument, or “...” after the first argument) on some platforms.
  • On some platforms, the second argument has type struct timezone* rather than void *, making it an error to redeclare the function with the POSIX signature: glibc. However, rather than penalize these systems with a replacement function, gnulib defines GETTIMEOFDAY_TIMEZONE to the appropriate type for use in avoiding a compiler warning if assigning gettimeofday to a function pointer.
  • This function has only a precision of 15.6 milliseconds on some platforms: mingw.

Portability problems not fixed by Gnulib:

  • Behavior is non-portable if the second argument to gettimeofday is not NULL.
  • This function is removed in POSIX.1-2024. Use the Gnulib module gettime or timespec_get instead. (POSIX recommends to use the function clock_gettime, but there is no corresponding Gnulib module for it yet.)

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10.454 getuid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getuid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.455 getutxent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getutxent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14, Android 9.0.

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10.456 getutxid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getutxid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14, Android 9.0.

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10.457 getutxline

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getutxline.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14, Android 9.0.

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10.458 getwc

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getwc.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.5.x.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.459 getwchar

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/getwchar.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.5.x.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.460 glob

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/glob.html

Gnulib module: glob

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 8.1.
  • This function does not list symbolic links to nonexistent files among the results, on some platforms: glibc 2.26, AIX 7.2, HP-UX 11, Solaris 11.4.
  • On platforms where off_t is a 32-bit type, this function may not work correctly on huge directories 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • Some platforms may store additional flags in the gl_flags field.

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10.461 globfree

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/globfree.html

Gnulib module: glob

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 8.1.

Portability problems not fixed by Gnulib:

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10.462 gmtime

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/gmtime.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • On some platforms, this function yields incorrect values for timestamps before the year 1: MacOS X 10.5, Solaris 11.3.
  • On some platforms, this function returns NULL for arguments < -43200, that is, for timestamps before 1969-12-31 12:00:00 UTC: mingw, MSVC.

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10.463 gmtime_r

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/gmtime_r.html

Gnulib module: time_r

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • This function is not declared unless _REENTRANT is defined, on some platforms: HP-UX 11.

Portability problems not fixed by Gnulib:

  • On some platforms, this function yields incorrect values for timestamps before the year 1: MacOS X 10.5, Solaris 11.3.

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10.464 grantpt

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/grantpt.html

Gnulib module: grantpt

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, mingw, MSVC 14, Android 4.4.

Portability problems not fixed by Gnulib:

  • This function reports success for invalid file descriptors on some platforms: OpenBSD, Cygwin 1.7.9, musl libc.

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10.465 hcreate

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/hcreate.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 8.1.

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10.466 hdestroy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/hdestroy.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 8.1.

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10.467 hsearch

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/hsearch.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 8.1.

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10.468 htonl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/htonl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11, mingw, MSVC 14, Android 4.4.

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10.469 htons

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/htons.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11, mingw, MSVC 14, Android 4.4.

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10.470 hypot

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/hypot.html

Gnulib module: hypot or hypot-ieee

Portability problems fixed by either Gnulib module hypot or hypot-ieee:

Portability problems fixed by Gnulib module hypot-ieee:

  • When the arguments are mixed NaN and Infinity, this function returns a wrong value on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.471 hypotf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/hypotf.html

Gnulib module: hypotf or hypotf-ieee

Portability problems fixed by either Gnulib module hypotf or hypotf-ieee:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 14.
  • This function produces wrong values on some platforms: NetBSD 5.1, OpenBSD 4.9.

Portability problems fixed by Gnulib module hypot-ieee:

  • When the arguments are mixed NaN and Infinity, this function returns a wrong value on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.472 hypotl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/hypotl.html

Gnulib module: hypotl or hypotl-ieee

Portability problems fixed by either Gnulib module hypotl or hypotl-ieee:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 14, Android 4.4.
  • This function produces very imprecise results on some platforms: NetBSD 10.0, OpenBSD 5.1/SPARC.

Portability problems fixed by Gnulib module hypotl-ieee:

  • When the arguments are mixed NaN and Infinity, this function returns a wrong value on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.473 iconv

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iconv.html

Gnulib module: iconv

Portability problems fixed by Gnulib:

  • GNU libiconv is not found if installed in $PREFIX/lib.

Portability problems handled by Gnulib (in the sense that HAVE_ICONV does not get defined if the system’s iconv function has this problem):

  • Failures are not distinguishable from successful returns on some platforms: macOS 14.4, AIX 5.1..7.2, Solaris 10.
  • A buffer overrun can occur on some platforms: AIX 6.1..7.1.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 8.1, when GNU libiconv is not installed.
  • This function was not correctly implemented in glibc versions before 2.2.
  • When iconv encounters an input character that is valid but that cannot be converted to the output character set, glibc’s and GNU libiconv’s iconv stop the conversion. Some other implementations put an implementation-defined character into the output buffer. Gnulib provides higher-level facilities striconv and striconveh (wrappers around iconv) that deal with conversion errors in a platform independent way.
  • This function returns a positive return value, instead of zero, when converting from ISO-8859-1 to UTF-8 on HP-UX 11.

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10.474 iconv_close

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iconv_close.html

Gnulib module: iconv

Portability problems fixed by Gnulib:

  • GNU libiconv is not found if installed in $PREFIX/lib.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 8.1, when GNU libiconv is not installed.

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10.475 iconv_open

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iconv_open.html

Gnulib module: iconv, iconv_open, iconv_open-utf

Portability problems fixed by either Gnulib module iconv or iconv_open:

  • GNU libiconv is not found if installed in $PREFIX/lib.

Portability problems handled by either Gnulib module iconv or iconv_open (in the sense that HAVE_ICONV does not get defined if the system’s iconv_open function has this problem):

  • No converter from EUC-JP to UTF-8 is provided on some platforms: HP-UX 11.

Portability problems fixed by Gnulib module iconv_open:

  • This function recognizes only non-standard aliases for many encodings (not the IANA registered encoding names) on many platforms: AIX 5.1, HP-UX 11, Solaris 11 2010-11, z/OS.

Portability problems fixed by Gnulib module iconv_open-utf:

  • This function does not support the encodings UTF-16BE, UTF-16LE, UTF-32BE, UTF-32LE on many platforms: AIX 5.1, HP-UX 11.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 8.1, when GNU libiconv is not installed.
  • For some encodings A and B, this function cannot convert directly from A to B, although an indirect conversion from A through UTF-8 to B is possible. This occurs on some platforms: Solaris 11 2010-11. Gnulib provides a higher-level facility striconveh (a wrapper around iconv) that deals with this problem.
  • The set of supported encodings and conversions is system dependent.

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10.476 if_freenameindex

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/if_freenameindex.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, HP-UX 11.23, Cygwin 1.5.x, mingw, MSVC 14, Android 6.0.
  • This is available only as a macro, rather than a function, on some platforms: OpenBSD 4.6, MirBSD 10.

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10.477 if_indextoname

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/if_indextoname.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.23, Cygwin 1.5.x, mingw, MSVC 14.

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10.478 if_nameindex

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/if_nameindex.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.23, Cygwin 1.5.x, mingw, MSVC 14, Android 6.0.

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10.479 if_nametoindex

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/if_nametoindex.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.23, Cygwin 1.5.x, mingw, MSVC 14.

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10.480 ilogb

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ilogb.html

Gnulib module: ilogb

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, MSVC 9.
  • This function returns a wrong result for a zero argument on some platforms: OpenBSD 6.7, AIX 5.1.
  • This function returns a wrong result for denormalized arguments on some platforms: Mac OS X 10.5 64-bit, AIX 7.1 64-bit.
  • This function returns a wrong result for an infinite argument on some platforms: NetBSD 7.1, OpenBSD 6.7.
  • This function returns a wrong result for a NaN argument on some platforms: NetBSD 7.1, OpenBSD 6.7.

Portability problems not fixed by Gnulib:

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10.481 ilogbf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ilogbf.html

Gnulib module: ilogbf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.
  • This function returns a wrong result for a zero argument on some platforms: OpenBSD 6.7.
  • This function returns a wrong result for an infinite argument on some platforms: NetBSD 7.1, OpenBSD 6.7.

Portability problems not fixed by Gnulib:

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10.482 ilogbl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ilogbl.html

Gnulib module: ilogbl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 7.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9.
  • This function returns a wrong result for a zero argument on some platforms: Cygwin 2.9.
  • This function returns a wrong result for a NaN argument on some platforms: Cygwin 3.4.6.
  • This function returns a wrong result for denormalized arguments on some platforms: AIX 7.1 64-bit, Haiku 2017.

Portability problems not fixed by Gnulib:

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10.483 imaxabs

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/imaxabs.html

Gnulib module: imaxabs

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11.23, Solaris 9, MSVC 9, Android 4.3.

Portability problems not fixed by Gnulib:

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10.484 imaxdiv

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/imaxdiv.html

Gnulib module: imaxdiv

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11.23, Solaris 9, MSVC 9, Android 4.3.

Portability problems not fixed by Gnulib:

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10.485 inet_addr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/inet_addr.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • POSIX.1-2024 says this function is obsolescent and it is planned to be removed in a future version. Use the function inet_pton instead.
  • On some old platforms, this function returns a ‘struct in_addr’ rather than a scalar type such as ‘unsigned int’ or ‘unsigned long’.

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10.486 inet_ntoa

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/inet_ntoa.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • POSIX.1-2024 says this function is obsolescent and it is planned to be removed in a future version. Use the function inet_ntop instead.
  • The inet_ntoa function need not be reentrant, and consequently is not required to be thread safe. Implementations of inet_ntoa typically write the timestamp into static buffer. If two threads call inet_ntoa at roughly the same time, you might end up with the wrong date in one of the threads, or some undefined string.

Note: inet_ntoa is specific for IPv4 addresses. A protocol independent function is inet_ntop.

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10.487 inet_ntop

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/inet_ntop.html

Gnulib module: inet_ntop

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11.00, mingw, MSVC 14.
  • This function is declared in <netdb.h> instead of <arpa/inet.h> on some platforms: NonStop Kernel.
  • This function is declared in <ws2tcpip.h>, with a POSIX incompatible declaration, on some platforms: MSVC 14 on Windows >= Vista.

Portability problems not fixed by Gnulib:

  • This function’s fourth argument type is size_t instead of socklen_t on some platforms: Solaris 10.

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10.488 inet_pton

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/inet_pton.html

Gnulib module: inet_pton

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11.00, mingw, MSVC 14.
  • This function is declared in <netdb.h> instead of <arpa/inet.h> on some platforms: NonStop Kernel.
  • This function is declared in <ws2tcpip.h>, with a POSIX incompatible declaration, on some platforms: MSVC 14 on Windows >= Vista.

Portability problems not fixed by Gnulib:

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10.489 initstate

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/initstate.html

Gnulib module: random

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4.
  • This function is not declared on some platforms: Cygwin 1.5.25.

Portability problems not fixed by Gnulib:

  • This function crashes if the state buffer is unaligned on some platforms: glibc 2.36/sparc.
  • The first parameter is unsigned long instead of unsigned int on some platforms: MidnightBSD 2.0.
  • The third parameter is long instead of size_t on some platforms: MidnightBSD 2.0.
  • This function makes out-of-bounds writes on some platforms: Haiku.

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10.490 insque

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/insque.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.5.x, mingw, MSVC 14, Android 4.4.

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10.491 ioctl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ioctl.html

LSB specification:

Gnulib module: ioctl

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), ioctl is called ioctlsocket, and error codes from this function are not placed in errno, and WSAGetLastError must be used instead.
  • The second parameter is of type unsigned long rather than int on some platforms: glibc 2.26, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Haiku 2017.

Portability problems not fixed by Gnulib:

  • Most ioctl requests are platform and hardware specific.

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10.492 isalnum

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isalnum.html

Gnulib module: ctype

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

Note: This function’s behaviour depends on the locale, but does not support the multibyte characters that occur in strings in locales with MB_CUR_MAX > 1 (this includes all the common UTF-8 locales). There are five alternative APIs:

c_isalnum

This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.

iswalnum

This function operates in a locale dependent way, on wide characters. In order to use it, you first have to convert from multibyte to wide characters, using the mbrtowc function. It is provided by the Gnulib module ‘wctype’.

c32isalnum

This function operates in a locale dependent way, on 32-bit wide characters. In order to use it, you first have to convert from multibyte to 32-bit wide characters, using the mbrtoc32 function. It is provided by the Gnulib module ‘c32isalnum’.

mb_isalnum

This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.

uc_is_alnum

This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-alnum’.

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10.493 isalnum_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isalnum_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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10.494 isalpha

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isalpha.html

Gnulib module: ctype

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

Note: This function’s behaviour depends on the locale, but does not support the multibyte characters that occur in strings in locales with MB_CUR_MAX > 1 (this includes all the common UTF-8 locales). There are five alternative APIs:

c_isalpha

This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.

iswalpha

This function operates in a locale dependent way, on wide characters. In order to use it, you first have to convert from multibyte to wide characters, using the mbrtowc function. It is provided by the Gnulib module ‘wctype’.

c32isalpha

This function operates in a locale dependent way, on 32-bit wide characters. In order to use it, you first have to convert from multibyte to 32-bit wide characters, using the mbrtoc32 function. It is provided by the Gnulib module ‘c32isalpha’.

mb_isalpha

This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.

uc_is_alpha

This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-alpha’.

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10.495 isalpha_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isalpha_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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10.496 isascii

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isascii.html

Gnulib module: ctype

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

  • This function is removed in POSIX.1-2024.

Note: This function’s behaviour depends on the locale, but requires special handling for the multibyte characters that occur in strings in locales with MB_CUR_MAX > 1 (this includes all the common UTF-8 locales). There are two alternative APIs:

c_isascii

This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.

mb_isascii

This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.

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10.497 isastream

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isastream.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.498 isatty

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isatty.html

Gnulib module: isatty

Portability problems fixed by Gnulib:

  • This function is declared in a different header file (namely, <io.h>) on some platforms: MSVC 14.
  • On native Windows, this function also returns true for character devices such as NUL.
  • On native Windows, this function returns false for Cygwin consoles.
  • This function crashes when invoked with invalid arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.499 isblank

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isblank.html

Gnulib module: isblank

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Solaris 9, mingw, MSVC 9.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

Note: This function’s behaviour depends on the locale, but does not support the multibyte characters that occur in strings in locales with MB_CUR_MAX > 1 (this includes all the common UTF-8 locales). There are five alternative APIs:

c_isblank

This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.

iswblank

This function operates in a locale dependent way, on wide characters. In order to use it, you first have to convert from multibyte to wide characters, using the mbrtowc function. It is provided by the Gnulib module ‘wctype’.

c32isblank

This function operates in a locale dependent way, on 32-bit wide characters. In order to use it, you first have to convert from multibyte to 32-bit wide characters, using the mbrtoc32 function. It is provided by the Gnulib module ‘c32isblank’.

mb_isblank

This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.

uc_is_blank

This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-blank’.

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10.500 isblank_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isblank_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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10.501 iscntrl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iscntrl.html

Gnulib module: ctype

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

Note: This function’s behaviour depends on the locale, but does not support the multibyte characters that occur in strings in locales with MB_CUR_MAX > 1 (this includes all the common UTF-8 locales). There are five alternative APIs:

c_iscntrl

This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.

iswcntrl

This function operates in a locale dependent way, on wide characters. In order to use it, you first have to convert from multibyte to wide characters, using the mbrtowc function. It is provided by the Gnulib module ‘wctype’.

c32iscntrl

This function operates in a locale dependent way, on 32-bit wide characters. In order to use it, you first have to convert from multibyte to 32-bit wide characters, using the mbrtoc32 function. It is provided by the Gnulib module ‘c32iscntrl’.

mb_iscntrl

This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.

uc_is_cntrl

This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-cntrl’.

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10.502 iscntrl_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iscntrl_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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10.503 isdigit

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isdigit.html

Gnulib module: ctype

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

Note: This function’s behaviour depends on the locale, but does not support the multibyte characters that occur in strings in locales with MB_CUR_MAX > 1 (this includes all the common UTF-8 locales). There are five alternative APIs:

c_isdigit

This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.

iswdigit

This function operates in a locale dependent way, on wide characters. In order to use it, you first have to convert from multibyte to wide characters, using the mbrtowc function. It is provided by the Gnulib module ‘wctype’.

c32isdigit

This function operates in a locale dependent way, on 32-bit wide characters. In order to use it, you first have to convert from multibyte to 32-bit wide characters, using the mbrtoc32 function. It is provided by the Gnulib module ‘c32isdigit’.

mb_isdigit

This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.

uc_is_digit

This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-digit’.

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10.504 isdigit_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isdigit_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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10.505 isfinite

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isfinite.html

Gnulib module: isfinite

Portability problems fixed by Gnulib:

  • This macro is missing on some platforms: macOS 14, OpenBSD 6.7, AIX 5.1, Solaris 11.4.
  • This macro incorrectly yields true for some ‘double’ and for some ‘long double’ arguments, on some platforms: Linux/ia64 (NaNs).

Portability problems not fixed by Gnulib:

  • It is implementation-dependent whether isfinite raises an exception given a signaling NaN operand.
  • This macro returns an unspecified result when given noncanonical values such as unnormalized numbers, pseudo-denormals, pseudo-NaNs, pseudo-Infinities, and pseudo-zeroes.

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10.506 isgraph

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isgraph.html

Gnulib module: ctype

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

Note: This function’s behaviour depends on the locale, but does not support the multibyte characters that occur in strings in locales with MB_CUR_MAX > 1 (this includes all the common UTF-8 locales). There are five alternative APIs:

c_isgraph

This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.

iswgraph

This function operates in a locale dependent way, on wide characters. In order to use it, you first have to convert from multibyte to wide characters, using the mbrtowc function. It is provided by the Gnulib module ‘wctype’.

c32isgraph

This function operates in a locale dependent way, on 32-bit wide characters. In order to use it, you first have to convert from multibyte to 32-bit wide characters, using the mbrtoc32 function. It is provided by the Gnulib module ‘c32isgraph’.

mb_isgraph

This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.

uc_is_graph

This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-graph’.

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10.507 isgraph_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isgraph_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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10.508 isgreater

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isgreater.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, AIX 5.1, Solaris 11.4, Android 9.0.

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10.509 isgreaterequal

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isgreaterequal.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, AIX 5.1, Solaris 11.4, Android 9.0.

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10.510 isinf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isinf.html

Gnulib module: isinf

Portability problems fixed by Gnulib:

  • This macro is missing on some platforms: AIX 5.1, Solaris 11.4.

Portability problems not fixed by Gnulib:

  • This macro returns an unspecified result when given noncanonical values such as unnormalized numbers, pseudo-denormals, pseudo-NaNs, pseudo-Infinities, and pseudo-zeroes.

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10.511 isless

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isless.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, AIX 5.1, Solaris 11.4, Android 9.0.

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10.512 islessequal

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/islessequal.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, AIX 5.1, Solaris 11.4, Android 9.0.

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10.513 islessgreater

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/islessgreater.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, AIX 5.1, Solaris 11.4, Android 9.0.

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10.514 islower

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/islower.html

Gnulib module: ctype

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

Note: This function’s behaviour depends on the locale, but does not support the multibyte characters that occur in strings in locales with MB_CUR_MAX > 1 (this includes all the common UTF-8 locales). There are five alternative APIs:

c_islower

This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.

iswlower

This function operates in a locale dependent way, on wide characters. In order to use it, you first have to convert from multibyte to wide characters, using the mbrtowc function. It is provided by the Gnulib module ‘wctype’.

c32islower

This function operates in a locale dependent way, on 32-bit wide characters. In order to use it, you first have to convert from multibyte to 32-bit wide characters, using the mbrtoc32 function. It is provided by the Gnulib module ‘c32islower’.

mb_islower

This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.

uc_is_lower

This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-lower’.

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10.515 islower_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/islower_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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10.516 isnan

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isnan.html

Gnulib module: isnan

Portability problems fixed by Gnulib:

  • This macro is missing on some platforms: MSVC 9.
  • isnan was introduced with C99 and is thus commonly not present on pre-C99 systems.
  • isnan is not a macro on some platforms: Solaris 11.4.
  • This macro does not work on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

  • This macro returns an unspecified result when given noncanonical values such as unnormalized numbers, pseudo-denormals, pseudo-NaNs, pseudo-Infinities, and pseudo-zeroes.

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10.517 isnormal

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isnormal.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, OpenBSD 6.7, AIX 5.1, Solaris 11.4, Android 4.4.

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10.518 isprint

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isprint.html

Gnulib module: ctype

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

Note: This function’s behaviour depends on the locale, but does not support the multibyte characters that occur in strings in locales with MB_CUR_MAX > 1 (this includes all the common UTF-8 locales). There are five alternative APIs:

c_isprint

This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.

iswprint

This function operates in a locale dependent way, on wide characters. In order to use it, you first have to convert from multibyte to wide characters, using the mbrtowc function. It is provided by the Gnulib module ‘wctype’.

c32isprint

This function operates in a locale dependent way, on 32-bit wide characters. In order to use it, you first have to convert from multibyte to 32-bit wide characters, using the mbrtoc32 function. It is provided by the Gnulib module ‘c32isprint’.

mb_isprint

This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.

uc_is_print

This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-print’.

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10.519 isprint_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isprint_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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10.520 ispunct

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ispunct.html

Gnulib module: ctype

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

Note: This function’s behaviour depends on the locale, but does not support the multibyte characters that occur in strings in locales with MB_CUR_MAX > 1 (this includes all the common UTF-8 locales). There are five alternative APIs:

c_ispunct

This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.

iswpunct

This function operates in a locale dependent way, on wide characters. In order to use it, you first have to convert from multibyte to wide characters, using the mbrtowc function. It is provided by the Gnulib module ‘wctype’.

c32ispunct

This function operates in a locale dependent way, on 32-bit wide characters. In order to use it, you first have to convert from multibyte to 32-bit wide characters, using the mbrtoc32 function. It is provided by the Gnulib module ‘c32ispunct’.

mb_ispunct

This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.

uc_is_punct

This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-punct’.

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10.521 ispunct_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ispunct_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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10.522 isspace

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isspace.html

Gnulib module: ctype

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

Note: This function’s behaviour depends on the locale, but does not support the multibyte characters that occur in strings in locales with MB_CUR_MAX > 1 (this includes all the common UTF-8 locales). There are five alternative APIs:

c_isspace

This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.

iswspace

This function operates in a locale dependent way, on wide characters. In order to use it, you first have to convert from multibyte to wide characters, using the mbrtowc function. It is provided by the Gnulib module ‘wctype’.

c32isspace

This function operates in a locale dependent way, on 32-bit wide characters. In order to use it, you first have to convert from multibyte to 32-bit wide characters, using the mbrtoc32 function. It is provided by the Gnulib module ‘c32isspace’.

mb_isspace

This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.

uc_is_space

This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-space’.

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10.523 isspace_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isspace_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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10.524 isunordered

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isunordered.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, AIX 5.1, Solaris 11.4, Android 9.0.

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10.525 isupper

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isupper.html

Gnulib module: ctype

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

Note: This function’s behaviour depends on the locale, but does not support the multibyte characters that occur in strings in locales with MB_CUR_MAX > 1 (this includes all the common UTF-8 locales). There are five alternative APIs:

c_isupper

This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.

iswupper

This function operates in a locale dependent way, on wide characters. In order to use it, you first have to convert from multibyte to wide characters, using the mbrtowc function. It is provided by the Gnulib module ‘wctype’.

c32isupper

This function operates in a locale dependent way, on 32-bit wide characters. In order to use it, you first have to convert from multibyte to 32-bit wide characters, using the mbrtoc32 function. It is provided by the Gnulib module ‘c32isupper’.

mb_isupper

This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.

uc_is_upper

This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-upper’.

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10.526 isupper_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isupper_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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10.527 iswalnum

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswalnum.html

Gnulib module: wctype-h

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32isalnum, provided by Gnulib module c32isalnum, operates on 32-bit wide characters and therefore does not have this limitation.

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10.528 iswalnum_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswalnum_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.529 iswalpha

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswalpha.html

Gnulib module: wctype-h

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32isalpha, provided by Gnulib module c32isalpha, operates on 32-bit wide characters and therefore does not have this limitation.

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10.530 iswalpha_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswalpha_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.531 iswblank

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswblank.html

Gnulib module: iswblank

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Solaris 9, mingw, MSVC 9, Android 4.4.
  • This function is not declared (without -D_GNU_SOURCE) on some platforms: glibc 2.8.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32isblank, provided by Gnulib module c32isblank, operates on 32-bit wide characters and therefore does not have this limitation.

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10.532 iswblank_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswblank_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.533 iswcntrl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswcntrl.html

Gnulib module: wctype-h

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32iscntrl, provided by Gnulib module c32iscntrl, operates on 32-bit wide characters and therefore does not have this limitation.
  • This function returns 0 for U+2028 (LINE SEPARATOR) and U+2029 (PARAGRAPH SEPARATOR) on some platforms: macOS 14.

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10.534 iswcntrl_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswcntrl_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.535 iswctype

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswctype.html

Gnulib module: iswctype

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.
  • This function is declared in <wchar.h>, not in <wctype.h>, on some platforms: HP-UX 11.00.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32_apply_type_test, provided by Gnulib module c32_apply_type_test, operates on 32-bit wide characters and therefore does not have this limitation.

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10.536 iswctype_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswctype_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.537 iswdigit

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswdigit.html

Gnulib module: iswdigit

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.
  • This function is not ISO C 99 compliant on some platforms: FreeBSD 14.0, NetBSD 10.0, Solaris 11.4, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32isdigit, provided by Gnulib module c32isdigit, operates on 32-bit wide characters and therefore does not have this limitation.

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10.538 iswdigit_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswdigit_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.539 iswgraph

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswgraph.html

Gnulib module: wctype-h

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32isgraph, provided by Gnulib module c32isgraph, operates on 32-bit wide characters and therefore does not have this limitation.

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10.540 iswgraph_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswgraph_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.541 iswlower

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswlower.html

Gnulib module: wctype-h

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32islower, provided by Gnulib module c32islower, operates on 32-bit wide characters and therefore does not have this limitation.

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10.542 iswlower_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswlower_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.543 iswprint

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswprint.html

Gnulib module: wctype-h

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.
  • This function returns true for the tab ('\t') character on some platforms: mingw.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32isprint, provided by Gnulib module c32isprint, operates on 32-bit wide characters and therefore does not have this limitation.

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10.544 iswprint_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswprint_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.545 iswpunct

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswpunct.html

Gnulib module: iswpunct

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.
  • This function is inconsistent with the ispunct function, because it returns false for the characters '$', '+', '<', '=', '>', '^', '`' , '|', '~' on some platforms: Android 11.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32ispunct, provided by Gnulib module c32ispunct, operates on 32-bit wide characters and therefore does not have this limitation.

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10.546 iswpunct_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswpunct_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.547 iswspace

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswspace.html

Gnulib module: wctype-h

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32isspace, provided by Gnulib module c32isspace, operates on 32-bit wide characters and therefore does not have this limitation.

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10.548 iswspace_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswspace_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.549 iswupper

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswupper.html

Gnulib module: wctype-h

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32isupper, provided by Gnulib module c32isupper, operates on 32-bit wide characters and therefore does not have this limitation.

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10.550 iswupper_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswupper_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.551 iswxdigit

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswxdigit.html

Gnulib module: iswxdigit

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.
  • This function is not ISO C 99 compliant on some platforms: FreeBSD 14.0, NetBSD 10.0, Solaris 11.4, MSVC 14.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32isxdigit, provided by Gnulib module c32isxdigit, operates on 32-bit wide characters and therefore does not have this limitation.

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10.552 iswxdigit_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/iswxdigit_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.553 isxdigit

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isxdigit.html

Gnulib module: ctype

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

Note: This function’s behaviour depends on the locale, but does not support the multibyte characters that occur in strings in locales with MB_CUR_MAX > 1 (this includes all the common UTF-8 locales). There are five alternative APIs:

c_isxdigit

This function operates in a locale independent way and returns true only for ASCII characters. It is provided by the Gnulib module ‘c-ctype’.

iswxdigit

This function operates in a locale dependent way, on wide characters. In order to use it, you first have to convert from multibyte to wide characters, using the mbrtowc function. It is provided by the Gnulib module ‘wctype’.

c32isxdigit

This function operates in a locale dependent way, on 32-bit wide characters. In order to use it, you first have to convert from multibyte to 32-bit wide characters, using the mbrtoc32 function. It is provided by the Gnulib module ‘c32isxdigit’.

mb_isxdigit

This function operates in a locale dependent way, on multibyte characters. It is provided by the Gnulib module ‘mbchar’.

uc_is_xdigit

This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unictype/ctype-xdigit’.

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10.554 isxdigit_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/isxdigit_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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10.555 j0

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/j0.html

Gnulib module: j0

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.

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10.556 j1

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/j1.html

Gnulib module: j1

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.

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10.557 jn

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/jn.html

Gnulib module: jn

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.

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10.558 jrand48

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/jrand48.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.559 kill

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/kill.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-kill-3.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.560 killpg

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/killpg.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.561 l64a

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/l64a.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, Minix 3.1.8, mingw, MSVC 14, Android 9.0.
  • This function was not correctly implemented in glibc versions before 2.2.5.

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10.562 labs

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/labs.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Android 4.3.

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10.563 lchown

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lchown.html

Gnulib module: lchown

Portability problems fixed by Gnulib:

  • This function is missing on some platforms; however, the replacement fails with ENOSYS: mingw, MSVC 14.
  • This function is missing on some platforms; however, the replacement fails on symlinks: Minix 3.2.1.
  • Some platforms fail to detect trailing slash on non-directories, as in lchown("link-to-file/",uid,gid): FreeBSD 7.2, Solaris 9.
  • Some platforms fail to update the change time when at least one argument was not -1, but no ownership changes resulted. However, without lchmod, the replacement only fixes this for non-symlinks: OpenBSD 4.0.

Portability problems not fixed by Gnulib:

  • This function sometimes fails with EACCES when the failure is due to lack of appropriate privileges (EPERM), not to search permission denied on the file name prefix (EACCES): Linux kernel 5.15 with glibc 2.35 and a CIFS v1 file system (see https://bugs.gnu.org/65599).

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10.564 lcong48

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lcong48.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 5.1.

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10.565 ldexp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ldexp.html

Gnulib module: ldexp

Portability problems fixed by Gnulib:

  • This function produces wrong results on some platforms: OpenBSD 7.3/mips64.

Portability problems not fixed by Gnulib:

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10.566 ldexpf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ldexpf.html

Gnulib module: ldexpf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.567 ldexpl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ldexpl.html

Gnulib module: ldexpl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.
  • This function has no prototype in <math.h> on some platforms: Mac OS X.
  • This function does not work on finite numbers on some platforms: AIX 5.1.

Portability problems not fixed by Gnulib:

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10.568 ldiv

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ldiv.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.569 lfind

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lfind.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Android 4.4.

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10.570 lgamma

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lgamma.html

Gnulib module: lgamma

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, MSVC 9.

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10.571 lgammaf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lgammaf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.

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10.572 lgammal

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lgammal.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 9.3, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9, Android 4.4.

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10.574 linkat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/linkat.html

Gnulib module: linkat

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Mac OS X 10.9, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 4.4. But the replacement function is not safe to be used in libraries and is not multithread-safe.
  • This function fails to directly hardlink symlinks on some platforms: Mac OS X 10.10.
  • This function fails to reject trailing slashes on non-directories on some platforms: macOS 14, AIX 7.1, Solaris 11.3.
  • This functions does not support AT_SYMLINK_FOLLOW on some platforms: Linux kernel 2.6.17.

Portability problems not fixed by Gnulib:

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10.575 lio_listio

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lio_listio.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, this function may not work correctly on files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.576 listen

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/listen.html

Gnulib module: listen

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), error codes from this function are not placed in errno, and WSAGetLastError must be used instead.

Portability problems not fixed by Gnulib:

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10.577 llabs

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/llabs.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.23, MSVC 9, Android 4.3.

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10.578 lldiv

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lldiv.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, HP-UX 11.23, MSVC 9.

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10.579 llogb

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Exponents-and-Logarithms.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.580 llogbf

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Exponents-and-Logarithms.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.581 llogbl

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Exponents-and-Logarithms.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.582 llrint

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/llrint.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, Cygwin 1.5.x, MSVC 9.

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10.583 llrintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/llrintf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.5.x, MSVC 9.

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10.584 llrintl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/llrintl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 9.3, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.5.x, MSVC 9, Android 4.4.

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10.585 llround

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/llround.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, Cygwin 1.7.7, MSVC 9.

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10.586 llroundf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/llroundf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.7, MSVC 9.

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10.587 llroundl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/llroundl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 7.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9.

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10.588 localeconv

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/localeconv.html

Gnulib module: localeconv

Portability problems fixed by Gnulib:

  • The struct lconv type does not contain any members on some platforms: Android up to 2014.
  • The struct lconv type does not contain the members int_p_cs_precedes, int_p_sign_posn, int_p_sep_by_space, int_n_cs_precedes, int_n_sign_posn, int_n_sep_by_space on some platforms: glibc, OpenBSD 4.9, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.
  • The values of fields of struct lconv of type char are -1 instead of CHAR_MAX on some platforms: mingw.

Portability problems not fixed by Gnulib:

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10.589 localtime

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/localtime.html

Gnulib module: localtime

Portability problems fixed by Gnulib:

  • On native Windows platforms (mingw, MSVC), this function works incorrectly when the environment variable TZ has been set by Cygwin.

Portability problems not fixed by Gnulib:

  • On some platforms, this function loops forever for values near extrema (such as the year -2**31): Mac OS X 10.6. You can use the time_rz module to work around the problem.
  • On some platforms, this function returns nonsense values for unsupported arguments (like 2^56), rather than failing: FreeBSD 10.
  • On some platforms, this function yields incorrect values for timestamps before the year 1: MacOS X 10.5, Solaris 11.3.
  • On some platforms, this function returns NULL for negative arguments, that is, for timestamps before 1970-01-01 00:00:00 local time: mingw, MSVC.
  • Native Windows platforms (mingw, MSVC) support only a subset of time zones supported by GNU or specified by POSIX. See tzset.

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10.590 localtime_r

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/localtime_r.html

Gnulib module: time_r

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • This function is not declared unless _REENTRANT is defined, on some platforms: HP-UX 11.

Portability problems not fixed by Gnulib:

  • On some platforms, this function loops forever for values near extrema (such as the year -2**31): Mac OS X 10.6. You can use the time_rz module to work around the problem.
  • On some platforms, this function returns nonsense values for unsupported arguments (like 2^56), rather than failing: FreeBSD 10.
  • On some platforms, this function yields incorrect values for timestamps before the year 1: MacOS X 10.5, Solaris 11.3.

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10.591 lockf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lockf.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, this function may not work correctly across the entire data range of files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.5.x, mingw, MSVC 14, Android 6.0.

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10.592 log

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log.html

Gnulib module: log or log-ieee

Portability problems fixed by either Gnulib module log or log-ieee:

Portability problems fixed by Gnulib module log-ieee:

  • This function returns a wrong value for a negative argument on some platforms: NetBSD 5.1, Solaris 11.4.

Portability problems not fixed by Gnulib:

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10.593 log10

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log10.html

Gnulib module: log10 or log10-ieee

Portability problems fixed by either Gnulib module log10 or log10-ieee:

Portability problems fixed by Gnulib module log10-ieee:

  • This function returns a wrong value for a negative argument on some platforms: NetBSD 5.1, Solaris 11.4.

Portability problems not fixed by Gnulib:

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10.594 log10f

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log10f.html

Gnulib module: log10f or log10f-ieee

Portability problems fixed by either Gnulib module log10f or log10f-ieee:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems fixed by Gnulib module log10f-ieee:

  • This function returns a wrong value for a negative argument on some platforms: NetBSD 5.1.

Portability problems not fixed by Gnulib:

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10.595 log10l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log10l.html

Gnulib module: log10l

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, Android 4.4.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.
  • This function is not declared and does not work on some platforms: AIX 5.1.
  • This function produces results which are accurate to only 16 digits on some platforms: musl libc 1.2.2/arm64, musl libc 1.2.2/s390x, NetBSD 10.0.

Portability problems not fixed by Gnulib:

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10.596 log1p

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log1p.html

Gnulib module: log1p or log1p-ieee

Portability problems fixed by either Gnulib module log1p or log1p-ieee:

  • This function is missing on some platforms: Minix 3.1.8, MSVC 9.

Portability problems fixed by Gnulib module log1p-ieee:

  • This function has problems when the argument is minus zero on some platforms: AIX 7.1, HP-UX 11.

Portability problems not fixed by Gnulib:

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10.597 log1pf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log1pf.html

Gnulib module: log1pf or log1pf-ieee

Portability problems fixed by either Gnulib module log1pf or log1pf-ieee:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.

Portability problems fixed by Gnulib module log1pf-ieee:

  • This function has problems when the argument is minus zero on some platforms: OpenBSD 4.9, AIX 7.1.

Portability problems not fixed by Gnulib:

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10.598 log1pl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log1pl.html

Gnulib module: log1pl or log1pl-ieee

Portability problems fixed by either Gnulib module log1pl or log1pl-ieee:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 9.3, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9, Android 4.4.
  • This function produces results which are accurate to only 16 digits on some platforms: musl libc 1.2.2/arm64, musl libc 1.2.2/s390x, NetBSD 10.0.

Portability problems fixed by Gnulib module log1pl-ieee:

  • This function has problems when the argument is minus zero on some platforms: AIX 7.1.

Portability problems not fixed by Gnulib:

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10.599 log2

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log2.html

Gnulib module: log2 or log2-ieee

Portability problems fixed by either Gnulib module log2 or log2-ieee:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, MSVC 9, Android 4.2.
  • This function is only provided as a macro on some platforms: Cygwin 1.5.x.
  • This function returns slightly wrong values for exact powers of 2 on some platforms: Cygwin 1.7.9.

Portability problems fixed by Gnulib module log2-ieee:

  • This function returns a wrong value for a negative argument on some platforms: NetBSD 5.1, Solaris 10/x86_64.

Portability problems not fixed by Gnulib:

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10.600 log2f

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log2f.html

Gnulib module: log2f or log2f-ieee

Portability problems fixed by either Gnulib module log2f or log2f-ieee:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, MSVC 9, Android 4.2.
  • This function is only provided as a macro on some platforms: Cygwin 1.5.x.
  • This function returns slightly wrong values for exact powers of 2 on some platforms: Cygwin 1.7.9.

Portability problems fixed by Gnulib module log2f-ieee:

  • This function returns a wrong value for a negative argument on some platforms: NetBSD 5.1, Solaris 10/x86_64.

Portability problems not fixed by Gnulib:

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10.601 log2l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/log2l.html

Gnulib module: log2l

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 9.3, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9, Android 4.2.
  • This function produces results which are accurate to only 16 digits on some platforms: musl libc 1.2.2/arm64, musl libc 1.2.2/s390x.
  • This function returns Infinity for some large finite arguments on some platforms: musl libc 1.2.2/arm64, musl libc 1.2.2/s390x, NetBSD 10.0.

Portability problems not fixed by Gnulib:

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10.602 logb

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/logb.html

Gnulib module: logb

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, MSVC 9.
  • This function is missing a declaration on some platforms: Cygwin 1.5.x.
  • This function produces wrong results for subnormal numbers on some platforms: glibc 2.17/ppc, glibc 2.7/sparc, glibc 2.7/hppa, Solaris 11.4, Cygwin 1.5.x.

Portability problems not fixed by Gnulib:

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10.603 logbf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/logbf.html

Gnulib module: logbf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.
  • This function produces wrong results for subnormal numbers on some platforms: glibc 2.11/ppc, glibc 2.7/sparc, glibc 2.7/hppa, Solaris 11.4.

Portability problems not fixed by Gnulib:

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10.604 logbl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/logbl.html

Gnulib module: logbl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9, Android 4.2.
  • This function goes into an endless loop for arguments such as 1.6810515715560467531313389086608763012990396724232e-4932L on some platforms: OpenBSD 7.3/mips64.
  • This function produces wrong results for subnormal numbers on some platforms: glibc 2.11/powerpc, glibc 2.7/sparc, glibc 2.7/hppa, Solaris 11.4, glibc 2.23/powerpc64le.

Portability problems not fixed by Gnulib:

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10.605 logf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/logf.html

Gnulib module: logf or logf-ieee

Portability problems fixed by either Gnulib module logf or logf-ieee:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems fixed by Gnulib module logf-ieee:

  • This function returns a wrong value for a negative argument on some platforms: NetBSD 5.1.

Portability problems not fixed by Gnulib:

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10.606 logl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/logl.html

Gnulib module: logl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, Android 4.4.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.
  • This function returns wrong results on some platforms: glibc 2.7 on Linux/SPARC64.
  • This function produces results which are accurate to only 16 digits on some platforms: musl libc 1.2.2/arm64, musl libc 1.2.2/s390x, NetBSD 10.0.

Portability problems not fixed by Gnulib:

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10.607 longjmp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/longjmp.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • The effects of this call are system and compiler optimization dependent, since it restores the contents of register-allocated variables but not the contents of stack-allocated variables.
  • When longjumping out of a signal handler that was being executed on an alternate stack (installed through sigaltstack), on FreeBSD, NetBSD, OpenBSD, you need to clear the SS_ONSTACK flag in the stack_t structure managed by the kernel.

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10.608 lrand48

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lrand48.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.609 lrint

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lrint.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, MSVC 9.

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10.610 lrintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lrintf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.

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10.611 lrintl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lrintl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 9.3, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.5.x, MSVC 9, Android 4.4.

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10.612 lround

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lround.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, MSVC 9.

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10.613 lroundf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lroundf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.

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10.614 lroundl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lroundl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 7.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9.

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10.615 lsearch

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lsearch.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Android 4.4.

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10.616 lseek

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lseek.html

Gnulib module: lseek

Portability problems fixed by Gnulib:

  • On some platforms, lseek (fd, offset, SEEK_DATA) returns a value greater than offset even when offset addresses data: macOS 14.
  • This function is declared in a different header file (namely, <io.h>) on some platforms: MSVC 14.
  • On platforms where off_t is a 32-bit type, lseek does not work correctly with files 2 GiB and larger. See Large File Support.
  • This function mistakenly succeeds on pipes on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • POSIX does not specify which file descriptors support seeking and which don’t. In practice, regular files and block devices support seeking, and ttys, pipes, and most character devices don’t support it.
  • Some systems do not support SEEK_DATA and SEEK_HOLE: AIX, HP-UX, Microsoft Windows, NetBSD, OpenBSD, Cygwin 3.4.6.
  • Some systems have a buggy SEEK_DATA and SEEK_HOLE, and Gnulib works around the problem via #undef SEEK_DATA and #undef SEEK_HOLE: FreeBSD 13, macOS 12.

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10.617 lstat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/lstat.html

Gnulib module: lstat

Portability problems fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, lstat may not correctly report the size of files or block devices 2 GiB and larger. See Large File Support.
  • On Linux/x86 and Linux/x86_64, applications compiled in 32-bit mode cannot access files that happen to have a 64-bit inode number. This can occur with file systems such as XFS (typically on large disks) and NFS. See Large File Support.
  • For symlinks, when the argument ends in a slash, some platforms don’t dereference the argument: Solaris 9.
  • On some platforms, lstat("file/",buf) succeeds instead of failing with ENOTDIR. macOS 14, Solaris 9.
  • On macOS 12.6, when this function yields a timestamp with a nonpositive tv_sec value, tv_nsec might be in the range -999999999..-1, representing a negative nanoseconds offset from tv_sec. Solaris 11.4 is similar, except that tv_sec might also be -1000000000.
  • On Windows platforms (excluding Cygwin), symlinks are not supported, so lstat does not exist.

Portability problems not fixed by Gnulib:

  • See sys/stat.h, for general portability problems with struct stat.

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10.618 malloc

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/malloc.html

Gnulib module: malloc-posix

Portability problems fixed by Gnulib:

  • Upon failure, the function does not set errno to ENOMEM on some platforms: mingw, MSVC 14.
  • On some platforms, malloc (n) can succeed even if n exceeds PTRDIFF_MAX. Although this behavior is arguably allowed by POSIX it can lead to behavior not defined by POSIX later, so malloc-posix does not allow going over the limit.

Extension: Gnulib provides a module ‘malloc-gnu’ that substitutes a malloc implementation that behaves more like the glibc implementation, by fixing this portability problem:

  • malloc (0) returns NULL on success on some platforms: AIX 7.2.

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10.619 mblen

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mblen.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Android 7.1.

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10.620 mbrlen

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mbrlen.html

Gnulib module: mbrlen

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.00, mingw.
  • In the C or POSIX locales, this function can return (size_t) -1 and set errno to EILSEQ: glibc 2.35.
  • This function returns 0 instead of (size_t) -2 when the input is empty: glibc 2.19.
  • This function returns (size_t) -1 instead of (size_t) -2 when the input is empty: AIX 5.1.
  • This function does not put the state into non-initial state when parsing an incomplete multibyte character on some platforms: AIX 5.1.
  • This function returns the total number of bytes that make up the multibyte character, not the number of bytes that were needed to complete the multibyte character, on some platforms: HP-UX 11.11, Solaris 11 2010-11.
  • This function may not return 0 when parsing the NUL character on some platforms: Solaris 9.

Portability problems not fixed by Gnulib:

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10.621 mbrtoc8

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on most platforms: glibc 2.35, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.3.0, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.4.6, mingw, MSVC 14, Android 9.0.

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10.622 mbrtoc16

Gnulib module: mbrtoc16

Portability problems fixed by Gnulib:

  • This function is missing on most non-glibc platforms: glibc 2.15, macOS 14, FreeBSD 6.4, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 3.4.6, mingw, MSVC 9, Android 4.4.
  • This function may crash when the first argument is NULL on some platforms: glibc 2.36.
  • In the C or POSIX locales, this function can return (size_t) -1 and set errno to EILSEQ: glibc 2.36.
  • This function returns 0 instead of (size_t) -2 when the input is empty: glibc 2.19, Android 11.
  • This function returns the total number of bytes that make up the multibyte character, not the number of bytes that were needed to complete the multibyte character, on some platforms: mingw.
  • This function returns (size_t) -3 instead of a byte count when it has stored a high surrogate, and returns a byte count instead of (size_t) -3 when it has stored a low surrogate, on some platforms: Android.
  • This function does not recognize multibyte sequences that mbrtowc recognizes on some platforms: FreeBSD 13.2, Solaris 11.4, MSVC 14.

Portability problems not fixed by Gnulib:

  • After mbrtoc16 returns a char16_t value, mbsinit cannot be used to determine whether the function is ready to return another char16_t value. To do so, instead call mbrtoc16 again, with an appropriately incremented const char * argument and an appropriately decremented size_t argument.

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10.623 mbrtoc32

Gnulib module: mbrtoc32 or mbrtoc32-regular

Portability problems fixed by either Gnulib module mbrtoc32 or mbrtoc32-regular:

  • This function is missing on most non-glibc platforms: glibc 2.15, macOS 14, FreeBSD 6.4, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 3.4.6, mingw, MSVC 9, Android 4.4.
  • In the C or POSIX locales, this function can return (size_t) -1 and set errno to EILSEQ: glibc 2.35.
  • This function returns 0 instead of (size_t) -2 when the input is empty: glibc 2.19, mingw, Android 11, Haiku.
  • This function does not recognize multibyte sequences that mbrtowc recognizes on some platforms: FreeBSD 13.2, Solaris 11.4, mingw, MSVC 14.
  • This function does not work when it’s fed the input bytes one-by-one on some platforms: Cygwin 3.5.3.

Portability problems fixed by Gnulib module mbrtoc32-regular:

  • This function can map some multibyte characters to a sequence of two or more Unicode characters, and may thus return (size_t) -3. No known implementation currently (2023) behaves that way, but it may theoretically happen. With the mbrtoc32-regular module, you have the guarantee that the Gnulib-provided mbrtoc32 function maps each multibyte character to exactly one Unicode character and thus never returns (size_t) -3.
  • This function behaves incorrectly when converting precomposed characters from the BIG5-HKSCS encoding: glibc 2.36.

Portability problems not fixed by Gnulib:

  • This function is only defined as an inline function on some platforms: Haiku 2020.

Note: If you want the guarantee that the char32_t values returned by this function are Unicode code points, you also need to request the uchar-c23 module.

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10.624 mbrtowc

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mbrtowc.html

Gnulib module: mbrtowc

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.00, mingw.
  • In the C or POSIX locales, this function can return (size_t) -1 and set errno to EILSEQ: glibc 2.35.
  • This function returns 0 instead of (size_t) -2 when the input is empty: glibc 2.19, MSVC 14, Android 11.
  • This function returns (size_t) -1 instead of (size_t) -2 when the input is empty: AIX 7.2.
  • This function does not put the state into non-initial state when parsing an incomplete multibyte character on some platforms: AIX 7.2.
  • This function stores a wide character when parsing an incomplete multibyte character on some platforms: MSVC 14.
  • This function returns the total number of bytes that make up the multibyte character, not the number of bytes that were needed to complete the multibyte character, on some platforms: HP-UX 11.11, Solaris 11 2010-11, mingw, MSVC 14.
  • This function may not return 0 when parsing the NUL character on some platforms: Solaris 9.

Portability problems not fixed by Gnulib:

  • In UTF-8 locales, this function may return wide characters up to 0x7FFFFFFF (that is, beyond 0x0010FFFF) on some platforms: glibc 2.34.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the ISO C11 function mbrtoc32, provided by Gnulib module mbrtoc32, operates on 32-bit wide characters and therefore does not have this limitation.

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10.625 mbsinit

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mbsinit.html

Gnulib module: mbsinit

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.00, MSVC 14.
  • This function always returns 1, even in multibyte locales, on some platforms: mingw.

Portability problems not fixed by Gnulib:

  • This function is not useful after calls to mbrtoc16 or mbrtoc8.

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10.626 mbsnrtowcs

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mbsnrtowcs.html

Gnulib module: mbsnrtowcs

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 11.3, Cygwin 1.5.x, mingw, MSVC 14, Android 4.4.
  • This function produces invalid wide characters on some platforms: Solaris 11.4.
  • In the C or POSIX locales, this function can return (size_t) -1 and set errno to EILSEQ: glibc 2.35.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function mbsnrtoc32s, provided by Gnulib module mbsnrtoc32s, operates on 32-bit wide characters and therefore does not have this limitation.
  • The specification is not clear about whether this function should update the conversion state when the first argument (the destination pointer) is NULL. The glibc, Mac OS X, FreeBSD implementations do update the state in this case. For portability, when passing a NULL destination argument, it is best to pass a pointer to a temporary copy of the conversion state.

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10.627 mbsrtowcs

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mbsrtowcs.html

Gnulib module: mbsrtowcs

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.00, mingw.
  • This function does not work on some platforms: HP-UX 11, Solaris 11 2010-11.
  • In the C or POSIX locales, this function can return (size_t) -1 and set errno to EILSEQ: glibc 2.35.
  • This function does not work when the first argument is NULL on some platforms: mingw.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function mbsrtoc32s, provided by Gnulib module mbsrtoc32s, operates on 32-bit wide characters and therefore does not have this limitation.
  • The specification is not clear about whether this function should update the conversion state when the first argument (the destination pointer) is NULL. The glibc implementation does not update the state in this case; the macOS and FreeBSD implementations do. For portability, when passing a NULL destination argument, it is best to pass a pointer to a temporary copy of the conversion state.

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10.628 mbstowcs

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mbstowcs.html

Gnulib module: mbstowcs

Portability problems fixed by Gnulib:

  • In the C or POSIX locales, this function can return (size_t) -1 and set errno to EILSEQ: glibc 2.35.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function mbstoc32s, provided by Gnulib module mbstoc32s, operates on 32-bit wide characters and therefore does not have this limitation.

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10.629 mbtowc

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mbtowc.html

Gnulib module: mbtowc

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Android 4.4.

Portability problems not fixed by Gnulib:

  • In UTF-8 locales, this function may return wide characters up to 0x7FFFFFFF (that is, beyond 0x0010FFFF) on some platforms: glibc 2.34.
  • This function accumulates hidden state on some platforms: glibc 2.8 (see https://sourceware.org/bugzilla/show_bug.cgi?id=9674).
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.630 memccpy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/memccpy.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.631 memchr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/memchr.html

Gnulib module: memchr

Portability problems fixed by Gnulib:

  • This function dereferences too much memory on some platforms: glibc 2.10 on x86_64, IA-64; glibc 2.11 on Alpha, AIX 7.2.
  • This function returns NULL if the character argument is not in the range of an unsigned char on some platforms: Android 5.0.

Portability problems not fixed by Gnulib:

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10.632 memcmp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/memcmp.html

Gnulib module: memcmp

Portability problems fixed by Gnulib:

  • This function fails when comparing 16 bytes or more and with at least one buffer not starting on a 4-byte boundary on some older platforms: NeXTstep/x86.

Portability problems not fixed by Gnulib:

  • This function produces wrong results when the arguments are constant strings and the compiler is clang 6.0.1.

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10.633 memcpy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/memcpy.html

Gnulib module: memcpy

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

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10.634 memmove

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/memmove.html

Gnulib module: memmove

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

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10.635 memset

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/memset.html

Gnulib module: memset

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

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10.636 memset_explicit

Documentation:

Gnulib module: memset_explicit

The memset_explicit function is an approximation to what is needed, and does not suffice in general to erase information. Although calling memset_explicit should clear the memory in question, the information that was in memory may still be available elsewhere on the machine. Proper implementation of information erasure requires support from levels below C code.

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.36, FreeBSD 13.1, NetBSD 10.0, OpenBSD 7.2, macOS 13, Solaris 11.4, Android API level 33, and many other systems.

Portability problems not fixed by Gnulib:

  • Although the module’s implementation should set the memory on platforms compatible with GCC and on platforms using traditional linkers, it may not set the memory on non-GCC platforms that use whole-program optimization.

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10.637 mkdir

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mkdir.html

Gnulib module: sys_stat or mkdir

Portability problems fixed by either Gnulib module sys_stat or mkdir:

  • This function is declared in different header files (namely, <io.h> or <direct.h>) on some platforms: mingw, MSVC 14.
  • On Windows platforms (excluding Cygwin), this function is called _mkdir and takes only one argument. The fix (without Gnulib) is to define a macro like this: 
    #define mkdir ((int (*)()) _mkdir)

    or 

    #define mkdir(path,mode) _mkdir (path)

Portability problems fixed by Gnulib module mkdir:

  • When the argument ends in a slash, the function call fails on some platforms.
  • This function mistakenly succeeds on ‘mkdir("d/./",mode)’ on some platforms: Cygwin 1.5.x, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.638 mkdirat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mkdirat.html

Gnulib module: mkdirat

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14. But the replacement function is not safe to be used in libraries and is not multithread-safe.

Portability problems not fixed by Gnulib:

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10.639 mkdtemp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mkdtemp.html

Gnulib module: mkdtemp

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 10, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.640 mkfifo

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mkfifo.html

Gnulib module: mkfifo

Portability problems fixed by Gnulib:

  • This function mishandles trailing slash on some platforms: FreeBSD 7.2, Solaris 9.
  • This function is missing on some platforms; however, the replacement always fails with ENOSYS: mingw, MSVC 14, Android 4.4.

Portability problems not fixed by Gnulib:

  • If the argument exists and is a directory, this function fails with EISDIR instead of the correct EEXIST: HP-UX 11.11.

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10.641 mkfifoat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mkfifoat.html

Gnulib module: mkfifoat

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 12, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 5.1. But the replacement function is not safe to be used in libraries and is not multithread-safe.
  • This function does not fail when the file name argument ends in a slash and (without the slash) names a nonexistent file, on some platforms: AIX 7.2.
  • This function does not fail when the file name argument ends in a slash and (without the slash) names a symbolic link, on some platforms: macOS 14.

Portability problems not fixed by Gnulib:

  • The gnulib replacement function always fails with ‘ENOSYS’ on some platforms: mingw, MSVC 14.
  • If the argument exists and is a directory, the gnulib replacement function fails with EISDIR instead of the correct EEXIST: HP-UX 11.11.

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10.642 mknod

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mknod.html

Gnulib module: mknod

Portability problems fixed by Gnulib:

  • This function requires super-user privileges to create a fifo: FreeBSD 7.2, NetBSD 8.0, OpenBSD 6.7.
  • This function mishandles trailing slash on some platforms: FreeBSD 7.2, Solaris 9.
  • This function is missing on some platforms; however, the replacement always fails with ENOSYS: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • Use of this function for anything except fifos is not portable, generally requiring super-user privileges and knowledge of supported device numbers.
  • If the argument exists and is a directory, this function fails with EISDIR instead of the correct EEXIST: HP-UX 11.11.

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10.643 mknodat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mknodat.html

Gnulib module: mkfifoat

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 12, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 4.4. But the replacement function is not safe to be used in libraries and is not multithread-safe.
  • This function does not fail when the file name argument ends in a slash and (without the slash) names a nonexistent file, on some platforms: AIX 7.2.

Portability problems not fixed by Gnulib:

  • The gnulib replacement function always fails with ‘ENOSYS’ on some platforms: mingw, MSVC 14.
  • If the argument exists and is a directory, the gnulib replacement function fails with EISDIR instead of the correct EEXIST: HP-UX 11.11.

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10.644 mkstemp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mkstemp.html

Gnulib module: mkstemp

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • On platforms where off_t is a 32-bit type, mkstemp may not work correctly to create files 2 GiB and larger. See Large File Support.
  • On some older platforms, mkstemp can create a world or group writable or readable file, if you haven’t set the process umask to 077. This is a security risk.

Portability problems not fixed by Gnulib:

The gnulib module clean-temp can create temporary files that will not be left behind after signals such as SIGINT.

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10.645 mktime

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mktime.html

Gnulib module: mktime

Portability problems fixed by Gnulib:

  • On native Windows platforms (mingw, MSVC), this function works incorrectly when the environment variable TZ has been set by Cygwin.
  • mktime may go into an endless loop on some platforms.
  • mktime may occasionally return wrong results on some platforms.

Portability problems not fixed by Gnulib:

  • On some platforms, this function yields incorrect values for timestamps before the year 1: MacOS X 10.5, Solaris 11.3.
  • Native Windows platforms (mingw, MSVC) support only a subset of time zones supported by GNU or specified by POSIX. See tzset.

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10.646 mlock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mlock.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.647 mlockall

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mlockall.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 4.1.

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10.648 mmap

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mmap.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, this function may not work correctly across the entire data range of files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • To get anonymous memory, on some platforms, you can use the flags MAP_ANONYMOUS | MAP_PRIVATE and -1 instead of a file descriptor; on others you have to use a read-only file descriptor of /dev/zero.
  • On HP-UX, passing a non-NULL first argument, as a hint for the address (even without MAP_FIXED), often causes mmap to fail. Better pass NULL in this case.
  • On HP-UX, MAP_FIXED basically never works. On other platforms, it depends on the circumstances whether memory can be returned at a given address.

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10.649 modf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/modf.html

Gnulib module: modf or modf-ieee

Portability problems fixed by either Gnulib module modf or modf-ieee:

Portability problems fixed by Gnulib module modf-ieee:

  • This function has problems with a NaN argument on some platforms: NetBSD 5.1, Cygwin.
  • This function has problems with infinite arguments on some platforms: FreeBSD 6.4, OpenBSD 6.7.

Portability problems not fixed by Gnulib:

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10.650 modff

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/modff.html

Gnulib module: modff or modff-ieee

Portability problems fixed by either Gnulib module modff or modff-ieee:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11.
  • This function is only defined as a buggy macro with arguments on some platforms: MSVC 14.

Portability problems fixed by Gnulib module modff-ieee:

  • This function has problems with a NaN argument on some platforms: NetBSD 5.1, OpenBSD 6.7, Solaris 9, Cygwin.
  • This function has problems with infinite arguments on some platforms: mingw.

Portability problems not fixed by Gnulib:

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10.651 modfl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/modfl.html

Gnulib module: modfl or modfl-ieee

Portability problems fixed by either Gnulib module modfl or modfl-ieee:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, Android 4.4.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.
  • This function produces wrong results on some platforms: NetBSD 10.0/arm64.

Portability problems fixed by Gnulib module modfl-ieee:

  • This function has problems with infinite arguments on some platforms: mingw.

Portability problems not fixed by Gnulib:

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10.652 mprotect

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mprotect.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.
  • This function does not set errno on some platforms: mingw.
  • On AIX, it is not possible to use mprotect on memory regions allocated with malloc.

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10.653 mq_close

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_close.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

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10.654 mq_getattr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_getattr.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

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10.655 mq_notify

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_notify.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

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10.656 mq_open

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_open.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

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10.657 mq_receive

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_receive.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

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10.658 mq_send

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_send.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

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10.659 mq_setattr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_setattr.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

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10.660 mq_timedreceive

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_timedreceive.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

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10.661 mq_timedsend

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mq_timedsend.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

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10.663 mrand48

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/mrand48.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.664 msgctl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/msgctl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 7.1.

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10.665 msgget

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/msgget.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 7.1.

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10.666 msgrcv

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/msgrcv.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 7.1.

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10.667 msgsnd

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/msgsnd.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 7.1.

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10.668 msync

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/msync.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.
  • On NetBSD, msync takes only two arguments.

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10.669 mtx_destroy

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Mutexes.html.

Gnulib module: mtx

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.670 mtx_init

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Mutexes.html.

Gnulib module: mtx

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.671 mtx_lock

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Mutexes.html.

Gnulib module: mtx

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.672 mtx_timedlock

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Mutexes.html.

Gnulib module: mtx

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.673 mtx_trylock

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Mutexes.html.

Gnulib module: mtx

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.674 mtx_unlock

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Mutexes.html.

Gnulib module: mtx

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.675 munlock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/munlock.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.676 munlockall

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/munlockall.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 4.1.

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10.677 munmap

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/munmap.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.678 nan

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nan.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, MSVC 9.

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10.679 nanf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nanf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.

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10.680 nanl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nanl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9, Android 3.1.

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10.681 nanosleep

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nanosleep.html

Gnulib module: nanosleep

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • This function mishandles large arguments when interrupted by a signal on some platforms: Linux 64-bit, Solaris 64-bit.
  • This function cannot sleep longer than 49.7 days on some platforms: Cygwin 1.5.x.
  • This function does not fail when passed a negative nanosecond value on some platforms: newer 32-bit mingw.

Portability problems not fixed by Gnulib:

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10.682 nearbyint

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nearbyint.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, AIX 5.1, Solaris 9, MSVC 9.

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10.683 nearbyintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nearbyintf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.

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10.684 nearbyintl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nearbyintl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9, Android 4.4.

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10.685 newlocale

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/newlocale.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 9.0, NetBSD 5.0, OpenBSD 6.1, Minix 3.1.8, AIX 6.1, HP-UX 11, Solaris 11.3, Cygwin 2.5.x, mingw, MSVC 14, Android 4.4.
  • This function is useless because the locale_t type is not defined on some platforms: z/OS.
  • This function is useless because the locale_t type contains basically no information on some platforms: OpenBSD 6.3.

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10.686 nextafter

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nextafter.html

Gnulib module: nextafter

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, MSVC 9.

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10.687 nextafterf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nextafterf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9, MSVC 9.

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10.688 nextafterl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nextafterl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 4.4.

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10.689 nextdown

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.23, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.690 nextdownf

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.23, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.691 nextdownl

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.23, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.692 nexttoward

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nexttoward.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 4.2.

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10.693 nexttowardf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nexttowardf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9.

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10.694 nexttowardl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nexttowardl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 8.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 9, Android 4.2.

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10.695 nextup

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.23, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.696 nextupf

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.23, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.697 nextupl

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.23, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.698 nftw

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nftw.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, this function may not correctly report the size of files or block devices 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 3.0, Minix 3.1.8, mingw, MSVC 14, Android 4.1.

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10.699 nice

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nice.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • In glibc before glibc 2.2.4, nice returned 0 upon success.

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10.700 nl_langinfo

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nl_langinfo.html

Gnulib module: nl_langinfo

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 7.1.
  • The constant CODESET is not supported on some platforms: OpenBSD 3.8.
  • The constants ALTMON_1 to ALTMON_12 are not defined on some platforms: glibc 2.26, musl libc, macOS 14, NetBSD 8.0, OpenBSD 6.7, AIX 7.2, HP-UX 11.31, Solaris 11.4, Haiku, Cygwin 2.9.
  • The constants ERA, ERA_D_FMT, ERA_D_T_FMT, ERA_T_FMT, ALT_DIGITS are not supported on some platforms: OpenBSD 6.7.
  • This function is not multithread-safe on some platforms: Solaris 11.3.

Portability problems not fixed by Gnulib:

  • On Cygwin 1.5.x, which doesn’t have locales, nl_langinfo(CODESET) always returns "US-ASCII".
  • On Cygwin 1.7.0, only the charset portion of a locale designation is honored.
  • On NetBSD 5.0, in some locales, nl_langinfo(CRNCYSTR) returns the empty string, although the local currency symbol, as returned by localeconv()->currency_symbol, is non-empty.
  • On NetBSD 5.1, in the "C" locale, the results of nl_langinfo(ABMON_1) ... nl_langinfo(ABMON_12) are full month names, not abbreviated month names.

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10.701 nl_langinfo_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nl_langinfo_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 7.1.

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10.702 nrand48

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/nrand48.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.703 ntohl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ntohl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11, mingw, MSVC 14, Android 4.4.

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10.704 ntohs

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ntohs.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11, mingw, MSVC 14, Android 4.4.

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10.705 open

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/open.html

Gnulib module: open, fchdir

Portability problems fixed by the Gnulib module open:

  • Some platforms do not support O_CLOEXEC: Mac OS X 10.6, FreeBSD 8.4, NetBSD 5.1, OpenBSD 4.9, Minix 3.1.8, AIX 7.1, HP-UX 11, Solaris 10, Cygwin 1.7.x, mingw, MSVC 14.
  • On platforms where off_t is a 32-bit type, open may not work correctly with files 2 GiB and larger. See Large File Support.
  • This function does not fail when the file name argument ends in a slash and (without the slash) names a nonexistent file or a file that is not a directory, on some platforms: macOS 14, FreeBSD 7.2, AIX 7.1, HP-UX 11.00, Solaris 9.
  • This function does not support the O_NONBLOCK flag when it is defined by the gnulib module nonblocking on some platforms: mingw, MSVC 14.
  • On Windows platforms (excluding Cygwin), this function does usually not recognize the /dev/null filename.

Portability problems fixed by the Gnulib module fchdir:

  • On Windows platforms (excluding Cygwin), this function fails to open a read-only descriptor for directories.

Portability problems not fixed by Gnulib:

  • The Gnulib replacement for O_CLOEXEC is not atomic, and so is not safe in the presence of multiple threads or signal handlers.
  • open ("symlink", O_CREAT ...) fails when the argument points to a nonexistent file in an existing directory on some platforms: Haiku.
  • open ("symlink", O_NOFOLLOW ...) fails with errno set to EMLINK instead of the POSIX-required ELOOP on some platforms: FreeBSD 10.1.
  • open ("symlink", O_NOFOLLOW ...) fails with errno set to EFTYPE instead of the POSIX-required ELOOP on some platforms: NetBSD 6.1.
  • On Windows, this function returns a file handle in O_TEXT mode by default; this means that it translates '\n' to CR/LF by default. Use the O_BINARY flag if you need reliable binary I/O.

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10.706 openat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/openat.html

Gnulib module: openat

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.5.x, mingw, MSVC 14. But the replacement function is not safe to be used in libraries and is not multithread-safe.
  • Some platforms do not support O_CLOEXEC: AIX 7.1, Solaris 10.
  • On platforms where off_t is a 32-bit type, open may not work correctly with files 2 GiB and larger. See Large File Support.
  • This function does not fail when the file name argument ends in a slash and (without the slash) names a nonexistent file or a file that is not a directory, on some platforms: Solaris 9.

Portability problems not fixed by Gnulib:

  • The Gnulib replacement for O_CLOEXEC is not atomic, and so is not safe in the presence of multiple threads or signal handlers.
  • openat (fd, "symlink", O_NOFOLLOW ...) fails with errno set to EMLINK instead of the POSIX-required ELOOP on some platforms: FreeBSD 10.1.
  • openat (fd, "symlink", O_NOFOLLOW ...) fails with errno set to EFTYPE instead of the POSIX-required ELOOP on some platforms: NetBSD 6.1.

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10.707 opendir

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/opendir.html

Gnulib module: opendir

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: MSVC 14.
  • On platforms where off_t is a 32-bit type, this function may not work correctly on huge directories 2 GiB and larger. Also, on platforms where ino_t is a 32-bit type, this function may report inode numbers incorrectly. See Large File Support.

Portability problems not fixed by Gnulib:

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10.708 openlog

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/openlog.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.709 open_memstream

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/open_memstream.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 7.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.5.x, mingw, MSVC 14, Android 5.1.

An alternative to the open_memstream function is the Gnulib module string-buffer.

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10.710 open_wmemstream

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/open_wmemstream.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Mac OS X 10.5, FreeBSD 6.0, NetBSD 7.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.5.x, mingw, MSVC 14, Android 5.1.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.711 optarg

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/optarg.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on some platforms: Mac OS X 10.5, MSVC 14.

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10.712 opterr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/opterr.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on some platforms: MSVC 14.

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10.713 optind

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/optind.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on some platforms: MSVC 14.

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10.714 optopt

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/optopt.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on some platforms: Mac OS X 10.5, MSVC 14.

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10.715 pathconf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pathconf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.716 pause

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pause.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.717 pclose

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pclose.html

Gnulib module: pclose

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.718 perror

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/perror.html

Gnulib module: perror

Portability problems fixed by Gnulib:

  • This function does not support the error values that are specified by POSIX but not defined by the system, on some platforms: OpenBSD 4.0, Cygwin 1.5.x, mingw, MSVC 14.
  • This function treats errno of 0 like failure, although POSIX requires that the message declare it as a success, on some platforms: FreeBSD 8.2, OpenBSD 4.7, macOS 14.
  • This function clobbers the strerror buffer on some platforms: Cygwin 1.7.9, Android 11.
  • This function fails to print a useful a string for out-of-range integers on some platforms: HP-UX 11.

Portability problems not fixed by Gnulib:

  • POSIX requires that this function set the stream error bit (detected by ferror) on write failure, but not all platforms do this: glibc 2.13, cygwin 1.7.9.
  • POSIX requires that this function not alter stream orientation, but the gnulib replacement locks in byte orientation and fails on wide character streams.

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10.719 pipe

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pipe.html

Gnulib module: pipe-posix

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • This function crashes rather than failing with EMFILE if no resources are left on some platforms: Cygwin 1.7.9.

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10.720 poll

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/poll.html

Gnulib module: poll

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, HP NonStop.
  • This function doesn’t work on special files like /dev/null and ttys like /dev/tty on some platforms: macOS 14, AIX 5.3.

Portability problems not fixed by Gnulib:

  • Under Windows, when passing a pipe, Gnulib’s poll replacement might return 0 even before the timeout has passed. Programs using it with pipes can thus busy wait.
  • On some platforms, file descriptors other than sockets do not support POLLHUP; they will return a "readable" or "writable" status instead: AIX 7.2, Cygwin 3.4.6, HP NonStop, mingw, MSVC.

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10.721 popen

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/popen.html

Gnulib module: popen

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: MSVC 14.
  • Some platforms start the child with closed stdin or stdout if the standard descriptors were closed in the parent: Cygwin 1.5.x.

Portability problems not fixed by Gnulib:

  • On native Windows platforms, this functions terminates the current process with exit code 127 if the environment variable COMSPEC is not set.
  • Some platforms mistakenly set the close-on-exec bit, then if it is cleared by the application, the platform then leaks file descriptors from earlier popen calls into subsequent popen children: Cygwin 1.5.x.

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10.722 posix_fadvise

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_fadvise.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, this function may not work correctly across the entire data range of files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11.23, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 4.4.

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10.723 posix_fallocate

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_fallocate.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, this function may not work correctly across the entire data range of files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 4.4.
  • POSIX specifies that EINVAL should be returned when the file system doesn’t support the allocation operation directly. glibc however emulates the file system allocation with writes where unsupported, and apps have depended on that long term implementation. This is both inefficient, and as of glibc 2.21 at least, buggy on certain NFS setups.

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10.724 posix_madvise

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_madvise.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 5.1.

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10.725 posix_mem_offset

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_mem_offset.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.726 posix_memalign

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_memalign.html

Gnulib module: posix_memalign

Portability problems fixed by Gnulib:

  • This function produces misaligned results on some platforms: OpenBSD 6.1.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 4.1.

The Gnulib module aligned-malloc provides functions for allocating and freeing blocks of suitably aligned memory.

The Gnulib module pagealign_alloc provides a similar API for allocating and freeing blocks of memory aligned on a system page boundary.

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10.727 posix_openpt

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_openpt.html

Gnulib module: posix_openpt

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.x, mingw, MSVC 14, Android 4.4. However, the replacement may fail with ENOSYS or ENOENT on some platforms.

Portability problems not fixed by Gnulib:

Note that when using this function to open the master side of a pseudo-terminal, you still need platform dependent code to open the corresponding slave side. The Gnulib module openpty provides an easy-to-use API that does both at once.

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10.728 posix_spawn

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawn.html

Gnulib module: posix_spawn

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.3, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.
  • When this function fails, it causes the stdio buffer contents to be output twice on some platforms: AIX 6.1.
  • When the program to be invoked is an executable script without a ‘#!’ marker in the first line, this function executes the script as if it were a shell script, on some platforms: GNU/Hurd.

Portability problems not fixed by Gnulib:

  • This function does not work on some platforms: AIX 6.1 (under particular circumstances).

The Gnulib modules posix_spawn_file_actions_addchdir and posix_spawn_file_actions_addfchdir provide additional actions, that consist in changing the current directory of the child process before starting the specified program.

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10.729 posix_spawn_file_actions_addclose

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawn_file_actions_addclose.html

Gnulib module: posix_spawn_file_actions_addclose

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.
  • This function does not reject a negative file descriptor on some platforms: musl libc.

Portability problems not fixed by Gnulib:

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10.730 posix_spawn_file_actions_adddup2

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawn_file_actions_adddup2.html

Gnulib module: posix_spawn_file_actions_adddup2

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.
  • This function does not reject a too large file descriptor on some platforms: musl libc, Solaris 11.4.

Portability problems not fixed by Gnulib:

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10.731 posix_spawn_file_actions_addopen

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawn_file_actions_addopen.html

Gnulib module: posix_spawn_file_actions_addopen

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.
  • This function does not reject a too large file descriptor on some platforms: musl libc, Solaris 11.4.

Portability problems not fixed by Gnulib:

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10.732 posix_spawn_file_actions_destroy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawn_file_actions_destroy.html

Gnulib module: posix_spawn_file_actions_destroy

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

Portability problems not fixed by Gnulib:

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10.733 posix_spawn_file_actions_init

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawn_file_actions_init.html

Gnulib module: posix_spawn_file_actions_init

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

Portability problems not fixed by Gnulib:

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10.734 posix_spawnattr_destroy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_destroy.html

Gnulib module: posix_spawnattr_destroy

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

Portability problems not fixed by Gnulib:

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10.735 posix_spawnattr_getflags

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_getflags.html

Gnulib module: posix_spawnattr_getflags

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

Portability problems not fixed by Gnulib:

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10.736 posix_spawnattr_getpgroup

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_getpgroup.html

Gnulib module: posix_spawnattr_getpgroup

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

Portability problems not fixed by Gnulib:

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10.737 posix_spawnattr_getschedparam

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_getschedparam.html

Gnulib module: posix_spawnattr_getschedparam

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

Portability problems not fixed by Gnulib:

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10.738 posix_spawnattr_getschedpolicy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_getschedpolicy.html

Gnulib module: posix_spawnattr_getschedpolicy

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

Portability problems not fixed by Gnulib:

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10.739 posix_spawnattr_getsigdefault

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_getsigdefault.html

Gnulib module: posix_spawnattr_getsigdefault

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

Portability problems not fixed by Gnulib:

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10.740 posix_spawnattr_getsigmask

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_getsigmask.html

Gnulib module: posix_spawnattr_getsigmask

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

Portability problems not fixed by Gnulib:

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10.741 posix_spawnattr_init

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_init.html

Gnulib module: posix_spawnattr_init

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

Portability problems not fixed by Gnulib:

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10.742 posix_spawnattr_setflags

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_setflags.html

Gnulib module: posix_spawnattr_setflags

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

Portability problems not fixed by Gnulib:

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10.743 posix_spawnattr_setpgroup

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_setpgroup.html

Gnulib module: posix_spawnattr_setpgroup

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

Portability problems not fixed by Gnulib:

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10.744 posix_spawnattr_setschedparam

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_setschedparam.html

Gnulib module: posix_spawnattr_setschedparam

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

Portability problems not fixed by Gnulib:

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10.745 posix_spawnattr_setschedpolicy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_setschedpolicy.html

Gnulib module: posix_spawnattr_setschedpolicy

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

Portability problems not fixed by Gnulib:

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10.746 posix_spawnattr_setsigdefault

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_setsigdefault.html

Gnulib module: posix_spawnattr_setsigdefault

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

Portability problems not fixed by Gnulib:

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10.747 posix_spawnattr_setsigmask

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnattr_setsigmask.html

Gnulib module: posix_spawnattr_setsigmask

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

Portability problems not fixed by Gnulib:

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10.748 posix_spawnp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawnp.html

Gnulib module: posix_spawnp

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.3, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.
  • When this function fails, it causes the stdio buffer contents to be output twice on some platforms: AIX 6.1.
  • When the program to be invoked is an executable script without a ‘#!’ marker in the first line, this function executes the script as if it were a shell script, on some platforms: glibc 2.14/Linux, glibc 2.32/Hurd, macOS 14, FreeBSD 14.0, OpenBSD 7.2, AIX 7.2, Solaris 11.4, Cygwin 3.4.6.

Portability problems not fixed by Gnulib:

  • This function does not work on some platforms: AIX 6.1 (under particular circumstances).

The Gnulib modules posix_spawn_file_actions_addchdir and posix_spawn_file_actions_addfchdir provide additional actions, that consist in changing the current directory of the child process before starting the specified program.

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10.749 posix_trace_attr_destroy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_destroy.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.750 posix_trace_attr_getclockres

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getclockres.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.751 posix_trace_attr_getcreatetime

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getcreatetime.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.752 posix_trace_attr_getgenversion

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getgenversion.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.753 posix_trace_attr_getinherited

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getinherited.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.754 posix_trace_attr_getlogfullpolicy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getlogfullpolicy.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.755 posix_trace_attr_getlogsize

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getlogsize.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.756 posix_trace_attr_getmaxdatasize

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getmaxdatasize.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.757 posix_trace_attr_getmaxsystemeventsize

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getmaxsystemeventsize.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.758 posix_trace_attr_getmaxusereventsize

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getmaxusereventsize.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.759 posix_trace_attr_getname

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getname.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.760 posix_trace_attr_getstreamfullpolicy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getstreamfullpolicy.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.761 posix_trace_attr_getstreamsize

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_getstreamsize.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.762 posix_trace_attr_init

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_init.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.763 posix_trace_attr_setinherited

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_setinherited.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.764 posix_trace_attr_setlogfullpolicy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_setlogfullpolicy.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.765 posix_trace_attr_setlogsize

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_setlogsize.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.766 posix_trace_attr_setmaxdatasize

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_setmaxdatasize.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.767 posix_trace_attr_setname

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_setname.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.768 posix_trace_attr_setstreamfullpolicy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_setstreamfullpolicy.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.769 posix_trace_attr_setstreamsize

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_attr_setstreamsize.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.770 posix_trace_clear

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_clear.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.771 posix_trace_close

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_close.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.772 posix_trace_create

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_create.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.773 posix_trace_create_withlog

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_create_withlog.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.774 posix_trace_event

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_event.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.775 posix_trace_eventid_equal

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventid_equal.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.776 posix_trace_eventid_get_name

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventid_get_name.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.777 posix_trace_eventid_open

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventid_open.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.778 posix_trace_eventset_add

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventset_add.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.779 posix_trace_eventset_del

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventset_del.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.780 posix_trace_eventset_empty

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventset_empty.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.781 posix_trace_eventset_fill

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventset_fill.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.782 posix_trace_eventset_ismember

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventset_ismember.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.783 posix_trace_eventtypelist_getnext_id

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventtypelist_getnext_id.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.784 posix_trace_eventtypelist_rewind

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_eventtypelist_rewind.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.785 posix_trace_flush

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_flush.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.786 posix_trace_get_attr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_get_attr.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.787 posix_trace_get_filter

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_get_filter.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.788 posix_trace_get_status

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_get_status.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.789 posix_trace_getnext_event

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_getnext_event.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.790 posix_trace_open

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_open.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.791 posix_trace_rewind

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_rewind.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.792 posix_trace_set_filter

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_set_filter.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.793 posix_trace_shutdown

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_shutdown.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.794 posix_trace_start

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_start.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.795 posix_trace_stop

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_stop.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.796 posix_trace_timedgetnext_event

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_timedgetnext_event.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.797 posix_trace_trid_eventid_open

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_trid_eventid_open.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.798 posix_trace_trygetnext_event

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_trace_trygetnext_event.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.799 posix_typed_mem_get_info

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_typed_mem_get_info.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.800 posix_typed_mem_open

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_typed_mem_open.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.801 pow

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pow.html

Gnulib module: pow

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: ISO C and POSIX Function Substitutes   [Contents][Index]

10.802 powf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/powf.html

Gnulib module: powf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 9.

Portability problems not fixed by Gnulib:

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10.803 powl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/powl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, Android 4.4.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.
  • This function produces results which are accurate to only 16 digits on some platforms: NetBSD 10.0.

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10.804 pread

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pread.html

Gnulib module: pread

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • On platforms where off_t is a 32-bit type, this function may not work correctly on files 2 GiB and larger. See Large File Support.
  • This function returns zero instead of positive values when large file support is enabled on some platforms: HP-UX 11.11.
  • This function does not fail on pipes on some platforms: HP-UX 11.31.

Portability problems not fixed by Gnulib:

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10.805 printf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/printf.html

Gnulib module: printf-posix or printf-gnu or stdio, nonblocking, sigpipe

Portability problems fixed by either Gnulib module printf-posix or printf-gnu:

  • This function does not support size specifiers as in C99 (hh, ll, j, t, z) on some platforms: AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • printf of ‘long double’ numbers is unsupported on some platforms: mingw, MSVC 14.
  • printf "%f", "%e", "%g" of Infinity and NaN yields an incorrect result on some platforms: AIX 7.3, Solaris 11.4, mingw, MSVC 14.
  • This function does not support the ‘a’ and ‘A’ directives on some platforms: FreeBSD 5.2.1, OpenBSD 4.0, AIX 5.2, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support the ‘F’ directive on some platforms: NetBSD 3.0, AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘ls’ directive on some platforms: OpenBSD 4.0, Cygwin 1.5.x, Haiku.
  • This function does not support precisions in the ‘ls’ directive correctly on some platforms: Solaris 11.4.
  • This function does not support format directives that access arguments in an arbitrary order, such as "%2$s", on some platforms: NetBSD 3.0, mingw, MSVC 14.
  • This function doesn’t support the ' flag on some platforms: NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
  • This function does not round the argument of the ‘a’ directive correctly on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4.
  • printf "%010f" of NaN and Infinity yields an incorrect result (padded with zeroes, or wrong capitalization) on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 7.3, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC/clang.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • This function does not support precisions larger than 512 or 1024 in integer, floating-point and pointer output on some platforms: AIX 7.1, Solaris 10/x86, mingw, MSVC/clang.
  • This function mishandles large floating point precisions (for example, formatting 1.0 with ‘"%.511f"’) on some platforms: Solaris 10.
  • This function produces wrong output for the ‘lc’ directive with a NUL wide character argument on some platforms: musl libc 1.2.4.
  • This function can crash in out-of-memory conditions on some platforms: FreeBSD 14.0, NetBSD 5.0.

Portability problems fixed by Gnulib module printf-gnu:

  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.

Portability problems fixed by either Gnulib module printf-posix or printf-gnu and additionally the Gnulib module printf-with-n-directive:

  • This function does not support the ‘n’ directive on some platforms: glibc when used with _FORTIFY_SOURCE >= 2 (set by default on Ubuntu), macOS 14, OpenBSD, MSVC 14, Android.

Portability problems fixed by Gnulib module stdio or printf-posix or printf-gnu, together with module nonblocking:

  • When writing to a non-blocking pipe whose buffer is full, this function fails with errno being set to ENOSPC instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems fixed by Gnulib module stdio or printf-posix or printf-gnu, together with module sigpipe:

  • When writing to a pipe with no readers, this function fails, instead of obeying the current SIGPIPE handler, on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.
  • Formatting noncanonical ‘long double’ numbers produces nonmeaningful results on some platforms: glibc and others, on x86, x86_64, IA-64 CPUs.
  • When formatting an integer with grouping flag, this function inserts thousands separators even in the "C" locale on some platforms: NetBSD 5.1.
  • Attempting to write to a read-only stream fails with EOF but does not set the error flag for ferror on some platforms: glibc 2.13, cygwin 1.7.9.

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10.806 pselect

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pselect.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11.23, Solaris 9, mingw, MSVC 14.
  • On some platforms, this function fails to detect invalid fds with EBADF, but only if they lie beyond the current maximum open fd: FreeBSD 8.2.

Portability problems not fixed by Gnulib:

  • This function has a slightly incompatible declaration on some platforms: AIX 7.1 (when _ALL_SOURCE is defined).
  • When the sigmask argument is nonnull on platforms that do not natively support this function, race conditions are possible when its gnulib implementation temporarily modifies the signal mask, and the behavior is unspecified in a multi-threaded process.

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10.807 psiginfo

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/psiginfo.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.9, macOS 14, FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.7.9, mingw, MSVC 14, Android 4.1.

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10.808 psignal

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/psignal.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11, Cygwin 1.7.9, mingw, MSVC 14, Android 4.1.

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10.809 pthread_atfork

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_atfork.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, mingw, MSVC 14, Android 3.0.

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10.810 pthread_attr_destroy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_destroy.html

Gnulib module: pthread-thread

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.811 pthread_attr_getdetachstate

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_getdetachstate.html

Gnulib module: pthread-thread

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.812 pthread_attr_getguardsize

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_getguardsize.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, Cygwin 1.7.9, mingw, MSVC 14.

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10.813 pthread_attr_getinheritsched

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_getinheritsched.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 8.1.

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10.814 pthread_attr_getschedparam

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_getschedparam.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.815 pthread_attr_getschedpolicy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_getschedpolicy.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.816 pthread_attr_getscope

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_getscope.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.817 pthread_attr_getstack

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_getstack.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11.11, Solaris 9, Cygwin 1.7.9, mingw, MSVC 14.

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10.818 pthread_attr_getstacksize

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_getstacksize.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.819 pthread_attr_init

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_init.html

Gnulib module: pthread-thread

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.
  • This function is only defined as an inline function on some platforms: HP-UX 11.11.

Portability problems not fixed by Gnulib:

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10.820 pthread_attr_setdetachstate

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_setdetachstate.html

Gnulib module: pthread-thread

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.821 pthread_attr_setguardsize

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_setguardsize.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, Cygwin 1.7.9, mingw, MSVC 14.

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10.822 pthread_attr_setinheritsched

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_setinheritsched.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 8.1.

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10.823 pthread_attr_setschedparam

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_setschedparam.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.824 pthread_attr_setschedpolicy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_setschedpolicy.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.825 pthread_attr_setscope

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_setscope.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.826 pthread_attr_setstack

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_setstack.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11.11, Solaris 9, Cygwin 1.7.9, mingw, MSVC 14.

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10.827 pthread_attr_setstacksize

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_attr_setstacksize.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.828 pthread_barrier_destroy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_barrier_destroy.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 6.0.

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10.829 pthread_barrier_init

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_barrier_init.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 6.0.

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10.830 pthread_barrier_wait

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_barrier_wait.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 6.0.

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10.831 pthread_barrierattr_destroy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_barrierattr_destroy.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 6.0.

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10.832 pthread_barrierattr_getpshared

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_barrierattr_getpshared.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.2, macOS 14, FreeBSD 5.2.1, NetBSD 10.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 6.0.

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10.833 pthread_barrierattr_init

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_barrierattr_init.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 6.0.

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10.834 pthread_barrierattr_setpshared

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_barrierattr_setpshared.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 5.2.1, NetBSD 10.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 6.0.

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10.835 pthread_cancel

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cancel.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 9.0.

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10.836 pthread_cleanup_pop

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cleanup_pop.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, NetBSD 10.0, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.837 pthread_cleanup_push

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cleanup_push.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, NetBSD 10.0, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.838 pthread_cond_broadcast

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_broadcast.html

Gnulib module: pthread-cond

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.839 pthread_cond_destroy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_destroy.html

Gnulib module: pthread-cond

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.840 pthread_cond_init

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_init.html

Gnulib module: pthread-cond

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.841 pthread_cond_signal

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_signal.html

Gnulib module: pthread-cond

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.842 pthread_cond_timedwait

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_timedwait.html

Gnulib module: pthread-cond

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

  • This function sometimes waits indefinitely instead of up to the specified time point, on some platforms (glibc/Linux, musl libc) in some hypervisors: VirtualBox 6.1.50_Ubuntu with paravirtualization set to "Default" or "KVM".

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10.843 pthread_cond_wait

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_cond_wait.html

Gnulib module: pthread-cond

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.844 pthread_condattr_destroy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_condattr_destroy.html

Gnulib module: pthread-cond

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.845 pthread_condattr_getclock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_condattr_getclock.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.2, macOS 14, FreeBSD 5.2.1, NetBSD 7.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.9, mingw, MSVC 14, Android 4.4.

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10.846 pthread_condattr_getpshared

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_condattr_getpshared.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14.

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10.847 pthread_condattr_init

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_condattr_init.html

Gnulib module: pthread-cond

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.848 pthread_condattr_setclock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_condattr_setclock.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.2, macOS 14, FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.9, mingw, MSVC 14, Android 4.4.

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10.849 pthread_condattr_setpshared

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_condattr_setpshared.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14.

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10.850 pthread_create

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_create.html

Gnulib module: pthread-thread

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.
  • This function is only defined as an inline function on some platforms: HP-UX 11.11.

Portability problems not fixed by Gnulib:

  • On Linux/glibc platforms before the advent of NPTL in 2003, signals could only be sent to one particular thread. In POSIX, signals are sent to the entire process and executed by any thread of the process that happens to have the particular signal currently unblocked.

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10.851 pthread_detach

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_detach.html

Gnulib module: pthread-thread

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.852 pthread_equal

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_equal.html

Gnulib module: pthread-thread

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.853 pthread_exit

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_exit.html

Gnulib module: pthread-thread

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.854 pthread_getconcurrency

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_getconcurrency.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 10.0, Minix 3.1.8, mingw, MSVC 14, Android 9.0.
  • This function is removed in POSIX.1-2024. You can remove calls to this function.

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10.855 pthread_getcpuclockid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_getcpuclockid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 7.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.9, mingw, MSVC 14.

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10.856 pthread_getschedparam

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_getschedparam.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.857 pthread_getspecific

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_getspecific.html

Gnulib module: pthread-tss

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.858 pthread_join

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_join.html

Gnulib module: pthread-thread

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.859 pthread_key_create

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_key_create.html

Gnulib module: pthread-tss

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.860 pthread_key_delete

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_key_delete.html

Gnulib module: pthread-tss

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.861 pthread_kill

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_kill.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.862 pthread_mutex_consistent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_consistent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.11, macOS 14, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.863 pthread_mutex_destroy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_destroy.html

Gnulib module: pthread-mutex

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.864 pthread_mutex_getprioceiling

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_getprioceiling.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, NetBSD 7.1, Minix 3.1.8, mingw, MSVC 14, Android 9.0.

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10.865 pthread_mutex_init

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_init.html

Gnulib module: pthread-mutex

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 4.3. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.866 pthread_mutex_lock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_lock.html

Gnulib module: pthread-mutex

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.867 pthread_mutex_setprioceiling

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_setprioceiling.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, NetBSD 7.1, Minix 3.1.8, mingw, MSVC 14, Android 9.0.

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10.868 pthread_mutex_timedlock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_timedlock.html

Gnulib module: pthread_mutex_timedlock

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 5.2.1, NetBSD 7.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.869 pthread_mutex_trylock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_trylock.html

Gnulib module: pthread-mutex

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.870 pthread_mutex_unlock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutex_unlock.html

Gnulib module: pthread-mutex

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.871 pthread_mutexattr_destroy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_destroy.html

Gnulib module: pthread-mutex

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.872 pthread_mutexattr_getprioceiling

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_getprioceiling.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, NetBSD 7.1, Minix 3.1.8, mingw, MSVC 14, Android 9.0.

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10.873 pthread_mutexattr_getprotocol

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_getprotocol.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, NetBSD 7.1, Minix 3.1.8, mingw, MSVC 14, Android 8.1.

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10.874 pthread_mutexattr_getpshared

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_getpshared.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14.

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10.875 pthread_mutexattr_getrobust

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_getrobust.html

Gnulib module: pthread-mutex

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.11, macOS 14, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 2.9, mingw, MSVC 14, Android 9.0. But the provided replacement is just a dummy.

Portability problems not fixed by Gnulib:

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10.876 pthread_mutexattr_gettype

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_gettype.html

Gnulib module: pthread-mutex

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.877 pthread_mutexattr_init

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_init.html

Gnulib module: pthread-mutex

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.878 pthread_mutexattr_setprioceiling

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_setprioceiling.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, NetBSD 7.1, Minix 3.1.8, mingw, MSVC 14, Android 9.0.

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10.879 pthread_mutexattr_setprotocol

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_setprotocol.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, NetBSD 7.1, Minix 3.1.8, mingw, MSVC 14, Android 8.1.

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10.880 pthread_mutexattr_setpshared

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_setpshared.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14.

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10.881 pthread_mutexattr_setrobust

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_setrobust.html

Gnulib module: pthread-mutex

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.11, macOS 14, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 2.9, mingw, MSVC 14, Android 9.0. But the provided replacement is just a dummy.

Portability problems not fixed by Gnulib:

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10.882 pthread_mutexattr_settype

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_settype.html

Gnulib module: pthread-mutex

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.883 pthread_once

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_once.html

Gnulib module: pthread-once

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.
  • This function makes applications hang forever on some platforms: Cygwin 3.5.3.

Portability problems not fixed by Gnulib:

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10.884 pthread_rwlock_destroy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_destroy.html

Gnulib module: pthread-rwlock

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 4.3. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.885 pthread_rwlock_init

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_init.html

Gnulib module: pthread-rwlock

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 4.3. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.886 pthread_rwlock_rdlock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_rdlock.html

Gnulib module: pthread-rwlock

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 4.3. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

  • This function prefers readers to writers (meaning, when this function is called on an rwlock that is already taken by one or more readers, and another writer is already waiting to take it, this function may return successfully immediately) – a behaviour that may lead to writer starvation – on some platforms: glibc 2.28. As a workaround, you can use the gl_rwlock_t type from the Gnulib module ‘lock’.

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10.887 pthread_rwlock_timedrdlock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_timedrdlock.html

Gnulib module: pthread-rwlock

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 4.3. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

  • This function prefers readers to writers (meaning, when this function is called on an rwlock that is already taken by one or more readers, and another writer is already waiting to take it, this function may return successfully immediately) – a behaviour that may lead to writer starvation – on some platforms: glibc 2.28.

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10.888 pthread_rwlock_timedwrlock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_timedwrlock.html

Gnulib module: pthread-rwlock

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 4.3. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.889 pthread_rwlock_tryrdlock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_tryrdlock.html

Gnulib module: pthread-rwlock

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 4.3. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

  • This function prefers readers to writers (meaning, when this function is called on an rwlock that is already taken by one or more readers, and another writer is already waiting to take it, this function may return successfully immediately) – a behaviour that may lead to writer starvation – on some platforms: glibc 2.28.

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10.890 pthread_rwlock_trywrlock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_trywrlock.html

Gnulib module: pthread-rwlock

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 4.3. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.891 pthread_rwlock_unlock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_unlock.html

Gnulib module: pthread-rwlock

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 4.3. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.892 pthread_rwlock_wrlock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlock_wrlock.html

Gnulib module: pthread-rwlock

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 4.3. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.893 pthread_rwlockattr_destroy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlockattr_destroy.html

Gnulib module: pthread-rwlock

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.894 pthread_rwlockattr_getpshared

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlockattr_getpshared.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 10.0, Minix 3.1.8, mingw, MSVC 14.

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10.895 pthread_rwlockattr_init

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlockattr_init.html

Gnulib module: pthread-rwlock

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.896 pthread_rwlockattr_setpshared

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_rwlockattr_setpshared.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 10.0, Minix 3.1.8, mingw, MSVC 14.

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10.897 pthread_self

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_self.html

Gnulib module: pthread-thread

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.898 pthread_setcancelstate

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_setcancelstate.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 9.0.

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10.899 pthread_setcanceltype

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_setcanceltype.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 9.0.

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10.900 pthread_setconcurrency

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_setconcurrency.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 10.0, Minix 3.1.8, mingw, MSVC 14, Android 9.0.
  • This function is removed in POSIX.1-2024. You can remove calls to this function.

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10.901 pthread_setschedparam

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_setschedparam.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.902 pthread_setschedprio

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_setschedprio.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.3, macOS 14, FreeBSD 14.0, NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.9, mingw, MSVC 14, Android 8.1.

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10.903 pthread_setspecific

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_setspecific.html

Gnulib module: pthread-tss

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.904 pthread_sigmask

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_sigmask.html

Gnulib module: pthread_sigmask

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.
  • This function is declared in <pthread.h> instead of <signal.h> on some platforms: FreeBSD 6.4, OpenBSD 3.8.
  • This function does nothing and always returns 0 in programs that are not linked with -lpthread on some platforms: FreeBSD 14.0, MidnightBSD 1.1, HP-UX 11.31, Solaris 9.
  • When it fails, this functions returns -1 instead of the error number on some platforms: Cygwin 1.7.5.

Portability problems not fixed by Gnulib:

  • On platforms that do not natively support this function, it has unspecified behavior in a multi-threaded process.
  • In case of failure, the return value is wrong on some platforms: NetBSD 9.3 when libpthread is not in use.

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10.905 pthread_spin_destroy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_spin_destroy.html

Gnulib module: pthread-spin

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.9, mingw, MSVC 14, Android 6.0. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.906 pthread_spin_init

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_spin_init.html

Gnulib module: pthread-spin

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.9, mingw, MSVC 14, Android 6.0. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.907 pthread_spin_lock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_spin_lock.html

Gnulib module: pthread-spin

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.9, mingw, MSVC 14, Android 6.0. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.908 pthread_spin_trylock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_spin_trylock.html

Gnulib module: pthread-spin

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.9, mingw, MSVC 14, Android 6.0. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.909 pthread_spin_unlock

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_spin_unlock.html

Gnulib module: pthread-spin

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.9, mingw, MSVC 14, Android 6.0. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.910 pthread_testcancel

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pthread_testcancel.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 9.0.

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10.911 ptsname

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ptsname.html

Gnulib module: ptsname

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, mingw, MSVC 14.
  • This function fails to set errno on failure on some platforms: FreeBSD 8.2.

Portability problems not fixed by Gnulib:

  • On Solaris 11 2010-11, this function fails on all BSD-style /dev/pty* device files.
  • This function is not thread-safe on some platforms: Cygwin 1.7.9. Likewise, the gnulib replacement is not thread-safe.

Note that the Gnulib module ptsname_r is a version of this function that is more likely to be thread-safe.

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10.912 putc

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/putc.html

Gnulib module: stdio, nonblocking, sigpipe

Portability problems fixed by Gnulib module stdio, together with module nonblocking:

  • When writing to a non-blocking pipe whose buffer is full, this function fails with errno being set to ENOSPC instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems fixed by Gnulib module stdio, together with module sigpipe:

  • When writing to a pipe with no readers, this function fails, instead of obeying the current SIGPIPE handler, on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • On some platforms, this function does not set errno or the stream error indicator on attempts to write to a read-only stream: Cygwin 1.7.9.

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10.913 putc_unlocked

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/putc_unlocked.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.
  • On some platforms, this function does not set errno or the stream error indicator on attempts to write to a read-only stream: Cygwin 1.7.9.

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10.914 putchar

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/putchar.html

Gnulib module: stdio, nonblocking, sigpipe

Portability problems fixed by Gnulib module stdio, together with module nonblocking:

  • When writing to a non-blocking pipe whose buffer is full, this function fails with errno being set to ENOSPC instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems fixed by Gnulib module stdio, together with module sigpipe:

  • When writing to a pipe with no readers, this function fails, instead of obeying the current SIGPIPE handler, on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • On some platforms, this function does not set errno or the stream error indicator on attempts to write to a read-only stream: Cygwin 1.7.9.

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10.915 putchar_unlocked

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/putchar_unlocked.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.
  • On some platforms, this function does not set errno or the stream error indicator on attempts to write to a read-only stream: Cygwin 1.7.9.

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10.916 putenv

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/putenv.html, amended through https://www.austingroupbugs.net/view.php?id=1598.

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Environment-Access.html.

Note: POSIX putenv supports adding or changing the value of an environment variable, while glibc also supports removing an environment variable (as if by unsetenv).

Gnulib module: putenv-gnu

Portability problems fixed by Gnulib:

  • This function does not support removing an environment variable on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, mingw, MSVC 14, Android 11.0.

Portability problems not fixed by Gnulib:

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10.917 putmsg

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/putmsg.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.918 putpmsg

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/putpmsg.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.919 puts

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/puts.html

Gnulib module: stdio, nonblocking, sigpipe

Portability problems fixed by Gnulib module stdio, together with module nonblocking:

  • When writing to a non-blocking pipe whose buffer is full, this function fails with errno being set to ENOSPC instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems fixed by Gnulib module stdio, together with module sigpipe:

  • When writing to a pipe with no readers, this function fails, instead of obeying the current SIGPIPE handler, on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • On some platforms, this function does not set errno or the stream error indicator on attempts to write to a read-only stream: Cygwin 1.7.9.

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10.920 pututxline

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pututxline.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14, Android 9.0.

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10.921 putwc

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/putwc.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.5.x.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.
  • On some platforms, this function does not set errno or the stream error indicator on attempts to write to a read-only stream: Cygwin 1.7.9.

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10.922 putwchar

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/putwchar.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.5.x.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.
  • On some platforms, this function does not set errno or the stream error indicator on attempts to write to a read-only stream: Cygwin 1.7.9.

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10.923 pwrite

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/pwrite.html

Gnulib module: pwrite

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • On platforms where off_t is a 32-bit type, this function may not work correctly on files 2 GiB and larger. See Large File Support.
  • This function does not fail when an invalid (negative) offset is passed when large file support is enabled on some platforms: HP-UX 11.11.
  • This function uses an arbitrary offset instead of the off_t argument when large file support is enabled on some platforms: HP-UX 11.11.

Portability problems not fixed by Gnulib:

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10.924 qsort

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/qsort.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.925 quick_exit

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.9, macOS 14, FreeBSD 6.4, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 9, Android 4.4.

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10.926 raise

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/raise.html

Gnulib module: raise

Portability problems fixed by Gnulib:

  • This function is missing on some old platforms.
  • This function crashes when invoked with invalid arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.927 rand

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/rand.html

Gnulib module: rand

Portability problems fixed by Gnulib:

  • This function crashes when used in multithreaded programs on some platforms: CheriBSD.

Portability problems not fixed by Gnulib:

  • This function is only defined as an inline function on some platforms: Android 4.4.
  • This function is not multithread-safe on some platforms: musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, AIX 7.1, Solaris 11.4.

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10.928 rand_r

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/rand_r.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 4.4.
  • This function is removed in POSIX.1-2024. Use the function random_r from Gnulib module random_r instead.

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10.929 random

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/random.html

Gnulib module: random

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • This function is only defined as an inline function on some platforms: Android 4.4.
  • This function is not multithread-safe on some platforms: macOS 14, FreeBSD 13.2, Solaris 11.4, Cygwin 3.4.6, Haiku.

Portability problems not fixed by Gnulib:

  • This function has a slightly incompatible declaration (the return type being ‘int’ instead of ‘long’) on some platforms: Cygwin 1.5.25, Haiku.
  • When ‘srandom’ was not called, this function returns a non-deterministic sequence rather than a deterministic sequence of numbers on some platforms: OpenBSD 7.4.

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10.930 read

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/read.html

Gnulib module: read, stdio, nonblocking

Portability problems fixed by Gnulib module read:

  • This function is declared in a different header file (namely, <io.h>) on some platforms: mingw, MSVC 14.
  • This function crashes when invoked with invalid arguments on some platforms: MSVC 14.

Portability problems fixed by Gnulib module stdio, together with module nonblocking:

  • When reading from a non-blocking pipe whose buffer is empty, this function fails with errno being set to EINVAL instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • This function may fail with error EINTR, even in programs that don’t install any signal handlers, on some platforms: macOS 14.

For handling EINTR, Gnulib provides a module ‘safe-read’ with a function safe_read.

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10.931 readdir

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/readdir.html

Gnulib module: readdir

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: MSVC 14.
  • On platforms where off_t is a 32-bit type, this function may not work correctly on huge directories 2 GiB and larger. Also, on platforms where ino_t is a 32-bit type, this function may report inode numbers incorrectly. This can occur with file systems such as XFS (typically on large disks) and NFS. See Large File Support.

Portability problems not fixed by Gnulib:

  • Although POSIX places no restrictions on d_ino values, some older systems are rumored to return d_ino values equal to zero for directory entries that do not really exist. Although Gnulib formerly attempted to cater to these older systems, this caused misbehavior on standard systems and so Gnulib does not attempt to cater to them any more. If you know of any problems caused by this, please send a bug report.

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10.932 readdir_r

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/readdir_r.html

Gnulib module: extensions

Portability problems fixed by Gnulib:

  • This function is planned to be removed from POSIX and to be deprecated in glibc. Portable applications should use readdir.
  • This function has an incompatible declaration on some platforms: Solaris 11.4 (when _POSIX_PTHREAD_SEMANTICS is not defined).
  • On platforms where off_t is a 32-bit type, this function may not work correctly on huge directories 2 GiB and larger. Also, on platforms where ino_t is a 32-bit type, this function may report inode numbers incorrectly. This can occur with file systems such as XFS (typically on large disks) and NFS. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.934 readlinkat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/readlinkat.html

Gnulib module: readlinkat

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Mac OS X 10.9, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 4.4. But the replacement function is not safe to be used in libraries and is not multithread-safe.
  • Some platforms mistakenly succeed on file names ending in /: macOS 14.
  • On some platforms, this function returns int instead of ssize_t: AIX 7.1.
  • For the file name /dev/null, this function returns \Device\Null, which is unusable, on some platforms: Cygwin 3.3.6.

Portability problems mostly fixed by Gnulib:

  • On some platforms, this function fails and sets errno to ERANGE rather than returning truncated contents: AIX 7.2. The Gnulib replacement normally works as POSIX requires by returning the truncated contents. However, if the full link contents are unreasonably large (more than 4000 bytes) the replacement clears the entire buffer and returns the buffer size; although this is not a complete fix, it suffices for typical callers, which ignore the buffer contents anyway.

Portability problems not fixed by Gnulib:

  • This function always fails on platforms that don’t support symlinks: mingw, MSVC 14.
  • When this function is called on a directory: In the case of NFS mounted directories, Cygwin sets errno to ENOENT or EIO instead of EINVAL. To avoid this problem, check for a directory before calling this function.
  • When this function is called on a file that is not a symbolic link: Cygwin may set errno to EACCES instead of EINVAL.
  • When this function fails because it is called on an existing non-directory’s name concatenated to /, it sets errno to EINVAL: AIX 7.2.
  • When this function is called on an empty file name, it fails with error EBADF instead of ENOENT: Cygwin 3.4.6.
  • Symlink contents do not always have a trailing null byte, and there is no indication if symlink contents were truncated if the return value matches the length. Furthermore, Linux sets errno to EINVAL if the requested length is zero. Use the gnulib module areadlink for improved ability to read symlink contents.

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10.935 readv

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/readv.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.936 realloc

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/realloc.html

Gnulib module: realloc-posix

Portability problems fixed by Gnulib:

  • Upon failure, the function does not set errno to ENOMEM on some platforms: mingw, MSVC 14.
  • On some platforms, realloc (p, n) can succeed even if n exceeds PTRDIFF_MAX. Although this behavior is arguably allowed by POSIX it can lead to behavior not defined by POSIX later, so realloc-posix does not allow going over the limit.

Without the ‘realloc-gnu’ module described below, it is not portable to call realloc with a size of 0. With a NULL pointer argument, this is the same ambiguity as malloc (0) on whether a unique zero-size object is created. With a non-NULL pointer argument p, C17 says that it is implementation-defined whether realloc (p, 0) frees p. Behavior varies on whether realloc (p, 0) always frees p and successfully returns a null pointer, or always fails and leaves p valid, or usually succeeds and returns a unique zero-size object; a program not suspecting these variations in semantics will leak memory (either the still-valid p, or the non-NULL return value).

Extension: Gnulib provides a module ‘realloc-gnu’ that substitutes a realloc implementation that behaves more like the glibc implementation. It fixes these portability problems:

  • realloc (NULL, 0) returns NULL on success on some platforms: AIX 7.2.
  • On some platforms, realloc (p, 0) with non-null p might not free p, or might clobber errno, or might not return NULL.

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10.937 realpath

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/realpath.html

Gnulib module: canonicalize-lgpl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • This function does not allow for a NULL ‘resolved’ parameter on some platforms: Mac OS X 10.5, FreeBSD 6.4, OpenBSD 4.4, Solaris 10.
  • This function does not always return an absolute path on some platforms: Solaris 10.
  • This function fails to detect trailing slashes on non-directories on some platforms: glibc 2.3.5, macOS 14, OpenBSD 6.0.
  • This function fails to recognize non-directories or symlinks to non-directories followed by ‘..’ on some platforms: macOS 14, Cygwin 2.9.
  • This function misbehaves on consecutive slashes on some platforms: musl libc 1.2.2, AIX 7.

Portability problems not fixed by Gnulib:

  • This function does not allow to determine the required size of output buffer; the use of a non-NULL ‘resolved’ buffer is non-portable, since PATH_MAX, if it is defined, is nothing more than a guess.

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10.938 recv

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/recv.html

Gnulib module: recv

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), error codes from this function are not placed in errno, and WSAGetLastError must be used instead.

Portability problems not fixed by Gnulib:

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10.939 recvfrom

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/recvfrom.html

Gnulib module: recvfrom

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), error codes from this function are not placed in errno, and WSAGetLastError must be used instead.
  • On HP-UX 11, in 64-bit mode, when the macro _HPUX_ALT_XOPEN_SOCKET_API is not defined, this function behaves incorrectly because it is declared to take a pointer to a 64-bit wide socklen_t entity but in fact considers it as a pointer to a 32-bit wide unsigned int entity.

Portability problems not fixed by Gnulib:

  • Some platforms don’t have a socklen_t type; in this case this function’s sixth argument type is ‘int *’.

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10.940 recvmsg

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/recvmsg.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.941 regcomp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/regcomp.html

Gnulib module: regex

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • Many regular expression implementations have bugs.

Portability problems not fixed by Gnulib:

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10.942 regerror

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/regerror.html

Gnulib module: regex

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.943 regexec

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/regexec.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-regexec-2.html

Gnulib module: regex

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • Many regular expression implementations have bugs.

Portability problems not fixed by Gnulib:

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10.944 regfree

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/regfree.html

Gnulib module: regex

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.945 remainder

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/remainder.html

Gnulib module: remainder or remainder-ieee

Portability problems fixed by either Gnulib module remainder or remainder-ieee:

  • This function is missing on some platforms: MSVC 9.

Portability problems fixed by Gnulib module remainder-ieee:

Portability problems not fixed by Gnulib:

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10.946 remainderf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/remainderf.html

Gnulib module: remainderf or remainderf-ieee

Portability problems fixed by either Gnulib module remainderf or remainderf-ieee:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.

Portability problems fixed by Gnulib module remainderf-ieee:

Portability problems not fixed by Gnulib:

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10.947 remainderl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/remainderl.html

Gnulib module: remainderl or remainderl-ieee

Portability problems fixed by either Gnulib module remainderl or remainderl-ieee:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 9.3, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9, Android 4.4.
  • This function returns completely wrong values on some platforms: OpenBSD 5.1/SPARC.
  • This function produces results which are accurate to only 16 digits on some platforms: musl libc 1.2.2/arm64, musl libc 1.2.2/s390x, NetBSD 10.0.

Portability problems fixed by Gnulib module remainderl-ieee:

Portability problems not fixed by Gnulib:

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10.948 remove

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/remove.html

Gnulib module: remove

Portability problems fixed by Gnulib:

  • This function fails to reject trailing slashes on non-directories on some platforms: FreeBSD 7.2, Solaris 9.
  • This function mistakenly removes a directory with remove("dir/./") on some platforms: Cygwin 1.5.x.
  • This function does not remove empty directories on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.949 remque

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/remque.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.5.x, mingw, MSVC 14, Android 4.4.

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10.950 remquo

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/remquo.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, MSVC 9.

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10.951 remquof

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/remquof.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.

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10.952 remquol

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/remquol.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 9.3, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9, Android 4.4.

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10.953 rename

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/rename.html

Gnulib module: rename

Portability problems fixed by Gnulib:

  • This function does not allow trailing slashes when creating a destination directory, as in rename("dir","new/"): NetBSD 1.6.
  • This function does not reject trailing slashes on the destination for non-directories on some platforms, as in rename("file","new/"): AIX 7.1, Solaris 11.3, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not reject trailing slashes on symlinks to non-directories on some platforms, as in rename("link-to-file/","f"): FreeBSD 7.2.
  • This function ignores trailing slashes on symlinks on some platforms, such that rename("link/","new") corrupts link: Solaris 9.
  • This function incorrectly reduces the link count when comparing two spellings of a hard link on some platforms: NetBSD 1.6, Cygwin 1.5.x.
  • This function will not always replace an existing destination on some platforms: Cygwin 1.5.x, mingw, MSVC 14. However, the replacement is not atomic for directories, and may end up losing the empty destination if the source could not be renamed.
  • This function mistakenly allows names ending in ‘.’ or ‘..’ on some platforms: Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not reject attempts to rename existing directories and non-directories onto one another on some platforms: Cygwin 1.5.x, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • POSIX requires that rename("symlink-to-dir/","dir2") rename dir and leave symlink-to-dir dangling; likewise, it requires that rename("dir","dangling/") rename dir so that dangling is no longer a dangling symlink. This behavior is counter-intuitive, so on some systems, rename fails with ENOTDIR if either argument is a symlink with a trailing slash: glibc, OpenBSD, Cygwin 1.7.
  • POSIX requires that rename do nothing and return 0 if the source and destination are hard links to the same file. This behavior is counterintuitive, and on some systems renameat is a no-op in this way only if the source and destination identify the same directory entry. On these systems, for example, although renaming ./f to f is a no-op, renaming f to g deletes f when f and g are hard links to the same file: NetBSD 7.0.
  • After renaming a non-empty directory over an existing empty directory, the old directory name is still visible through the stat function for 30 seconds after the rename, on NFS file systems, on some platforms: Linux 2.6.18.
  • This function will not rename a source that is currently opened by any process: mingw, MSVC 14.

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10.954 renameat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/renameat.html

Gnulib module: renameat

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.5.x, mingw, MSVC 14. But the replacement function is not safe to be used in libraries and is not multithread-safe.
  • This function is declared in <unistd.h>, not in <stdio.h>, on some platforms: NetBSD 7.0, Solaris 11.4.
  • This function is declared in <sys/stat.h>, not in <stdio.h>, on some platforms: Android 4.3.
  • This function does not reject trailing slashes on non-directories on some platforms, as in renameat(fd,"file",fd,"new/"): Solaris 11.4.
  • This function ignores trailing slashes on symlinks on some platforms, such that renameat(fd,"link/",fd,"new") corrupts link: Solaris 9.

Portability problems not fixed by Gnulib:

  • POSIX requires that renameat(fd,"symlink-to-dir/",fd,"dir2") rename dir and leave symlink-to-dir dangling; likewise, it requires that renameat(fd,"dir",fd,"dangling/") rename dir so that dangling is no longer a dangling symlink. This behavior is counter-intuitive, so on some systems, renameat fails with ENOTDIR if either argument is a symlink with a trailing slash: glibc, OpenBSD, Cygwin 1.7.
  • POSIX requires that renameat do nothing and return 0 if the source and destination are hard links to the same file. This behavior is counterintuitive, and on some systems renameat is a no-op in this way only if the source and destination identify the same directory entry. On these systems, for example, although renaming ./f to f is a no-op, renaming f to g deletes f when f and g are hard links to the same file: NetBSD 7.0.
  • After renaming a non-empty directory over an existing empty directory, the old directory name is still visible through the stat function for 30 seconds after the rename, on NFS file systems, on some platforms: Linux 2.6.18.
  • This function will not rename a source that is currently opened by any process: mingw, MSVC 14.

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10.955 rewind

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/rewind.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.

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10.956 rewinddir

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/rewinddir.html

Gnulib module: rewinddir

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: MSVC 14.
  • On Mac OS X platforms where long int is a 32-bit type, this function may not work correctly on huge directories 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

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10.957 rint

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/rint.html

Gnulib module: rint

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: MSVC 9.

Portability problems not fixed by Gnulib:

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10.958 rintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/rintf.html

Gnulib module: rintf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.

Portability problems not fixed by Gnulib:

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10.959 rintl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/rintl.html

Gnulib module: rintl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.5.x, MSVC 9, Android 4.4.
  • This function produces wrong results for negative numbers on some platforms: NetBSD 8.0.

Portability problems not fixed by Gnulib:

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10.960 rmdir

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/rmdir.html

Gnulib module: rmdir

Portability problems fixed by Gnulib:

  • This function is declared in different header files (namely, <io.h> or <direct.h>) on some platforms: mingw, MSVC 14.
  • This function mistakenly removes a directory with rmdir("dir/./") on some platforms: Cygwin 1.5.x.
  • This function fails with EINVAL instead of the expected ENOTDIR for rmdir("file/") on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • When rmdir fails because the specified directory is not empty, the errno value is system dependent.
  • POSIX requires that rmdir("link-to-empty/") remove empty and leave link-to-empty as a dangling symlink. This is counter-intuitive, so some systems fail with ENOTDIR instead: glibc

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10.961 round

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/round.html

Gnulib module: round or round-ieee

Portability problems fixed by either Gnulib module round or round-ieee:

  • This function is missing on some platforms: FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, MSVC 9.
  • This function is not declared on some platforms: glibc 2.8.
  • This functions returns a wrong result for x = 1/2 - 2^-54 on some platforms: NetBSD 3.0, AIX 7.1.

Portability problems fixed by Gnulib module round-ieee:

  • This function returns a positive zero for an argument between -0.5 and 0 on some platforms: AIX 7.1.

Portability problems not fixed by Gnulib:

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10.962 roundeven

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.963 roundevenf

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.964 roundevenl

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.965 roundf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/roundf.html

Gnulib module: roundf or roundf-ieee

Portability problems fixed by either Gnulib module roundf or roundf-ieee:

  • This function is missing on some platforms: FreeBSD 5.2.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.
  • This function is not declared on some platforms: glibc 2.8.
  • This functions returns a wrong result for x = 1/2 - 2^-25 on some platforms: mingw.

Portability problems fixed by Gnulib module roundf-ieee:

  • This function returns a positive zero for an argument between -0.5 and 0 on some platforms: AIX 7.1.

Portability problems not fixed by Gnulib:

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10.966 roundl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/roundl.html

Gnulib module: roundl or roundl-ieee

Portability problems fixed by either Gnulib module roundl or roundl-ieee:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9.
  • This function is not declared on some platforms: glibc 2.8.

Portability problems fixed by Gnulib module roundl-ieee:

  • This function returns a positive zero for an argument between -0.5 and 0 on some platforms: AIX 7.1.

Portability problems not fixed by Gnulib:

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10.967 scalbln

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/scalbln.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9, Android 9.0.

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10.968 scalblnf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/scalblnf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9, Android 9.0.

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10.969 scalblnl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/scalblnl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9, Android 9.0.

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10.970 scalbn

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/scalbn.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, MSVC 9.

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10.971 scalbnf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/scalbnf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.

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10.972 scalbnl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/scalbnl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9.

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10.973 scandir

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/scandir.html

Gnulib module: scandir

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Solaris 9, mingw, MSVC 14.
  • On platforms where off_t is a 32-bit type, this function may not work correctly on huge directories 2 GiB and larger. Also, on platforms where ino_t is a 32-bit type, this function may report inode numbers incorrectly. See Large File Support.

Portability problems not fixed by Gnulib:

  • The fourth parameter of this function is declared as int (*) (const void *, const void *) on some platforms: glibc 2.3.6, macOS 10.7, FreeBSD 6.0, NetBSD 7.1, OpenBSD 6.7.
  • The fourth parameter of this function is declared as int (*) (void *, void *) on some platforms: AIX 5.1.

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10.974 scanf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/scanf.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-scanf.html

Gnulib module: stdio, nonblocking

Portability problems fixed by Gnulib module stdio, together with module nonblocking:

  • When reading from a non-blocking pipe whose buffer is empty, this function fails with errno being set to EINVAL instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • C99 and POSIX.1-2001 and later require end-of-file to be sticky, that is, they require this function to act as if it reads end-of-file if feof would return nonzero. However, on some systems this function attempts to read from the underlying file descriptor even if the stream’s end-of-file indicator is set. These systems include glibc and default Solaris.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.38, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.2, AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • On Windows, this function doesn’t support the hh, ll, j, t, z size specifiers.

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10.975 sched_get_priority_max

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_get_priority_max.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, HP-UX 11, mingw, MSVC 14.

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10.976 sched_get_priority_min

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_get_priority_min.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, HP-UX 11, mingw, MSVC 14.

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10.977 sched_getparam

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_getparam.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14.

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10.978 sched_getscheduler

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_getscheduler.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14.

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10.979 sched_rr_get_interval

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_rr_get_interval.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, mingw, MSVC 14.

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10.980 sched_setparam

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_setparam.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14.

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10.981 sched_setscheduler

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_setscheduler.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sched-setscheduler.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14.

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10.982 sched_yield

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sched_yield.html

Gnulib module: sched_yield

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14. But the provided replacement is just a dummy on some of these platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

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10.983 seed48

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/seed48.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.984 seekdir

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/seekdir.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where long int is a 32-bit type, this function may not work correctly on huge directories 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: MSVC 14, Android 5.1.

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10.985 select

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/select.html

Gnulib module: select

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), select can only be called on descriptors created by the socket function, not on regular file descriptors.
  • On Windows platforms (excluding Cygwin), error codes from this function are not placed in errno, and WSAGetLastError must be used instead.
  • On some platforms, this function fails to detect invalid fds with EBADF, but only if they lie beyond the current maximum open fd: FreeBSD 8.2.

Portability problems not fixed by Gnulib:

  • When you call select with a timeout, some implementations modify the timeout parameter so that upon return from the function, it contains the amount of time not slept. Other implementations leave the timeout parameter unmodified.
  • Under Windows, when passing a pipe, Gnulib’s select replacement might return 0 even before the timeout has passed. Programs using it with pipes can thus busy wait.
  • On Linux, when some file descriptor refers to a regular file, select may fail, setting errno to EBADF.

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10.986 sem_close

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_close.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.987 sem_destroy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_destroy.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.
  • This function is not implemented on some platforms: Mac OS X 10.11.

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10.988 sem_getvalue

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_getvalue.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.
  • This function is not implemented on some platforms: Mac OS X 10.11.

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10.989 sem_init

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_init.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.
  • This function is not implemented on some platforms: Mac OS X 10.11.

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10.990 sem_open

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_open.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.991 sem_post

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_post.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.992 sem_timedwait

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_timedwait.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, mingw, MSVC 14.

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10.993 sem_trywait

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_trywait.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.995 sem_wait

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sem_wait.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.996 semctl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/semctl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 7.1.

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10.997 semget

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/semget.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 7.1.

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10.998 semop

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/semop.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 7.1.

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10.999 send

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/send.html

Gnulib module: send

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), error codes from this function are not placed in errno, and WSAGetLastError must be used instead.

Portability problems not fixed by Gnulib:

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10.1000 sendmsg

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sendmsg.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.1001 sendto

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sendto.html

Gnulib module: sendto

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), error codes from this function are not placed in errno, and WSAGetLastError must be used instead.

Portability problems not fixed by Gnulib:

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10.1002 setbuf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setbuf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.1003 setegid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setegid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11.23, mingw, MSVC 14.

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10.1004 setenv

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setenv.html

Gnulib module: setenv

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11.23, Solaris 9, mingw, MSVC 14.
  • On some platforms, this function does not fail with ‘EINVAL’ when passed an empty string or a string containing ‘=’: Mac OS X 10.5, FreeBSD 6.0, NetBSD 1.6, OpenBSD 6.7, Cygwin 1.5.x.
  • On some platforms, this function removes a leading ‘=’ from the value argument: Cygwin 1.5.x.

Portability problems not fixed by Gnulib:

  • Older versions of POSIX required that setenv(NULL,"",0) gracefully fail with EINVAL, but not all implementations guarantee this, and the requirement was removed.

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10.1005 seteuid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/seteuid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11.23, mingw, MSVC 14.

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10.1006 setgid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setgid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.1007 setgrent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setgrent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 7.1.

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10.1008 sethostent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sethostent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 8.1.

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10.1009 setitimer

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setitimer.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • This function is removed in POSIX.1-2024. Use the functions timer_create and timer_settime instead.

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10.1010 setjmp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setjmp.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • POSIX does not specify whether setjmp saves the signal mask in the jmp_buf. It does on BSD platforms, and on glibc platforms when _BSD_SOURCE (and/or _DEFAULT_SOURCE on glibc >= 2.19) is defined; in this case setjmp behaves like sigsetjmp(.,1), and functions _setjmp and _longjmp are available that don’t save or restore the signal mask. On System V platforms (excluding HP-UX), and on glibc platforms by default, setjmp doesn’t save the signal mask.

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10.1011 setkey

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setkey.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.34, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function is not declared in <stdlib.h> (without -D_GNU_SOURCE) on some platforms: glibc (at least 2.11–2.13).
  • POSIX.1-2024 says this function is obsolescent and it is planned to be removed in a future version.

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10.1012 setlocale

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setlocale.html

Gnulib module: setlocale, setlocale-null

Portability problems fixed by Gnulib module setlocale:

  • On Windows platforms (excluding Cygwin), setlocale(category,"") and setlocale(category,NULL) both ignore the environment variables LC_ALL, category, and LANG.
  • On Windows platforms (excluding Cygwin) and Cygwin 1.5.x, setlocale(LC_ALL,name) succeeds and sets the LC_CTYPE category to ‘C’ when it does not support the encoding, instead of failing.
  • On Windows platforms (excluding Cygwin), setlocale understands different locale names, that are not based on ISO 639 language names and ISO 3166 country names.
  • On Android < 5.0, which doesn’t have locales, the setlocale function always fails. The replacement, however, supports only the locale names "C" and "POSIX".

Portability problems fixed by Gnulib module setlocale or setlocale-null:

  • Invocations of setlocale (..., NULL) are not multithread-safe on some platforms: musl libc, macOS, FreeBSD, NetBSD, OpenBSD, AIX, Haiku, Cygwin. To make these invocations multithread-safe, you need the Gnulib module setlocale, or you need to change the code to invoke setlocale_null or setlocale_null_r instead.

Portability problems not fixed by Gnulib:

  • On Cygwin 1.5.x, which doesn’t have locales, setlocale(LC_ALL,NULL) always returns "C".
  • On Cygwin 1.7.0, only the charset portion of a locale designation is honored.
  • On OpenBSD, setlocale(LC_ALL,"") will only update categories that are deemed appropriate for the LC_ALL environment value, even if there are other categories set to different values in the environment. In addition any value is accepted for LC_CTYPE, and so NULL is never returned to indicate a failure to set locale. To verify category values, each category must be set individually with setlocale(LC_COLLATE,"") etc.
  • On Android 5.0 and newer, the default locale (i.e. the locale in use when setlocale was not called) is the "C.UTF-8" locale, not the "C" locale. Additionally, a setlocale call that is meant to set the "C" or "POSIX" locale actually sets an equivalent of the "C.UTF-8" locale.

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10.1013 setlogmask

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setlogmask.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.1014 setnetent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setnetent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Cygwin 2.9, mingw, MSVC 14, Android 8.1.

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10.1015 setpayload

Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.

Gnulib module: setpayload

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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10.1016 setpayloadf

Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.

Gnulib module: setpayloadf

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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10.1017 setpayloadl

Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.

Gnulib module: setpayloadl

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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10.1018 setpayloadsig

Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.

Gnulib module: setpayloadsig

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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10.1019 setpayloadsigf

Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.

Gnulib module: setpayloadsigf

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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10.1020 setpayloadsigl

Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Bit-Twiddling.html.

Gnulib module: setpayloadsigl

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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10.1021 setpgid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setpgid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.1022 setpgrp

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setpgrp.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.
  • This function is removed in POSIX.1-2024. Use the function setpgid or setsid instead, as appropriate.

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10.1023 setpriority

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setpriority.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.1024 setprotoent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setprotoent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 8.1.

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10.1025 setpwent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setpwent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 7.1.

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10.1026 setregid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setregid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.1027 setreuid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setreuid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.1028 setrlimit

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setrlimit.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getrlimit-1.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where rlim_t is a 32-bit type, this function does not allow to set limits 4 GiB and larger, such as for RLIMIT_FSIZE. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.1029 setservent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setservent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.1030 setsid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setsid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.1031 setsockopt

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setsockopt.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-setsockopt-2.html

Gnulib module: setsockopt

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), error codes from this function are not placed in errno, and WSAGetLastError must be used instead.

Portability problems not fixed by Gnulib:

  • Many socket options are not available on all platforms.

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10.1032 setstate

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setstate.html

Gnulib module: random

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4.
  • This function is not declared on some platforms: Cygwin 1.5.25.

Portability problems not fixed by Gnulib:

  • This function has a slightly incompatible declaration (the argument type being ‘const char *’ instead of ‘char *’) on some platforms: macOS 14, AIX 7.1, HP-UX 11.31, Solaris 11.4, Solaris 11 OpenIndiana.

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10.1033 setuid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setuid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.1034 setutxent

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setutxent.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14, Android 9.0.

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10.1035 setvbuf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/setvbuf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • On Windows platforms (excluding Cygwin), _IOLBF (line-buffering) is treated as if it were _IOFBF (full buffering), possibly with a warning generated.

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10.1036 shm_open

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/shm_open.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

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10.1038 shmat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/shmat.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 7.1.
  • On Linux, the flag SHM_REMAP is needed in order to force shmat to replace existing memory mappings in the specify address range. On other platforms, it is not needed.

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10.1039 shmctl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/shmctl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 7.1.

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10.1040 shmdt

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/shmdt.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 7.1.

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10.1041 shmget

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/shmget.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 7.1.
  • On many platforms (not Linux), SHMMAX is so small that it is unusable for reasonable applications, and/or shmget requires superuser privileges.

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10.1042 shutdown

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/shutdown.html

Gnulib module: shutdown

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), error codes from this function are not placed in errno, and WSAGetLastError must be used instead.

Portability problems not fixed by Gnulib:

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10.1043 sigaction

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigaction.html

Gnulib module: sigaction

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • POSIX recommends that when specifying SA_RESETHAND, SA_NODEFER must also be specified.
  • Support for SA_ONSTACK is missing on some platforms: mingw, MSVC 14, cygwin.
  • Support for SA_SIGINFO is missing on some platforms: mingw, MSVC 14.
  • Support for SIGCHLD, and thus for SA_NOCLDSTOP and SA_NOCLDWAIT, is missing on some platforms: mingw, MSVC 14.
  • Support for SA_RESETHAND is missing on some platforms: NonStop.
  • Support for SA_RESTART is missing on some platforms: mingw, MSVC 14, NonStop.
  • The symbolic value SIG_IGN for the SIGCHLD signal is equivalent to a signal handler 
    void handle_child (int sigchld)
{
  while (waitpid (-1, NULL, WNOHANG) > 0)
    ;
}

    except that SIG_IGN for SIGCHLD has the effect that the children execution times are not accounted in the times function. On some platforms (BSD? SystemV? Linux?), you need to use the sigaction flag SA_NOCLDWAIT in order to obtain this behavior.

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10.1044 sigaddset

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigaddset.html

Gnulib module: sigprocmask

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

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10.1045 sigaltstack

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigaltstack.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.x, mingw, MSVC 14.
  • sigaltstack doesn’t work on HP-UX 11/IA-64 and OpenBSD 3.6/Sparc64.

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10.1046 sigdelset

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigdelset.html

Gnulib module: sigprocmask

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

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10.1047 sigemptyset

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigemptyset.html

Gnulib module: sigprocmask

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

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10.1048 sigfillset

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigfillset.html

Gnulib module: sigprocmask

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

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10.1049 sighold

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sighold.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14, Android 7.1.
  • This function is removed in POSIX.1-2024. Use the function sigprocmask instead.

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10.1050 sigignore

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigignore.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 1.5.x, mingw, MSVC 14, Android 7.1.
  • This function is removed in POSIX.1-2024. Use the function sigaction instead.

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10.1051 siginterrupt

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/siginterrupt.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.
  • This funciton is removed in POSIX.1-2024. Use the function sigaction instead.

Note: POSIX recommends using sigaction with SA_RESTART instead of siginterrupt (sig, 0).

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10.1052 sigismember

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigismember.html

Gnulib module: sigprocmask

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

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10.1053 siglongjmp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/siglongjmp.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.
  • This is only provided as a macro on some platforms: Cygwin.

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10.1054 signal

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/signal.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function crashes when invoked with invalid arguments on some platforms: MSVC 14.
  • On System V platforms, when the signal is triggered, the kernel uninstalls the handler (i.e. resets the signal’s action to SIG_DFL) before invoking the handler. This opens the door to race conditions: undesired things happen if the signal is triggered twice and the signal handler was not quick enough reinstalling itself as a handler. On BSD platforms and glibc platforms, on the other hand, when the signal is triggered, the kernel blocks the signal before invoking the handler. This is saner, but POSIX still allows either behavior. To avoid this problem, use sigaction instead of signal.

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10.1055 signbit

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/signbit.html

Gnulib module: signbit

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, OpenBSD 6.7, AIX 5.1, Solaris 11.0, MSVC 9, Android 9.0.

Portability problems not fixed by Gnulib:

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10.1056 signgam

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/signgam.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on some platforms: macOS 10.13, Minix 3.1.8, AIX 5.1, mingw, MSVC 14.

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10.1057 sigpause

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigpause.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sigpause-3.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 7.1.
  • This function is removed in POSIX.1-2024. Use the function sigsuspend instead.

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10.1058 sigpending

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigpending.html

Gnulib module: sigprocmask

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.1059 sigprocmask

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigprocmask.html

Gnulib module: sigprocmask

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • In case of failure, the return value is wrong on some platforms: NetBSD 10.0 when libpthread is in use.

Note: Although sigprocmask officially has undefined behaviour in multi-threaded programs, in practice it is essentially equivalent to pthread_sigmask, with only a difference regarding the error return convention. It’s simpler to use sigprocmask, since it does not require linking with -lpthread on some platforms: glibc, NetBSD, OpenBSD, AIX.

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10.1060 sigqueue

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigqueue.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14, Android 5.1.

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10.1061 sigrelse

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigrelse.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14, Android 7.1.
  • This function is removed in POSIX.1-2024. Use the function sigprocmask instead.

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10.1062 sigset

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigset.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 1.5.x, mingw, MSVC 14, Android 7.1.
  • This function is removed in POSIX.1-2024. Use the function sigaction instead.

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10.1063 sigsetjmp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigsetjmp.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.1064 sigsuspend

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigsuspend.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.1065 sigtimedwait

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigtimedwait.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 5.1.
  • Linux implements the meaning of NULL timeout by doing what sigwaitinfo does; other platforms may not do the same.

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10.1066 sigwait

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigwait.html

Gnulib module: extensions

Portability problems fixed by Gnulib:

  • This function has an incompatible declaration on some platforms: Solaris 11.4 (when _POSIX_PTHREAD_SEMANTICS is not defined).

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.
  • On Linux/glibc platforms before the advent of NPTL, signals could only be sent to one particular thread. In POSIX, signals are sent to the entire process and executed by any thread of the process that happens to have the particular signal currently unblocked.

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10.1067 sigwaitinfo

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sigwaitinfo.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14, Android 5.1.

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10.1068 sin

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sin.html

Gnulib module: sin

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.1069 sinf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sinf.html

Gnulib module: sinf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.1070 sinh

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sinh.html

Gnulib module: sinh

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.1071 sinhf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sinhf.html

Gnulib module: sinhf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.1072 sinhl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sinhl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, Android 4.4.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.
  • This function produces results which are accurate to only 16 digits on some platforms: NetBSD 10.0.

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10.1073 sinl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sinl.html

Gnulib module: sinl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, Android 4.4.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

  • This function produces results which are accurate to only 16 digits on some platforms: NetBSD 10.0.

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10.1074 sleep

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sleep.html

Gnulib module: sleep

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw (2005 or newer), MSVC 14.
  • This function takes milliseconds as argument and returns void on some platforms: mingw (2005 and older).
  • This function cannot sleep longer than 49.7 days on some platforms: Cygwin 1.5.x.

Portability problems not fixed by Gnulib:

  • According to POSIX, the sleep function may interfere with the program’s use of the SIGALRM signal. On Linux, it doesn’t; on other platforms, it may.

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10.1075 snprintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/snprintf.html

Gnulib module: snprintf or snprintf-posix or snprintf-gnu

Portability problems fixed by either Gnulib module snprintf or snprintf-posix or snprintf-gnu:

  • This function is missing on some platforms: MSVC 14.
  • This function does not support format directives that access arguments in an arbitrary order, such as "%2$s", on some platforms: NetBSD 3.0, mingw.
  • This function does not return a byte count as specified in C99 on some platforms: HP-UX 11, Solaris 9, mingw.

Portability problems fixed by either Gnulib module snprintf-posix or snprintf-gnu:

  • This function does not support size specifiers as in C99 (hh, ll, j, t, z) on some platforms: AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • printf of ‘long double’ numbers is unsupported on some platforms: mingw, MSVC 14.
  • printf "%f", "%e", "%g" of Infinity and NaN yields an incorrect result on some platforms: AIX 7.3, Solaris 11.4, mingw, MSVC 14.
  • This function does not support the ‘a’ and ‘A’ directives on some platforms: FreeBSD 5.2.1, OpenBSD 4.0, AIX 5.2, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support the ‘F’ directive on some platforms: NetBSD 3.0, AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘ls’ directive on some platforms: OpenBSD 4.0, Cygwin 1.5.x, Haiku.
  • This function does not support precisions in the ‘ls’ directive correctly on some platforms: Solaris 11.4.
  • This function doesn’t support the ' flag on some platforms: NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
  • This function does not round the argument of the ‘a’ directive correctly on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4.
  • printf "%010f" of NaN and Infinity yields an incorrect result (padded with zeroes, or wrong capitalization) on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 7.3, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC/clang.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • This function does not support precisions larger than 512 or 1024 in integer, floating-point and pointer output on some platforms: AIX 7.1, Solaris 10/x86, mingw, MSVC/clang.
  • This function mishandles large floating point precisions (for example, formatting 1.0 with ‘"%.511f"’) on some platforms: Solaris 10.
  • This function produces wrong output for the ‘lc’ directive with a NUL wide character argument on some platforms: musl libc 1.2.4.
  • This function can crash in out-of-memory conditions on some platforms: FreeBSD 14.0, NetBSD 5.0.
  • This function does not truncate the result as specified in C99 on some platforms: mingw, MSVC 14.
  • This function does not fully support the ‘n’ directive on some platforms: HP-UX 11, mingw.

Portability problems fixed by Gnulib module snprintf-gnu:

  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.

Portability problems fixed by either Gnulib module snprintf-posix or snprintf-gnu and additionally the Gnulib module printf-with-n-directive:

  • This function does not support the ‘n’ directive on some platforms: glibc when used with _FORTIFY_SOURCE >= 2 (set by default on Ubuntu), macOS 14, OpenBSD, MSVC 14, Android.

Portability problems not fixed by Gnulib:

  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.
  • Formatting noncanonical ‘long double’ numbers produces nonmeaningful results on some platforms: glibc and others, on x86, x86_64, IA-64 CPUs.
  • When formatting an integer with grouping flag, this function inserts thousands separators even in the "C" locale on some platforms: NetBSD 5.1.

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10.1076 sockatmark

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sockatmark.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.

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10.1077 socket

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/socket.html

Gnulib module: socket

Portability problems fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), the descriptors returned by the socket function cannot be used in calls to read, write, and close; you have to use recv, send, closesocket in these cases instead.
  • On Windows platforms (excluding Cygwin), error codes from this function are not placed in errno, and WSAGetLastError must be used instead.

Portability problems not fixed by Gnulib:

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10.1078 socketpair

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/socketpair.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.1079 sprintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sprintf.html

Gnulib module: sprintf-posix or sprintf-gnu

Portability problems fixed by either Gnulib module sprintf-posix or sprintf-gnu:

  • This function does not support size specifiers as in C99 (hh, ll, j, t, z) on some platforms: AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • printf of ‘long double’ numbers is unsupported on some platforms: mingw, MSVC 14.
  • printf "%f", "%e", "%g" of Infinity and NaN yields an incorrect result on some platforms: AIX 7.3, Solaris 11.4, mingw, MSVC 14.
  • This function does not support the ‘a’ and ‘A’ directives on some platforms: FreeBSD 5.2.1, OpenBSD 4.0, AIX 5.2, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support the ‘F’ directive on some platforms: NetBSD 3.0, AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘ls’ directive on some platforms: OpenBSD 4.0, Cygwin 1.5.x, Haiku.
  • This function does not support precisions in the ‘ls’ directive correctly on some platforms: Solaris 11.4.
  • This function does not support format directives that access arguments in an arbitrary order, such as "%2$s", on some platforms: NetBSD 3.0, mingw, MSVC 14.
  • This function doesn’t support the ' flag on some platforms: NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
  • This function does not round the argument of the ‘a’ directive correctly on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4.
  • printf "%010f" of NaN and Infinity yields an incorrect result (padded with zeroes, or wrong capitalization) on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 7.3, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC/clang.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • This function does not support precisions larger than 512 or 1024 in integer, floating-point and pointer output on some platforms: AIX 7.1, Solaris 10/x86, mingw, MSVC/clang.
  • This function mishandles large floating point precisions (for example, formatting 1.0 with ‘"%.511f"’) on some platforms: Solaris 10.
  • This function produces wrong output for the ‘lc’ directive with a NUL wide character argument on some platforms: musl libc 1.2.4.
  • This function can crash in out-of-memory conditions on some platforms: FreeBSD 14.0, NetBSD 5.0.
  • The compiler warns that this function is deprecated: macOS 14.

Portability problems fixed by Gnulib module sprintf-gnu:

  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.

Portability problems fixed by either Gnulib module sprintf-posix or sprintf-gnu and additionally the Gnulib module printf-with-n-directive:

  • This function does not support the ‘n’ directive on some platforms: glibc when used with _FORTIFY_SOURCE >= 2 (set by default on Ubuntu), macOS 14, OpenBSD, MSVC 14, Android.

Portability problems not fixed by Gnulib:

  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.
  • Formatting noncanonical ‘long double’ numbers produces nonmeaningful results on some platforms: glibc and others, on x86, x86_64, IA-64 CPUs.
  • When formatting an integer with grouping flag, this function inserts thousands separators even in the "C" locale on some platforms: NetBSD 5.1.

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10.1080 sqrt

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sqrt.html

Gnulib module: sqrt

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.1081 sqrtf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sqrtf.html

Gnulib module: sqrtf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.1082 sqrtl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sqrtl.html

Gnulib module: sqrtl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, Android 4.4.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.
  • This function produces very imprecise results on some platforms: OpenBSD 5.1/SPARC.

Portability problems not fixed by Gnulib:

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10.1083 srand

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/srand.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is only defined as an inline function on some platforms: Android 4.4.
  • This function has no effect on rand invocations in other threads on some platforms: Cygwin 3.4.6.

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10.1084 srand48

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/srand48.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.1085 srandom

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/srandom.html

Gnulib module: random

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • This function is only defined as an inline function on some platforms: Android 4.4.

Portability problems not fixed by Gnulib:

  • This function has a slightly incompatible declaration (the return type being ‘long’ instead of ‘void’) on some platforms: Cygwin 1.5.25.
  • The parameter is unsigned long instead of unsigned int on some platforms: MidnightBSD 2.0.
  • This function has no effect on some platforms: OpenBSD 7.4. This platform has, instead, a function srandom_deterministic.

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10.1086 sscanf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sscanf.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sscanf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.38, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.2, AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • On Windows, this function doesn’t support the hh, ll, j, t, z size specifiers.

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10.1087 stat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/stat.html

Gnulib module: stat

Portability problems fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, stat may not correctly report the size of files or block devices 2 GiB and larger. See Large File Support.
  • On Linux/x86 and Linux/x86_64, applications compiled in 32-bit mode cannot access files that happen to have a 64-bit inode number. This can occur with file systems such as XFS (typically on large disks) and NFS. See Large File Support.
  • The st_atime, st_ctime, st_mtime fields are affected by the current time zone and by the DST flag of the current time zone on some platforms: mingw, MSVC 14 (when the environment variable TZ is set).
  • On MSVC 14, this function fails with error ENOENT on files such as ‘C:\pagefile.sys’ and on directories such as ‘C:\System Volume Information’.
  • On some platforms, stat("link-to-file/",buf) succeeds instead of failing with ENOTDIR. macOS 14, FreeBSD 7.2, AIX 7.1, Solaris 9, mingw64.
  • On some platforms, stat(".",buf) and stat("./",buf) give different results: mingw, MSVC 14.
  • On macOS 12.6, when this function yields a timestamp with a nonpositive tv_sec value, tv_nsec might be in the range -999999999..-1, representing a negative nanoseconds offset from tv_sec. Solaris 11.4 is similar, except that tv_sec might also be -1000000000.

Portability problems not fixed by Gnulib:

  • See sys/stat.h, for general portability problems with struct stat.
  • Cygwin’s stat function sometimes sets errno to EACCES when ENOENT would be more appropriate.
  • This function sets st_ino only to the low-order 32 bits of the inode number of a socket or pipe, which thus can disagree with the st_ino obtained by fstat: macOS 14.
  • Because of the definition of struct stat, it is not possible to portably replace stat via an object-like macro. Therefore, expressions such as (islnk ? lstat : stat) (name, buf) are not portable, and should instead be written islnk ? lstat (name, buf) : stat (name, buf).

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10.1088 statvfs

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/statvfs.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where f_blocks in ‘struct statvfs’ is a 32-bit value, this function may not work correctly on files systems larger than 4 TiB. See Large File Support. This affects glibc/Hurd, HP-UX 11, Solaris.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, mingw, MSVC 14, Android 4.3.
  • This function can hang if it stats all preceding entries in /proc/mounts, and any of those file systems are hard-mounted and not available. This affects Linux < 2.6.36.

Gnulib provides a module fsusage that provides similar information as statvfs.

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10.1089 stdc_bit_ceil

Documentation:
ISO C23 (latest free draft http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf) section 7.18.16.

Gnulib module: stdc_bit_ceil

Portability problems fixed by Gnulib:

  • This macro is missing on many platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 17, Android 15.

Portability problems not fixed by Gnulib:

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10.1090 stdc_bit_floor

Documentation:
ISO C23 (latest free draft http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf) section 7.18.15.

Gnulib module: stdc_bit_floor

Portability problems fixed by Gnulib:

  • This macro is missing on many platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 17, Android 15.

Portability problems not fixed by Gnulib:

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10.1091 stdc_bit_width

Documentation:
ISO C23 (latest free draft http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf) section 7.18.14.

Gnulib module: stdc_bit_width

Portability problems fixed by Gnulib:

  • This macro is missing on many platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 17, Android 15.

Portability problems not fixed by Gnulib:

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10.1092 stdc_count_ones

Documentation:
ISO C23 (latest free draft http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf) section 7.18.12.

Gnulib module: stdc_count_ones

Portability problems fixed by Gnulib:

  • This macro is missing on many platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 17, Android 15.

Portability problems not fixed by Gnulib:

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10.1093 stdc_count_zeros

Documentation:
ISO C23 (latest free draft http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf) section 7.18.11.

Gnulib module: stdc_count_zeros

Portability problems fixed by Gnulib:

  • This macro is missing on many platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 17, Android 15.

Portability problems not fixed by Gnulib:

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10.1094 stdc_first_leading_one

Documentation:
ISO C23 (latest free draft http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf) section 7.18.8.

Gnulib module: stdc_first_leading_one

Portability problems fixed by Gnulib:

  • This macro is missing on many platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 17, Android 15.

Portability problems not fixed by Gnulib:

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10.1095 stdc_first_leading_zero

Documentation:
ISO C23 (latest free draft http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf) section 7.18.7.

Gnulib module: stdc_first_leading_zero

Portability problems fixed by Gnulib:

  • This macro is missing on many platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 17, Android 15.

Portability problems not fixed by Gnulib:

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10.1096 stdc_first_trailing_one

Documentation:
ISO C23 (latest free draft http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf) section 7.18.10.

Gnulib module: stdc_first_trailing_one

Portability problems fixed by Gnulib:

  • This macro is missing on many platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 17, Android 15.

Portability problems not fixed by Gnulib:

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10.1097 stdc_first_trailing_zero

Documentation:
ISO C23 (latest free draft http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf) section 7.18.9.

Gnulib module: stdc_first_trailing_zero

Portability problems fixed by Gnulib:

  • This macro is missing on many platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 17, Android 15.

Portability problems not fixed by Gnulib:

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10.1098 stdc_has_single_bit

Documentation:
ISO C23 (latest free draft http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf) section 7.18.13.

Gnulib module: stdc_has_single_bit

Portability problems fixed by Gnulib:

  • This macro is missing on many platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 17, Android 15.

Portability problems not fixed by Gnulib:

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10.1099 stdc_leading_ones

Documentation:
ISO C23 (latest free draft http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf) section 7.18.4.

Gnulib module: stdc_leading_ones

Portability problems fixed by Gnulib:

  • This macro is missing on many platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 17, Android 15.

Portability problems not fixed by Gnulib:

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10.1100 stdc_leading_zeros

Documentation:
ISO C23 (latest free draft http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf) section 7.18.3.

Gnulib module: stdc_leading_zeros

Portability problems fixed by Gnulib:

  • This macro is missing on many platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 17, Android 15.

Portability problems not fixed by Gnulib:

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10.1101 stdc_trailing_ones

Documentation:
ISO C23 (latest free draft http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf) section 7.18.6.

Gnulib module: stdc_trailing_ones

Portability problems fixed by Gnulib:

  • This macro is missing on many platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 17, Android 15.

Portability problems not fixed by Gnulib:

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10.1102 stdc_trailing_zeros

Documentation:
ISO C23 (latest free draft http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf) section 7.18.5.

Gnulib module: stdc_trailing_zeros

Portability problems fixed by Gnulib:

  • This macro is missing on many platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 17, Android 15.

Portability problems not fixed by Gnulib:

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10.1103 stderr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/stderr.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • stderr is created in 32-bit mode instead of 64-bit mode: Cygwin 1.5.x. One workaround is to use freopen(NULL, “r+”, stderr) on Cygwin 1.5.21 or newer. Another is to use the gnulib ftello module and do ftello(stderr).
  • POSIX states that a setuid application can guarantee that fd 2 is open, but some systems guarantee this even for non-setuid programs. If an application is executed with fd 2 closed, use of stderr can affect an unrelated file that happened to be assigned to fd 2. The gnulib *-safer modules may be used to guarantee that fd 2 stays reserved for stderr.

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10.1104 stdin

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/stdin.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • stdin is created in 32-bit mode instead of 64-bit mode: Cygwin 1.5.x. One workaround is to use freopen(NULL, “r”, stdin) on Cygwin 1.5.21 or newer. Another is to use the gnulib ftello module and do ftello(stdin).
  • POSIX states that a setuid application can guarantee that fd 0 is open, but some systems guarantee this even for non-setuid programs. If an application is executed with fd 0 closed, use of stdin can affect an unrelated file that happened to be assigned to fd 0. The gnulib *-safer modules may be used to guarantee that fd 0 stays reserved for stdin.

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10.1105 stdout

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/stdout.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • stdout is created in 32-bit mode instead of 64-bit mode: Cygwin 1.5.x. One workaround is to use freopen(NULL, “w”, stdout) on Cygwin 1.5.21 or newer. Another is to use the gnulib ftello module and do ftello(stdout).
  • POSIX states that a setuid application can guarantee that fd 1 is open, but some systems guarantee this even for non-setuid programs. If an application is executed with fd 1 closed, use of stdout can affect an unrelated file that happened to be assigned to fd 1. The gnulib *-safer modules may be used to guarantee that fd 1 stays reserved for stdout.

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10.1106 stpcpy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/stpcpy.html

Gnulib module: stpcpy

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 4.4.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

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10.1107 stpncpy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/stpncpy.html

Gnulib module: stpncpy

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 4.4.
  • This function has an incompatible return value on some platforms: AIX 5.1.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

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10.1108 strcasecmp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strcasecmp.html

Gnulib module: strcase

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

  • This function cannot work correctly on character strings in multibyte locales. Gnulib provides an alternative function mbscasecmp that does a case insensitive comparison of character strings and that works in all locales.

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10.1109 strcasecmp_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strcasecmp_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 5.1.

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10.1110 strcat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strcat.html

Gnulib module: string

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

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10.1111 strchr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strchr.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function cannot work correctly on character strings in some multibyte locales. Gnulib provides an alternative function mbschr that works on character strings in all locales.

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10.1112 strcmp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strcmp.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.1113 strcoll

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strcoll.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function fails, setting errno to EILSEQ, on Solaris 10, in UTF-8 locales, when at least one of the strings contains a Unicode character in a block that was not assigned in Unicode 4.0.

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10.1114 strcoll_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strcoll_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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10.1115 strcpy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strcpy.html

Gnulib module: string

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

Note: strcpy (dst, src) is only safe to use when you can guarantee that there are at least strlen (src) + 1 bytes allocated at dst.

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10.1116 strcspn

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strcspn.html

Gnulib module: strcspn

Portability problems fixed by Gnulib:

  • This function is missing on some old platforms.

Portability problems not fixed by Gnulib:

  • This function cannot work correctly on character strings in multibyte locales. Gnulib provides an alternative function mbscspn that works on character strings in all locales.

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10.1117 strdup

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strdup.html

Gnulib module: strdup or strdup-posix

Portability problems fixed by either Gnulib module strdup or strdup-posix:

  • This function has no prototype in <string.h> on some old platforms.

Portability problems fixed by Gnulib module strdup-posix:

  • Upon failure, the function does not set errno to ENOMEM on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.1118 strerror

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strerror.html

Gnulib module: strerror

Portability problems fixed by Gnulib:

  • This function does not support the error values that are specified by POSIX but not defined by the system, on some platforms: OpenBSD 4.0, NonStop Kernel, Cygwin 1.5.x, mingw, MSVC 14.
  • This function reports failure for strerror(0) (by setting errno or using a string similar to out-of-range values), although POSIX requires this to leave errno unchanged and report success, on some platforms: FreeBSD 8.2, NetBSD 10.0, OpenBSD 4.7, macOS 14.
  • This function fails to return a string for out-of-range integers on some platforms: HP-UX 11. (Some return NULL which is a POSIX violation, others return the empty string which is valid but not as useful); this can still cause bugs because most programs call strerror without setting and testing errno.)

Portability problems not fixed by Gnulib:

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10.1119 strerror_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strerror_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.5, macOS 14, FreeBSD 12.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 5.1.

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10.1120 strerror_r

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strerror_r.html

LSB specification:

Gnulib module: strerror_r-posix

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, Minix 3.1.8, HP-UX 11.23, Solaris 9, mingw, MSVC 14.
  • glibc, Cygwin, and Android have an incompatible version of this function. The POSIX compliant code 
    char *s = (strerror_r (err, buf, buflen) == 0 ? buf : NULL);

    is essentially equivalent to this code using the glibc function: 

    char *s = strerror_r (err, buf, buflen);
  • This function clobbers the strerror buffer on some platforms: Cygwin 1.7.9.
  • This function is sometimes not declared in <string.h> on some platforms: glibc 2.8.
  • The third argument is of type int instead of size_t on some platforms: AIX 5.1.
  • When this function fails, it returns -1 and sets errno, instead of returning the error number, on some platforms: glibc 2.12 with -D_POSIX_C_SOURCE=200112L, AIX 6.1.
  • When this function fails, it corrupts errno, on some platforms: Solaris 10.
  • This function does not support many error values defined in <errno.h> on some platforms: MSVC 14.
  • This function does not support the error values that are specified by POSIX but not defined by the system, on some platforms: OpenBSD 4.0, NonStop Kernel, Cygwin 1.5.x.
  • This function reports failure for strerror_r(0, buf, len), although POSIX requires this to succeed, on some platforms: FreeBSD 8.2.
  • This function produces a different string for 0 than strerror on some platforms: macOS 14.
  • This function always fails when the third argument is less than 80 on some platforms: HP-UX 11.31.
  • When the buffer is too small and the value is in range, this function does not fail, but instead truncates the result and returns 0 on some platforms: AIX 6.1, Haiku 2017.
  • When the value is not in range or the buffer is too small, this function fails to leave a NUL-terminated string in the buffer on some platforms: glibc 2.13, FreeBSD 8.2, Solaris 10.
  • When the value is out of range but the buffer is too small, this function does not always return the longest possible string on some platforms: OpenBSD 4.7.

Portability problems not fixed by Gnulib:

Note: Gnulib has a module xstrerror, with the property that xstrerror (NULL, errnum) returns the value of strerror_r as a freshly allocated string. (Recall that the expression strerror (errnum) is not multithread-safe.)

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10.1121 strfmon

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strfmon.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 1.7.1, mingw, MSVC 14, Android 9.0.

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10.1122 strfmon_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strfmon_l.html

Gnulib module: strfmon_l

Portability problems fixed by Gnulib:

  • This function ignores the locale argument on some platforms: FreeBSD 13.0, Cygwin 2.9.
  • This function uses a wrong locale for the numbers on some platforms: glibc 2.23.

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 7.1, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.

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10.1123 strfromd

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.1124 strfromf

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.1125 strfroml

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.1126 strftime

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strftime.html

Gnulib module: strftime-fixes

Portability problems fixed by Gnulib:

  • On native Windows platforms (mingw, MSVC), this function works incorrectly when the environment variable TZ has been set by Cygwin.

Portability problems not fixed by Gnulib:

  • The %c specifier does not work with a time retrieved through gmtime or gmtime_r, since it outputs also the current time zone, on some platforms: glibc 2.30, NetBSD 10.0, Solaris 11.4.
  • The %c specifier produces no weekday name and no month name, only a potentially ambiguous numerical output, on some platforms: mingw, MSVC.
  • The %h specifier produces empty output on some platforms: mingw, MSVC.
  • The %r specifier produces empty output on some platforms: mingw, MSVC.
  • The %r specifier produces empty output, at least in a French locale, on some platforms: macOS 12.5, FreeBSD 14.0.
  • The %r specifier includes an AM/PM indicator, at least in a French locale, on some platforms: NetBSD 10.0, Solaris 11.4.
  • The %p specifier produces non-empty output, at least in a French locale, on some platforms: NetBSD 10.0, Solaris 11.4.
  • The Windows C runtime library (which is used by MinGW) does not support the %e specifier (and possibly the other more recent SUS specifiers too, i.e., %C, %D, %h, %n, %r, %R, %t, and %T).
  • Native Windows platforms (mingw, MSVC) support only a subset of time zones supported by GNU or specified by POSIX. See tzset.

Extension: Gnulib offers a module ‘nstrftime’ that provides an nstrftime function with various GNU extensions.

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10.1127 strftime_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strftime_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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10.1128 strlcat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/<2024>/functions/strlcat.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.37, AIX 7.3.1, HP-UX 11.31, mingw, MSVC 14.

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10.1129 strlcpy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/<2024>/functions/strlcpy.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.37, AIX 7.3.1, HP-UX 11.31, mingw, MSVC 14.

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10.1130 strlen

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strlen.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.1131 strncasecmp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strncasecmp.html

Gnulib module: strcase

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

  • This function cannot work correctly on character strings in multibyte locales. Gnulib provides alternative functions mbsncasecmp and mbspcasecmp that do a case insensitive comparison of character strings and that work in all locales.

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10.1132 strncasecmp_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strncasecmp_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 5.1.

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10.1133 strncat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strncat.html

Gnulib module: strncat

Portability problems fixed by Gnulib:

  • This function dereferences too much memory on some platforms: Solaris 11.4 on SPARC, Solaris 11.0 on x86.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

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10.1134 strncmp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strncmp.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.1135 strncpy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strncpy.html

Gnulib module: string

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

Note: This function was designed for the use-case of filling a fixed-size record with a string, before writing it to a file. This function is not appropriate for copying a string into a bounded memory area, because you have no guarantee that the result will be NUL-terminated. Even if you add the NUL byte at the end yourself, this function is inefficient (as it spends time clearing unused memory) and will allow silent truncation to occur, which is not a good behavior for GNU programs. For more details, see https://meyering.net/crusade-to-eliminate-strncpy/.

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10.1136 strndup

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strndup.html

Gnulib module: strndup

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 10, mingw, MSVC 14.
  • This function does not NUL-terminate the result on some platforms: AIX 5.1.

Portability problems not fixed by Gnulib:

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10.1137 strnlen

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strnlen.html

Gnulib module: strnlen

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, HP-UX 11, Solaris 10, mingw.

Portability problems not fixed by Gnulib:

  • On some platforms, calls like strnlen (s, maxlen) can crash if s is null-terminated but address arithmetic overflows (i.e., s + maxlen < s): Android 5.0.

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10.1138 strpbrk

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strpbrk.html

Gnulib module: strpbrk

Portability problems fixed by Gnulib:

  • This function is missing on some old platforms.

Portability problems not fixed by Gnulib:

  • This function cannot work correctly on character strings in multibyte locales. Gnulib provides an alternative function mbspbrk that works on character strings in all locales.

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10.1139 strptime

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strptime.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-strptime-3.html

Gnulib module: strptime

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.1140 strrchr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strrchr.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function cannot work correctly on character strings in some multibyte locales. Gnulib provides an alternative function mbsrchr that works on character strings in all locales.

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10.1141 strsignal

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strsignal.html

Gnulib module: strsignal

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11, mingw, MSVC 14.
  • This function does not return a string for out-of-range numbers on some platforms: Solaris, AIX 5.1.
  • This function is declared in unistd.h instead of string.h on some platforms: NetBSD 5.0.

Portability problems not fixed by Gnulib:

  • This function returns const char * instead of char * on some platforms: cygwin 1.5.25.

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10.1142 strspn

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strspn.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function cannot work correctly on character strings in multibyte locales. Gnulib provides an alternative function mbsspn that works on character strings in all locales.

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10.1143 strstr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strstr.html

Gnulib module: strstr or strstr-simple

Portability problems fixed by either Gnulib module strstr-simple or strstr:

  • This function can trigger memchr bugs on some platforms: glibc 2.10.
  • This function can trigger false positives for long periodic needles on some platforms: glibc 2.12, Cygwin 1.7.7.
  • This function may fail to find matches on some platforms: glibc 2.28.

Portability problems fixed by Gnulib module strstr:

  • This function has quadratic instead of linear worst-case complexity on some platforms: glibc 2.8, macOS 14, FreeBSD 11.4, NetBSD 10.0, OpenBSD 6.1, AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • This function cannot work correctly on character strings in most multibyte locales. Gnulib provides an alternative function mbsstr that works on character strings in all locales.

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10.1144 strtod

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtod.html

Gnulib module: strtod or strtod-obsolete

Portability problems fixed by either Gnulib module strtod or strtod-obsolete:

  • This function mis-parses strings with leading ‘+’ on some old platforms: Old versions of Linux.
  • This function returns a wrong end pointer on some old platforms.
  • This function allows whitespace between ‘e’ and the exponent on some platforms: HP-UX 11.11.
  • This function returns the wrong end pointer for ‘-0x’ on some platforms: glibc 2.4, Mac OS X 10.5, FreeBSD 6.2, AIX 7.1, Cygwin < 1.5.25-11.
  • This function fails to parse Infinities and plain NaNs on some platforms: OpenBSD 4.0, HP-UX 11.11, Solaris 9, mingw, MSVC 14.
  • This function fails to parse ‘NaN()’ on some platforms: glibc-2.3.6, Mac OS X 10.5, FreeBSD 6.2, OpenBSD 4.0, AIX 7.1, HP-UX 11.11, Cygwin < 1.5.25-11, mingw, MSVC 14.
  • This function fails to parse ‘NaN(n-char-sequence)’ on some platforms: OpenBSD 4.0, HP-UX 11.11, mingw, MSVC 14.
  • This function parses ‘NaN(n-char-sequence)’, but returns the wrong end pointer on some platforms: glibc-2.4, AIX 7.1.
  • This function fails to parse C99 hexadecimal floating point on some platforms: NetBSD 5.0, OpenBSD 4.0, AIX 5.1, HP-UX 11.11, Solaris 11.4, mingw, MSVC 14.
  • In hexadecimal floats, this function allows whitespace between ‘p’ and the exponent on some platforms: HP-UX 11.31/ia64.
  • This function returns the wrong end pointer for ‘0x1p’ on some platforms: AIX 7.1.

Portability problems fixed by Gnulib module strtod-obsolete:

  • This function is missing on some old platforms.

Portability problems not fixed by Gnulib:

  • This function returns +0.0 (not -0.0) for negative underflow on some platforms: glibc 2.7, Cygwin 1.5.x, mingw, MSVC 14.
  • This function cannot distinguish between “nan” and “-nan” on some platforms: glibc 2.7, mingw, MSVC 14.
  • This function fails to correctly parse very long strings on some platforms: Mac OS X 10.5, FreeBSD 6.2, NetBSD 5.0, OpenBSD 4.0, Cygwin, mingw, MSVC 14.
  • The replacement function does not always return correctly rounded results.

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10.1145 strtof

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtof.html

Gnulib module: strtof

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, MSVC 9, Android 4.4.
  • This function returns the wrong end pointer for ‘-0x’ on some platforms: glibc 2.4, Mac OS X 10.5, FreeBSD 6.2.
  • This function fails to parse ‘NaN()’ on some platforms: glibc-2.5, FreeBSD 6.2.

Portability problems not fixed by Gnulib:

  • This function returns +0.0 (not -0.0) for negative underflow on some platforms: glibc 2.7, mingw, MSVC 14.
  • This function cannot distinguish between “nan” and “-nan” on some platforms: glibc 2.7, mingw, MSVC 14.
  • This function fails to correctly parse very long strings on some platforms: Mac OS X 10.5, FreeBSD 6.2, NetBSD 5.0, Cygwin, mingw, MSVC 14.
  • The replacement function does not always return correctly rounded results.

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10.1146 strtoimax

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtoimax.html

Gnulib module: strtoimax

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, Solaris 9, MSVC 9.
  • This function fails on valid input strings on some platforms: AIX 5.1.

Portability problems not fixed by Gnulib:

  • This function is only defined as a macro on some platforms: HP-UX 11.11.

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10.1147 strtok

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtok.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.1148 strtok_r

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtok_r.html

Gnulib module: strtok_r

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • This function crashes when invoked from code compiled with optimization enabled on some platforms: glibc 2.7.

Portability problems not fixed by Gnulib:

  • This function cannot work correctly on character strings in multibyte locales. Gnulib provides an alternative function mbstok_r that works on character strings in all locales.

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10.1149 strtol

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtol.html

Gnulib module: strtol

Portability problems fixed by Gnulib:

  • This function is missing on some old platforms.
  • This function does not parse the leading ‘0’ when the input string is "0x" and the base is 16 or 0 on some platforms: Minix 3.3, mingw, MSVC 14.
  • This function does not parse binary integers (with a ‘0b’ or ‘0B’ prefix) when the base is 2 or 0 on many platforms.

Portability problems not fixed by Gnulib:

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10.1150 strtold

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtold.html

Gnulib module: strtold

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, Solaris 9, older Cygwin 1.7.x, MSVC 9, Android 4.4.
  • This function returns a struct, not a long double, on some platforms: HP-UX 11.31/hppa.
  • This function allows whitespace between ‘e’ and the exponent on some platforms: HP-UX 11.31/ia64.
  • This function returns the wrong end pointer for ‘-0x’ on some platforms: glibc-2.3.2, Mac OS X 10.5, Haiku.
  • This function fails to parse Infinities and plain NaNs on some platforms: HP-UX 11.31/ia64.
  • This function fails to parse ‘NaN()’ on some platforms: glibc-2.3.2, mingw, Haiku.
  • This function parses ‘NaN(n-char-sequence)’, but returns the wrong end pointer on some platforms: glibc-2.3.2, mingw, Haiku.
  • This function fails to parse C99 hexadecimal floating point on some platforms: mingw.
  • In hexadecimal floats, this function allows whitespace between ‘p’ and the exponent on some platforms: HP-UX 11.31/ia64.
  • This function fails to set errno upon underflow on some platforms: Cygwin 2.9.

Portability problems not fixed by Gnulib:

  • The replacement function does not always return correctly rounded results.

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10.1151 strtoll

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtoll.html

Gnulib module: strtoll

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11.11, MSVC 9.
  • This function does not parse the leading ‘0’ when the input string is "0x" and the base is 16 or 0 on some platforms: Minix 3.3, mingw, MSVC 14.
  • This function does not parse binary integers (with a ‘0b’ or ‘0B’ prefix) when the base is 2 or 0 on many platforms.

Portability problems not fixed by Gnulib:

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10.1152 strtoul

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtoul.html

Gnulib module: strtoul

Portability problems fixed by Gnulib:

  • This function is missing on some old platforms.
  • This function does not parse the leading ‘0’ when the input string is "0x" and the base is 16 or 0 on some platforms: Minix 3.3, mingw, MSVC 14.
  • This function does not parse binary integers (with a ‘0b’ or ‘0B’ prefix) when the base is 2 or 0 on many platforms.

Portability problems not fixed by Gnulib:

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10.1153 strtoull

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtoull.html

Gnulib module: strtoull

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11.11, MSVC 9.
  • This function does not parse the leading ‘0’ when the input string is "0x" and the base is 16 or 0 on some platforms: Minix 3.3, mingw, MSVC 14.
  • This function does not parse binary integers (with a ‘0b’ or ‘0B’ prefix) when the base is 2 or 0 on many platforms.

Portability problems not fixed by Gnulib:

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10.1154 strtoumax

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strtoumax.html

Gnulib module: strtoumax

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, AIX 5.1, Solaris 9, MSVC 9.

Portability problems not fixed by Gnulib:

  • This function is only defined as a macro on some platforms: HP-UX 11.11.

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10.1155 strxfrm

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strxfrm.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function has a wrong return value on some platforms: Haiku.

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10.1156 strxfrm_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/strxfrm_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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10.1157 swab

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/swab.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Android 8.1.

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10.1158 swprintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/swprintf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11.00, Cygwin 1.5.x.
  • This function has a different signature on some platforms: MSVC 9.
  • This function is only defined as a macro on some platforms: MSVC 14.
  • This function does not support the ‘n’ directive on some platforms: glibc when used with _FORTIFY_SOURCE >= 2 (set by default on Ubuntu), macOS 14, OpenBSD, MSVC 14, Android.
  • This function sometimes returns a wrong value through the ‘n’ directive on some platforms: musl libc 1.2.3.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.
  • On Windows, this function does not take a buffer size as second argument.
  • This function produces wrong values for the ‘La’ directive on some platforms: glibc 2.15, Haiku, NetBSD 10.0.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • This function ignores the minimum field width in the ‘lc’ directive on some platforms: musl libc 1.2.3.
  • This function is broken when it produces output that contains null wide characters on some platforms: musl libc 1.2.3, macOS 14, FreeBSD 13.1, NetBSD 10.0, OpenBSD 7.2, AIX 7.2, mingw.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.
  • In the C or POSIX locales, the %c and %s conversions may fail on some platforms: glibc 2.35, musl libc 1.2.4, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.2, Cygwin 2.9.0.
  • The %lc directive may fail on some platforms: musl libc 1.2.4, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.2.
  • When formatting an integer with grouping flag, this function inserts thousands separators even in the "C" locale on some platforms: NetBSD 5.1.

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10.1159 swscanf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/swscanf.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-swscanf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11.00, Cygwin 1.5.x.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.38, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.2, AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1161 symlinkat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/symlinkat.html

Gnulib module: symlinkat

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 4.4. But the replacement function is not safe to be used in libraries and is not multithread-safe.
  • Some platforms declare this function in stdio.h instead of unistd.h: Cygwin 1.7.1.
  • On some systems, symlinkat(value, fd, "name/") mistakenly creates a symlink: macOS 14, AIX 7.1.

Portability problems not fixed by Gnulib:

  • This function always fails with ‘ENOSYS’ on platforms that don’t support symlinks: mingw, MSVC 14.

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10.1162 sync

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sync.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.1163 sysconf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/sysconf.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sysconf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.1164 syslog

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/syslog.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.1165 system

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/system.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-system-3.html

Gnulib module: system-posix

Portability problems fixed by Gnulib:

  • The macros WIFSIGNALED, WIFEXITED, WIFSTOPPED, WTERMSIG, WEXITSTATUS, WNOHANG, WUNTRACED, WSTOPSIG are not defined in <stdlib.h> (only in <sys/wait.h>) on some platforms: MirBSD 10.

Portability problems not fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), the command processor used by the system function is cmd.exe, not /bin/sh. Accordingly, the rules for quoting shell arguments containing spaces, quote or other special characters are different.

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10.1166 tan

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tan.html

Gnulib module: tan

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.1167 tanf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tanf.html

Gnulib module: tanf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.1168 tanh

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tanh.html

Gnulib module: tanh

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.1169 tanhf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tanhf.html

Gnulib module: tanhf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 9.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

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10.1170 tanhl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tanhl.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, Android 4.4.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.
  • This function produces results which are accurate to only 16 digits on some platforms: NetBSD 10.0.

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10.1171 tanl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tanl.html

Gnulib module: tanl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, Android 4.4.
  • This function is only defined as a macro with arguments on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

  • This function produces results which are accurate to only 16 digits on some platforms: NetBSD 10.0.

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10.1172 tcdrain

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcdrain.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4.
  • On some platforms, tcdrain on a non-tty fails with errno set to EINVAL or, on Mac OS X, also EOPNOTSUPP or ENODEV, rather than ENOTTY.

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10.1173 tcflow

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcflow.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4.

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10.1174 tcflush

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcflush.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4.
  • On some platforms, tcflush of TCIFLUSH on a non-tty fails with errno set to EINVAL rather than ENOTTY.
  • On some platforms, tcflush of TCOFLUSH on a non-tty fails with errno set to EINVAL or, on Mac OS X, also EOPNOTSUPP or ENODEV, rather than ENOTTY.

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10.1175 tcgetattr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcgetattr.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4.

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10.1176 tcgetpgrp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcgetpgrp.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.1177 tcgetsid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcgetsid.html

Gnulib module: tcgetsid

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, OpenBSD 4.5, Minix 3.1.8, Cygwin 1.7.9, mingw, MSVC 14, Android 4.4.
  • The declaration of this function in C++ compilation units has C++ linkage, not C linkage, on some platforms: HP-UX 11.00.

Portability problems not fixed by Gnulib:

  • This function always fails on some platforms: FreeBSD 6.0, Cygwin 1.7.8, mingw, MSVC 14.
  • This function returns int instead of pid_t on some platforms: Cygwin 1.7.11.

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10.1178 tcsendbreak

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcsendbreak.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4.

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10.1179 tcsetattr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcsetattr.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4.

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10.1180 tcsetpgrp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tcsetpgrp.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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10.1181 tdelete

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tdelete.html

Gnulib module: tsearch

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 4.0.4.
  • tdelete returns NULL when removing the last element of a tree on some platforms: OpenBSD 4.0.

Portability problems not fixed by Gnulib:

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10.1182 telldir

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/telldir.html

Gnulib module: —

Portability problems fixed by Gnulib:

  • On platforms where long int is a 32-bit type, this function may not work correctly on huge directories 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: MSVC 14, Android 5.1.

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10.1183 tempnam

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tempnam.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.
  • This function is removed in POSIX.1-2024. Use the function mkstemp instead.
  • This function is not appropriate for creating temporary files. (It has security risks.) Better use mkstemp instead.

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10.1184 tfind

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tfind.html

Gnulib module: tsearch

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 4.0.4.

Portability problems not fixed by Gnulib:

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10.1185 tgamma

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tgamma.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.

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10.1186 tgammaf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tgammaf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.

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10.1187 tgammal

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tgammal.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 9.3, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9, Android 4.4.

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10.1188 thrd_create

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread-Management.html.

Gnulib module: thrd

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.
  • This function uses an incorrectly defined thrd_start_t on some platforms: AIX 7.2.

Portability problems not fixed by Gnulib:

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10.1189 thrd_current

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread-Management.html.

Gnulib module: thrd

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.1190 thrd_detach

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread-Management.html.

Gnulib module: thrd

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.1191 thrd_equal

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread-Management.html.

Gnulib module: thrd

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.1192 thrd_exit

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread-Management.html.

Gnulib module: thrd

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.
  • The exit code provided to this function is discarded on some platforms: AIX 7.3.1.

Portability problems not fixed by Gnulib:

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10.1193 thrd_join

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread-Management.html.

Gnulib module: thrd

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.
  • This function never stores an exit code on some platforms: AIX 7.3.1.
  • This function crashes when the second argument is NULL on some platforms: Solaris 11.4.

Portability problems not fixed by Gnulib:

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10.1194 thrd_sleep

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread-Management.html.

Gnulib module: thrd

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.1195 thrd_yield

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread-Management.html.

Gnulib module: thrd

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.1196 time

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/time.html

Gnulib module: time

Portability problems fixed by Gnulib:

  • This function is not consistent with gettimeofday and timespec_get on some platforms: glibc 2.31 or newer on Linux, FreeBSD 14.0, AIX 7.2, native Windows. Namely, in the first 1 to 2.5 milliseconds of every second (or, on AIX and Windows, in the first 5 milliseconds of every second), time returns a value that is one less than the tv_sec part of the return value of gettimeofday or timespec_get.

Portability problems not fixed by Gnulib:

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10.1197 timegm

Documentation:

Gnulib module: timegm

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 11.3, mingw, MSVC 14, Android 3.0.

Portability problems not fixed by Gnulib:

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10.1198 timer_create

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_create.html

Gnulib module: timer-time

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.11, FreeBSD 6.4, Minix 3.1.8, mingw, MSVC 14.
  • This function fails with ENOSYS on some platforms: OpenBSD 4.9.

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10.1199 timer_delete

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_delete.html

Gnulib module: timer-time

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.11, FreeBSD 6.4, Minix 3.1.8, mingw, MSVC 14.
  • This function fails with ENOSYS on some platforms: OpenBSD 4.9.

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10.1200 timer_getoverrun

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_getoverrun.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.11, FreeBSD 6.0, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14.

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10.1201 timer_gettime

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_gettime.html

Gnulib module: timer-time

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.11, FreeBSD 6.4, Minix 3.1.8, mingw, MSVC 14.
  • This function fails with ENOSYS on some platforms: OpenBSD 4.9.

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10.1202 timer_settime

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/timer_settime.html

Gnulib module: timer-time

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.11, FreeBSD 6.4, Minix 3.1.8, mingw, MSVC 14.
  • This function fails with ENOSYS on some platforms: OpenBSD 4.9.

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10.1203 times

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/times.html

Gnulib module: times

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • There is no function on Windows to measure consumed process child times, thus the tms_cutime and tms_cstime will always be 0 when the module is used.

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10.1204 timespec_getres

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.29.2.7

Gnulib module: timespec_getres

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.33, macOS 12, FreeBSD 14.0, NetBSD 9.2, OpenBSD 7.0, Minix 3.3.0, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 34.

Portability problems not fixed by Gnulib:

  • On some platforms, this function returns a value other than the clock resolution of timespec_get, i.e., the minimum distance between differing timestamps. For example, on GNU/Linux it typically returns 1 nanosecond regardless of the actual clock resolution.

The Gnulib module gettime-res is a partial substitute; it implements the TIME_UTC functionality of timespec_getres.

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10.1205 timezone

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/timezone.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable’s contents are unreliable if you use a geographical TZ setting like TZ="America/Los_Angeles".
  • This variable is missing (and instead, a function named timezone exists) on some platforms: FreeBSD 14.0, OpenBSD 5.7.
  • This variable is called _timezone on some platforms: mingw with -DNO_OLDNAMES, MSVC.
  • The address of this variable is not a compile-time constant on some platforms: mingw, MSVC.
  • Native Windows platforms (mingw, MSVC) support only a subset of time zones supported by GNU or specified by POSIX. See tzset.

This variable is vestigial: it is not needed and does not suffice in general. It is planned to be removed from a future version of POSIX. A more portable way of getting the UTC offset is to use strftime with the %z format. See strftime.

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10.1206 tmpfile

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tmpfile.html

Gnulib module: tmpfile

Portability problems fixed by Gnulib:

  • This function always fails on some platforms: Android 4.3.
  • This function often fails for trivial reasons on some platforms: mingw, MSVC 14.
  • On platforms where off_t is a 32-bit type, tmpfile may not work correctly to create files 2 GiB and larger. See Large File Support.

Portability problems not fixed by Gnulib:

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10.1207 tmpnam

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tmpnam.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is not appropriate for creating temporary files. (It has security risks.) Better use mkstemp instead.

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10.1208 toascii

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/toascii.html

Gnulib module: ctype

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

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10.1209 tolower

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tolower.html

Gnulib module: ctype

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

Note: This function’s behaviour depends on the locale, but does not support the multibyte characters that occur in strings in locales with MB_CUR_MAX > 1 (this includes all the common UTF-8 locales). There are four alternative APIs:

c_tolower

This function operates in a locale independent way and returns a different value than the argument only for uppercase ASCII characters. It is provided by the Gnulib module ‘c-ctype’.

towlower

This function operates in a locale dependent way, on wide characters. In order to use it, you first have to convert from multibyte to wide characters, using the mbrtowc function. It is provided by the Gnulib module ‘wctype’.

c32tolower

This function operates in a locale dependent way, on 32-bit wide characters. In order to use it, you first have to convert from multibyte to 32-bit wide characters, using the mbrtoc32 function. It is provided by the Gnulib module ‘c32tolower’.

uc_tolower

This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unicase/tolower’.

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10.1210 tolower_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tolower_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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10.1211 totalorder

Documentation:

Gnulib module: totalorder

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function has a different signature on some platforms: glibc 2.30.

Portability problems not fixed by Gnulib:

  • This function treats signalling NaNs incorrectly on some platforms: glibc 2.35/sh4.

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10.1212 totalorderf

Documentation:

Gnulib module: totalorderf

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function has a different signature on some platforms: glibc 2.30.

Portability problems not fixed by Gnulib:

  • This function treats signalling NaNs incorrectly on some platforms: glibc 2.35/sh4.

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10.1213 totalorderl

Documentation:

Gnulib module: totalorderl

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function has a different signature on some platforms: glibc 2.30.

Portability problems not fixed by Gnulib:

  • This function treats signalling NaNs incorrectly on some platforms: glibc 2.35/sh4.

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10.1214 totalordermag

Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Comparison-Functions.html.

Gnulib module: totalordermag

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function has a different signature on some platforms: glibc 2.30.

Portability problems not fixed by Gnulib:

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10.1215 totalordermagf

Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Comparison-Functions.html.

Gnulib module: totalordermagf

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function has a different signature on some platforms: glibc 2.30.

Portability problems not fixed by Gnulib:

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10.1216 totalordermagl

Documentation:
https://www.gnu.org/software/libc/manual/html_node/FP-Comparison-Functions.html.

Gnulib module: totalordermagl

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function has a different signature on some platforms: glibc 2.30.

Portability problems not fixed by Gnulib:

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10.1217 toupper

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/toupper.html

Gnulib module: ctype

Portability problems fixed by Gnulib:

  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

Note: This function’s behaviour depends on the locale, but does not support the multibyte characters that occur in strings in locales with MB_CUR_MAX > 1 (this includes all the common UTF-8 locales). There are four alternative APIs:

c_toupper

This function operates in a locale independent way and returns a different value than the argument only for lowercase ASCII characters. It is provided by the Gnulib module ‘c-ctype’.

towupper

This function operates in a locale dependent way, on wide characters. In order to use it, you first have to convert from multibyte to wide characters, using the mbrtowc function. It is provided by the Gnulib module ‘wctype’.

c32toupper

This function operates in a locale dependent way, on 32-bit wide characters. In order to use it, you first have to convert from multibyte to 32-bit wide characters, using the mbrtoc32 function. It is provided by the Gnulib module ‘c32toupper’.

uc_toupper

This function operates in a locale independent way, on Unicode characters. It is provided by the Gnulib module ‘unicase/toupper’.

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10.1218 toupper_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/toupper_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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10.1219 towctrans

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/towctrans.html

Gnulib module: towctrans

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.00, mingw, MSVC 9, Android 7.1.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32_apply_mapping, provided by Gnulib module c32_apply_mapping, operates on 32-bit wide characters and therefore does not have this limitation.

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10.1220 towctrans_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/towctrans_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 7.1.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1221 towlower

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/towlower.html

Gnulib module: wctype-h

Portability problems fixed by Gnulib:

  • This function returns values of which the upper 16 bits are incorrect on some platforms: mingw.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32tolower, provided by Gnulib module c32tolower, operates on 32-bit wide characters and therefore does not have this limitation.
  • This function returns wrong values even for the ASCII characters in a zh_CN.GB18030 locale on some platforms: NetBSD 10.0.

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10.1222 towlower_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/towlower_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1223 towupper

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/towupper.html

Gnulib module: wctype-h

Portability problems fixed by Gnulib:

  • This function returns values of which the upper 16 bits are incorrect on some platforms: mingw.
  • This function cannot be called from plain inline or extern inline functions on some platforms: macOS 10.8.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32toupper, provided by Gnulib module c32toupper, operates on 32-bit wide characters and therefore does not have this limitation.
  • This function returns wrong values even for the ASCII characters in a zh_CN.GB18030 locale on some platforms: NetBSD 10.0.

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10.1224 towupper_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/towupper_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1225 trunc

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/trunc.html

Gnulib module: trunc or trunc-ieee

Portability problems fixed by either Gnulib module trunc or trunc-ieee:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 3.0, OpenBSD 3.8, Solaris 9, MSVC 9.
  • This function is not declared (without -D_GNU_SOURCE) on some platforms: glibc 2.8.

Portability problems fixed by Gnulib module trunc-ieee:

Portability problems not fixed by Gnulib:

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10.1226 truncate

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/truncate.html

Gnulib module: truncate

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4 with AC_SYS_LARGEFILE in effect.
  • On platforms where off_t is a 32-bit type, this function is not applicable to arbitrary lengths for files 2 GiB and larger. See Large File Support.
  • This function does not fail when the file name argument ends in a slash and (without the slash) names a non-directory, on some platforms: AIX 7.2.

Portability problems not fixed by Gnulib:

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10.1227 truncf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/truncf.html

Gnulib module: truncf or truncf-ieee

Portability problems fixed by either Gnulib module truncf or truncf-ieee:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, MSVC 9.
  • This function is not declared (without -D_GNU_SOURCE) on some platforms: glibc 2.8.

Portability problems fixed by Gnulib module truncf-ieee:

Portability problems not fixed by Gnulib:

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10.1228 truncl

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/truncl.html

Gnulib module: truncl or truncl-ieee

Portability problems fixed by either Gnulib module truncl or truncl-ieee:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9.
  • This function is not declared (without -D_GNU_SOURCE) on some platforms: glibc 2.8.

Portability problems fixed by Gnulib module truncl-ieee:

Portability problems not fixed by Gnulib:

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10.1229 tsearch

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tsearch.html

Gnulib module: tsearch

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 4.0.4.

Portability problems not fixed by Gnulib:

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10.1230 tss_create

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread_002dlocal-Storage.html.

Gnulib module: tss

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.1231 tss_delete

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread_002dlocal-Storage.html.

Gnulib module: tss

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.1232 tss_get

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread_002dlocal-Storage.html.

Gnulib module: tss

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.1233 tss_set

Documentation:
https://www.gnu.org/software/libc/manual/html_node/ISO-C-Thread_002dlocal-Storage.html.

Gnulib module: tss

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 9.3, NetBSD 8.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Portability problems not fixed by Gnulib:

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10.1234 ttyname

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ttyname.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.
  • This function is just a stub that produces an error message on standard error on some platforms: Android 4.3.

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10.1235 ttyname_r

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ttyname_r.html

Gnulib module: ttyname_r

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, Minix 3.1.8, mingw, MSVC 14.
  • This function is not declared unless _REENTRANT is defined, on some platforms: HP-UX 11.
  • This function has an incompatible declaration on some platforms: Solaris 11.4 (when _POSIX_PTHREAD_SEMANTICS is not defined).
  • This function refuses to do anything when the output buffer is less than 128 bytes large, on some platforms: Solaris 11 2010-11.
  • This function is just a stub that produces an error message on standard error on some platforms: Android 4.3.

Portability problems not fixed by Gnulib:

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10.1236 twalk

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/twalk.html

Gnulib module: tsearch

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 4.4.

Portability problems not fixed by Gnulib:

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10.1237 tzname

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tzname.html

Gnulib module: tzname

Portability problems fixed by Gnulib:

  • This variable is called _tzname on some platforms: mingw with -DNO_OLDNAMES, MSVC.

Portability problems not fixed by Gnulib:

  • This variable’s contents are unreliable if you use a geographical TZ setting like TZ="America/Los_Angeles".
  • The address of this variable is not a compile-time constant on some platforms: Cygwin, mingw, MSVC.
  • Native Windows platforms (mingw, MSVC) support only a subset of time zones supported by GNU or specified by POSIX. See tzset.

This variable is vestigial: it is not needed and does not suffice in general. It is planned to be removed from a future version of POSIX. A more portable way of getting the time zone abbreviation is to use strftime with the %Z format. See strftime.

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10.1238 tzset

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/tzset.html

Gnulib module: tzset

Portability problems fixed by Gnulib:

  • On native Windows platforms (mingw, MSVC), this function works incorrectly when the environment variable TZ has been set by Cygwin.

Portability problems not fixed by Gnulib:

  • Native Windows platforms (mingw, MSVC) support only a subset of POSIX-specified values for the TZ environment variable, consisting of a time zone abbreviation containing exactly three ASCII letters with no daylight saving time or angle brackets, and with no support for tz database settings like TZ='America/New_York'. Even this subset does not work on applications built via the Universal Windows Platform, as it does not make environment variables like TZ available to applications.
  • Older POSIX platforms do not support angle brackets in TZ values, as this feature was added in IEEE Std 1003.1-2001.

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10.1239 ufromfp

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.1240 ufromfpf

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.1241 ufromfpl

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.1242 ufromfpx

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.1243 ufromfpxf

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.1244 ufromfpxl

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Rounding-Functions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.24, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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10.1245 ulimit

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ulimit.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function is removed in POSIX.1-2024. Use the functions getrlimit and setrlimit instead.

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10.1246 umask

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/umask.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.1247 uname

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/uname.html

Gnulib module: uname

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.1248 ungetc

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ungetc.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.

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10.1249 ungetwc

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/ungetwc.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.5.x.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1251 unlinkat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/unlinkat.html

Gnulib module: unlinkat

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.5.x, mingw, MSVC 14. But the replacement function is not safe to be used in libraries and is not multithread-safe.
  • This function is declared in <fcntl.h>, not in <unistd.h>, on some platforms: Cygwin 1.7.1, Android 4.3.
  • On Mac OS X 10.10, in a writable HFS mount, unlinkat(fd, "..", 0) succeeds without doing anything.
  • Some systems mistakenly succeed on unlinkat(fd,"file/",flag): GNU/Hurd, Solaris 9.

Portability problems not fixed by Gnulib:

  • When unlinkat(fd,name,AT_REMOVEDIR) fails because the specified directory is not empty, the errno value is system dependent.
  • POSIX requires that unlinkdir(fd,"link-to-empty/",AT_REMOVEDIR) remove empty and leave link-to-empty as a dangling symlink. This is counter-intuitive, so some systems fail with ENOTDIR instead: glibc
  • Some systems allow a superuser to unlink directories, even though this can cause file system corruption. The error given if a process is not permitted to unlink directories varies across implementations; it is not always the POSIX value of EPERM. Meanwhile, if a process has the ability to unlink directories, POSIX requires that unlinkat(fd,"symlink-to-dir/",0) remove dir and leave symlink-to-dir dangling; this behavior is counter-intuitive. The gnulib module unlinkdir can help determine whether code must be cautious of unlinking directories.
  • Removing an open file is non-portable: On Unix this allows the programs that have the file already open to continue working with it; the file’s storage is only freed when the no process has the file open any more. On Windows, the attempt to remove an open file fails.

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10.1252 unlockpt

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/unlockpt.html

Gnulib module: unlockpt

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • This function reports success for invalid file descriptors on some platforms: NetBSD 5.1, Cygwin 1.7.9.

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10.1253 unsetenv

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/unsetenv.html

Gnulib module: unsetenv

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11.23, Solaris 9, mingw, MSVC 14.
  • This function has the return type ‘void’ instead of ‘int’ on some platforms: FreeBSD 6.0, NetBSD 1.6, OpenBSD 3.8.
  • On some platforms, this function does not fail with ‘EINVAL’ when passed an empty string or a string containing ‘=’: FreeBSD 6.0, NetBSD 1.6, OpenBSD 4.7.
  • This function removes only the first value association for the given environment variable, not all of them, on some platforms: Solaris 11.4, Haiku.

Portability problems not fixed by Gnulib:

  • Older versions of POSIX required that unsetenv(NULL) gracefully fail with EINVAL, but not all implementations guarantee this, and the requirement was removed.

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10.1254 uselocale

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/uselocale.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 9.0, NetBSD 10.0, OpenBSD 6.1, Minix 3.1.8, AIX 6.1, HP-UX 11, Solaris 11.3, Cygwin 2.5.x, mingw, MSVC 14, Android API level 20.
  • This function is not documented and leads to crashes in subsequent setlocale invocations on some platforms: AIX 7.2.
  • This function is useless because the locale_t type is not defined on some platforms: z/OS.
  • This function is useless because the locale_t type contains basically no information on some platforms: OpenBSD 7.4.

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10.1255 utime

Removed in POSIX.1-2024. POSIX.1-2017 specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/utime.html

Gnulib module: utime

Portability problems fixed by Gnulib:

  • The times that are set on the file are affected by the current time zone and by the DST flag of the current time zone on some platforms: mingw, MSVC 14 (when the environment variable TZ is set).
  • On some platforms, the prototype for utime omits const for the second argument: mingw, MSVC 14.
  • On some platforms, utime("link-to-file/",buf) succeeds instead of failing with ENOTDIR. macOS 14.

Portability problems not fixed by Gnulib:

  • On some platforms, this function mis-handles a trailing slash: Solaris 9.
  • This function cannot set full timestamp resolution. Use utimensat(AT_FDCWD,file,times,0), or the gnulib module utimens, instead.
  • This function is removed in POSIX.1-2024. You can use Gnulib module utimens instead.

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10.1256 utimensat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/utimensat.html

Gnulib module: utimensat

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.5, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 3.0. However, the replacement function may end up truncating timestamps to worse resolution than supported by the file system. Furthermore, the replacement function is not safe to be used in libraries and is not multithread-safe.
  • This function returns a bogus value instead of failing with ENOSYS on some platforms: Linux kernel 2.6.21.
  • This function fails with ENOSYS if passed the flag AT_SYMLINK_NOFOLLOW on a regular file: Linux kernel 2.6.22.
  • When using UTIME_OMIT or UTIME_NOW, some systems require the tv_sec argument to be 0, and don’t necessarily handle all file permissions in the manner required by POSIX: Linux kernel 2.6.25.
  • When using UTIME_OMIT for the modification time, but specifying an access time, some systems fail to update the change time: Linux kernel 2.6.32, macOS 14, NetBSD 10.0, Solaris 11.1.
  • Out-of-range values of tv_nsec do not lead to a failure on some platforms: Linux kernel 2.6.22.19 on hppa, NetBSD 10.0.
  • On some platforms, this function mis-handles a trailing slash: AIX 7.2.

Portability problems not fixed by Gnulib:

  • On some platforms, timestamps of symbolic links cannot be modified, so the replacement fails with ENOSYS if passed the flag AT_SYMLINK_NOFOLLOW on a symlink.
  • The mere act of using lstat modifies the access time of symlinks on some platforms, so utimensat with AT_SYMLINK_NOFOLLOW can only effectively change modification time: Cygwin.
  • The mere act of using stat modifies the access time of directories on some platforms, so utimensat can only effectively change directory modification time: Cygwin 1.5.x.

The gnulib module fdutimensat provides a similar interface.

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10.1257 utimes

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/utimes.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.
  • On some platforms, this function mis-handles a trailing slash: FreeBSD 7.2, Solaris 9.
  • This function cannot set full timestamp resolution. In particular, some platforms incorrectly round rather than truncate. Use utimensat(AT_FDCWD,file,times,0), or the gnulib module utimens, instead.
  • On some platforms, utimes (file, NULL) fails to set the file’s timestamp to the current time: glibc 2.3.3.
  • On some platforms, utimes failed on read-only files when utime worked fine. glibc 2.2.5.
  • On OS/2, this function cannot set the timestamp to earlier than the year 1980 in local time.
  • On OS/2, this function cannot set the timestamp to an odd number of seconds.
  • On OS/2, this function does not work on an opened file.

Extension: Gnulib provides a module ‘utimens’ that works around these problems and allows to set the time with nanosecond resolution (as far as supported by the file system).

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10.1258 va_arg

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/va_arg.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • The second argument of va_arg must be a type that is invariant under the “default argument promotions” (ISO C 99 6.5.2.2 paragraph 6). This means that the following are not valid here:
    ‘float’

    Use ‘double’ instead.

    ‘bool’

    Use ‘int’ instead.

    Integer types smaller than ‘int’.

    Use ‘int’ or ‘unsigned int’ instead.

    This is a portability problem because you don’t know the width of some abstract types like uid_t, gid_t, mode_t. So, instead of 

    mode = va_arg (ap, mode_t);

    you have to write 

    mode = (sizeof (mode_t) < sizeof (int)
        ? va_arg (ap, int)
        : va_arg (ap, mode_t));

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10.1259 va_copy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/va_copy.html

Gnulib module: stdarg

Portability problems fixed by Gnulib:

  • This macro is missing on some platforms: AIX 5.1 with cc or xlc, HP-UX 11 with cc.

Portability problems not fixed by Gnulib:

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10.1260 va_end

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/va_end.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.1261 va_start

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/va_start.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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10.1262 vdprintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vdprintf.html

Gnulib module: vdprintf or vdprintf-posix or vdprintf-gnu

Portability problems fixed by either Gnulib module vdprintf or vdprintf-posix or vdprintf-gnu:

  • This function is missing on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.5.x, mingw, MSVC 14.

Portability problems fixed by either Gnulib module vdprintf-posix or vdprintf-gnu:

  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • printf "%f", "%e", "%g" of Infinity and NaN yields an incorrect result on some platforms: AIX 7.3, Solaris 11.4.
  • This function does not support the ‘a’ and ‘A’ directives on some platforms: Solaris 11.4.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support precisions in the ‘ls’ directive correctly on some platforms: Solaris 11.4.
  • This function does not round the argument of the ‘a’ directive correctly on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4.
  • printf "%010f" of NaN and Infinity yields an incorrect result (padded with zeroes, or wrong capitalization) on some platforms: AIX 7.3, Solaris 11.4.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • This function does not support precisions larger than 512 or 1024 in integer, floating-point and pointer output on some platforms: AIX 7.1.
  • This function produces wrong output for the ‘lc’ directive with a NUL wide character argument on some platforms: musl libc 1.2.4.

Portability problems fixed by Gnulib module vdprintf-gnu:

  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.

Portability problems fixed by either Gnulib module vdprintf-posix or vdprintf-gnu and additionally the Gnulib module printf-with-n-directive:

  • This function does not support the ‘n’ directive on some platforms: glibc when used with _FORTIFY_SOURCE >= 2 (set by default on Ubuntu), macOS 14, OpenBSD, Android.

Portability problems not fixed by Gnulib:

  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.
  • Formatting noncanonical ‘long double’ numbers produces nonmeaningful results on some platforms: glibc and others, on x86, x86_64, IA-64 CPUs.
  • When formatting an integer with grouping flag, this function inserts thousands separators even in the "C" locale on some platforms: NetBSD 5.1.
  • On some platforms, this function does not set errno or the stream error indicator on attempts to write to a read-only stream: Cygwin 1.7.9.

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10.1263 vfprintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vfprintf.html

Gnulib module: vfprintf-posix or vfprintf-gnu or stdio, nonblocking, sigpipe

Portability problems fixed by either Gnulib module vfprintf-posix or vfprintf-gnu:

  • This function does not support size specifiers as in C99 (hh, ll, j, t, z) on some platforms: AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • printf of ‘long double’ numbers is unsupported on some platforms: mingw, MSVC 14.
  • printf "%f", "%e", "%g" of Infinity and NaN yields an incorrect result on some platforms: AIX 7.3, Solaris 11.4, mingw, MSVC 14.
  • This function does not support the ‘a’ and ‘A’ directives on some platforms: FreeBSD 5.2.1, OpenBSD 4.0, AIX 5.2, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support the ‘F’ directive on some platforms: NetBSD 3.0, AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘ls’ directive on some platforms: OpenBSD 4.0, Cygwin 1.5.x, Haiku.
  • This function does not support precisions in the ‘ls’ directive correctly on some platforms: Solaris 11.4.
  • This function does not support format directives that access arguments in an arbitrary order, such as "%2$s", on some platforms: NetBSD 3.0, mingw, MSVC 14.
  • This function doesn’t support the ' flag on some platforms: NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
  • This function does not round the argument of the ‘a’ directive correctly on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4.
  • printf "%010f" of NaN and Infinity yields an incorrect result (padded with zeroes, or wrong capitalization) on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 7.3, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC/clang.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • This function does not support precisions larger than 512 or 1024 in integer, floating-point and pointer output on some platforms: AIX 7.1, Solaris 10/x86, mingw, MSVC/clang.
  • This function mishandles large floating point precisions (for example, formatting 1.0 with ‘"%.511f"’) on some platforms: Solaris 10.
  • This function produces wrong output for the ‘lc’ directive with a NUL wide character argument on some platforms: musl libc 1.2.4.
  • This function can crash in out-of-memory conditions on some platforms: FreeBSD 14.0, NetBSD 5.0.

Portability problems fixed by Gnulib module vfprintf-gnu:

  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.

Portability problems fixed by either Gnulib module vfprintf-posix or vfprintf-gnu and additionally the Gnulib module printf-with-n-directive:

  • This function does not support the ‘n’ directive on some platforms: glibc when used with _FORTIFY_SOURCE >= 2 (set by default on Ubuntu), macOS 14, OpenBSD, MSVC 14, Android.

Portability problems fixed by Gnulib module stdio or vfprintf-posix or vfprintf-gnu, together with module nonblocking:

  • When writing to a non-blocking pipe whose buffer is full, this function fails with errno being set to ENOSPC instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems fixed by Gnulib module stdio or vfprintf-posix or vfprintf-gnu, together with module sigpipe:

  • When writing to a pipe with no readers, this function fails, instead of obeying the current SIGPIPE handler, on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.
  • Formatting noncanonical ‘long double’ numbers produces nonmeaningful results on some platforms: glibc and others, on x86, x86_64, IA-64 CPUs.
  • When formatting an integer with grouping flag, this function inserts thousands separators even in the "C" locale on some platforms: NetBSD 5.1.
  • Attempting to write to a read-only stream fails with EOF but does not set the error flag for ferror on some platforms: glibc 2.13, cygwin 1.7.9.

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10.1264 vfscanf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vfscanf.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-vfscanf.html

Gnulib module: vfscanf, nonblocking

Portability problems fixed by Gnulib module vfscanf, together with module nonblocking:

  • When reading from a non-blocking pipe whose buffer is empty, this function fails with errno being set to EINVAL instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.38, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.2, AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • On Windows, this function doesn’t support the hh, ll, j, t, z size specifiers.

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10.1265 vfwprintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vfwprintf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11.00, Cygwin 1.5.x.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.
  • In the C or POSIX locales, the %c and %s conversions may fail on some platforms: glibc 2.35.
  • When formatting an integer with grouping flag, this function inserts thousands separators even in the "C" locale on some platforms: NetBSD 5.1.
  • On some platforms, this function does not set errno or the stream error indicator on attempts to write to a read-only stream: Cygwin 1.7.9.

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10.1266 vfwscanf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vfwscanf.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-vfwscanf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11.23, Cygwin 1.5.x, Android 4.4.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.38, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.2, AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1267 vprintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vprintf.html

Gnulib module: vprintf-posix or vprintf-gnu or stdio, nonblocking, sigpipe

Portability problems fixed by either Gnulib module vprintf-posix or vprintf-gnu:

  • This function does not support size specifiers as in C99 (hh, ll, j, t, z) on some platforms: AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • printf of ‘long double’ numbers is unsupported on some platforms: mingw, MSVC 14.
  • printf "%f", "%e", "%g" of Infinity and NaN yields an incorrect result on some platforms: AIX 7.3, Solaris 11.4, mingw, MSVC 14.
  • This function does not support the ‘a’ and ‘A’ directives on some platforms: FreeBSD 5.2.1, OpenBSD 4.0, AIX 5.2, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support the ‘F’ directive on some platforms: NetBSD 3.0, AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘ls’ directive on some platforms: OpenBSD 4.0, Cygwin 1.5.x, Haiku.
  • This function does not support precisions in the ‘ls’ directive correctly on some platforms: Solaris 11.4.
  • This function does not support format directives that access arguments in an arbitrary order, such as "%2$s", on some platforms: NetBSD 3.0, mingw, MSVC 14.
  • This function doesn’t support the ' flag on some platforms: NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
  • This function does not round the argument of the ‘a’ directive correctly on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4.
  • printf "%010f" of NaN and Infinity yields an incorrect result (padded with zeroes, or wrong capitalization) on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 7.3, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC/clang.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • This function does not support precisions larger than 512 or 1024 in integer, floating-point and pointer output on some platforms: AIX 7.1, Solaris 10/x86, mingw, MSVC/clang.
  • This function mishandles large floating point precisions (for example, formatting 1.0 with ‘"%.511f"’) on some platforms: Solaris 10.
  • This function produces wrong output for the ‘lc’ directive with a NUL wide character argument on some platforms: musl libc 1.2.4.
  • This function can crash in out-of-memory conditions on some platforms: FreeBSD 14.0, NetBSD 5.0.

Portability problems fixed by Gnulib module vprintf-gnu:

  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.

Portability problems fixed by either Gnulib module vprintf-posix or vprintf-gnu and additionally the Gnulib module printf-with-n-directive:

  • This function does not support the ‘n’ directive on some platforms: glibc when used with _FORTIFY_SOURCE >= 2 (set by default on Ubuntu), macOS 14, OpenBSD, MSVC 14, Android.

Portability problems fixed by Gnulib module stdio or vprintf-posix or vprintf-gnu, together with module nonblocking:

  • When writing to a non-blocking pipe whose buffer is full, this function fails with errno being set to ENOSPC instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems fixed by Gnulib module stdio or vprintf-posix or vprintf-gnu, together with module sigpipe:

  • When writing to a pipe with no readers, this function fails, instead of obeying the current SIGPIPE handler, on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.
  • Formatting noncanonical ‘long double’ numbers produces nonmeaningful results on some platforms: glibc and others, on x86, x86_64, IA-64 CPUs.
  • When formatting an integer with grouping flag, this function inserts thousands separators even in the "C" locale on some platforms: NetBSD 5.1.
  • Attempting to write to a read-only stream fails with EOF but does not set the error flag for ferror on some platforms: glibc 2.13, cygwin 1.7.9.

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10.1268 vscanf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vscanf.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-vscanf.html

Gnulib module: vscanf, nonblocking

Portability problems fixed by Gnulib module vscanf, together with module nonblocking:

  • When reading from a non-blocking pipe whose buffer is empty, this function fails with errno being set to EINVAL instead of EAGAIN on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.38, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.2, AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • On Windows, these functions don’t support the hh, ll, j, t, z size specifiers.

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10.1269 vsnprintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vsnprintf.html

Gnulib module: vsnprintf or vsnprintf-posix or vsnprintf-gnu

Portability problems fixed by either Gnulib module vsnprintf or vsnprintf-posix or vsnprintf-gnu:

  • This function does not support format directives that access arguments in an arbitrary order, such as "%2$s", on some platforms: NetBSD 3.0, mingw, MSVC 14.
  • This function does not return a byte count as specified in C99 on some platforms: HP-UX 11, Solaris 9, mingw, MSVC 14.

Portability problems fixed by either Gnulib module vsnprintf-posix or vsnprintf-gnu:

  • This function does not support size specifiers as in C99 (hh, ll, j, t, z) on some platforms: AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • printf of ‘long double’ numbers is unsupported on some platforms: mingw, MSVC 14.
  • printf "%f", "%e", "%g" of Infinity and NaN yields an incorrect result on some platforms: AIX 7.3, Solaris 11.4, mingw, MSVC 14.
  • This function does not support the ‘a’ and ‘A’ directives on some platforms: FreeBSD 5.2.1, OpenBSD 4.0, AIX 5.2, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support the ‘F’ directive on some platforms: NetBSD 3.0, AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘ls’ directive on some platforms: OpenBSD 4.0, Cygwin 1.5.x, Haiku.
  • This function does not support precisions in the ‘ls’ directive correctly on some platforms: Solaris 11.4.
  • This function doesn’t support the ' flag on some platforms: NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
  • This function does not round the argument of the ‘a’ directive correctly on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4.
  • printf "%010f" of NaN and Infinity yields an incorrect result (padded with zeroes, or wrong capitalization) on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 7.3, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC/clang.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • This function does not support precisions larger than 512 or 1024 in integer, floating-point and pointer output on some platforms: AIX 7.1, Solaris 10/x86, mingw, MSVC/clang.
  • This function mishandles large floating point precisions (for example, formatting 1.0 with ‘"%.511f"’) on some platforms: Solaris 10.
  • This function produces wrong output for the ‘lc’ directive with a NUL wide character argument on some platforms: musl libc 1.2.4.
  • This function can crash in out-of-memory conditions on some platforms: FreeBSD 14.0, NetBSD 5.0.
  • This function does not truncate the result as specified in C99 on some platforms: mingw, MSVC 14.
  • This function overwrites memory even when a zero size argument is passed on some platforms: HP-UX 11.

Portability problems fixed by Gnulib module vsnprintf-gnu:

  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.

Portability problems fixed by either Gnulib module vsnprintf-posix or vsnprintf-gnu and additionally the Gnulib module printf-with-n-directive:

  • This function does not fully support the ‘n’ directive on some platforms: glibc when used with _FORTIFY_SOURCE >= 2 (set by default on Ubuntu), macOS 14, OpenBSD, HP-UX 11, mingw, MSVC 14, Android.

Portability problems not fixed by Gnulib:

  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.
  • Formatting noncanonical ‘long double’ numbers produces nonmeaningful results on some platforms: glibc and others, on x86, x86_64, IA-64 CPUs.
  • When formatting an integer with grouping flag, this function inserts thousands separators even in the "C" locale on some platforms: NetBSD 5.1.

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10.1270 vsprintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vsprintf.html

Gnulib module: vsprintf-posix or vsprintf-gnu

Portability problems fixed by either Gnulib module vsprintf-posix or vsprintf-gnu:

  • This function does not support size specifiers as in C99 (hh, ll, j, t, z) on some platforms: AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • printf of ‘long double’ numbers is unsupported on some platforms: mingw, MSVC 14.
  • printf "%f", "%e", "%g" of Infinity and NaN yields an incorrect result on some platforms: AIX 7.3, Solaris 11.4, mingw, MSVC 14.
  • This function does not support the ‘a’ and ‘A’ directives on some platforms: FreeBSD 5.2.1, OpenBSD 4.0, AIX 5.2, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support the ‘F’ directive on some platforms: NetBSD 3.0, AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘ls’ directive on some platforms: OpenBSD 4.0, Cygwin 1.5.x, Haiku.
  • This function does not support precisions in the ‘ls’ directive correctly on some platforms: Solaris 11.4.
  • This function does not support format directives that access arguments in an arbitrary order, such as "%2$s", on some platforms: NetBSD 3.0, mingw, MSVC 14.
  • This function doesn’t support the ' flag on some platforms: NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
  • This function does not round the argument of the ‘a’ directive correctly on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4.
  • printf "%010f" of NaN and Infinity yields an incorrect result (padded with zeroes, or wrong capitalization) on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 7.3, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC/clang.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • This function does not support precisions larger than 512 or 1024 in integer, floating-point and pointer output on some platforms: AIX 7.1, Solaris 10/x86, mingw, MSVC/clang.
  • This function mishandles large floating point precisions (for example, formatting 1.0 with ‘"%.511f"’) on some platforms: Solaris 10.
  • This function produces wrong output for the ‘lc’ directive with a NUL wide character argument on some platforms: musl libc 1.2.4.
  • This function can crash in out-of-memory conditions on some platforms: FreeBSD 14.0, NetBSD 5.0.
  • The compiler warns that this function is deprecated: macOS 14.

Portability problems fixed by Gnulib module vsprintf-gnu:

  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.

Portability problems fixed by either Gnulib module vsprintf-posix or vsprintf-gnu and additionally the Gnulib module printf-with-n-directive:

  • This function does not support the ‘n’ directive on some platforms: glibc when used with _FORTIFY_SOURCE >= 2 (set by default on Ubuntu), macOS 14, OpenBSD, MSVC 14, Android.

Portability problems not fixed by Gnulib:

  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.
  • Formatting noncanonical ‘long double’ numbers produces nonmeaningful results on some platforms: glibc and others, on x86, x86_64, IA-64 CPUs.
  • When formatting an integer with grouping flag, this function inserts thousands separators even in the "C" locale on some platforms: NetBSD 5.1.

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10.1271 vsscanf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vsscanf.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-vsscanf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: MSVC 14.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.38, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.2, AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
  • On Windows platforms (excluding Cygwin), this function does not set errno upon failure.
  • On Windows, these functions don’t support the hh, ll, j, t, z size specifiers.

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10.1272 vswprintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vswprintf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11.00, Cygwin 1.5.x.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.
  • On Windows, this function does not take a buffer size as second argument.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.
  • In the C or POSIX locales, the %c and %s conversions may fail on some platforms: glibc 2.35.
  • When formatting an integer with grouping flag, this function inserts thousands separators even in the "C" locale on some platforms: NetBSD 5.1.

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10.1273 vswscanf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vswscanf.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-vswscanf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11.23, Cygwin 1.5.x, MSVC 14, Android 4.4.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.38, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.2, AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1274 vwprintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vwprintf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11.00, Cygwin 1.7.
  • This function exists, but does not support wide arguments on some platforms: Cygwin 1.5.x.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.
  • In the C or POSIX locales, the %c and %s conversions may fail on some platforms: glibc 2.35.
  • When formatting an integer with grouping flag, this function inserts thousands separators even in the "C" locale on some platforms: NetBSD 5.1.
  • On some platforms, this function does not set errno or the stream error indicator on attempts to write to a read-only stream: Cygwin 1.7.9.

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10.1275 vwscanf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/vwscanf.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-vwscanf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11.23, Cygwin 1.5.x, Android 4.4.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.38, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.2, AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1276 wait

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wait.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.1277 waitid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/waitid.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 7.1, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14.
  • As of 2005, no system is known on which waitid with flag WNOWAIT works correctly.

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10.1278 waitpid

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/waitpid.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-waitpid-3.html

Gnulib module: waitpid

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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10.1279 wcpcpy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcpcpy.html

Gnulib module: wcpcpy

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14.
  • This function is not declared (without -D_GNU_SOURCE) on some platforms: glibc 2.13.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1280 wcpncpy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcpncpy.html

Gnulib module: wcpncpy

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14.
  • This function is not declared (without -D_GNU_SOURCE) on some platforms: glibc 2.13.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1281 wcrtomb

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcrtomb.html

Gnulib module: wcrtomb

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.00, mingw.
  • This function produces wrong characters in the C locale on some platforms: Android 4.3.
  • This function returns 0 when the first argument is NULL in some locales on some platforms: Solaris 11.3.
  • This function does not ignore the second argument when the first argument is NULL on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the ISO C11 function c32rtomb, provided by Gnulib module c32rtomb, operates on 32-bit wide characters and therefore does not have this limitation.

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10.1282 wcscasecmp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcscasecmp.html

Gnulib module: wcscasecmp

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1283 wcscasecmp_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcscasecmp_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: Mac OS X 10.5, FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 5.1.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1284 wcscat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcscat.html

Gnulib module: wcscat

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1285 wcschr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcschr.html

Gnulib module: wcschr

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1286 wcscmp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcscmp.html

Gnulib module: wcscmp

Portability problems fixed by Gnulib:

  • This function compares the wide characters as if they were unsigned, although wchar_t is signed, on some platforms: glibc 2.14.1 on x86 or x86_64, musl libc 1.2.3, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.2, Solaris 11.4.
  • This function may return a wrong result if the two arguments are of different length, on some platforms: glibc 2.37 on arm and arm64 CPUs, AIX 7.2 in 64-bit mode.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1287 wcscoll

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcscoll.html

Gnulib module: wcscoll

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1288 wcscoll_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcscoll_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1289 wcscpy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcscpy.html

Gnulib module: wcscpy

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

Note: wcscpy (dst, src) is only safe to use when you can guarantee that there are at least wcslen (src) + 1 wide characters allocated at dst.

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10.1290 wcscspn

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcscspn.html

Gnulib module: wcscspn

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1291 wcsdup

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsdup.html

Gnulib module: wcsdup

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, HP-UX 11, Solaris 10, Cygwin 1.5.x.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1292 wcsftime

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsftime.html

Gnulib module: wcsftime

Portability problems fixed by Gnulib:

  • On native Windows platforms (mingw, MSVC), this function works incorrectly when the environment variable TZ has been set by Cygwin.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, Cygwin 1.5.x.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.
  • Native Windows platforms (mingw, MSVC) support only a subset of time zones specified by POSIX. See tzset.

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10.1293 wcslen

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcslen.html

Gnulib module: wcslen

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1294 wcsncasecmp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsncasecmp.html

Gnulib module: wcsncasecmp

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1295 wcsncasecmp_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsncasecmp_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: Mac OS X 10.5, FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 5.1.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1296 wcsncat

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsncat.html

Gnulib module: wcsncat

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1297 wcsncmp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsncmp.html

Gnulib module: wcsncmp

Portability problems fixed by Gnulib:

  • This function compares the wide characters as if they were unsigned, although wchar_t is signed, on some platforms: glibc 2.14.1 on x86 or x86_64, musl libc 1.2.3, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.2, Solaris 11.4.
  • This function may return a wrong result if the two arguments are of different length, on some platforms: AIX 7.2 in 64-bit mode.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1298 wcsncpy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsncpy.html

Gnulib module: wcsncpy

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

Note: This function has no real use: It cannot be used for filling a fixed-size record with a wide string, before writing it to a file, because the wide string encoding is platform dependent and, on some platforms, also locale dependent. And this function is not appropriate for copying a wide string into a bounded memory area, because you have no guarantee that the result will be null-terminated. Even if you add the null character at the end yourself, this function is inefficient (as it spends time clearing unused memory) and will allow silent truncation to occur, which is not a good behavior for GNU programs.

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10.1299 wcsnlen

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsnlen.html

Gnulib module: wcsnlen

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 7.1, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1300 wcsnrtombs

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsnrtombs.html

Gnulib module: wcsnrtombs

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 11.3, Cygwin 1.5.x, mingw, MSVC 14, Android 4.4.
  • This function cannot consume valid sequences of wide characters on some platforms: Solaris 11.4.
  • In C++ mode, the system’s <wchar.h> defines std::wcsnrtombs but not ::wcsnrtombs on some platforms: Solaris 11 OpenIndiana.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32snrtombs, provided by Gnulib module c32snrtombs, operates on 32-bit wide characters and therefore does not have this limitation.

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10.1301 wcspbrk

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcspbrk.html

Gnulib module: wcspbrk

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1302 wcsrchr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsrchr.html

Gnulib module: wcsrchr

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1303 wcsrtombs

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsrtombs.html

Gnulib module: wcsrtombs

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.00, mingw.
  • This function does not ignore the length argument if the destination argument is NULL on some platforms: mingw.
  • This function updates the source pointer also if the destination argument is NULL on some platforms: HP-UX 11.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32srtombs, provided by Gnulib module c32srtombs, operates on 32-bit wide characters and therefore does not have this limitation.

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10.1304 wcsspn

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsspn.html

Gnulib module: wcsspn

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1305 wcsstr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsstr.html

Gnulib module: wcsstr or wcsstr-simple

Portability problems fixed by either Gnulib module wcsstr-simple or wcsstr:

  • This function is missing on some platforms: HP-UX 11.00.

Portability problems fixed by Gnulib module wcsstr:

  • This function has quadratic instead of linear worst-case complexity on some platforms: glibc 2.39, macOS 14, FreeBSD 13.1, NetBSD 10.0, OpenBSD 7.2, AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1306 wcstod

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstod.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.5.x.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1307 wcstof

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstof.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.5.x, MSVC 9, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1308 wcstoimax

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstoimax.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11.11, Solaris 9, Cygwin 1.5.x, MSVC 9, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1309 wcstok

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstok.html

Gnulib module: wcstok

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Cygwin 1.5.x.
  • This function takes only two arguments on some platforms: mingw, older MSVC.
  • This function may use hidden state, ignoring the third argument, and thus exhibit a bug when two or more wcstok iteration loops are being performed in the same thread, on some platforms: HP-UX 11.31.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1310 wcstol

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstol.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.5.x.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1311 wcstold

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstold.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11, Solaris 9, Cygwin 1.7.x, MSVC 9, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1312 wcstoll

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstoll.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.11, Solaris 9, Cygwin 1.5.x, MSVC 9, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1313 wcstombs

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstombs.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32stombs, provided by Gnulib module c32stombs, operates on 32-bit wide characters and therefore does not have this limitation.

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10.1314 wcstoul

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstoul.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.5.x.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1315 wcstoull

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstoull.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.11, Solaris 9, Cygwin 1.5.x, MSVC 9, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1316 wcstoumax

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcstoumax.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11.11, Solaris 9, Cygwin 1.5.x, MSVC 9, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1317 wcswidth

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcswidth.html

Gnulib module: wcswidth

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32swidth, provided by Gnulib module c32swidth, operates on 32-bit wide characters and therefore does not have this limitation.

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10.1318 wcsxfrm

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsxfrm.html

Gnulib module: wcsxfrm

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.5.x.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1319 wcsxfrm_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcsxfrm_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1320 wctob

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wctob.html

Gnulib module: wctob

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.00, mingw.
  • This function clobbers caller-owned registers on some platforms: Cygwin 1.7.5.
  • This function does not work on some platforms: Solaris 9.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32tob, provided by Gnulib module c32tob, operates on 32-bit wide characters and therefore does not have this limitation.

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10.1321 wctomb

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wctomb.html

Gnulib module: wctomb

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1322 wctrans

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wctrans.html

Gnulib module: wctrans

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.00, mingw, MSVC 9, Android 7.1.
  • This function does not support the "tolower" and "toupper" mappings on some platforms: NetBSD 10.0. (It returns non-null values for the arguments "towlower" and "towupper", but with these values, the function towctrans always crashes.)

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32_get_mapping, provided by Gnulib module c32_get_mapping, operates on 32-bit wide characters and therefore does not have this limitation.

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10.1323 wctrans_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wctrans_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 7.1.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1324 wctype

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wctype.html

Gnulib module: wctype

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, MSVC 9.
  • This function is declared in <wchar.h>, not in <wctype.h>, on some platforms: HP-UX 11.00.
  • This function does not support the "blank" character class on some platforms: mingw.
  • The object returned by this function for the "blank" character class is inconsistent with the iswblank and isblank functions on some platforms: MSVC 14.
  • The object returned by this function for the "punct" character class is inconsistent with the ispunct function on some platforms: Android 11.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32_get_type_test, provided by Gnulib module c32_get_type_test, operates on 32-bit wide characters and therefore does not have this limitation.

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10.1325 wctype_l

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wctype_l.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1326 wcwidth

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wcwidth.html

Gnulib module: wcwidth

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.
  • This function is not declared (without -D_GNU_SOURCE) on some platforms: glibc 2.8.
  • This function handles combining characters in UTF-8 locales incorrectly on some platforms: macOS 14, NetBSD 9.3, OpenBSD 5.8, MidnightBSD 1.1.
  • This function returns 2 for characters with ambiguous east asian width, even in Western locales, on some platforms: Solaris 11.4.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters. However, the Gnulib function c32width, provided by Gnulib module c32width, operates on 32-bit wide characters and therefore does not have this limitation.
  • This function treats zero-width spaces like control characters on some platforms: AIX 7.2.

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10.1327 wmemchr

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wmemchr.html

Gnulib module: wmemchr

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11.00, MSVC 14.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1328 wmemcmp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wmemcmp.html

Gnulib module: wmemcmp

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11.00, MSVC 14.
  • This function compares the wide characters as if they were unsigned, although wchar_t is signed, on some platforms: glibc 2.14.1 on x86 or x86_64, musl libc 1.2.3, NetBSD 10.0, OpenBSD 7.2, Solaris 11.4.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1329 wmemcpy

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wmemcpy.html

Gnulib module: wmemcpy

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11.00, MSVC 9.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1330 wmemmove

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wmemmove.html

Gnulib module: wmemmove

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11.00, MSVC 9.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1331 wmemset

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wmemset.html

Gnulib module: wmemset

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11.00, MSVC 9.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1332 wordexp

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wordexp.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.
  • On some platforms, this function does not set errno or the stream error indicator on attempts to write to a read-only stream: Cygwin 1.7.9.

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10.1333 wordfree

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wordfree.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

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10.1334 wprintf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wprintf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11.00.
  • This function exists, but does not support wide arguments on some platforms: Cygwin 1.5.x.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.
  • In the C or POSIX locales, the %c and %s conversions may fail on some platforms: glibc 2.35.
  • When formatting an integer with grouping flag, this function inserts thousands separators even in the "C" locale on some platforms: NetBSD 5.1.
  • On some platforms, this function does not set errno or the stream error indicator on attempts to write to a read-only stream: Cygwin 1.7.9.

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10.1335 write

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/write.html

Gnulib module: write, nonblocking, sigpipe

Portability problems fixed by Gnulib module write:

  • This function is declared in a different header file (namely, <io.h>) on some platforms: mingw, MSVC 14.
  • This function crashes when invoked with invalid arguments on some platforms: MSVC 14.

Portability problems fixed by Gnulib module stdio, together with module nonblocking:

  • When writing to a non-blocking pipe whose buffer is full, this function fails with errno being set to ENOSPC instead of EAGAIN on some platforms: mingw, MSVC 14.
  • When writing to a non-blocking pipe on which no reader is currently waiting an amount of bytes that exceeds the pipe buffer’s size, then—even if the pipe’s buffer is empty—this function fails, instead of performing a partial write into the pipe buffer, on some platforms: mingw, MSVC 14.

Portability problems fixed by Gnulib module stdio, together with module sigpipe:

  • When writing to a pipe with no readers, this function fails with error EINVAL, instead of obeying the current SIGPIPE handler, on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • This function may fail with error EINTR, even in programs that don’t install any signal handlers, on some platforms: macOS 14.

For handling EINTR, Gnulib provides a module ‘safe-write’ with a function safe_write.

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10.1336 writev

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/writev.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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10.1337 wscanf

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/wscanf.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-wscanf.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, HP-UX 11.00, Cygwin 1.5.x.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.38, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.2, AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9.0, mingw, MSVC 14.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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10.1338 y0

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/y0.html

Gnulib module: y0

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.

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10.1339 y1

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/y1.html

Gnulib module: y1

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.

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10.1340 yn

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/yn.html

Gnulib module: yn

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8.

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11 Past POSIX Function Substitutes

This chapter describes which functions and function-like macros specified by older versions of POSIX are substituted by Gnulib, which portability pitfalls are fixed by Gnulib, and which (known) portability problems are not worked around by Gnulib.

The notation “Gnulib module: —” means that Gnulib does not provide a module providing a substitute for the function. When the list “Portability problems not fixed by Gnulib” is empty, such a module is not needed: No portability problems are known. Otherwise, it indicates that such a module would be useful but is not available: No one so far found this function important enough to contribute a substitute for it. If you need this particular function, you may write to <bug-gnulib at gnu dot org>.

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11.1 bcmp

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/bcmp.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 9.0.
  • This function is removed in POSIX.1-2008. Better use memcmp instead.

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11.2 bcopy

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/bcopy.html

Gnulib module: bcopy

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

  • This function is removed in POSIX.1-2008. Better use memcpy or memmove instead.

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11.3 bsd_signal

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/bsd_signal.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.3, FreeBSD 14.0, NetBSD 7.1, Cygwin 2.9, mingw, MSVC 14.

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11.4 bzero

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/bzero.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 9.0.
  • This function is removed in POSIX.1-2008. Better use memset instead.

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11.5 ecvt

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/ecvt.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 14.0, NetBSD 10.0, Android 9.0.
  • This function is not declared on some platforms: Cygwin 2.9.
  • This function is removed in POSIX.1-2008. Better use sprintf instead.

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11.6 fcvt

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/fcvt.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 14.0, NetBSD 10.0, Android 9.0.
  • This function is not declared on some platforms: Cygwin 2.9.
  • This function is removed in POSIX.1-2008. Better use sprintf instead.

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11.7 ftime

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/ftime.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.3, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Android 9.0.
  • This function is not declared on some platforms: Android 13.
  • On native Windows platforms (mingw, MSVC), this function works incorrectly when the environment variable TZ has been set by Cygwin.
  • This function is removed in POSIX.1-2008. Better use clock_gettime instead, and use ftime only as a fallback for portability to Windows platforms.

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11.8 gcvt

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/gcvt.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.3, FreeBSD 14.0, NetBSD 10.0, Android 9.0.
  • This function is not declared on some platforms: Cygwin 2.9.
  • This function is removed in POSIX.1-2008. Better use sprintf instead.

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11.9 getcontext

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/getcontext.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.

Note: A third-party implementation is available at https://github.com/kaniini/libucontext/.

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11.10 gethostbyaddr

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/gethostbyaddr.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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11.11 gethostbyname

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/gethostbyname.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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11.12 getwd

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/getwd.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 9.0.
  • The size of the buffer required for this function is not a compile-time constant. Also, the function truncates a result that would be larger than the minimum buffer size. For these reasons, this function is removed in POSIX.1-2008. Better use the getcwd function instead.

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11.13 h_errno

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/h_errno.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.34, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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11.14 index

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/index.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 9.0.
  • This function is not declared on some platforms: Android 13.
  • This function is removed in POSIX.1-2008. Better use strchr instead.

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11.15 makecontext

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/makecontext.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.

Note: A third-party implementation is available at https://github.com/kaniini/libucontext/.

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11.16 mktemp

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/mktemp.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is not appropriate for creating temporary files. (It has security risks.) Therefore it is removed in POSIX.1-2008. Better use mkstemp instead.

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11.17 pthread_attr_getstackaddr

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/pthread_attr_getstackaddr.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11, Cygwin 1.7.9, mingw, MSVC 14, Android 9.0.
  • This function is not declared on some platforms: Android 13.

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11.18 pthread_attr_setstackaddr

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/pthread_attr_setstackaddr.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11, Cygwin 1.7.9, mingw, MSVC 14, Android 9.0.
  • This function is not declared on some platforms: Android 13.

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11.19 rindex

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/rindex.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 9.0.
  • This function is removed in POSIX.1-2008. Better use strrchr instead.

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11.20 scalb

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/scalb.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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11.21 setcontext

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/setcontext.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.
  • The effects of this call are system and compiler optimization dependent, since it restores the contents of register-allocated variables but not the contents of stack-allocated variables.

Note: A third-party implementation is available at https://github.com/kaniini/libucontext/.

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11.22 swapcontext

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/swapcontext.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.

Note: A third-party implementation is available at https://github.com/kaniini/libucontext/.

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11.23 ualarm

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/ualarm.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 9.0.

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11.24 usleep

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/usleep.html

Gnulib module: usleep

Portability problems fixed by Gnulib:

  • On some systems, usleep rejects attempts to sleep longer than 1 second, as allowed by POSIX: NetBSD 10.0, mingw.

Portability problems not fixed by Gnulib:

  • According to POSIX, the usleep function may interfere with the program’s use of the SIGALRM signal. On Linux, it doesn’t; on other platforms, it may.
  • On some systems, usleep may sleep for less than the indicated duration: Cygwin 3.5.3.

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11.25 vfork

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/vfork.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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11.26 wcswcs

Removed in POSIX.1-2008. POSIX.1-2004 specification: https://pubs.opengroup.org/onlinepubs/009695399/functions/wcswcs.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function is not declared on some platforms: Android 13.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.
  • This function is removed in POSIX.1-2008. Better use wcsstr instead.

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12 Glibc Header File Substitutes

This chapter describes which header files contained in GNU libc but not specified by ISO C or POSIX are substituted by Gnulib, which portability pitfalls are fixed by Gnulib, and which (known) portability problems are not worked around by Gnulib.

The notation “Gnulib module: —” means that Gnulib does not provide a module providing a substitute for the header file. When the list “Portability problems not fixed by Gnulib” is empty, such a module is not needed: No portability problems are known. Otherwise, it indicates that such a module would be useful but is not available: No one so far found this header file important enough to contribute a substitute for it. If you need this particular header file, you may write to <bug-gnulib at gnu dot org>.

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12.1 a.out.h

Describes the structure of executables (and object files?) in the old a.out format.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: macOS 14, Solaris 11.4, mingw, MSVC 14, Android 9.0.
  • This header file is useless because most executables and object files are in ELF format on some platforms: glibc 2.3.6, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7.

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12.2 aliases.h

Defines the type struct aliasent and declares the functions setaliasent, endaliasent, getaliasent, getaliasent_r, getaliasbyname, getaliasbyname_r.

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin, mingw, MSVC 14, Android 9.0.

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12.3 alloca.h

Declares the alloca function of function-like macro.

Documentation:

Gnulib module: alloca

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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12.4 ar.h

Describes the structure of files produced by the ‘ar’ program. Defines the type struct ar_hdr and the macros ARMAG, SARMAG, ARFMAG.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.

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12.5 argp.h

Documentation:

Gnulib module: argp

Portability problems fixed by Gnulib:

  • This header file is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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12.6 argz.h

Documentation:

Gnulib module: argz

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.
  • The argz functions do not work on some platforms: Cygwin.

Portability problems not fixed by Gnulib:

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12.7 byteswap.h

Defines the functions or function-like macros bswap_16, bswap_32, bswap_64.

Gnulib module: byteswap

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: macOS 14, FreeBSD 13.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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12.8 crypt.h

Defines the type struct crypt_data and declares the functions crypt, crypt_r, setkey, setkey_r, encrypt, encrypt_r.

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14, Android 9.0.
  • The functions crypt, setkey, encrypt are missing on some platforms: HP-UX 11.
  • The type struct crypt_data and the functions crypt_r, setkey_r, encrypt_r are missing on some platforms: Solaris 11.4, Cygwin.

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12.9 endian.h

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/libc-ddefs.html

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=162

Describes the platform’s endianness (byte ordering of words stored in memory). Defines the macros BYTE_ORDER, LITTLE_ENDIAN, BIG_ENDIAN, PDP_ENDIAN.

Gnulib module: endian

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: macOS 14, FreeBSD 13.0, NetBSD 7.1, OpenBSD 3.8, Minix 3.1.8, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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12.10 envz.h

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.

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12.11 err.h

Declares the functions warn, vwarn, warnx, vwarnx, err, verr, errx, verrx.

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 10, mingw, MSVC 14.

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12.12 error.h

Declares the functions error, error_at_line and the variables error_print_progname, error_message_count, error_one_per_line.

Documentation:

Gnulib module: error-h

Portability problems fixed by Gnulib:

  • This header file is missing on many platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.9, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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12.13 execinfo.h

Declares the functions backtrace, backtrace_symbols, backtrace_symbols_fd.

Documentation:

Gnulib module: execinfo

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: musl libc, FreeBSD 9.3, NetBSD 6.1, OpenBSD 6.9, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

  • On platforms where the header file is missing, the Gnulib substitute implementation is just a stub, and does nothing.

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12.14 fpu_control.h

Handling of the FPU control word. Defines the fpu_control_t type, declares the __fpu_control variable, and defines the _FPU_GETCW, _FPU_SETCW macros.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin, mingw, MSVC 14, Android 9.0.

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12.15 fstab.h

Defines the type struct fstab, the macros FSTAB_*, _PATH_FSTAB, and declares the functions setfsent, endfsent, getfsent, getfsspec, getfsfile.

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: Minix 3.1.8, Solaris 11.4, Cygwin, mingw, MSVC 14, Android 9.0.
  • The macro _PATH_FSTAB is missing on some platforms: AIX 5.1, HP-UX 11.

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12.16 fts.h

Defines the types FTS, FTSENT and the macros FTS_*, and declares the functions fts_open, fts_read, fts_children, fts_set, fts_close.

Documentation:

Gnulib module: fts

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 11.3, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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12.17 getopt.h

Defines the type struct option and declares the variables optarg, optind, opterr, optopt and the functions getopt, getopt_long, getopt_long_only.

Documentation:

Gnulib module: getopt-gnu

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: AIX 7.2, HP-UX 11, MSVC 14.
  • The function getopt_long is missing on some platforms: Solaris 9.
  • The function getopt_long_only is missing on some platforms: FreeBSD 5.2.1, NetBSD 10.0, Solaris 9, mingw.
  • The method to reset options is incompatible on some platforms: FreeBSD 6.0, NetBSD 10.0(?), OpenBSD 6.7, Cygwin 1.5.x, mingw.
  • The function getopt does not handle a leading ‘+’ character in the options string on some platforms: Solaris 11 2010-11.

Portability problems not fixed by Gnulib:

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12.18 gshadow.h

Defines the type struct sgrp and declares the functions setsgent, endsgent, getsgent, getsgnam, sgetsgent, fgetsgent, putsgent, getsgent_r, getsgnam_r, sgetsgent_r, fgetsgent_r.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin, mingw, MSVC 14, Android 9.0.

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12.19 ieee754.h

Defines the types union ieee754_float, union ieee754_double, union ieee854_long_double.

Gnulib module: —

Portability problems fixed by Gnulib:

  • This header file is missing on all non-glibc platforms: glibc/sparc64 in 32-bit mode, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

  • The substitute for this header file has not been tested for long double and does not work on some platforms.
  • The substitute for this header file returns nonsense on (now-quite-rare) platforms that do not use IEEE floating point.

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12.20 ifaddrs.h

Defines the type struct ifaddrs and declares the functions getifaddrs, freeifaddrs.

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14.

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12.21 libintl.h

Defines the macros __USE_GNU_GETTEXT, __GNU_GETTEXT_SUPPORTED_REVISION, and declares the functions gettext, dgettext, dcgettext, ngettext, dngettext, dcngettext, textdomain, bindtextdomain, bind_textdomain_codeset.

Documentation:

Gnulib module: gettext

Portability problems fixed by Gnulib, if GNU gettext is installed:

  • This header file is missing on some platforms: macOS 14, FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14, Android 9.0.
  • The functions cannot deal with GNU .mo files with system-dependent strings (of major version 1 or of minor version 1) on some non-glibc platforms: NetBSD 3.0, Solaris 10.

Portability problems not fixed by Gnulib:

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12.23 malloc.h

Declares the function memalign and functions for customizing the malloc behavior.

Documentation:

Gnulib module: malloc-h

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: macOS 14, OpenBSD 6.7.

Portability problems not fixed by Gnulib:

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12.24 mcheck.h

Defines the type enum mcheck_status and declares the functions mcheck, mcheck_pedantic, mcheck_check_all, mprobe, mtrace, muntrace.

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin, mingw, MSVC 14, Android 9.0.

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12.25 mntent.h

Defines the type struct mntent and the macros MNTTAB, MOUNTED, MNTTYPE_*, MNTOPT_*, and declares the functions setmntent, getmntent, getmntent_r, addmntent, endmntent, hasmntopt.

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, mingw, MSVC 14.
  • The function getmntent_r is missing on all non-glibc platforms: AIX 5.1, HP-UX 11, Cygwin, Android 9.0.

Gnulib module mountlist provides a higher-level abstraction.

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12.26 obstack.h

Documentation:

Gnulib module: obstack

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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12.27 paths.h

Defines the macros _PATH_*.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: Minix 3.1.8, HP-UX 11, Solaris 11 2010-11, mingw, MSVC 14.
  • The set of _PATH_* macros is platform dependent.

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12.28 printf.h

Defines the type struct printf_info and the macros and enum values PA_*, and declares the functions printf_function, printf_arginfo_function, register_printf_function, parse_printf_format, printf_size, printf_size_info.

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin, mingw, MSVC 14, Android 9.0.

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12.29 pty.h

Declares the functions openpty and forkpty.

Documentation:

Gnulib module: pty

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms that declare the forkpty and openpty functions in util.h or libutil.h instead: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7.
  • This header file is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4.

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.

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12.30 resolv.h

Defines the types res_sendhookact, res_send_qhook, res_send_rhook, res_state, struct res_sym and the macros _PATH_RESCONF, RES_*, and declares the functions res_close, res_init, res_mkquery, res_query, res_querydomain, res_search, res_send.

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: Cygwin 1.5.x, mingw, MSVC 14.
  • The functions are missing on some platforms: HP-UX 11.

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12.31 shadow.h

Defines the type struct spwd and declares the functions setspent, endspent, getspent, getspent_r, getspnam, getspnam_r, sgetspent, sgetspent_r, fgetspent, fgetspent_r, putspent, lckpwdf, ulckpwdf.

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Cygwin, mingw, MSVC 14, Android 9.0.
  • The functions getspent_r, getspnam_r, sgetspent_r, fgetspent, fgetspent_r, putspent are missing on some platforms: HP-UX 11.
  • The functions sgetspent, sgetspent_r are missing on some platforms: HP-UX 11, Solaris 11.4.

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12.32 sys/file.h

Declares the function flock.

Gnulib module: sys_file

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: MSVC 14.

Portability problems not fixed by Gnulib:

  • This header file does not declare the flock function on some platforms: AIX 7.1, HP-UX 11.23, Solaris 11.4.

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12.33 sys/ioctl.h

Declares the function ioctl.

Documentation:

Gnulib module: sys_ioctl

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.
  • This header file does not declare the ioctl function on some platforms: AIX 5.1, Solaris 11.4, Haiku 2017.

Portability problems not fixed by Gnulib:

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12.34 sys/random.h

Declares the function getrandom and the flags for it.

Documentation:

Gnulib module: sys_random

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: glibc 2.24, NetBSD 9.3, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.11, Cygwin 2.6.x, mingw, MSVC 14.
  • This header file is not self-contained on some platforms: uClibc, macOS 11.1.

Portability problems not fixed by Gnulib:

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12.35 sysexits.h

Defines the EX_* macros, including EX_OK.

Gnulib module: sysexits

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: mingw, MSVC 14.
  • This header file defines no EX_* macros if _BSD_SOURCE is not defined on some platforms: Haiku.
  • The macro EX_CONFIG is missing on some platforms: HP-UX 11.

Portability problems not fixed by Gnulib:

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12.36 ttyent.h

Defines the type struct ttyent and declares the functions setttyent, endttyent, getttyent, getttynam.

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This header file is missing on some platforms: HP-UX 11, Solaris 11.4, Cygwin, mingw, MSVC 14, Android 9.0.

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12.37 utmp.h

Defines functions for login and logout (to a tty session) and for examining the history of logins and logouts.

Documentation:

Gnulib module: utmp

Portability problems fixed by Gnulib:

  • This header file is missing on some platforms: FreeBSD 14.0, mingw, MSVC 14.
  • <sys/types.h> is a prerequisite of <utmp.h> on some platforms: FreeBSD 8.0, OpenBSD 7.2.

Portability problems not fixed by Gnulib:

  • While some platforms have the struct utmp field ut_user, older platforms have the field ut_name.
  • The struct utmp fields ut_id, ut_pid, ut_type do not exist on some platforms: macOS, old FreeBSD, NetBSD, OpenBSD, Minix.
  • The struct utmp field ut_host does not exist on some platforms: Solaris.
  • The struct utmp field ut_exit does not exist on some platforms: macOS, old FreeBSD, NetBSD, OpenBSD, Minix, Cygwin.
  • The struct utmp field ut_session does not exist on some platforms: macOS, old FreeBSD, NetBSD, OpenBSD, Minix, AIX, HP-UX, Solaris, Cygwin.
  • The struct utmp field ut_addr or ut_addr_v6 does not exist on some platforms: macOS, old FreeBSD, NetBSD, OpenBSD, Minix, AIX, Solaris.
  • On some platforms, this API does not support timestamps past the year 2038: glibc 2.38 on 32-bit platforms like x86 and ARM where time_t was historically 32 bits.
  • On some platforms, this header misbehaves if the year2038 or year2038-recommended modules are used and the program is configured without the --disable-year2038 option. The readutmp module works around this problem: glibc 2.38 on 32-bit platforms like x86 and ARM where time_t was historically 32 bits. See Avoiding the year 2038 problem.

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13 Glibc Function Substitutes

This chapter describes which functions and function-like macros provided as extensions by at least GNU libc are also supported by Gnulib, which portability pitfalls are fixed by Gnulib, and which (known) portability problems are not worked around by Gnulib.

The notation “Gnulib module: —” means that Gnulib does not provide a module providing a substitute for the function. When the list “Portability problems not fixed by Gnulib” is empty, such a module is not needed: No portability problems are known. Otherwise, it indicates that such a module would be useful but is not available: No one so far found this function important enough to contribute a substitute for it. If you need this particular function, you may write to <bug-gnulib at gnu dot org>.

This list of functions is sorted according to the header that declares them.

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13.1 Glibc Extensions to <aio.h>

Up: Glibc Extensions to <aio.h>   [Contents][Index]

13.1.1 aio_init

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.2 Glibc <aliases.h>

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13.2.1 endaliasent

Documentation:
man endaliasent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.2.2 getaliasbyname

Documentation:
man getaliasbyname

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.2.3 getaliasbyname_r

Documentation:
man getaliasbyname_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.2.4 getaliasent

Documentation:
man getaliasent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.2.5 getaliasent_r

Documentation:
man getaliasent_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.2.6 setaliasent

Documentation:
man setaliasent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.3 Glibc <argp.h>

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13.3.1 argp_err_exit_status

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp-Global-Variables.html.

Gnulib module: argp

Portability problems fixed by Gnulib:

  • This variable is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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13.3.2 argp_error

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp-Helper-Functions.html.

Gnulib module: argp

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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13.3.3 argp_failure

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp-Helper-Functions.html.

Gnulib module: argp

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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13.3.4 argp_help

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp-Help.html.

Gnulib module: argp

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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13.3.5 argp_parse

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp.html.

Gnulib module: argp

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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13.3.6 argp_program_bug_address

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp-Global-Variables.html.

Gnulib module: argp

Portability problems fixed by Gnulib:

  • This variable is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc <argp.h>   [Contents][Index]

13.3.7 argp_program_version

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp-Global-Variables.html.

Gnulib module: argp

Portability problems fixed by Gnulib:

  • This variable is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc <argp.h>   [Contents][Index]

13.3.8 argp_program_version_hook

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp-Global-Variables.html.

Gnulib module: argp

Portability problems fixed by Gnulib:

  • This variable is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc <argp.h>   [Contents][Index]

13.3.9 argp_state_help

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp-Helper-Functions.html.

Gnulib module: argp

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

Previous: , Up: Glibc <argp.h>   [Contents][Index]

13.3.10 argp_usage

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Argp-Helper-Functions.html.

Gnulib module: argp

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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13.4 Glibc <argz.h>

Next: , Up: Glibc <argz.h>   [Contents][Index]

13.4.1 argz_add

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html

Documentation:

Gnulib module: argz

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.
  • This function is broken on some platforms: Cygwin 1.5.24.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc <argz.h>   [Contents][Index]

13.4.2 argz_add_sep

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html

Documentation:

Gnulib module: argz

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.
  • This function is broken on some platforms: Cygwin 1.5.24.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc <argz.h>   [Contents][Index]

13.4.3 argz_append

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html

Documentation:

Gnulib module: argz

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.
  • This function is broken on some platforms: Cygwin 1.5.24.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc <argz.h>   [Contents][Index]

13.4.4 argz_count

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html

Documentation:

Gnulib module: argz

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.
  • This function is broken on some platforms: Cygwin 1.5.24.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc <argz.h>   [Contents][Index]

13.4.5 argz_create

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html

Documentation:

Gnulib module: argz

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.
  • This function is broken on some platforms: Cygwin 1.5.24.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc <argz.h>   [Contents][Index]

13.4.6 argz_create_sep

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html

Documentation:

Gnulib module: argz

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.
  • This function is broken on some platforms: Cygwin 1.5.24.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc <argz.h>   [Contents][Index]

13.4.7 argz_delete

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html

Documentation:

Gnulib module: argz

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.
  • This function is broken on some platforms: Cygwin 1.5.24.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc <argz.h>   [Contents][Index]

13.4.8 argz_extract

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html

Documentation:

Gnulib module: argz

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.
  • This function is broken on some platforms: Cygwin 1.5.24.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc <argz.h>   [Contents][Index]

13.4.9 argz_insert

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html

Documentation:

Gnulib module: argz

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.
  • This function is broken on some platforms: Cygwin 1.5.24.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc <argz.h>   [Contents][Index]

13.4.10 argz_next

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html

Documentation:

Gnulib module: argz

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.
  • This function is broken on some platforms: Cygwin 1.5.24.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc <argz.h>   [Contents][Index]

13.4.11 argz_replace

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html

Documentation:

Gnulib module: argz

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.
  • This function is broken on some platforms: Cygwin 1.5.24.

Portability problems not fixed by Gnulib:

Previous: , Up: Glibc <argz.h>   [Contents][Index]

13.4.12 argz_stringify

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-argz-add.html

Documentation:

Gnulib module: argz

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.
  • This function is broken on some platforms: Cygwin 1.5.24.

Portability problems not fixed by Gnulib:

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13.5 Glibc Extensions to <arpa/inet.h>

Next: , Up: Glibc Extensions to <arpa/inet.h>   [Contents][Index]

13.5.1 inet_aton

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-inet-aton-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <arpa/inet.h>   [Contents][Index]

13.5.2 inet_lnaof

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 4.4.

Next: , Previous: , Up: Glibc Extensions to <arpa/inet.h>   [Contents][Index]

13.5.3 inet_makeaddr

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 4.4.

Next: , Previous: , Up: Glibc Extensions to <arpa/inet.h>   [Contents][Index]

13.5.4 inet_net_ntop

Documentation:
man inet_net_ntop

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.00, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <arpa/inet.h>   [Contents][Index]

13.5.5 inet_net_pton

Documentation:
man inet_net_pton

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.00, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <arpa/inet.h>   [Contents][Index]

13.5.6 inet_netof

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 4.4.

Next: , Previous: , Up: Glibc Extensions to <arpa/inet.h>   [Contents][Index]

13.5.7 inet_network

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 4.4.

Next: , Previous: , Up: Glibc Extensions to <arpa/inet.h>   [Contents][Index]

13.5.8 inet_nsap_addr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, HP-UX 11.00, Cygwin 2.9, mingw, MSVC 14.

Previous: , Up: Glibc Extensions to <arpa/inet.h>   [Contents][Index]

13.5.9 inet_nsap_ntoa

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, HP-UX 11.00, Cygwin 2.9, mingw, MSVC 14.

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13.6 Glibc Extensions to <arpa/nameser.h>

Next: , Up: Glibc Extensions to <arpa/nameser.h>   [Contents][Index]

13.6.1 ns_name_compress

Documentation:
http://web.deu.edu.tr/doc/oreily/networking/dnsbind/ch14_02.htm

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.33, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, HP-UX 11.11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <arpa/nameser.h>   [Contents][Index]

13.6.2 ns_name_ntop

Documentation: —

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.33, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, HP-UX 11.11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <arpa/nameser.h>   [Contents][Index]

13.6.3 ns_name_pack

Documentation: —

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.33, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, HP-UX 11.11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <arpa/nameser.h>   [Contents][Index]

13.6.4 ns_name_pton

Documentation: —

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.33, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, HP-UX 11.11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <arpa/nameser.h>   [Contents][Index]

13.6.5 ns_name_skip

Documentation:
http://web.deu.edu.tr/doc/oreily/networking/dnsbind/ch14_02.htm

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.33, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, HP-UX 11.11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <arpa/nameser.h>   [Contents][Index]

13.6.6 ns_name_uncompress

Documentation:
http://web.deu.edu.tr/doc/oreily/networking/dnsbind/ch14_02.htm

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.33, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, HP-UX 11.11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc Extensions to <arpa/nameser.h>   [Contents][Index]

13.6.7 ns_name_unpack

Documentation: —

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.33, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, HP-UX 11.11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

https://man7.org/linux/man-pages/man3/libsres.3.html https://www.kernel.org/doc/man-pages/online/pages/man3/

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13.7 Glibc <byteswap.h>

Next: , Up: Glibc <byteswap.h>   [Contents][Index]

13.7.1 bswap_16

Documentation:
man bswap_16

Gnulib module: byteswap

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <byteswap.h>   [Contents][Index]

13.7.2 bswap_32

Documentation:
man bswap_32

Gnulib module: byteswap

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <byteswap.h>   [Contents][Index]

13.7.3 bswap_64

Documentation:
man bswap_64

Gnulib module: byteswap

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.8 Glibc Extensions to <complex.h>

Next: , Up: Glibc Extensions to <complex.h>   [Contents][Index]

13.8.1 clog10

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib---clog10.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 9, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <complex.h>   [Contents][Index]

13.8.2 clog10f

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib---clog10f.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 9, Android 9.0.

Previous: , Up: Glibc Extensions to <complex.h>   [Contents][Index]

13.8.3 clog10l

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib---clog10l.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 9, Android 9.0.

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13.9 Glibc Extensions to <ctype.h>

Up: Glibc Extensions to <ctype.h>   [Contents][Index]

13.9.1 isctype

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.10 Glibc Extensions to <dirent.h>

Next: , Up: Glibc Extensions to <dirent.h>   [Contents][Index]

13.10.1 getdirentries

Documentation:
man getdirentries

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • On platforms where off_t is a 32-bit type, this function may not work correctly on huge directories larger than 2 GB. The fix is to use the AC_SYS_LARGEFILE macro.

Next: , Previous: , Up: Glibc Extensions to <dirent.h>   [Contents][Index]

13.10.2 scandirat

Documentation:
man scandirat

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.14, macOS 14, FreeBSD 13.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 1.7.10, mingw, MSVC 14, Android 6.0.

Previous: , Up: Glibc Extensions to <dirent.h>   [Contents][Index]

13.10.3 versionsort

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 13.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.

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13.11 Glibc Extensions to <dlfcn.h>

Next: , Up: Glibc Extensions to <dlfcn.h>   [Contents][Index]

13.11.1 dladdr

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dladdr-3.html

Documentation:
man dladdr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Cygwin 1.7.x, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <dlfcn.h>   [Contents][Index]

13.11.2 dladdr1

Documentation:
man dladdr1

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <dlfcn.h>   [Contents][Index]

13.11.3 dlinfo

Documentation:
man dlinfo

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <dlfcn.h>   [Contents][Index]

13.11.4 dlmopen

Documentation:
man dlmopen

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <dlfcn.h>   [Contents][Index]

13.11.5 dlvsym

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dlvsym-1.html

Documentation:
man dlvsym

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 6.0.

Previous: , Up: Glibc Extensions to <dlfcn.h>   [Contents][Index]

13.11.6 _dl_find_object

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Dynamic-Linker-Introspection.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.12 Glibc <envz.h>

Next: , Up: Glibc <envz.h>   [Contents][Index]

13.12.1 envz_add

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-envz-add.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <envz.h>   [Contents][Index]

13.12.2 envz_entry

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-envz-add.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <envz.h>   [Contents][Index]

13.12.3 envz_get

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-envz-add.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <envz.h>   [Contents][Index]

13.12.4 envz_merge

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-envz-add.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <envz.h>   [Contents][Index]

13.12.5 envz_remove

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-envz-add.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <envz.h>   [Contents][Index]

13.12.6 envz_strip

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-envz-add.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.

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13.13 Glibc <err.h>

Next: , Up: Glibc <err.h>   [Contents][Index]

13.13.1 err

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-err-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 10, mingw, MSVC 14.

Next: , Previous: , Up: Glibc <err.h>   [Contents][Index]

13.13.2 errx

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-errx-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 10, mingw, MSVC 14.

Next: , Previous: , Up: Glibc <err.h>   [Contents][Index]

13.13.3 verr

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 10, mingw, MSVC 14.

Next: , Previous: , Up: Glibc <err.h>   [Contents][Index]

13.13.4 verrx

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-verrx-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 10, mingw, MSVC 14.

Next: , Previous: , Up: Glibc <err.h>   [Contents][Index]

13.13.5 vwarn

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 10, mingw, MSVC 14.

Next: , Previous: , Up: Glibc <err.h>   [Contents][Index]

13.13.6 vwarnx

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 10, mingw, MSVC 14.

Next: , Previous: , Up: Glibc <err.h>   [Contents][Index]

13.13.7 warn

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-warn-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 10, mingw, MSVC 14.

Previous: , Up: Glibc <err.h>   [Contents][Index]

13.13.8 warnx

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-warnx-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 10, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.14 Glibc Extensions to <errno.h>

Next: , Up: Glibc Extensions to <errno.h>   [Contents][Index]

13.14.1 program_invocation_name

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.7, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc Extensions to <errno.h>   [Contents][Index]

13.14.2 program_invocation_short_name

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.7, mingw, MSVC 14, Android 9.0.

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13.15 Glibc <error.h>

Next: , Up: Glibc <error.h>   [Contents][Index]

13.15.1 error

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-error-n.html

Documentation:

Gnulib module: error

Portability problems fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.9, mingw, MSVC 14, Android 5.1.
  • This function outputs an extra space if error_print_progname is set, on some platforms: Android 11.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc <error.h>   [Contents][Index]

13.15.2 error_at_line

Documentation:

Gnulib module: error

Portability problems fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.9, mingw, MSVC 14, Android 5.1.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc <error.h>   [Contents][Index]

13.15.3 error_message_count

Documentation:

Gnulib module: error

Portability problems fixed by Gnulib:

  • This variable is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.9, mingw, MSVC 14, Android 5.1.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc <error.h>   [Contents][Index]

13.15.4 error_one_per_line

Documentation:

Gnulib module: error

Portability problems fixed by Gnulib:

  • This variable is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.9, mingw, MSVC 14, Android 5.1.

Portability problems not fixed by Gnulib:

Previous: , Up: Glibc <error.h>   [Contents][Index]

13.15.5 error_print_progname

Documentation:
man error_print_progname

Gnulib module: error

Portability problems fixed by Gnulib:

  • This variable is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.9, mingw, MSVC 14, Android 5.1.

Portability problems not fixed by Gnulib:

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13.16 Glibc <execinfo.h>

Next: , Up: Glibc <execinfo.h>   [Contents][Index]

13.16.1 backtrace

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-backtrace-1.html

Documentation:

Gnulib module: execinfo

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: musl libc, FreeBSD 9.3, NetBSD 6.1, OpenBSD 6.9, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 2.9, mingw, MSVC 14, Android API level 32.

Portability problems not fixed by Gnulib:

  • The second argument is of type size_t, not int, on some platforms: FreeBSD, NetBSD, OpenBSD.
  • The return value may be (size_t)(-1) instead of 0 on some platforms: FreeBSD 12.4/i386.
  • The returned stack trace is empty if it would not entirely fit into the provided buffer on some platforms: FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5.
  • The returned stack trace is always empty on some platforms: FreeBSD 11.0/i386, FreeBSD 12.2/sparc64.
  • On platforms where the function is missing, the Gnulib substitute implementation is just a stub, and does nothing.

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13.16.2 backtrace_symbols

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-backtrace-1.html

Documentation:

Gnulib module: execinfo

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: musl libc, FreeBSD 9.3, NetBSD 6.1, OpenBSD 6.9, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 2.9, mingw, MSVC 14, Android API level 32.

Portability problems not fixed by Gnulib:

  • The second argument is of type size_t, not int, on some platforms: FreeBSD, NetBSD, OpenBSD.
  • On platforms where the function is missing, the Gnulib substitute implementation is just a stub, and does nothing.

Previous: , Up: Glibc <execinfo.h>   [Contents][Index]

13.16.3 backtrace_symbols_fd

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-backtrace-1.html

Documentation:

Gnulib module: execinfo

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: musl libc, FreeBSD 9.3, NetBSD 6.1, OpenBSD 6.9, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 2.9, mingw, MSVC 14, Android API level 32.

Portability problems not fixed by Gnulib:

  • The second argument is of type size_t, not int, on some platforms: FreeBSD, NetBSD, OpenBSD.
  • The strings printed by this function not the same as the strings returned by backtrace_symbols on some platforms: glibc 2.39.
  • On platforms where the function is missing, the Gnulib substitute implementation is just a stub, and does nothing.

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13.17 Glibc Extensions to <fcntl.h>

Next: , Up: Glibc Extensions to <fcntl.h>   [Contents][Index]

13.17.1 fallocate

Documentation:
man fallocate

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.9, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 3.4.6, mingw, MSVC 14, Android 4.4.
  • On platforms where off_t is a 32-bit type, this function may not work correctly across the entire data range of files larger than 2 GB. The fix is to use the AC_SYS_LARGEFILE macro.

Next: , Previous: , Up: Glibc Extensions to <fcntl.h>   [Contents][Index]

13.17.2 name_to_handle_at

Documentation:
man name_to_handle_at

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on all non-glibc platforms: glibc 2.13, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <fcntl.h>   [Contents][Index]

13.17.3 readahead

Documentation:
man readahead

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 4.0.4.

Next: , Previous: , Up: Glibc Extensions to <fcntl.h>   [Contents][Index]

13.17.4 open_by_handle_at

Documentation:
man open_by_handle_at

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on all non-glibc platforms: glibc 2.13, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc Extensions to <fcntl.h>   [Contents][Index]

13.17.5 sync_file_range

Documentation:
man sync_file_range

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: glibc 2.5, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 4.3.

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13.18 Glibc Extensions to <fenv.h>

Next: , Up: Glibc Extensions to <fenv.h>   [Contents][Index]

13.18.1 fedisableexcept

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fedisableexcept.html

Documentation:

Gnulib module: fenv-exceptions-trapping

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, musl libc, FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.7, mingw, MSVC 14, Android 4.4.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc Extensions to <fenv.h>   [Contents][Index]

13.18.2 feenableexcept

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-feenableexcept.html

Documentation:

Gnulib module: fenv-exceptions-trapping

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, musl libc, FreeBSD 5.2.1, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.7, mingw, MSVC 14, Android 4.4.
  • This function does not detect failures on glibc 2.19/aarch64, FreeBSD 12.2/arm, FreeBSD 12.2/arm64, NetBSD 10.0/arm64.

Portability problems not fixed by Gnulib:

  • The resulting signal is SIGILL instead of SIGFPE on some platforms: Linux/hppa, macOS 14/arm64.

Previous: , Up: Glibc Extensions to <fenv.h>   [Contents][Index]

13.18.3 fegetexcept

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fegetexcept.html

Documentation:

Gnulib module: fenv-exceptions-trapping

Portability problems fixed by Gnulib:

  • This function is missing on many non-glibc platforms: Mac OS X 10.4, musl libc, FreeBSD 14.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.7, mingw, MSVC 14, Android 4.4.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.19 Glibc Extensions to <fmtmsg.h>

Up: Glibc Extensions to <fmtmsg.h>   [Contents][Index]

13.19.1 addseverity

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.20 Glibc <fstab.h>

Next: , Up: Glibc <fstab.h>   [Contents][Index]

13.20.1 endfsent

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <fstab.h>   [Contents][Index]

13.20.2 getfsent

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <fstab.h>   [Contents][Index]

13.20.3 getfsfile

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <fstab.h>   [Contents][Index]

13.20.4 getfsspec

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <fstab.h>   [Contents][Index]

13.20.5 setfsent

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.21 Glibc <fts.h>

Next: , Up: Glibc <fts.h>   [Contents][Index]

13.21.1 fts_children

Documentation:
man fts_children

Gnulib module: fts

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 11.3, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, this function may not correctly report the size of files or block devices larger than 2 GB and may not work correctly on huge directories larger than 2 GB. Also, on platforms where ino_t is a 32-bit type, this function may report inode numbers incorrectly. The fix is to use the AC_SYS_LARGEFILE macro (only on Mac OS X systems).

Next: , Previous: , Up: Glibc <fts.h>   [Contents][Index]

13.21.2 fts_close

Documentation:
man fts_close

Gnulib module: fts

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 11.3, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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13.21.3 fts_open

Documentation:
man fts_open

Gnulib module: fts

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 11.3, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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13.21.4 fts_read

Documentation:
man fts_read

Gnulib module: fts

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 11.3, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • On platforms where off_t is a 32-bit type, this function may not correctly report the size of files or block devices larger than 2 GB and may not work correctly on huge directories larger than 2 GB. Also, on platforms where ino_t is a 32-bit type, this function may report inode numbers incorrectly. The fix is to use the AC_SYS_LARGEFILE macro (only on Mac OS X systems).

Previous: , Up: Glibc <fts.h>   [Contents][Index]

13.21.5 fts_set

Documentation:
man fts_set

Gnulib module: fts

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 11.3, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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13.22 Glibc <getopt.h>

Next: , Up: Glibc <getopt.h>   [Contents][Index]

13.22.1 getopt_long

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getopt-long-3.html

Documentation:

Gnulib module: getopt-gnu

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, MSVC 14.
  • The function getopt_long does not obey the combination of ‘+’ and ‘:’ flags in the options string on some platforms: glibc 2.11.
  • The use of ‘W;’ in the optstring argument to does not always allow -W foo to behave synonymously with --foo: glibc 2.11.
  • The function getopt_long does not support the ‘+’ flag in the options string on some platforms: macOS 14, AIX 5.2, Solaris 10.
  • The value of optind after a missing required argument is wrong on some platforms: macOS 14.
  • The function getopt_long does not obey the ‘-’ flag in the options string when POSIXLY_CORRECT is set on some platforms: Cygwin 1.7.0.
  • Some implementations fail to reset state, including re-checking POSIXLY_CORRECT, when optind is set to ‘0’: NetBSD, Cygwin 1.7.0.
  • The function getopt_long does not support options with optional arguments on some platforms: macOS 14, OpenBSD 4.0, AIX 5.2, Solaris 11 2010-11, Cygwin 1.5.x.
  • This function crashes if the option string includes W; but there are no long options, on some platforms: glibc 2.14.

Portability problems not fixed by Gnulib:

Previous: , Up: Glibc <getopt.h>   [Contents][Index]

13.22.2 getopt_long_only

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getopt-long-only-3.html

Documentation:

Gnulib module: getopt-gnu

Portability problems fixed by Gnulib:

  • The function getopt_long_only does not obey the combination of ‘+’ and ‘:’ flags in the options string on some platforms: glibc 2.11.
  • The use of ‘W;’ in the optstring argument to does not always allow -W foo to behave synonymously with --foo: glibc 2.11.
  • The function getopt_long_only does not support the ‘+’ flag in the options string on some platforms: macOS 14, AIX 5.2, Solaris 10.
  • The value of optind after a missing required argument is wrong on some platforms: macOS 14.
  • The function getopt_long_only does not obey the ‘-’ flag in the options string when POSIXLY_CORRECT is set on some platforms: Cygwin 1.7.0.
  • Some implementations fail to reset state, including re-checking POSIXLY_CORRECT, when optind is set to ‘0’: NetBSD, Cygwin 1.7.0.
  • The function getopt_long_only does not support options with optional arguments on some platforms: macOS 14, OpenBSD 4.0, AIX 5.2, Solaris 11 2010-11, Cygwin 1.5.x.
  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 10.0, Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14.
  • This function crashes if the option string includes W; but there are no long options, on some platforms: glibc 2.14.

Portability problems not fixed by Gnulib:

  • Some implementations return success instead of reporting an ambiguity if user’s option is a prefix of two long options with the same outcome: FreeBSD.
  • The GNU Coding Standards discourage the use of getopt_long_only in new programs.

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13.23 Glibc Extensions to <glob.h>

Up: Glibc Extensions to <glob.h>   [Contents][Index]

13.23.1 glob_pattern_p

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on most non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

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13.24 Glibc Extensions to <gnu/libc-version.h>

Next: , Up: Glibc Extensions to <gnu/libc-version.h>   [Contents][Index]

13.24.1 gnu_get_libc_release

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gnu-get-libc-version-1.html

Documentation:
man gnu_get_libc_release

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc Extensions to <gnu/libc-version.h>   [Contents][Index]

13.24.2 gnu_get_libc_version

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gnu-get-libc-version-1.html

Documentation:
man gnu_get_libc_version

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.25 Glibc Extensions to <grp.h>

Next: , Up: Glibc Extensions to <grp.h>   [Contents][Index]

13.25.1 fgetgrent

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <grp.h>   [Contents][Index]

13.25.2 fgetgrent_r

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <grp.h>   [Contents][Index]

13.25.3 getgrent_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getgrent-r-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.25.4 getgrouplist

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getgrouplist-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function takes int instead of gid_t parameters on some platforms: OS X 10.11.
  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.0, Cygwin 1.7.9, mingw, MSVC 14.

The Gnulib module getugroups provides a similar API.

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13.25.5 initgroups

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-initgroups-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is unsafe to call between fork and exec if the parent process is multi-threaded. Instead, use getgroups or getgrouplist (or use the gnulib module mgetgroups) before forking, and setgroups in the child.
  • This function is missing on some platforms: mingw, MSVC 14.

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13.25.6 putgrent

Documentation:
man putgrent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc Extensions to <grp.h>   [Contents][Index]

13.25.7 setgroups

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-setgroups-2.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, mingw, MSVC 14.
  • On very old systems, this function operated on an array of ‘int’, even though that was a different size than an array of ‘gid_t’; you can use autoconf’s AC_TYPE_GETGROUPS to set GETGROUPS_T to the appropriate size (since getgroups and setgroups share the same bug).

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13.26 Glibc <gshadow.h>

Next: , Up: Glibc <gshadow.h>   [Contents][Index]

13.26.1 endsgent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.9, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <gshadow.h>   [Contents][Index]

13.26.2 fgetsgent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.9, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <gshadow.h>   [Contents][Index]

13.26.3 fgetsgent_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.9, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.26.4 getsgent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.9, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <gshadow.h>   [Contents][Index]

13.26.5 getsgent_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.9, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.26.6 getsgnam

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.9, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.26.7 getsgnam_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.9, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <gshadow.h>   [Contents][Index]

13.26.8 putsgent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.9, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.26.9 setsgent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.9, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.26.10 sgetsgent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.9, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <gshadow.h>   [Contents][Index]

13.26.11 sgetsgent_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.9, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.27 Glibc <ifaddrs.h>

Next: , Up: Glibc <ifaddrs.h>   [Contents][Index]

13.27.1 getifaddrs

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getifaddrs.html

Documentation:
man getifaddrs

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 6.0.

Previous: , Up: Glibc <ifaddrs.h>   [Contents][Index]

13.27.2 freeifaddrs

Documentation:
man freeifaddrs

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 6.0.

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13.28 Glibc <libintl.h>

Next: , Up: Glibc <libintl.h>   [Contents][Index]

13.28.1 bind_textdomain_codeset

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-bind-textdomain-codeset.html

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1122

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <libintl.h>   [Contents][Index]

13.28.2 bindtextdomain

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-bindtextdomain.html

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1122

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.28.3 dcgettext

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dcgettext.html

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1122

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.28.4 dcngettext

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dcngettext.html

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1122

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.28.5 dgettext

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dgettext.html

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1122

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <libintl.h>   [Contents][Index]

13.28.6 dngettext

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dngettext.html

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1122

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <libintl.h>   [Contents][Index]

13.28.7 gettext

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gettext.html

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1122

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.28.8 ngettext

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-ngettext.html

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1122

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <libintl.h>   [Contents][Index]

13.28.9 textdomain

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-textdomain.html

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1122

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.30 Glibc <malloc.h>

Next: , Up: Glibc <malloc.h>   [Contents][Index]

13.30.1 mallinfo

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11 2010-11, mingw, MSVC 14.

Next: , Previous: , Up: Glibc <malloc.h>   [Contents][Index]

13.30.2 mallinfo2

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.32, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.3.0, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

Next: , Previous: , Up: Glibc <malloc.h>   [Contents][Index]

13.30.3 malloc_info

Documentation:
man malloc_info

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.9, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 5.1.

Next: , Previous: , Up: Glibc <malloc.h>   [Contents][Index]

13.30.4 malloc_stats

Documentation:
man malloc_stats

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <malloc.h>   [Contents][Index]

13.30.5 malloc_trim

Documentation:
man malloc_trim

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <malloc.h>   [Contents][Index]

13.30.6 malloc_usable_size

Documentation:
man malloc_usable_size

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11.00, Solaris 11.4, mingw, MSVC 14, Android 4.1.

Next: , Previous: , Up: Glibc <malloc.h>   [Contents][Index]

13.30.7 mallopt

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11 2010-11, mingw, MSVC 14, Android 7.1.

Next: , Previous: , Up: Glibc <malloc.h>   [Contents][Index]

13.30.8 memalign

Documentation:

Gnulib module: memalign

Portability problems fixed by Gnulib:

  • This function is declared in <stdlib.h> instead of <malloc.h> on some platforms: Solaris 11.
  • This function doesn’t accept an alignment of 1 or 2 on some platforms: Solaris 11.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 12.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11.00, mingw, MSVC 14.

The Gnulib module aligned-malloc provides functions for allocating and freeing blocks of suitably aligned memory.

Previous: , Up: Glibc <malloc.h>   [Contents][Index]

13.30.9 pvalloc

Documentation:
man pvalloc

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.31 Glibc Extensions to <math.h>

Next: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.1 drem

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-drem.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11, Solaris 11.4, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.2 dremf

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dremf.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.3 dreml

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-dreml.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.4 exp10

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-exp10.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.5 exp10f

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-exp10f.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.6 exp10l

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-exp10l.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.7 finite

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-finite.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.8 finitef

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-finitef.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.9 finitel

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-finitel.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.10 gamma

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gamma.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.11 gammaf

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gammaf.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.12 gammal

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gammal.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.13 isinff

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 4.4.
  • This function is not declared on some platforms: Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.14 isinfl

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • This function is not declared on some platforms: Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.15 isnanf

Documentation:

Gnulib module: isnanf

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, Minix 3.1.8, AIX 5.1, HP-UX 11, MSVC 14.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.16 isnanl

Documentation:

Gnulib module: isnanl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.7.x, MSVC 14, Android 4.4.
  • This function is not declared on some platforms: Android 9.0.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.17 j0f

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-j0f.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.18 j0l

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-j0l.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.19 j1f

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-j1f.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.20 j1l

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-j1l.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.21 jnf

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-jnf.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.22 jnl

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-jnl.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.31.23 lgamma_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-lgamma-r.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.5 x86, Minix 3.1.8, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.24 lgammaf_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-lgammaf-r.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.5, Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.25 lgammal_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-lgammal-r.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 1.7.x, mingw, MSVC 14, Android 5.1.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.26 matherr

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-matherr-1.html

Documentation:
man matherr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.27 pow10

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-pow10.html

Documentation:
man pow10

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.28 pow10f

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-pow10f.html

Documentation:
man pow10f

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

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13.31.29 pow10l

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-pow10l.html

Documentation:
man pow10l

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.30 scalbf

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-scalbf.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.31 scalbl

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-scalbl.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.32 significand

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-significand.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.33 significandf

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-significandf.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.34 significandl

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-significandl.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14.

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13.31.35 sincos

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sincos.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 11.0, NetBSD 9.3, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.36 sincosf

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sincosf.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 11.0, NetBSD 9.3, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.37 sincosl

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sincosl.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 11.0, NetBSD 9.3, OpenBSD 6.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.7.x, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.38 y0f

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-y0f.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.39 y0l

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-y0l.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.40 y1f

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-y1f.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.41 y1l

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-y1l.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.42 ynf

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-ynf.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14.

Previous: , Up: Glibc Extensions to <math.h>   [Contents][Index]

13.31.43 ynl

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-ynl.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.32 Glibc <mcheck.h>

Next: , Up: Glibc <mcheck.h>   [Contents][Index]

13.32.1 mcheck

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <mcheck.h>   [Contents][Index]

13.32.2 mcheck_check_all

Documentation:
man mcheck_check_all

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <mcheck.h>   [Contents][Index]

13.32.3 mcheck_pedantic

Documentation:
man mcheck_pedantic

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <mcheck.h>   [Contents][Index]

13.32.4 mprobe

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <mcheck.h>   [Contents][Index]

13.32.5 mtrace

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <mcheck.h>   [Contents][Index]

13.32.6 muntrace

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.33 Glibc <mntent.h>

Next: , Up: Glibc <mntent.h>   [Contents][Index]

13.33.1 addmntent

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <mntent.h>   [Contents][Index]

13.33.2 endmntent

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, mingw, MSVC 14, Android 4.4.

Next: , Previous: , Up: Glibc <mntent.h>   [Contents][Index]

13.33.3 getmntent

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14.

Next: , Previous: , Up: Glibc <mntent.h>   [Contents][Index]

13.33.4 getmntent_r

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

Next: , Previous: , Up: Glibc <mntent.h>   [Contents][Index]

13.33.5 hasmntopt

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 7.1.

Previous: , Up: Glibc <mntent.h>   [Contents][Index]

13.33.6 setmntent

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, mingw, MSVC 14, Android 4.4.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.34 Glibc Extensions to <netdb.h>

Next: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.1 endnetgrent

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.2 gethostbyaddr_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gethostbyaddr-r-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 5.1.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.3 gethostbyname2

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gethostbyname2-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.4 gethostbyname2_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gethostbyname2-r-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 5.1.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.5 gethostbyname_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-gethostbyname-r-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.6 gethostent_r

Documentation:
man gethostent_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.7 getnetbyaddr_r

Documentation:
man getnetbyaddr_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.8 getnetbyname_r

Documentation:
man getnetbyname_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.9 getnetent_r

Documentation:
man getnetent_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.10 getnetgrent

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.11 getnetgrent_r

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.12 getprotobyname_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getprotobyname-r.html

Documentation:
man getprotobyname_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.13 getprotobynumber_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getprotobynumber-r.html

Documentation:
man getprotobynumber_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.14 getprotoent_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getprotoent-r.html

Documentation:
man getprotoent_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.15 getservbyname_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getservbyname-r.html

Documentation:
man getservbyname_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.16 getservbyport_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getservbyport-r.html

Documentation:
man getservbyport_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.17 getservent_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getservent-r.html

Documentation:
man getservent_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.18 herror

Documentation:
man herror

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.19 hstrerror

Documentation:
man hstrerror

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.20 innetgr

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.21 rcmd

Documentation:
man rcmd

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.22 rcmd_af

Documentation:
man rcmd_af

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11.11, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.23 rexec

Documentation:
man rexec

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.24 rexec_af

Documentation:
man rexec_af

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11.11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.25 rresvport

Documentation:
man rresvport

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.26 rresvport_af

Documentation:
man rresvport_af

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11.11, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.27 ruserok

Documentation:
man ruserok

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.28 ruserok_af

Documentation:
man ruserok_af

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc Extensions to <netdb.h>   [Contents][Index]

13.34.29 setnetgrent

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.35 Glibc <netinet/ether.h>

Next: , Up: Glibc <netinet/ether.h>   [Contents][Index]

13.35.1 ether_aton

Documentation:
man ether_aton

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 2.3.

Next: , Previous: , Up: Glibc <netinet/ether.h>   [Contents][Index]

13.35.2 ether_aton_r

Documentation:
man ether_aton_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 2.3.

Next: , Previous: , Up: Glibc <netinet/ether.h>   [Contents][Index]

13.35.3 ether_hostton

Documentation:
man ether_hostton

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <netinet/ether.h>   [Contents][Index]

13.35.4 ether_line

Documentation:
man ether_line

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <netinet/ether.h>   [Contents][Index]

13.35.5 ether_ntoa

Documentation:
man ether_ntoa

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 2.3.

Next: , Previous: , Up: Glibc <netinet/ether.h>   [Contents][Index]

13.35.6 ether_ntoa_r

Documentation:
man ether_ntoa_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 2.3.

Previous: , Up: Glibc <netinet/ether.h>   [Contents][Index]

13.35.7 ether_ntohost

Documentation:
man ether_ntohost

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.36 Glibc Extensions to <netinet/in.h>

Next: , Up: Glibc Extensions to <netinet/in.h>   [Contents][Index]

13.36.1 bindresvport

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-bindresvport-3.html

Documentation:
man bindresvport

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11, Cygwin 1.5.x, mingw, MSVC 14.

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13.36.2 getipv4sourcefilter

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11.23, Solaris 10, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.3 getsourcefilter

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11.23, Solaris 10, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.4 in6addr_any

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Host-Address-Data-Type.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This constant is missing on some platforms: Minix 3.1.8, HP-UX 11.00, Cygwin 1.5.x, mingw, MSVC 14, Android 6.0.

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13.36.5 in6addr_loopback

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Host-Address-Data-Type.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This constant is missing on some platforms: Minix 3.1.8, HP-UX 11.00, Cygwin 1.5.x, mingw, MSVC 14, Android 6.0.

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13.36.6 inet6_option_alloc

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.7 inet6_option_append

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.8 inet6_option_find

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.9 inet6_option_init

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.10 inet6_option_next

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.11 inet6_option_space

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.12 inet6_opt_append

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.4, Mac OS X 10.5, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.2, HP-UX 11.31, Solaris 9, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.13 inet6_opt_find

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.4, Mac OS X 10.5, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.2, HP-UX 11.31, Solaris 9, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.14 inet6_opt_finish

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.4, Mac OS X 10.5, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.2, HP-UX 11.31, Solaris 9, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.15 inet6_opt_get_val

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.4, Mac OS X 10.5, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.2, HP-UX 11.31, Solaris 9, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.16 inet6_opt_init

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.4, Mac OS X 10.5, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.2, HP-UX 11.31, Solaris 9, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.17 inet6_opt_next

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.4, Mac OS X 10.5, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.2, HP-UX 11.31, Solaris 9, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.18 inet6_opt_set_val

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.4, Mac OS X 10.5, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.2, HP-UX 11.31, Solaris 9, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.19 inet6_rth_add

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.4, Mac OS X 10.5, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.2, HP-UX 11.31, Solaris 9, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.20 inet6_rth_getaddr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.4, Mac OS X 10.5, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.2, HP-UX 11.31, Solaris 9, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.21 inet6_rth_init

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.4, Mac OS X 10.5, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.2, HP-UX 11.31, Solaris 9, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.22 inet6_rth_reverse

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.4, Mac OS X 10.5, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.2, HP-UX 11.31, Solaris 9, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.23 inet6_rth_segments

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.4, Mac OS X 10.5, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.2, HP-UX 11.31, Solaris 9, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.24 inet6_rth_space

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.4, Mac OS X 10.5, NetBSD 3.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.2, HP-UX 11.31, Solaris 9, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.25 setipv4sourcefilter

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11.23, Solaris 10, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.36.26 setsourcefilter

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11.23, Solaris 10, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.37 Glibc <obstack.h>

Next: , Up: Glibc <obstack.h>   [Contents][Index]

13.37.1 obstack_alloc_failed_handler

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Preparing-for-Obstacks.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.37.2 obstack_exit_failure

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.37.3 obstack_free

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Freeing-Obstack-Objects.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.37.4 obstack_printf

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Dynamic-Output.html.

Gnulib module: obstack-printf or obstack-printf-posix or obstack-printf-gnu

Portability problems fixed by either Gnulib module obstack-printf or obstack-printf-posix or obstack-printf-gnu:

  • This function is missing on all non-glibc platforms: musl libc, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.1.8, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.

Portability problems fixed by either Gnulib module obstack-printf-posix or obstack-printf-gnu:

  • This function does not support size specifiers as in C99 (hh, ll, j, t, z) on some platforms: AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37.
  • printf of ‘long double’ numbers is unsupported on some platforms: mingw, MSVC 14.
  • printf "%f", "%e", "%g" of Infinity and NaN yields an incorrect result on some platforms: AIX 7.3, Solaris 11.4, mingw, MSVC 14.
  • This function does not support the ‘a’ and ‘A’ directives on some platforms: FreeBSD 5.2.1, OpenBSD 4.0, AIX 5.2, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support the ‘F’ directive on some platforms: NetBSD 3.0, AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘ls’ directive on some platforms: OpenBSD 4.0, Cygwin 1.5.x, Haiku.
  • This function does not support precisions in the ‘ls’ directive correctly on some platforms: Solaris 11.4.
  • This function does not support format directives that access arguments in an arbitrary order, such as "%2$s", on some platforms: NetBSD 3.0, mingw, MSVC 14.
  • This function doesn’t support the ' flag on some platforms: NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
  • This function does not round the argument of the ‘a’ directive correctly on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4.
  • printf "%010f" of NaN and Infinity yields an incorrect result (padded with zeroes) on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 7.3, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC/clang.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • This function does not support precisions larger than 512 or 1024 in integer, floating-point and pointer output on some platforms: Solaris 10/x86, mingw, MSVC/clang.
  • This function produces wrong output for the ‘lc’ directive with a NUL wide character argument on some platforms: musl libc 1.2.4.
  • This function can crash in out-of-memory conditions on some platforms: FreeBSD 14.0, NetBSD 5.0.

Portability problems fixed by Gnulib module obstack-printf-gnu:

  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.

Portability problems fixed by either Gnulib module obstack-printf-posix or obstack-printf-gnu and additionally the Gnulib module printf-with-n-directive:

  • This function does not support the ‘n’ directive on some platforms: MSVC 14.
  • This function does not fully support the ‘n’ directive on some platforms: HP-UX 11, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.

Previous: , Up: Glibc <obstack.h>   [Contents][Index]

13.37.5 obstack_vprintf

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Variable-Arguments-Output.html.

Gnulib module: obstack-printf or obstack-printf-posix or obstack-printf-gnu

Portability problems fixed by either Gnulib module obstack-printf or obstack-printf-posix or obstack-printf-gnu:

  • This function is missing on all non-glibc platforms: musl libc, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.1.8, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.

Portability problems fixed by either Gnulib module obstack-printf-posix or obstack-printf-gnu:

  • This function does not support size specifiers as in C99 (hh, ll, j, t, z) on some platforms: AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.24, old mingw, MSVC 9.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37.
  • printf of ‘long double’ numbers is unsupported on some platforms: mingw, MSVC 14.
  • printf "%f", "%e", "%g" of Infinity and NaN yields an incorrect result on some platforms: AIX 7.3, Solaris 11.4, mingw, MSVC 14.
  • This function does not support the ‘a’ and ‘A’ directives on some platforms: FreeBSD 5.2.1, OpenBSD 4.0, AIX 5.2, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support the ‘F’ directive on some platforms: NetBSD 3.0, AIX 5.1, HP-UX 11.23, Solaris 9, Cygwin 1.5.x, mingw, MSVC 14.
  • This function does not support the ‘ls’ directive on some platforms: OpenBSD 4.0, Cygwin 1.5.x, Haiku.
  • This function does not support precisions in the ‘ls’ directive correctly on some platforms: Solaris 11.4.
  • This function does not support format directives that access arguments in an arbitrary order, such as "%2$s", on some platforms: NetBSD 3.0, mingw, MSVC 14.
  • This function doesn’t support the ' flag on some platforms: NetBSD 3.0, Cygwin 1.5.24, mingw, MSVC 14.
  • This function does not round the argument of the ‘a’ directive correctly on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4.
  • printf "%010f" of NaN and Infinity yields an incorrect result (padded with zeroes) on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 7.3, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC/clang.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • This function does not support precisions larger than 512 or 1024 in integer, floating-point and pointer output on some platforms: Solaris 10/x86, mingw, MSVC/clang.
  • This function produces wrong output for the ‘lc’ directive with a NUL wide character argument on some platforms: musl libc 1.2.4.
  • This function can crash in out-of-memory conditions on some platforms: FreeBSD 14.0, NetBSD 5.0.

Portability problems fixed by Gnulib module obstack-printf-gnu:

  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.

Portability problems fixed by either Gnulib module obstack-printf-posix or obstack-printf-gnu and additionally the Gnulib module printf-with-n-directive:

  • This function does not support the ‘n’ directive on some platforms: MSVC 14.
  • This function does not fully support the ‘n’ directive on some platforms: HP-UX 11, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.

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13.38 Glibc Extensions to <poll.h>

Up: Glibc Extensions to <poll.h>   [Contents][Index]

13.38.1 ppoll

Documentation:
man ppoll

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 6.4, NetBSD 9.3, OpenBSD 3.8, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 10, Cygwin 1.7.x, mingw, MSVC 14, Android 4.3.

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13.39 Glibc <printf.h>

Next: , Up: Glibc <printf.h>   [Contents][Index]

13.39.1 parse_printf_format

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Parsing-a-Template-String.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.39.2 printf_size

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Predefined-Printf-Handlers.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.39.3 printf_size_info

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Predefined-Printf-Handlers.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.39.4 register_printf_function

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Registering-New-Conversions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <printf.h>   [Contents][Index]

13.39.5 register_printf_modifier

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.9, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.39.6 register_printf_specifier

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.9, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.39.7 register_printf_type

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.9, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.40 Glibc Extensions to <pthread.h>

Next: , Up: Glibc Extensions to <pthread.h>   [Contents][Index]

13.40.1 pthread_attr_getaffinity_np

Documentation:
man pthread_attr_getaffinity_np

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.3.2, macOS 14, FreeBSD 6.4, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function has a different signature on some platforms: glibc 2.3.3.

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13.40.2 pthread_attr_setaffinity_np

Documentation:
man pthread_attr_setaffinity_np

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.3.2, macOS 14, FreeBSD 6.4, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function has a different signature on some platforms: glibc 2.3.3.

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13.40.3 pthread_attr_getsigmask_np

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Initial-Thread-Signal-Mask.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.31, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.40.4 pthread_attr_setsigmask_np

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Initial-Thread-Signal-Mask.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.31, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.40.5 pthread_clockjoin_np

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.40.6 pthread_cond_clockwait

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1485#c5385

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

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13.40.7 pthread_getaffinity_np

Documentation:
man pthread_getaffinity_np

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.3.2, macOS 14, FreeBSD 6.4, NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function has a different signature on some platforms: glibc 2.3.3.
  • The third parameter has a different type on some platforms: FreeBSD 14.0, NetBSD 10.0.

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13.40.8 pthread_getattr_default_np

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.17, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.40.9 pthread_getattr_np

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-pthread-getattr-np-1.html

Documentation:
man pthread_getattr_np

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.9, mingw, MSVC 14.

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13.40.10 pthread_getname_np

Documentation:
man pthread_getname_np

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.11, Mac OS X 10.5, FreeBSD 12.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.0, Cygwin 1.7.x, mingw, MSVC 14, Android 7.1.

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13.40.11 pthread_kill_other_threads_np

Documentation:
man pthread_kill_other_threads_np

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.40.12 pthread_mutex_clocklock

Documentation: —

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

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13.40.13 pthread_rwlock_clockrdlock

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1216

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

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13.40.14 pthread_rwlock_clockwrlock

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1216

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

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13.40.15 pthread_rwlockattr_getkind_np

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-pthread-rwlockattr-getkind-np-1.html

Documentation:
man pthread_rwlockattr_getkind_np

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 5.1.

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13.40.16 pthread_rwlockattr_setkind_np

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-pthread-rwlockattr-getkind-np-1.html

Documentation:
man pthread_rwlockattr_setkind_np

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 5.1.

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13.40.17 pthread_setaffinity_np

Documentation:
man pthread_setaffinity_np

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.3.2, macOS 14, FreeBSD 6.4, NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function has a different signature on some platforms: glibc 2.3.3.
  • The third parameter has a different type on some platforms: FreeBSD 14.0, NetBSD 10.0.

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13.40.18 pthread_setattr_default_np

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.17, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.40.19 pthread_setname_np

Documentation:
man pthread_setname_np

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.11, Mac OS X 10.5, FreeBSD 12.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.0, Cygwin 1.7.x, mingw, MSVC 14.
  • This function has a different signature on some platforms: NetBSD 10.0. On NetBSD the second argument is interpreted as a printf format string, with the third argument as parameter.

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13.40.20 pthread_sigqueue

Documentation:
man pthread_sigqueue

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.10, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.0, Cygwin 1.7.9, mingw, MSVC 14, Android 9.0.

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13.40.21 pthread_timedjoin_np

Documentation:
man pthread_timedjoin_np

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.3.2, macOS 14, FreeBSD 6.4, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • FreeBSD 6.4 has a function of this name in libthr but not in libpthread, and it also is missing a declaration.

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13.40.22 pthread_tryjoin_np

Documentation:
man pthread_tryjoin_np

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.3.2, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.41 Glibc <pty.h>

Next: , Up: Glibc <pty.h>   [Contents][Index]

13.41.1 forkpty

Documentation:

Gnulib module: forkpty

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Android 5.1.
  • One some systems (at least including Cygwin and Mac OS X) linking with -lutil is not required.
  • On glibc, OpenBSD, NetBSD and FreeBSD linking with -lutil is required.
  • The function is declared in pty.h on glibc and Cygwin. It is declared in util.h on Mac OS X, OpenBSD, and NetBSD. It is declared in libutil.h on FreeBSD. It is declared in termios.h on Solaris.
  • Some platforms declare the function without marking the last two parameters const. FreeBSD 14.0, Solaris 11.4, Cygwin 1.7.1.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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13.41.2 openpty

Documentation:

Gnulib module: openpty

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 11.3, Android 5.1.
  • One some systems (at least including Cygwin and Mac OS X) linking with -lutil is not required.
  • On glibc, OpenBSD, NetBSD and FreeBSD linking with -lutil is required.
  • The function is declared in pty.h on glibc and Cygwin. It is declared in util.h on Mac OS X, OpenBSD, and NetBSD. It is declared in libutil.h on FreeBSD. It is declared in termios.h on Solaris.
  • Some platforms declare the function without marking the last two parameters const. FreeBSD 14.0, Solaris 11.4, Cygwin 1.7.1.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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13.42 Glibc Extensions to <pwd.h>

Next: , Up: Glibc Extensions to <pwd.h>   [Contents][Index]

13.42.1 fgetpwent

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.42.2 fgetpwent_r

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.42.3 getpw

Documentation:
man getpw

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.42.4 getpwent_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getpwent-r-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc Extensions to <pwd.h>   [Contents][Index]

13.42.5 putpwent

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.43 Glibc Extensions to <regex.h>

Next: , Up: Glibc Extensions to <regex.h>   [Contents][Index]

13.43.1 re_comp

Documentation:
man re_comp

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <regex.h>   [Contents][Index]

13.43.2 re_compile_fastmap

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <regex.h>   [Contents][Index]

13.43.3 re_compile_pattern

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <regex.h>   [Contents][Index]

13.43.4 re_exec

Documentation:
man re_exec

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <regex.h>   [Contents][Index]

13.43.5 re_match

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <regex.h>   [Contents][Index]

13.43.6 re_match_2

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <regex.h>   [Contents][Index]

13.43.7 re_search

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <regex.h>   [Contents][Index]

13.43.8 re_search_2

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.43.9 re_set_registers

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.43.10 re_set_syntax

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc Extensions to <regex.h>   [Contents][Index]

13.43.11 re_syntax_options

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.44 Glibc <regexp.h>

Next: , Up: Glibc <regexp.h>   [Contents][Index]

13.44.1 advance

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.44.2 loc1

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <regexp.h>   [Contents][Index]

13.44.3 loc2

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <regexp.h>   [Contents][Index]

13.44.4 locs

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <regexp.h>   [Contents][Index]

13.44.5 step

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.45 Glibc <resolv.h>

Next: , Up: Glibc <resolv.h>   [Contents][Index]

13.45.1 dn_comp

Documentation:
man dn_comp

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, OpenBSD 6.7, Minix 3.3.0, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <resolv.h>   [Contents][Index]

13.45.2 dn_expand

Documentation:
man dn_expand

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Cygwin 1.5.x, mingw, MSVC 14.

Next: , Previous: , Up: Glibc <resolv.h>   [Contents][Index]

13.45.3 dn_skipname

Documentation:
man dn_skipname

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.3.0, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <resolv.h>   [Contents][Index]

13.45.4 res_dnok

Documentation:
man res_dnok

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.3.0, HP-UX 11.11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <resolv.h>   [Contents][Index]

13.45.5 res_hnok

Documentation:
man res_hnok

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.3.0, HP-UX 11.11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <resolv.h>   [Contents][Index]

13.45.6 res_init

Documentation:
man res_init

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Cygwin 1.5.x, mingw, MSVC 14.

Next: , Previous: , Up: Glibc <resolv.h>   [Contents][Index]

13.45.7 res_mailok

Documentation:
man res_mailok

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.3.0, HP-UX 11.11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <resolv.h>   [Contents][Index]

13.45.8 res_mkquery

Documentation:
man res_mkquery

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, Cygwin 1.5.x, mingw, MSVC 14.

Next: , Previous: , Up: Glibc <resolv.h>   [Contents][Index]

13.45.9 res_nmkquery

Documentation:
man res_nmkquery

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.3.0, HP-UX 11.31, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <resolv.h>   [Contents][Index]

13.45.10 res_nquery

Documentation:
man res_nquery

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.3.0, HP-UX 11.31, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <resolv.h>   [Contents][Index]

13.45.11 res_nquerydomain

Documentation:
man res_nquerydomain

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.3.0, HP-UX 11.31, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <resolv.h>   [Contents][Index]

13.45.12 res_nsearch

Documentation:
man res_nsearch

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.3.0, HP-UX 11.31, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <resolv.h>   [Contents][Index]

13.45.13 res_nsend

Documentation:
man res_nsend

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.3.0, HP-UX 11.31, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <resolv.h>   [Contents][Index]

13.45.14 res_ownok

Documentation:
man res_ownok

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.3.0, HP-UX 11.11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <resolv.h>   [Contents][Index]

13.45.15 res_query

Documentation:
man res_query

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Cygwin 1.5.x, mingw, MSVC 14.

Next: , Previous: , Up: Glibc <resolv.h>   [Contents][Index]

13.45.16 res_querydomain

Documentation:
man res_querydomain

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, Minix 3.3.0, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <resolv.h>   [Contents][Index]

13.45.17 res_search

Documentation:
man res_search

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Cygwin 1.5.x, mingw, MSVC 14.

Previous: , Up: Glibc <resolv.h>   [Contents][Index]

13.45.18 res_send

Documentation:
man res_send

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, OpenBSD 6.7, Minix 3.3.0, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.46 Glibc <rpc/auth.h>

Next: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.1 authdes_create

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.2 authdes_pk_create

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.3 authnone_create

Documentation:
man authnone_create

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.4 authunix_create

Documentation:
man authunix_create

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.5 authunix_create_default

Documentation:
man authunix_create_default

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.6 getnetname

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.7 host2netname

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.8 key_decryptsession

Documentation:
man key_decryptsession

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.9 key_decryptsession_pk

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.10 key_encryptsession

Documentation:
man key_encryptsession

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.11 key_encryptsession_pk

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.12 key_gendes

Documentation:
man key_gendes

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.13 key_get_conv

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.14 key_secretkey_is_set

Documentation:
man key_secretkey_is_set

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.15 key_setsecret

Documentation:
man key_setsecret

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.16 netname2host

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.17 netname2user

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.18 user2netname

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.19 xdr_des_block

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <rpc/auth.h>   [Contents][Index]

13.46.20 xdr_opaque_auth

Documentation:
man xdr_opaque_auth

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.47 Glibc <rpc/auth_des.h>

Next: , Up: Glibc <rpc/auth_des.h>   [Contents][Index]

13.47.1 authdes_getucred

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth_des.h>   [Contents][Index]

13.47.2 getpublickey

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/auth_des.h>   [Contents][Index]

13.47.3 getsecretkey

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <rpc/auth_des.h>   [Contents][Index]

13.47.4 rtime

Documentation:
man rtime

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.48 Glibc <rpc/auth_unix.h>

Up: Glibc <rpc/auth_unix.h>   [Contents][Index]

13.48.1 xdr_authunix_parms

Documentation:
man xdr_authunix_parms

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.49 Glibc <rpc/clnt.h>

Next: , Up: Glibc <rpc/clnt.h>   [Contents][Index]

13.49.1 callrpc

Documentation:
man callrpc

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/clnt.h>   [Contents][Index]

13.49.2 clnt_create

Documentation:
man clnt_create

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/clnt.h>   [Contents][Index]

13.49.3 clnt_pcreateerror

Documentation:
man clnt_pcreateerror

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/clnt.h>   [Contents][Index]

13.49.4 clnt_perrno

Documentation:
man clnt_perrno

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/clnt.h>   [Contents][Index]

13.49.5 clnt_perror

Documentation:
man clnt_perror

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/clnt.h>   [Contents][Index]

13.49.6 clnt_spcreateerror

Documentation:
man clnt_spcreateerror

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/clnt.h>   [Contents][Index]

13.49.7 clnt_sperrno

Documentation:
man clnt_sperrno

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/clnt.h>   [Contents][Index]

13.49.8 clnt_sperror

Documentation:
man clnt_sperror

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/clnt.h>   [Contents][Index]

13.49.9 clntraw_create

Documentation:
man clntraw_create

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/clnt.h>   [Contents][Index]

13.49.10 clnttcp_create

Documentation:
man clnttcp_create

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/clnt.h>   [Contents][Index]

13.49.11 clntudp_bufcreate

Documentation:
man clntudp_bufcreate

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/clnt.h>   [Contents][Index]

13.49.12 clntudp_create

Documentation:
man clntudp_create

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/clnt.h>   [Contents][Index]

13.49.13 clntunix_create

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/clnt.h>   [Contents][Index]

13.49.14 get_myaddress

Documentation:
man get_myaddress

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/clnt.h>   [Contents][Index]

13.49.15 getrpcport

Documentation:
man getrpcport

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <rpc/clnt.h>   [Contents][Index]

13.49.16 rpc_createerr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on some platforms: Minix 3.1.8, AIX 5.1, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.50 Glibc <rpc/key_prot.h>

Next: , Up: Glibc <rpc/key_prot.h>   [Contents][Index]

13.50.1 xdr_cryptkeyarg

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/key_prot.h>   [Contents][Index]

13.50.2 xdr_cryptkeyarg2

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/key_prot.h>   [Contents][Index]

13.50.3 xdr_cryptkeyres

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/key_prot.h>   [Contents][Index]

13.50.4 xdr_getcredres

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/key_prot.h>   [Contents][Index]

13.50.5 xdr_key_netstarg

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/key_prot.h>   [Contents][Index]

13.50.6 xdr_key_netstres

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/key_prot.h>   [Contents][Index]

13.50.7 xdr_keybuf

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/key_prot.h>   [Contents][Index]

13.50.8 xdr_keystatus

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/key_prot.h>   [Contents][Index]

13.50.9 xdr_netnamestr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <rpc/key_prot.h>   [Contents][Index]

13.50.10 xdr_unixcred

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.51 Glibc <rpc/netdb.h>

Next: , Up: Glibc <rpc/netdb.h>   [Contents][Index]

13.51.1 endrpcent

Documentation:
man endrpcent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/netdb.h>   [Contents][Index]

13.51.2 getrpcbyname

Documentation:
man getrpcbyname

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/netdb.h>   [Contents][Index]

13.51.3 getrpcbyname_r

Documentation:
man getrpcbyname_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/netdb.h>   [Contents][Index]

13.51.4 getrpcbynumber

Documentation:
man getrpcbynumber

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/netdb.h>   [Contents][Index]

13.51.5 getrpcbynumber_r

Documentation:
man getrpcbynumber_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/netdb.h>   [Contents][Index]

13.51.6 getrpcent

Documentation:
man getrpcent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/netdb.h>   [Contents][Index]

13.51.7 getrpcent_r

Documentation:
man getrpcent_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <rpc/netdb.h>   [Contents][Index]

13.51.8 setrpcent

Documentation:
man setrpcent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.52 Glibc <rpc/pmap_clnt.h>

Next: , Up: Glibc <rpc/pmap_clnt.h>   [Contents][Index]

13.52.1 clnt_broadcast

Documentation:
man clnt_broadcast

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/pmap_clnt.h>   [Contents][Index]

13.52.2 pmap_getmaps

Documentation:
man pmap_getmaps

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/pmap_clnt.h>   [Contents][Index]

13.52.3 pmap_getport

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-pmap-getport-3.html

Documentation:
man pmap_getport

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/pmap_clnt.h>   [Contents][Index]

13.52.4 pmap_rmtcall

Documentation:
man pmap_rmtcall

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/pmap_clnt.h>   [Contents][Index]

13.52.5 pmap_set

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-pmap-set-3.html

Documentation:
man pmap_set

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <rpc/pmap_clnt.h>   [Contents][Index]

13.52.6 pmap_unset

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-pmap-unset-3.html

Documentation:
man pmap_unset

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.53 Glibc <rpc/pmap_prot.h>

Next: , Up: Glibc <rpc/pmap_prot.h>   [Contents][Index]

13.53.1 xdr_pmap

Documentation:
man xdr_pmap

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <rpc/pmap_prot.h>   [Contents][Index]

13.53.2 xdr_pmaplist

Documentation:
man xdr_pmaplist

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.54 Glibc <rpc/pmap_rmt.h>

Next: , Up: Glibc <rpc/pmap_rmt.h>   [Contents][Index]

13.54.1 xdr_rmtcall_args

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <rpc/pmap_rmt.h>   [Contents][Index]

13.54.2 xdr_rmtcallres

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.55 Glibc <rpc/rpc_msg.h>

Next: , Up: Glibc <rpc/rpc_msg.h>   [Contents][Index]

13.55.1 xdr_callhdr

Documentation:
man xdr_callhdr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/rpc_msg.h>   [Contents][Index]

13.55.2 xdr_callmsg

Documentation:
man xdr_callmsg

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <rpc/rpc_msg.h>   [Contents][Index]

13.55.3 xdr_replymsg

Documentation:
man xdr_replymsg

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.56 Glibc <rpc/svc.h>

Next: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.1 svc_exit

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.2 svc_fdset

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.3 svc_getreq

Documentation:
man svc_getreq

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.4 svc_getreq_common

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, Minix 3.1.8, AIX 5.1, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.5 svc_getreq_poll

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.6 svc_getreqset

Documentation:
man svc_getreqset

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.7 svc_max_pollfd

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.8 svc_pollfd

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.9 svc_register

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-svc-register-3.html

Documentation:
man svc_register

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.10 svc_run

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-svc-run-3.html

Documentation:
man svc_run

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.11 svc_sendreply

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-svc-sendreply-3.html

Documentation:
man svc_sendreply

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.12 svc_unregister

Documentation:
man svc_unregister

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.13 svcerr_auth

Documentation:
man svcerr_auth

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.14 svcerr_decode

Documentation:
man svcerr_decode

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.15 svcerr_noproc

Documentation:
man svcerr_noproc

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.16 svcerr_noprog

Documentation:
man svcerr_noprog

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.17 svcerr_progvers

Documentation:
man svcerr_progvers

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.18 svcerr_systemerr

Documentation:
man svcerr_systemerr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.19 svcerr_weakauth

Documentation:
man svcerr_weakauth

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.20 svcraw_create

Documentation:
man svcraw_create

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.21 svctcp_create

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-svctcp-create-3.html

Documentation:
man svctcp_create

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.22 svcudp_bufcreate

Documentation:
man svcudp_bufcreate

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.23 svcudp_create

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-svcudp-create-3.html

Documentation:
man svcudp_create

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.24 svcunix_create

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.25 xprt_register

Documentation:
man xprt_register

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <rpc/svc.h>   [Contents][Index]

13.56.26 xprt_unregister

Documentation:
man xprt_unregister

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.57 Glibc <rpc/xdr.h>

Next: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.1 xdr_array

Documentation:
man xdr_array

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.2 xdr_bool

Documentation:
man xdr_bool

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.3 xdr_bytes

Documentation:
man xdr_bytes

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.4 xdr_char

Documentation:
man xdr_char

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.5 xdr_double

Documentation:
man xdr_double

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.6 xdr_enum

Documentation:
man xdr_enum

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.7 xdr_float

Documentation:
man xdr_float

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.8 xdr_free

Documentation:
man xdr_free

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.9 xdr_hyper

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.10 xdr_int

Documentation:
man xdr_int

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.11 xdr_int16_t

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.12 xdr_int32_t

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.13 xdr_int64_t

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.14 xdr_int8_t

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.15 xdr_long

Documentation:
man xdr_long

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.16 xdr_longlong_t

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.17 xdr_netobj

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.18 xdr_opaque

Documentation:
man xdr_opaque

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.19 xdr_pointer

Documentation:
man xdr_pointer

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.20 xdr_quad_t

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.21 xdr_reference

Documentation:
man xdr_reference

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.22 xdr_short

Documentation:
man xdr_short

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.23 xdr_sizeof

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.24 xdr_string

Documentation:
man xdr_string

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.25 xdr_u_char

Documentation:
man xdr_u_char

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.26 xdr_u_hyper

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.27 xdr_u_int

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-xdr-u-int-3.html

Documentation:
man xdr_u_int

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.28 xdr_u_long

Documentation:
man xdr_u_long

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.29 xdr_u_longlong_t

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.30 xdr_u_quad_t

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.31 xdr_u_short

Documentation:
man xdr_u_short

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.32 xdr_uint16_t

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.
  • This function is not declared in the header on some platforms: Cygwin 1.7.5.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.33 xdr_uint32_t

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function is not declared in the header on some platforms: Cygwin 1.7.5.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.34 xdr_uint64_t

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function is not declared in the header on some platforms: Cygwin 1.7.5.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.35 xdr_uint8_t

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function is not declared in the header on some platforms: Cygwin 1.7.5.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.36 xdr_union

Documentation:
man xdr_union

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.37 xdr_vector

Documentation:
man xdr_vector

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.38 xdr_void

Documentation:
man xdr_void

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.39 xdr_wrapstring

Documentation:
man xdr_wrapstring

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.40 xdrmem_create

Documentation:
man xdrmem_create

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.41 xdrrec_create

Documentation:
man xdrrec_create

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.42 xdrrec_endofrecord

Documentation:
man xdrrec_endofrecord

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.43 xdrrec_eof

Documentation:
man xdrrec_eof

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.44 xdrrec_skiprecord

Documentation:
man xdrrec_skiprecord

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <rpc/xdr.h>   [Contents][Index]

13.57.45 xdrstdio_create

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-xdrstdio-create-3.html

Documentation:
man xdrstdio_create

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.4, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.58 Glibc <rpcsvc/nislib.h>

Next: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.1 nis_add

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.2 nis_add_entry

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.3 nis_addmember

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.4 nis_checkpoint

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.5 nis_clone_object

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.6 nis_creategroup

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.7 nis_destroy_object

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.8 nis_destroygroup

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.9 nis_dir_cmp

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.10 nis_domain_of

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.11 nis_domain_of_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.12 nis_first_entry

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.13 nis_freenames

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.14 nis_freeresult

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.15 nis_freeservlist

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.16 nis_freetags

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.17 nis_getnames

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.18 nis_getservlist

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.19 nis_ismember

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.20 nis_leaf_of

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.21 nis_leaf_of_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.22 nis_lerror

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.23 nis_list

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.24 nis_local_directory

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.25 nis_local_group

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.26 nis_local_host

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.27 nis_local_principal

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.28 nis_lookup

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.29 nis_mkdir

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.30 nis_modify

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.31 nis_modify_entry

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.32 nis_name_of

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.33 nis_name_of_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.34 nis_next_entry

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.35 nis_perror

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.36 nis_ping

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.37 nis_print_directory

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.38 nis_print_entry

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.39 nis_print_group

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.40 nis_print_group_entry

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.42 nis_print_object

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.43 nis_print_result

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.44 nis_print_rights

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.45 nis_print_table

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.46 nis_remove

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.47 nis_remove_entry

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.48 nis_removemember

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.49 nis_rmdir

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.50 nis_servstate

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.51 nis_sperrno

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.52 nis_sperror

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.53 nis_sperror_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.54 nis_stats

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <rpcsvc/nislib.h>   [Contents][Index]

13.58.55 nis_verifygroup

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.59 Glibc <rpcsvc/nis_callback.h>

Next: , Up: Glibc <rpcsvc/nis_callback.h>   [Contents][Index]

13.59.1 xdr_cback_data

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <rpcsvc/nis_callback.h>   [Contents][Index]

13.59.2 xdr_obj_p

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.60 Glibc <rpcsvc/yp.h>

Next: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.1 xdr_domainname

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.2 xdr_keydat

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 5.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.3 xdr_valdat

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 5.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.4 xdr_ypbind_resptype

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 5.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.5 xdr_ypmap_parms

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, OpenBSD 3.8, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.6 xdr_ypmaplist

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.7 xdr_yppushresp_xfr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, OpenBSD 3.8, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.8 xdr_ypreq_key

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.9 xdr_ypreq_nokey

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.10 xdr_ypreq_xfr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, OpenBSD 3.8, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.11 xdr_ypresp_all

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 5.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.12 xdr_ypresp_key_val

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.13 xdr_ypresp_maplist

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.14 xdr_ypresp_master

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.15 xdr_ypresp_order

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.16 xdr_ypresp_val

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.17 xdr_ypresp_xfr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.18 xdr_ypstat

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 5.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <rpcsvc/yp.h>   [Contents][Index]

13.60.19 xdr_ypxfrstat

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.61 Glibc <rpcsvc/ypclnt.h>

Next: , Up: Glibc <rpcsvc/ypclnt.h>   [Contents][Index]

13.61.1 yp_all

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/ypclnt.h>   [Contents][Index]

13.61.2 yp_bind

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/ypclnt.h>   [Contents][Index]

13.61.3 yp_first

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/ypclnt.h>   [Contents][Index]

13.61.4 yp_get_default_domain

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/ypclnt.h>   [Contents][Index]

13.61.5 yp_master

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/ypclnt.h>   [Contents][Index]

13.61.6 yp_match

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/ypclnt.h>   [Contents][Index]

13.61.7 yp_next

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/ypclnt.h>   [Contents][Index]

13.61.8 yp_order

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/ypclnt.h>   [Contents][Index]

13.61.9 yp_unbind

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/ypclnt.h>   [Contents][Index]

13.61.10 ypbinderr_string

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <rpcsvc/ypclnt.h>   [Contents][Index]

13.61.11 yperr_string

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <rpcsvc/ypclnt.h>   [Contents][Index]

13.61.12 ypprot_err

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.62 Glibc Extensions to <sched.h>

Next: , Up: Glibc Extensions to <sched.h>   [Contents][Index]

13.62.1 clone

Documentation:
man clone

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <sched.h>   [Contents][Index]

13.62.2 getcpu

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on all non-glibc platforms: glibc 2.28, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <sched.h>   [Contents][Index]

13.62.3 sched_getaffinity

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sched-getaffinity.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 13.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 3.0.

Next: , Previous: , Up: Glibc Extensions to <sched.h>   [Contents][Index]

13.62.4 sched_getcpu

Documentation:
man sched_getcpu

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on most non-glibc platforms: glibc 2.5, macOS 14, FreeBSD 13.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <sched.h>   [Contents][Index]

13.62.5 sched_setaffinity

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sched-setaffinity.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 13.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 3.0.

Previous: , Up: Glibc Extensions to <sched.h>   [Contents][Index]

13.62.6 setns

Documentation:
man setns

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: glibc 2.13, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 4.4.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.63 Glibc Extensions to <search.h>

Next: , Up: Glibc Extensions to <search.h>   [Contents][Index]

13.63.1 hcreate_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-hcreate-r.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 8.1.

Next: , Previous: , Up: Glibc Extensions to <search.h>   [Contents][Index]

13.63.2 hdestroy_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-hdestroy-r.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 8.1.

Next: , Previous: , Up: Glibc Extensions to <search.h>   [Contents][Index]

13.63.3 hsearch_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-hsearch-r.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 8.1.

Next: , Previous: , Up: Glibc Extensions to <search.h>   [Contents][Index]

13.63.4 tdestroy

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.0, mingw, MSVC 14, Android 4.0.4.

Previous: , Up: Glibc Extensions to <search.h>   [Contents][Index]

13.63.5 twalk_r

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.64 Glibc Extensions to <selinux/selinux.h>

Next: , Up: Glibc Extensions to <selinux/selinux.h>   [Contents][Index]

13.64.1 fgetfilecon

Documentation:
man fgetfilecon

Gnulib module: selinux-h

Portability problems fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0. On those platforms, this module provides a stub that always sets errno to ENOTSUP and returns ‘-1’.
  • On systems with SELinux support, this module provides a wrapper for the fgetfilecon function that insulates the caller from API-nonconforming behavior. Without this wrapper, fgetfilecon can return ‘0’ and set the context pointer to NULL, and in another scenario can return ‘10’ and set the context pointer to ‘unlabeled’. This wrapper returns ‘-1’ in each case and sets errno to ENOTSUP and ENODATA respectively. While the conditions that can provoke such behavior are rare, the average caller does not handle them because the possibility of such behavior is not documented.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc Extensions to <selinux/selinux.h>   [Contents][Index]

13.64.2 getfilecon

Documentation:
man getfilecon

Gnulib module: selinux-h

Portability problems fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0. On those platforms, this module provides a stub that always sets errno to ENOTSUP and returns ‘-1’.
  • On systems with SELinux support, this module provides a wrapper for the getfilecon function that insulates the caller from API-nonconforming behavior. Without this wrapper, getfilecon can return ‘0’ and set the context pointer to NULL, and in another scenario can return ‘10’ and set the context pointer to ‘unlabeled’. This wrapper returns ‘-1’ in each case and sets errno to ENOTSUP and ENODATA respectively. While the conditions that can provoke such behavior are rare, the average caller does not handle them because the possibility of such behavior is not documented.

Portability problems not fixed by Gnulib:

Previous: , Up: Glibc Extensions to <selinux/selinux.h>   [Contents][Index]

13.64.3 lgetfilecon

Documentation:
man lgetfilecon

Gnulib module: selinux-h

Portability problems fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0. On those platforms, this module provides a stub that always sets errno to ENOTSUP and returns ‘-1’.
  • On systems with SELinux support, this module provides a wrapper for the lgetfilecon function that insulates the caller from API-nonconforming behavior. Without this wrapper, lgetfilecon can return ‘0’ and set the context pointer to NULL, and in another scenario can return ‘10’ and set the context pointer to ‘unlabeled’. This wrapper returns ‘-1’ in each case and sets errno to ENOTSUP and ENODATA respectively. While the conditions that can provoke such behavior are rare, the average caller does not handle them because the possibility of such behavior is not documented.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.65 Glibc Extensions to <semaphore.h>

Up: Glibc Extensions to <semaphore.h>   [Contents][Index]

13.65.1 sem_clockwait

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1216

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

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13.66 Glibc <shadow.h>

Next: , Up: Glibc <shadow.h>   [Contents][Index]

13.66.1 endspent

Documentation:
man endspent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <shadow.h>   [Contents][Index]

13.66.2 fgetspent

Documentation:
man fgetspent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <shadow.h>   [Contents][Index]

13.66.3 fgetspent_r

Documentation:
man fgetspent_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <shadow.h>   [Contents][Index]

13.66.4 getspent

Documentation:
man getspent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <shadow.h>   [Contents][Index]

13.66.5 getspent_r

Documentation:
man getspent_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <shadow.h>   [Contents][Index]

13.66.6 getspnam

Documentation:
man getspnam

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <shadow.h>   [Contents][Index]

13.66.7 getspnam_r

Documentation:
man getspnam_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <shadow.h>   [Contents][Index]

13.66.8 lckpwdf

Documentation:
man lckpwdf

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <shadow.h>   [Contents][Index]

13.66.9 putspent

Documentation:
man putspent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <shadow.h>   [Contents][Index]

13.66.10 setspent

Documentation:
man setspent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <shadow.h>   [Contents][Index]

13.66.11 sgetspent

Documentation:
man sgetspent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <shadow.h>   [Contents][Index]

13.66.12 sgetspent_r

Documentation:
man sgetspent_r

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <shadow.h>   [Contents][Index]

13.66.13 ulckpwdf

Documentation:
man ulckpwdf

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.67 Glibc Extensions to <signal.h>

Next: , Up: Glibc Extensions to <signal.h>   [Contents][Index]

13.67.1 gsignal

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <signal.h>   [Contents][Index]

13.67.2 sigandset

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sigandset.html

Documentation:
man sigandset

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 12.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <signal.h>   [Contents][Index]

13.67.3 sigblock

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <signal.h>   [Contents][Index]

13.67.4 siggetmask

Documentation:
man siggetmask

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <signal.h>   [Contents][Index]

13.67.5 sigisemptyset

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sigisemptyset.html

Documentation:
man sigisemptyset

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 12.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <signal.h>   [Contents][Index]

13.67.6 sigorset

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sigorset.html

Documentation:
man sigorset

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 12.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <signal.h>   [Contents][Index]

13.67.7 sigreturn

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sigreturn-2.html

Documentation:
man sigreturn

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.67.8 sigsetmask

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.67.9 sigstack

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.67.10 sigvec

Documentation:
man sigvec

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.67.11 ssignal

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.67.12 sys_siglist

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Signal-Messages.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This constant is missing on some platforms: Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 1.7.9, mingw, MSVC 14.

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13.67.13 sysv_signal

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.67.14 tgkill

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on most non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.68 Glibc Extensions to <spawn.h>

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13.68.1 pidfd_spawn

Documentation:
https://lwn.net/Articles/943022/

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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13.68.2 pidfd_spawnp

Documentation:
https://lwn.net/Articles/943022/

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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13.68.3 posix_spawn_file_actions_addchdir_np

posix_spawn_file_actions_addchdir is specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1208

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.28, macOS 10.14, FreeBSD 13.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.0, Cygwin 3.4.6, mingw, MSVC 14, Android API level 33.

Note: Gnulib has a module posix_spawn_file_actions_addchdir that provides equivalent functionality, just without the suffix _np.

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13.68.4 posix_spawn_file_actions_addclosefrom_np

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.33, macOS 14, FreeBSD 13.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.3.0, AIX 7.1, HP-UX 11.31, Solaris 10, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.68.5 posix_spawn_file_actions_addfchdir_np

posix_spawn_file_actions_addfchdir is specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1208

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.28, macOS 10.14, FreeBSD 13.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.4.6, mingw, MSVC 14, Android API level 33.

Note: Gnulib has a module posix_spawn_file_actions_addfchdir that provides equivalent functionality, just without the suffix _np.

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13.68.6 posix_spawn_file_actions_addtcsetpgrp_np

Documentation: —

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android.

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13.68.7 posix_spawnattr_getcgroup_np

Documentation:
https://sourceware.org/pipermail/libc-alpha/2023-August/151106.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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13.68.8 posix_spawnattr_setcgroup_np

Documentation:
https://sourceware.org/pipermail/libc-alpha/2023-August/151106.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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13.69 Glibc Extensions to <stdio.h>

Next: , Up: Glibc Extensions to <stdio.h>   [Contents][Index]

13.69.1 asprintf

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-asprintf.html

Documentation:

Gnulib module: vasprintf or vasprintf-posix or vasprintf-gnu

Portability problems fixed by either Gnulib module vasprintf or vasprintf-posix or vasprintf-gnu:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 10, mingw, MSVC 14.

Portability problems fixed by either Gnulib module vasprintf-posix or vasprintf-gnu:

  • This function does not support size specifiers as in C99 (hh, ll, j, t, z) on some platforms: Cygwin 1.5.24.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • printf "%f", "%e", "%g" of Infinity and NaN yields an incorrect result on some platforms: AIX 7.3, Solaris 11.4.
  • This function does not support the ‘a’ and ‘A’ directives on some platforms: FreeBSD 5.2.1, OpenBSD 4.0, Solaris 11.4, Cygwin 1.5.x.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support the ‘F’ directive on some platforms: NetBSD 3.0, Cygwin 1.5.x.
  • This function does not support the ‘ls’ directive on some platforms: OpenBSD 4.0, Cygwin 1.5.x, Haiku.
  • This function does not support precisions in the ‘ls’ directive correctly on some platforms: Solaris 11.4.
  • This function does not support format directives that access arguments in an arbitrary order, such as "%2$s", on some platforms: NetBSD 3.0.
  • This function doesn’t support the ' flag on some platforms: NetBSD 3.0, Cygwin 1.5.24.
  • This function does not round the argument of the ‘a’ directive correctly on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4.
  • printf "%010f" of NaN and Infinity yields an incorrect result (padded with zeroes) on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 7.3, Solaris 11.4, Cygwin 1.5.x.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • This function produces wrong output for the ‘lc’ directive with a NUL wide character argument on some platforms: musl libc 1.2.4.
  • This function can crash in out-of-memory conditions on some platforms: FreeBSD 14.0, NetBSD 5.0.

Portability problems fixed by Gnulib module vasprintf-gnu:

  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.

Portability problems not fixed by Gnulib:

  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.

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13.69.2 cuserid

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, mingw, MSVC 14, Android 9.0.

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13.69.3 clearerr_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-clearerr-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 5.1.

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13.69.4 fcloseall

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, mingw, Android 9.0.
  • This functions returns void instead of int on some platforms: FreeBSD 14.0.

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13.69.5 feof_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-feof-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 5.1.

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13.69.6 ferror_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-ferror-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 5.1.

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13.69.7 fflush_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fflush-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 12.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

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13.69.8 fgetc_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fgetc-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

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13.69.9 fgets_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fgets-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

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13.69.10 fileno_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fileno-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 6.0.

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13.69.11 fopencookie

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 10.4, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

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13.69.12 fputc_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fputc-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 12.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

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13.69.13 fputs_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fputs-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 12.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

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13.69.14 fread_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fread-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 12.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

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13.69.15 fwrite_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fwrite-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 12.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

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13.69.16 getw

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Android 9.0.

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13.69.17 putw

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is not declared on some platforms: Android 9.0.

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13.69.18 renameat2

Documentation:
man renameat2

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.8.x, mingw, MSVC 14, Android API level 29.
  • This function succeeds when the RENAME_NOREPLACE flag is specified and the source and destination are the same file, on some platforms: Cygwin 3.4.6.

The renameatu module addresses some of these portability issues.

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13.69.19 setbuffer

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-setbuffer-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11, mingw, MSVC 14.

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13.69.20 setlinebuf

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.23, mingw, MSVC 14.

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13.69.21 sys_errlist

Documentation:
man sys_errlist

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, Android 9.0.

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13.69.22 sys_nerr

Documentation:
man sys_nerr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on some platforms: Minix 3.1.8, Cygwin 2.9, mingw, Android 9.0.

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13.69.23 tmpnam_r

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.69.24 vasprintf

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-vasprintf.html

Documentation:

Gnulib module: vasprintf or vasprintf-posix or vasprintf-gnu

Portability problems fixed by either Gnulib module vasprintf or vasprintf-posix or vasprintf-gnu:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 10, mingw, MSVC 14.

Portability problems fixed by either Gnulib module vasprintf-posix or vasprintf-gnu:

  • This function does not support size specifiers as in C99 (hh, ll, j, t, z) on some platforms: Cygwin 1.5.24.
  • This function does not support size specifiers as in C23 (w8, w16, w32, w64, wf8, wf16, wf32, wf64) on some platforms: glibc 2.37, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.
  • printf "%f", "%e", "%g" of Infinity and NaN yields an incorrect result on some platforms: AIX 7.3, Solaris 11.4.
  • This function does not support the ‘a’ and ‘A’ directives on some platforms: FreeBSD 5.2.1, OpenBSD 4.0, Solaris 11.4, Cygwin 1.5.x.
  • This function does not support the ‘b’ directive, required by ISO C23, on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, HP-UX 11, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android 9.0.
  • This function does not support the ‘F’ directive on some platforms: NetBSD 3.0, Cygwin 1.5.x.
  • This function does not support the ‘ls’ directive on some platforms: OpenBSD 4.0, Cygwin 1.5.x, Haiku.
  • This function does not support precisions in the ‘ls’ directive correctly on some platforms: Solaris 11.4.
  • This function does not support format directives that access arguments in an arbitrary order, such as "%2$s", on some platforms: NetBSD 3.0.
  • This function doesn’t support the ' flag on some platforms: NetBSD 3.0, Cygwin 1.5.24.
  • This function does not round the argument of the ‘a’ directive correctly on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4.
  • printf "%010f" of NaN and Infinity yields an incorrect result (padded with zeroes) on some platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, AIX 7.3, Solaris 11.4, Cygwin 1.5.x.
  • printf "%#.0x" or "%#.0X" with a zero argument yields an incorrect result (non-empty) on some platforms: Mac OS X 10.6.
  • This function produces wrong output for the ‘lc’ directive with a NUL wide character argument on some platforms: musl libc 1.2.4.
  • This function can crash in out-of-memory conditions on some platforms: FreeBSD 14.0, NetBSD 5.0.

Portability problems fixed by Gnulib module vasprintf-gnu:

  • This function does not support the ‘B’ directive on some platforms: glibc 2.34, musl libc, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 7.5, AIX 7.3, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC, Android 9.0.

Portability problems not fixed by Gnulib:

  • The %m directive is not portable, use %s mapped to an argument of strerror(errno) (or a version of strerror_r) instead.

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13.70 Glibc Extensions to <stdlib.h>

Next: , Up: Glibc Extensions to <stdlib.h>   [Contents][Index]

13.70.1 arc4random

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.35, AIX 7.3.1, HP-UX 11.31, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14.

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13.70.2 arc4random_buf

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.35, AIX 7.3.1, HP-UX 11.31, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14.

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13.70.3 arc4random_uniform

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.35, AIX 7.3.1, HP-UX 11.31, Solaris 11.3, Cygwin 1.7.x, mingw, MSVC 14.

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13.70.4 canonicalize_file_name

Documentation:

Gnulib module: canonicalize-lgpl

Portability problems fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.
  • This function fails to detect trailing slashes on non-directories on some platforms: glibc 2.3.5.

Portability problems not fixed by Gnulib:

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13.70.5 cfree

Documentation:
man cfree

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.70.6 clearenv

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, Solaris 10, Cygwin 2.9, mingw, MSVC 14.

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13.70.7 drand48_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-drand48-r-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.70.8 ecvt_r

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.70.9 erand48_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-erand48-r-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.70.10 fcvt_r

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.70.11 getloadavg

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getloadavg-3.html

Documentation:

Gnulib module: getloadavg

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.
  • This function is declared in <sys/loadavg.h>, not <stdlib.h>, on some platforms: Solaris 11.4.

Portability problems not fixed by Gnulib:

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13.70.12 getpt

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.9, mingw, MSVC 14.

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13.70.13 initstate_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-initstate-r-1.html

Documentation:

Gnulib module: random_r

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function has an incompatible declaration on some platforms: AIX 7.1.

Portability problems not fixed by Gnulib:

  • This function crashes if the state buffer is unaligned on some platforms: glibc 2.36/sparc.
  • This function has a slightly different (but compatible) declaration on some platforms: Haiku 2017.

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13.70.14 jrand48_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-jrand48-r-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.70.15 lcong48_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-lcong48-r-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.70.16 lrand48_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-lrand48-r-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.70.17 mkostemp

Documentation:
man mkostemp

Gnulib module: mkostemp

Portability problems fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.6, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.5, mingw, MSVC 14, Android 5.1.
  • This function is declared in <unistd.h> instead of <stdlib.h> on some platforms: macOS 14.
  • On platforms where off_t is a 32-bit type, mkostemp may not work correctly to create files larger than 2 GB. (Cf. AC_SYS_LARGEFILE.)

Portability problems not fixed by Gnulib:

The gnulib module clean-temp can create temporary files that will not be left behind after signals such as SIGINT.

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13.70.18 mkostemps

Documentation:
man mkostemps

Gnulib module: mkostemps

Portability problems fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.10, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.5, mingw, MSVC 14, Android 5.1.
  • This function is declared in <unistd.h> instead of <stdlib.h> on some platforms: macOS 14.
  • On platforms where off_t is a 32-bit type, mkostemps may not work correctly to create files larger than 2 GB. (Cf. AC_SYS_LARGEFILE.)

Portability problems not fixed by Gnulib:

The gnulib module clean-temp can create temporary files that will not be left behind after signals such as SIGINT.

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13.70.19 mkstemps

Documentation:
man mkstemps

Gnulib module: mkstemps

Portability problems fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.10, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14.
  • This function is declared in <unistd.h> instead of <stdlib.h> on some platforms: macOS 14.
  • On platforms where off_t is a 32-bit type, mkstemps may not work correctly to create files larger than 2 GB. (Cf. AC_SYS_LARGEFILE.)

Portability problems not fixed by Gnulib:

The gnulib module clean-temp can create temporary files that will not be left behind after signals such as SIGINT.

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13.70.20 mrand48_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-mrand48-r-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.70.21 nrand48_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-nrand48-r-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.70.22 on_exit

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.

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13.70.23 ptsname_r

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=508

Documentation:

Gnulib module: ptsname_r

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.12, FreeBSD 12.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.9, mingw, MSVC 14.
  • When this function fails, it returns -1 instead of the error code on some platforms: macOS 14, FreeBSD 14.0, Android 4.3.
  • When this function fails with ERANGE, it stores an empty string as result on some platforms: NetBSD 10.0.

Portability problems not fixed by Gnulib:

  • When this function fails, it returns 0 and stores an empty string as result on some platforms: Cygwin 2.9.

Note: Portable programs should expect to find the error code as the return value of this function, not as the value of errno. This is needed for compatibility with musl libc and with the forthcoming POSIX Issue 8.

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13.70.24 qecvt

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.70.25 qecvt_r

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.70.26 qfcvt

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.70.27 qfcvt_r

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.70.28 qgcvt

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.70.29 qsort_r

Documentation:
man qsort_r

Gnulib module: —

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.7, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.
  • This function has an incompatible API on some platforms: FreeBSD 13.2.

Portability problems not fixed by Gnulib:

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13.70.30 random_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-random-r-1.html

Documentation:

Gnulib module: random_r

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function has an incompatible declaration on some platforms: AIX 7.1.

Portability problems not fixed by Gnulib:

  • This function has a slightly different (but compatible) declaration on some platforms: Haiku 2017.

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13.70.31 rpmatch

Documentation:

Gnulib module: rpmatch

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 10.14, FreeBSD 5.2.1, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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13.70.32 secure_getenv

Documentation:

Gnulib module: secure_getenv

Portability problems fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.16, macOS 14, FreeBSD 13.2, NetBSD 10.0, OpenBSD 5.2, Minix 3.2.0, AIX 7.1, HP-UX 11, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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13.70.33 seed48_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-seed48-r-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.70.34 setstate_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-setstate-r-1.html

Documentation:

Gnulib module: random_r

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function has an incompatible declaration on some platforms: AIX 7.1.

Portability problems not fixed by Gnulib:

  • This function has a slightly different (but compatible) declaration on some platforms: Haiku 2017.

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13.70.35 srand48_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-srand48-r-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.70.36 srandom_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-srandom-r-1.html

Documentation:

Gnulib module: random_r

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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13.70.37 strtod_l

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 7.1.

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13.70.38 strtof_l

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 7.1.

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13.70.39 strtol_l

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 7.1.

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13.70.40 strtold_l

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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13.70.41 strtoll_l

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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13.70.42 strtoq

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-strtoq-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.
  • This function is not declared on some platforms: Android 9.0.

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13.70.43 strtoul_l

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 7.1.

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13.70.44 strtoull_l

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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13.70.45 strtouq

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-strtouq-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.
  • This function is not declared on some platforms: Android 9.0.

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13.70.46 valloc

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14.

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13.71 Glibc Extensions to <string.h>

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13.71.1 explicit_bzero

Documentation:

Gnulib module: explicit_bzero

The explicit_bzero function is an approximation to what is needed, and does not suffice in general to erase information. Although calling explicit_bzero should clear the memory in question, the information that was in memory may still be available elsewhere on the machine. Proper implementation of information erasure requires support from levels below C code.

C23 specifies the function memset_explicit, which should be preferred to explicit_bzero in new code. See memset_explicit.

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.24, FreeBSD 10, NetBSD 7.1, OpenBSD 5.4, macOS 10.12, Solaris 11.4, Android 9.0, and many other systems.

Portability problems not fixed by Gnulib:

  • Although the module’s implementation should clear the memory on platforms compatible with GCC and on platforms using traditional linkers, it may not clear the memory on non-GCC platforms that use whole-program optimization.

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13.71.2 ffsl

Documentation:
man ffsl

Gnulib module: ffsl

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 5.2.1, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.
  • This function is declared in <strings.h> instead of <string.h> on some platforms: AIX 7.2, Android 13.

Portability problems not fixed by Gnulib:

  • This function is only defined as an inline function on some platforms: Android 13.

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13.71.3 ffsll

Documentation:
man ffsll

Gnulib module: ffsll

Portability problems fixed by Gnulib:

  • This function is missing on many non-glibc platforms: Mac OS X 10.5, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.
  • This function is declared in <strings.h> instead of <string.h> on some platforms: AIX 7.2, Android 13.
  • This function returns completely wrong values on some platforms: AIX 7.2 in 32-bit mode.

Portability problems not fixed by Gnulib:

  • This function is only defined as an inline function on some platforms: Android 13.

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13.71.4 memfrob

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.71.5 memmem

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-memmem-3.html

Documentation:

Gnulib module: memmem or memmem-simple

Both modules implement the same replacement for the memmem function with the memmem module providing a replacement on more platforms where the existing memmem function has a quadratic worst-case complexity.

Portability problems fixed by either Gnulib module memmem-simple or memmem:

  • This function is missing on some platforms: Mac OS X 10.5, FreeBSD 5.2.1, OpenBSD 4.0, Minix 3.1.8, HP-UX 11, Solaris 10, mingw, MSVC 14.
  • This function has reversed arguments on some older platforms: Linux libc 5.0.9
  • This function can trigger false positives for long periodic needles on some platforms: glibc 2.12, Cygwin 1.7.7.
  • This function returns incorrect values in some cases, such as when given an empty needle: glibc <= 2.0, macOS 14, AIX 7.2, Solaris 11.3, Cygwin 1.5.x.

Performance problems fixed by Gnulib module memmem:

  • This function has quadratic instead of linear worst-case complexity on some platforms: glibc 2.8, macOS 14, FreeBSD 11.4, NetBSD 8.2, OpenBSD 6.6, AIX 7.2, Solaris 11.4, Cygwin 1.5.x. Note for small needles the replacement may be slower.

Portability problems not fixed by Gnulib:

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13.71.6 mempcpy

Documentation:

Gnulib module: mempcpy

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 13.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 5.1.

Portability problems not fixed by Gnulib:

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13.71.7 memrchr

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-memrchr.html

Documentation:

Gnulib module: memrchr

Portability problems fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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13.71.8 rawmemchr

Documentation:

Gnulib module: rawmemchr

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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13.71.9 sigabbrev_np

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Signal-Messages.html.

Gnulib module: sigabbrev_np

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.31, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

Note: Gnulib has a module sig2str that contains an equivalent function and also one that does the opposite conversion, from an abbreviated signal name to a signal number.

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13.71.10 sigdescr_np

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Signal-Messages.html.

Gnulib module: sigdescr_np

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.31, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

  • The description of SIGCHLD is wrong on some platforms: glibc.
  • The description of SIGEMT is completely unintelligible on some platforms: glibc.

Note: This function is hardly useful, because it returns English strings, not internationalized strings. Better use the function strsignal, which returns internationalized strings.

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13.71.11 strcasestr

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-strcasestr.html

Documentation:

Gnulib module: strcasestr or strcasestr-simple

Portability problems fixed by either Gnulib module strcasestr-simple or strcasestr:

  • This function is missing on some platforms: AIX 7.2, HP-UX 11, Solaris 10, Cygwin 1.5.x, mingw, MSVC 14.
  • This function can trigger memchr bugs on some platforms: glibc 2.10.
  • This function can trigger false positives for long periodic needles on some platforms: glibc 2.12, Cygwin 1.7.7.
  • This function may fail to find matches on some platforms: glibc 2.28.

Portability problems fixed by Gnulib module strcasestr:

  • This function has quadratic instead of linear worst-case complexity on some platforms: glibc 2.8, musl libc 1.2.3, macOS 14, FreeBSD 13.1, NetBSD 10.0, OpenBSD 7.2, Solaris 11.4.

Portability problems not fixed by Gnulib:

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13.71.12 strchrnul

Documentation:

Gnulib module: strchrnul

Portability problems fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 6.0, NetBSD 7.1, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.7.8, mingw, MSVC 14, Android 6.0.
  • This function crashes when no occurrence is found on some platforms: Cygwin 1.7.9.

Portability problems not fixed by Gnulib:

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13.71.13 strerrordesc_np

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Error-Messages.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.31, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.71.14 strerrorname_np

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Error-Messages.html.

Gnulib module: strerrorname_np

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.31, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function returns wrong values on some platforms: glibc 2.37.

Portability problems not fixed by Gnulib:

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13.71.15 strfry

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.71.16 strsep

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-strsep-3.html

Documentation:

Gnulib module: strsep

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11, Solaris 10, mingw, MSVC 14.

Portability problems not fixed by Gnulib:

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13.71.17 strverscmp

Documentation:

Gnulib module: strverscmp

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: macOS 14, FreeBSD 13.1, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.
  • This function treats ASCII letters as smaller than a digit sequence on some platforms: musl libc 1.2.3, Cygwin 3.4.6.

Portability problems not fixed by Gnulib:

  • On older glibc platforms, this function does not always properly treat digit strings with leading zeros as fractions (for example, strverscmp ("B0075022800016.gbp.corp.com", "B007502357019.GBP.CORP.COM") does not yield a negative number as it should): glibc 2.9

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13.72 Glibc <sys/auxv.h>

Up: Glibc <sys/auxv.h>   [Contents][Index]

13.72.1 getauxval

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.15, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.73 Glibc <sys/capability.h>

Next: , Up: Glibc <sys/capability.h>   [Contents][Index]

13.73.1 capget

Documentation:
man capget

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.73.2 capset

Documentation:
man capset

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.74 Glibc <sys/epoll.h>

Next: , Up: Glibc <sys/epoll.h>   [Contents][Index]

13.74.1 epoll_create

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-epoll-create-1.html

Documentation:
man epoll_create

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and illumos and is therefore missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.74.2 epoll_create1

Documentation:
man epoll_create1

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and illumos and is therefore missing on many non-glibc platforms: glibc 2.8, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 4.3.

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13.74.3 epoll_ctl

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-epoll-ctl-1.html

Documentation:
man epoll_ctl

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and illumos and is therefore missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.74.4 epoll_pwait

Documentation:
man epoll_pwait

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and illumos and is therefore missing on many non-glibc platforms: glibc 2.5, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 4.3.

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13.74.5 epoll_pwait2

Documentation:
man epoll_pwait2

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.34, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

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13.74.6 epoll_wait

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-epoll-wait-1.html

Documentation:
man epoll_wait

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and illumos and is therefore missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.75 Glibc <sys/eventfd.h>

Next: , Up: Glibc <sys/eventfd.h>   [Contents][Index]

13.75.1 eventfd

Documentation:
man eventfd

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux, FreeBSD, NetBSD, and illumos and is therefore missing on many non-glibc platforms: glibc 2.6, macOS 14, FreeBSD 12.0, NetBSD 9.3, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.75.2 eventfd_read

Documentation:
man eventfd_read

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux, FreeBSD, NetBSD, and illumos and is therefore missing on many non-glibc platforms: glibc 2.6, macOS 14, FreeBSD 12.0, NetBSD 9.3, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.75.3 eventfd_write

Documentation:
man eventfd_write

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux, FreeBSD, NetBSD, and illumos and is therefore missing on many non-glibc platforms: glibc 2.6, macOS 14, FreeBSD 12.0, NetBSD 9.3, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.76 Glibc <sys/fanotify.h>

Next: , Up: Glibc <sys/fanotify.h>   [Contents][Index]

13.76.1 fanotify_init

Documentation:
man fanotify_init

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on all non-glibc platforms: glibc 2.12, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.76.2 fanotify_mark

Documentation:
man fanotify_mark

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on all non-glibc platforms: glibc 2.12, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.77 Glibc <sys/file.h>

Up: Glibc <sys/file.h>   [Contents][Index]

13.77.1 flock

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-flock-2.html

Documentation:
man flock

Gnulib module: flock

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14
  • This function is missing on some platforms: AIX 7.1, HP-UX 11.23, Solaris 11.4. But the replacement function does not really work; it exhibits test failures.

Portability problems not fixed by Gnulib:

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13.78 Glibc <sys/fsuid.h>

Next: , Up: Glibc <sys/fsuid.h>   [Contents][Index]

13.78.1 setfsgid

Documentation:
man setfsgid

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 4.4.

Previous: , Up: Glibc <sys/fsuid.h>   [Contents][Index]

13.78.2 setfsuid

Documentation:
man setfsuid

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 4.4.

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13.79 Glibc <sys/gmon.h>

Up: Glibc <sys/gmon.h>   [Contents][Index]

13.79.1 monstartup

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.80 Glibc <sys/inotify.h>

Next: , Up: Glibc <sys/inotify.h>   [Contents][Index]

13.80.1 inotify_add_watch

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-inotify-add-watch.html

Documentation:
man inotify_add_watch

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on most non-glibc platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

Next: , Previous: , Up: Glibc <sys/inotify.h>   [Contents][Index]

13.80.2 inotify_init

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-inotify-init.html

Documentation:
man inotify_init

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on most non-glibc platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

Next: , Previous: , Up: Glibc <sys/inotify.h>   [Contents][Index]

13.80.3 inotify_init1

Documentation:
man inotify_init1

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on most non-glibc platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 4.3.

Previous: , Up: Glibc <sys/inotify.h>   [Contents][Index]

13.80.4 inotify_rm_watch

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-inotify-rm-watch.html

Documentation:
man inotify_rm_watch

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on most non-glibc platforms: glibc 2.3.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.81 Glibc <sys/io.h>, <sys/perm.h>

Next: , Up: Glibc <sys/io.h>, <sys/perm.h>   [Contents][Index]

13.81.1 ioperm

Documentation:
man ioperm

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <sys/io.h>, <sys/perm.h>   [Contents][Index]

13.81.2 iopl

Documentation:
man iopl

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.82 Glibc <sys/kdaemon.h>

Up: Glibc <sys/kdaemon.h>   [Contents][Index]

13.82.1 bdflush

Documentation:
man bdflush

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.83 Glibc <sys/klog.h>

Up: Glibc <sys/klog.h>   [Contents][Index]

13.83.1 klogctl

Documentation:
man klogctl

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.84 Glibc Extensions to <sys/mman.h>

Next: , Up: Glibc Extensions to <sys/mman.h>   [Contents][Index]

13.84.1 madvise

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Cygwin 1.7.7, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <sys/mman.h>   [Contents][Index]

13.84.2 memfd_create

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and FreeBSD and is therefore missing on many non-glibc platforms: glibc 2.26, macOS 14, FreeBSD 12.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Next: , Previous: , Up: Glibc Extensions to <sys/mman.h>   [Contents][Index]

13.84.3 mincore

Documentation:
man mincore

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <sys/mman.h>   [Contents][Index]

13.84.4 mlock2

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many platforms: glibc 2.26, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android API level 29.

Next: , Previous: , Up: Glibc Extensions to <sys/mman.h>   [Contents][Index]

13.84.5 mremap

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-mremap.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: macOS 14, FreeBSD 14.0, NetBSD 3.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <sys/mman.h>   [Contents][Index]

13.84.6 pkey_alloc

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on all non-glibc platforms: glibc 2.26, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <sys/mman.h>   [Contents][Index]

13.84.7 pkey_free

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on all non-glibc platforms: glibc 2.26, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <sys/mman.h>   [Contents][Index]

13.84.8 pkey_get

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Memory-Protection.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on all non-glibc platforms: glibc 2.26, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <sys/mman.h>   [Contents][Index]

13.84.9 pkey_mprotect

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on all non-glibc platforms: glibc 2.26, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <sys/mman.h>   [Contents][Index]

13.84.10 pkey_set

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Memory-Protection.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on all non-glibc platforms: glibc 2.26, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <sys/mman.h>   [Contents][Index]

13.84.11 process_madvise

Documentation:
man process_madvise

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: glibc 2.35, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

Next: , Previous: , Up: Glibc Extensions to <sys/mman.h>   [Contents][Index]

13.84.12 process_mrelease

Documentation:
https://lwn.net/Articles/864184/

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: glibc 2.35, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

Previous: , Up: Glibc Extensions to <sys/mman.h>   [Contents][Index]

13.84.13 remap_file_pages

Documentation:
man remap_file_pages

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.85 Glibc <sys/mount.h>

Next: , Up: Glibc <sys/mount.h>   [Contents][Index]

13.85.1 fsconfig

Documentation:
https://lore.kernel.org/all/159827191245.306468.4903071494263813779.stgit@warthog.procyon.org.uk/

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: glibc 2.35, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

Next: , Previous: , Up: Glibc <sys/mount.h>   [Contents][Index]

13.85.2 fsmount

Documentation:
https://lore.kernel.org/all/159827190508.306468.12755090833140558156.stgit@warthog.procyon.org.uk/

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: glibc 2.35, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

Next: , Previous: , Up: Glibc <sys/mount.h>   [Contents][Index]

13.85.3 fsopen

Documentation:
https://lore.kernel.org/all/159827190508.306468.12755090833140558156.stgit@warthog.procyon.org.uk/

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: glibc 2.35, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

Next: , Previous: , Up: Glibc <sys/mount.h>   [Contents][Index]

13.85.4 fspick

Documentation:
https://lore.kernel.org/all/159827189767.306468.1803062787718957199.stgit@warthog.procyon.org.uk/

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: glibc 2.35, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

Next: , Previous: , Up: Glibc <sys/mount.h>   [Contents][Index]

13.85.5 mount

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

Next: , Previous: , Up: Glibc <sys/mount.h>   [Contents][Index]

13.85.6 mount_setattr

Documentation:
man mount_setattr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: glibc 2.35, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

Next: , Previous: , Up: Glibc <sys/mount.h>   [Contents][Index]

13.85.7 move_mount

Documentation:
https://lore.kernel.org/all/159827189025.306468.4916341547843731338.stgit@warthog.procyon.org.uk/

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: glibc 2.35, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

Next: , Previous: , Up: Glibc <sys/mount.h>   [Contents][Index]

13.85.8 open_tree

Documentation:
https://lore.kernel.org/all/159827188271.306468.16962617119460123110.stgit@warthog.procyon.org.uk/

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: glibc 2.35, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

Next: , Previous: , Up: Glibc <sys/mount.h>   [Contents][Index]

13.85.9 umount

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, AIX 5.1, mingw, MSVC 14.

Previous: , Up: Glibc <sys/mount.h>   [Contents][Index]

13.85.10 umount2

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11.23, Cygwin 2.9, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.86 Glibc <sys/personality.h>

Up: Glibc <sys/personality.h>   [Contents][Index]

13.86.1 personality

Documentation:
man personality

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 4.0.2.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.87 Glibc <sys/pidfd.h>

Next: , Up: Glibc <sys/pidfd.h>   [Contents][Index]

13.87.1 pidfd_getfd

Documentation:
man pidfd_getfd

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: glibc 2.35, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

Next: , Previous: , Up: Glibc <sys/pidfd.h>   [Contents][Index]

13.87.2 pidfd_getpid

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.38, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

Next: , Previous: , Up: Glibc <sys/pidfd.h>   [Contents][Index]

13.87.3 pidfd_open

Documentation:
man pidfd_open

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: glibc 2.35, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

Previous: , Up: Glibc <sys/pidfd.h>   [Contents][Index]

13.87.4 pidfd_send_signal

Documentation:
man pidfd_send_signal

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: glibc 2.35, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.5.3, mingw, MSVC 14, Android.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.88 Glibc <sys/prctl.h>

Up: Glibc <sys/prctl.h>   [Contents][Index]

13.88.1 prctl

Documentation:
man prctl

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.89 Glibc <sys/profil.h>

Up: Glibc <sys/profil.h>   [Contents][Index]

13.89.1 sprofil

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11.11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.90 Glibc <sys/ptrace.h>

Up: Glibc <sys/ptrace.h>   [Contents][Index]

13.90.1 ptrace

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-ptrace-1.html

Documentation:
man ptrace

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, Cygwin 2.9, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.91 Glibc <sys/quota.h>

Up: Glibc <sys/quota.h>   [Contents][Index]

13.91.1 quotactl

Documentation:
man quotactl

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 7.1.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.92 Glibc <sys/random.h>

Next: , Up: Glibc <sys/random.h>   [Contents][Index]

13.92.1 getentropy

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1134

Documentation:

Gnulib module: getentropy

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.24, Mac OS X 10.11, FreeBSD 11.0, NetBSD 9.3, OpenBSD 5.5, Minix 3.3, AIX 7.1, HP-UX 11.31, Solaris 11.0, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.
  • This function is declared in <sys/random.h>, not in <unistd.h>, on some platforms: macOS 14, Solaris 11.4, Android 9.0.

Portability problems not fixed by Gnulib:

Although this function is intended to produce random data, the data’s security properties may not be appropriate for your application. For example, identical “random” data streams might be produced by rebooted virtual machines. If this is of concern you may need to use additional techniques such as hedging.1

Related modules include getrandom, which has a more-flexible but more-complex API, and crypto/gc-random, which is likely a better match for code already using the other crypto APIs.

Previous: , Up: Glibc <sys/random.h>   [Contents][Index]

13.92.2 getrandom

Documentation:

Gnulib module: getrandom

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.24, macOS 14, FreeBSD 11.0, NetBSD 9.3, OpenBSD 6.7, Minix 3.3, AIX 7.1, HP-UX 11.31, Solaris 11.0, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.
  • This function has a different return type on some platforms: Solaris 11.4.

Portability problems not fixed by Gnulib:

  • The GRND_INSECURE flag is missing on some platforms: glibc 2.34, macOS 10.15, GNU/kFreeBSD, FreeBSD 12.0, OpenBSD 6.7, Minix 3.3, Haiku.
  • The GRND_RANDOM flag has different effects on different platforms. Some platforms ignore the flag, or yield data that can fail to be random in some cases.

Although this function is intended to produce random data, the data’s security properties may not be appropriate for your application. For example, identical “random” data streams might be produced by rebooted virtual machines. If this is of concern you may need to use additional techniques such as hedging.2

Related modules include getentropy, which has a simpler but more-limited API, and crypto/gc-random, which is likely a better match for code already using the other crypto APIs.

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13.93 Glibc <sys/reboot.h>

Up: Glibc <sys/reboot.h>   [Contents][Index]

13.93.1 reboot

Documentation:
man reboot

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, Cygwin 2.9, mingw, MSVC 14.

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13.94 Glibc Extensions to <sys/resource.h>

Up: Glibc Extensions to <sys/resource.h>   [Contents][Index]

13.94.1 prlimit

Documentation:
man prlimit

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: glibc 2.12, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 6.0.

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13.95 Glibc Extensions to <sys/sem.h>

Up: Glibc Extensions to <sys/sem.h>   [Contents][Index]

13.95.1 semtimedop

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11.11, Cygwin 2.9, mingw, MSVC 14, Android 7.1.

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13.96 Glibc <sys/sendfile.h>

Up: Glibc <sys/sendfile.h>   [Contents][Index]

13.96.1 sendfile

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sendfile.html

Documentation:
man sendfile

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Solaris 11 2010-11, Cygwin 2.9, mingw, MSVC 14, Android 4.4.
  • On platforms where off_t is a 32-bit type, this function may not work correctly on files larger than 2 GB. The fix is to use the AC_SYS_LARGEFILE macro.

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13.97 Glibc <sys/signalfd.h>

Up: Glibc <sys/signalfd.h>   [Contents][Index]

13.97.1 signalfd

Documentation:
man signalfd

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and illumos and is therefore missing on many non-glibc platforms: glibc 2.6, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.98 Glibc <sys/single_threaded.h>

Up: Glibc <sys/single_threaded.h>   [Contents][Index]

13.98.1 __libc_single_threaded

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Single_002dThreaded.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This variable is missing on all non-glibc platforms: glibc 2.31, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.99 Glibc Extensions to <sys/socket.h>

Next: , Up: Glibc Extensions to <sys/socket.h>   [Contents][Index]

13.99.1 accept4

Documentation:
man accept4

Gnulib module: accept4

Portability problems fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.9, macOS 14, FreeBSD 6.0, NetBSD 7.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.1, mingw, MSVC 14, Android 4.4. But the replacement function is not atomic; this matters in multi-threaded programs that spawn child processes.

Portability problems not fixed by Gnulib:

  • SOCK_CLOEXEC and SOCK_NONBLOCK may not be defined as they’re also significant to the socket() function.

Next: , Previous: , Up: Glibc Extensions to <sys/socket.h>   [Contents][Index]

13.99.2 isfdtype

Documentation:
man isfdtype

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <sys/socket.h>   [Contents][Index]

13.99.3 recvmmsg

Documentation:
man recvmmsg

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.11, macOS 14, FreeBSD 6.4, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android 4.4.

Previous: , Up: Glibc Extensions to <sys/socket.h>   [Contents][Index]

13.99.4 sendmmsg

Documentation:
man sendmmsg

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.13, macOS 14, FreeBSD 6.4, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android 4.4.

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13.100 Glibc Extensions to <sys/stat.h>

Next: , Up: Glibc Extensions to <sys/stat.h>   [Contents][Index]

13.100.1 getumask

Documentation:

Gnulib module: getumask

Portability problems fixed by Gnulib:

  • This function exists only on Hurd and is therefore missing on all non-glibc platforms: glibc/Linux, glibc/kFreeBSD, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.3, AIX 7.2, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc Extensions to <sys/stat.h>   [Contents][Index]

13.100.2 lchmod

Gnulib module: lchmod

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • This function is not declared on some platforms: HP-UX 11.31.
  • This function always fails with errno set to ENOSYS, even when the file is not a symbolic link: GNU/Linux with glibc 2.31.
  • This function does not fail when the file name argument ends in a slash and (without the slash) names a non-directory, on some platforms: AIX 7.2.

Portability problems not fixed by Gnulib:

  • Some platforms do not allow changing the access bits on symbolic links.
  • This function can fail with errno set to EMFILE or ENFILE, and it fails with errno set to EOPNOTSUPP if the /proc file system is not mounted: GNU/Linux with glibc 2.34.

Previous: , Up: Glibc Extensions to <sys/stat.h>   [Contents][Index]

13.100.3 statx

Documentation:
man statx

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.27, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android API level 29.
  • There is an incompatible function of the same name on some platforms: AIX 5.2 or newer.

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13.101 Glibc <sys/statfs.h>

Next: , Up: Glibc <sys/statfs.h>   [Contents][Index]

13.101.1 fstatfs

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fstatfs-2.html

Documentation:
man fstatfs

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, mingw, MSVC 14.
  • On platforms where f_blocks in ‘struct statfs’ is a 32-bit value, this function may not work correctly on files systems larger than 4 TiB. The fix is to use the AC_SYS_LARGEFILE macro. This affects Mac OS X.

Previous: , Up: Glibc <sys/statfs.h>   [Contents][Index]

13.101.2 statfs

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-statfs-2.html

Documentation:
man statfs

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, mingw, MSVC 14.
  • On platforms where f_blocks in ‘struct statfs’ is a 32-bit value, this function may not work correctly on files systems larger than 4 TiB. The fix is to use the AC_SYS_LARGEFILE macro. This affects Mac OS X.

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13.102 Glibc <sys/swap.h>

Next: , Up: Glibc <sys/swap.h>   [Contents][Index]

13.102.1 swapoff

Documentation:
man swapoff

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 4.3.

Previous: , Up: Glibc <sys/swap.h>   [Contents][Index]

13.102.2 swapon

Documentation:
man swapon

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 4.3.

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13.103 Glibc <sys/sysctl.h>

Up: Glibc <sys/sysctl.h>   [Contents][Index]

13.103.1 sysctl

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.34, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.104 Glibc <sys/sysinfo.h>

Next: , Up: Glibc <sys/sysinfo.h>   [Contents][Index]

13.104.1 get_avphys_pages

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.1, mingw, MSVC 14, Android 5.1.

Next: , Previous: , Up: Glibc <sys/sysinfo.h>   [Contents][Index]

13.104.2 get_nprocs

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.7.1, mingw, MSVC 14, Android 5.1.

Gnulib provides the module nproc that performs a similar function but is portable to more systems.

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13.104.3 get_nprocs_conf

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 10, Cygwin 1.7.1, mingw, MSVC 14, Android 5.1.

Next: , Previous: , Up: Glibc <sys/sysinfo.h>   [Contents][Index]

13.104.4 get_phys_pages

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.1, mingw, MSVC 14, Android 5.1.

Previous: , Up: Glibc <sys/sysinfo.h>   [Contents][Index]

13.104.5 sysinfo

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sysinfo-1.html

Documentation:
man sysinfo

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Cygwin 1.7.9, mingw, MSVC 14.
  • This function is not declared and thus not part of the Android API for Android API levels < 9.

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13.105 Glibc <sys/syslog.h>

Up: Glibc <sys/syslog.h>   [Contents][Index]

13.105.1 vsyslog

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-vsyslog-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14.

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13.106 Glibc <sys/sysmacros.h>

Next: , Up: Glibc <sys/sysmacros.h>   [Contents][Index]

13.106.1 gnu_dev_major

Documentation:
man gnu_dev_major

Gnulib module: —

Portability problems fixed by Gnulib:

  • The AC_HEADER_MAJOR macro in Autoconf 2.69 and earlier fails to set MAJOR_IN_SYSMACROS when it detects namespace pollution in sys/types.h; which in turn provokes deprecation warnings in glibc 2.25.

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <sys/sysmacros.h>   [Contents][Index]

13.106.2 gnu_dev_makedev

Documentation:
man gnu_dev_makedev

Gnulib module: —

Portability problems fixed by Gnulib:

  • The AC_HEADER_MAJOR macro in Autoconf 2.69 and earlier fails to set MAJOR_IN_SYSMACROS when it detects namespace pollution in sys/types.h; which in turn provokes deprecation warnings in glibc 2.25.

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <sys/sysmacros.h>   [Contents][Index]

13.106.3 gnu_dev_minor

Documentation:
man gnu_dev_minor

Gnulib module: —

Portability problems fixed by Gnulib:

  • The AC_HEADER_MAJOR macro in Autoconf 2.69 and earlier fails to set MAJOR_IN_SYSMACROS when it detects namespace pollution in sys/types.h; which in turn provokes deprecation warnings in glibc 2.25.

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.107 Glibc Extensions to <sys/time.h>

Next: , Up: Glibc Extensions to <sys/time.h>   [Contents][Index]

13.107.1 adjtime

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-adjtime-2.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <sys/time.h>   [Contents][Index]

13.107.2 futimes

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-futimes.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 7.1.
  • This function cannot set full timestamp resolution. Use futimens(fd,times) instead.

Next: , Previous: , Up: Glibc Extensions to <sys/time.h>   [Contents][Index]

13.107.3 futimesat

Documentation:
man futimesat

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.3.6, macOS 14, FreeBSD 6.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.5.x, mingw, MSVC 14, Android 7.1.
  • On some platforms, this function mis-handles a trailing slash: Solaris 9.
  • This function cannot set full timestamp resolution. Use 
    file ? utimensat(fd, file, times, 0)
     : futimens(fd, times)

    or the gnulib module fdutimensat, instead.

Next: , Previous: , Up: Glibc Extensions to <sys/time.h>   [Contents][Index]

13.107.4 lutimes

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 7.1.
  • This function cannot set full timestamp resolution. Use utimensat(AT_FDCWD,file,times,AT_SYMLINK_NOFOLLOW), or the gnulib module utimens, instead.
  • The mere act of using lstat modifies the access time of symlinks on some platforms, so lutimes can only effectively change modification time: Cygwin.

Previous: , Up: Glibc Extensions to <sys/time.h>   [Contents][Index]

13.107.5 settimeofday

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.108 Glibc <sys/timerfd.h>

Next: , Up: Glibc <sys/timerfd.h>   [Contents][Index]

13.108.1 timerfd_create

Documentation:
man timerfd_create

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux, FreeBSD, NetBSD, and illumos and is therefore missing on many non-glibc platforms: glibc 2.7, macOS 14, FreeBSD 13.2, NetBSD 9.3, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 4.3.

Next: , Previous: , Up: Glibc <sys/timerfd.h>   [Contents][Index]

13.108.2 timerfd_gettime

Documentation:
man timerfd_gettime

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux, FreeBSD, NetBSD, and illumos and is therefore missing on many non-glibc platforms: glibc 2.7, macOS 14, FreeBSD 13.2, NetBSD 9.3, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 4.3.

Previous: , Up: Glibc <sys/timerfd.h>   [Contents][Index]

13.108.3 timerfd_settime

Documentation:
man timerfd_settime

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux, FreeBSD, NetBSD, and illumos and is therefore missing on many non-glibc platforms: glibc 2.7, macOS 14, FreeBSD 13.2, NetBSD 9.3, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 4.3.

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13.109 Glibc <sys/timex.h>

Next: , Up: Glibc <sys/timex.h>   [Contents][Index]

13.109.1 adjtimex

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 6.0.

Next: , Previous: , Up: Glibc <sys/timex.h>   [Contents][Index]

13.109.2 ntp_adjtime

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.5, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <sys/timex.h>   [Contents][Index]

13.109.3 ntp_gettime

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Mac OS X 10.5, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <sys/timex.h>   [Contents][Index]

13.109.4 ntp_gettimex

Documentation:
man ntp_gettimex

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.11, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.110 Glibc Extensions to <sys/uio.h>

Next: , Up: Glibc Extensions to <sys/uio.h>   [Contents][Index]

13.110.1 preadv

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.9, macOS 10.15, FreeBSD 5.2.1, Minix 3.1.8, AIX 5.2, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 6.0.
  • On platforms where off_t is a 32-bit type, this function may not work correctly on files larger than 2 GB. The fix is to use the AC_SYS_LARGEFILE macro.

Next: , Previous: , Up: Glibc Extensions to <sys/uio.h>   [Contents][Index]

13.110.2 preadv2

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many platforms: glibc 2.25, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android API level 32.

Next: , Previous: , Up: Glibc Extensions to <sys/uio.h>   [Contents][Index]

13.110.3 process_vm_readv

Documentation:
man process_vm_readv

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: glibc 2.14, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 5.1.

Next: , Previous: , Up: Glibc Extensions to <sys/uio.h>   [Contents][Index]

13.110.4 process_vm_writev

Documentation:
man process_vm_writev

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: glibc 2.14, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 5.1.

Next: , Previous: , Up: Glibc Extensions to <sys/uio.h>   [Contents][Index]

13.110.5 pwritev

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.9, macOS 10.15, FreeBSD 5.2.1, Minix 3.1.8, AIX 5.2, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 6.0.
  • On platforms where off_t is a 32-bit type, this function may not work correctly on files larger than 2 GB. The fix is to use the AC_SYS_LARGEFILE macro.

Previous: , Up: Glibc Extensions to <sys/uio.h>   [Contents][Index]

13.110.6 pwritev2

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many platforms: glibc 2.25, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android API level 32.

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13.111 Glibc <sys/ustat.h>

Up: Glibc <sys/ustat.h>   [Contents][Index]

13.111.1 ustat

Documentation:
man ustat

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.112 Glibc <sys/vlimit.h>

Up: Glibc <sys/vlimit.h>   [Contents][Index]

13.112.1 vlimit

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.113 Glibc Extensions to <sys/wait.h>

Next: , Up: Glibc Extensions to <sys/wait.h>   [Contents][Index]

13.113.1 wait3

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 9.0.
  • This function is not declared on some platforms: Android 13.

Previous: , Up: Glibc Extensions to <sys/wait.h>   [Contents][Index]

13.113.2 wait4

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-wait4-2.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11.11, mingw, MSVC 14, Android 4.2.

Next: , Previous: , Up: Glibc Function Substitutes   [Contents][Index]

13.114 Glibc <sys/xattr.h>

Next: , Up: Glibc <sys/xattr.h>   [Contents][Index]

13.114.1 fgetxattr

Documentation:
man fgetxattr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 4.0.4.
  • This function has extra offset and options parameters on some platforms: macOS 14.

Next: , Previous: , Up: Glibc <sys/xattr.h>   [Contents][Index]

13.114.2 flistxattr

Documentation:
man flistxattr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 4.0.4.
  • This function has an extra options parameter on some platforms: macOS 14.

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13.114.3 fremovexattr

Documentation:
man fremovexattr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 4.0.4.
  • This function has an extra options parameter on some platforms: macOS 14.

Next: , Previous: , Up: Glibc <sys/xattr.h>   [Contents][Index]

13.114.4 fsetxattr

Documentation:
man fsetxattr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 4.0.4.
  • This function has extra offset and options parameters and no flags parameter on some platforms: macOS 14.

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13.114.5 getxattr

Documentation:
man getxattr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 4.0.4.
  • This function has extra offset and options parameters on some platforms: macOS 14.

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13.114.6 lgetxattr

Documentation:
man lgetxattr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 4.0.4.

Next: , Previous: , Up: Glibc <sys/xattr.h>   [Contents][Index]

13.114.7 listxattr

Documentation:
man listxattr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 4.0.4.
  • This function has an extra options parameter on some platforms: macOS 14.

Next: , Previous: , Up: Glibc <sys/xattr.h>   [Contents][Index]

13.114.8 llistxattr

Documentation:
man llistxattr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 4.0.4.

Next: , Previous: , Up: Glibc <sys/xattr.h>   [Contents][Index]

13.114.9 lremovexattr

Documentation:
man lremovexattr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 4.0.4.

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13.114.10 lsetxattr

Documentation:
man lsetxattr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 4.0.4.

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13.114.11 removexattr

Documentation:
man removexattr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 4.0.4.
  • This function has an extra options parameter on some platforms: macOS 14.

Previous: , Up: Glibc <sys/xattr.h>   [Contents][Index]

13.114.12 setxattr

Documentation:
man setxattr

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: FreeBSD 14.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 4.0.4.
  • This function has extra offset and options parameters and no flags parameter on some platforms: macOS 14.

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13.115 Glibc Extensions to <termios.h>

Next: , Up: Glibc Extensions to <termios.h>   [Contents][Index]

13.115.1 cfmakeraw

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-cfmakeraw-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 1.5.x, mingw, MSVC 14, Android 4.4.

Previous: , Up: Glibc Extensions to <termios.h>   [Contents][Index]

13.115.2 cfsetspeed

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-cfsetspeed-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.

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13.116 Glibc Extensions to <time.h>

Next: , Up: Glibc Extensions to <time.h>   [Contents][Index]

13.116.1 clock_adjtime

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on many non-glibc platforms: glibc 2.13, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 6.0.

Next: , Previous: , Up: Glibc Extensions to <time.h>   [Contents][Index]

13.116.2 dysize

Documentation:
man dysize

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <time.h>   [Contents][Index]

13.116.3 getdate_r

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.116.4 stime

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-stime-2.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.

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13.116.5 strptime_l

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.

Next: , Previous: , Up: Glibc Extensions to <time.h>   [Contents][Index]

13.116.6 timelocal

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, HP-UX 11, Solaris 11.3, mingw, MSVC 14, Android 3.0.

Previous: , Up: Glibc Extensions to <time.h>   [Contents][Index]

13.116.7 timespec_get

ISO C23 specification:
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n3096.pdf section 7.29.2.6

Gnulib module: timespec_get

Portability problems fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.15, macOS 10.14, FreeBSD 11.0, NetBSD 7.1, OpenBSD 6.0, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.3, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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13.117 Glibc <ttyent.h>

Next: , Up: Glibc <ttyent.h>   [Contents][Index]

13.117.1 endttyent

Documentation:
man endttyent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <ttyent.h>   [Contents][Index]

13.117.2 getttyent

Documentation:
man getttyent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc <ttyent.h>   [Contents][Index]

13.117.3 getttynam

Documentation:
man getttynam

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Previous: , Up: Glibc <ttyent.h>   [Contents][Index]

13.117.4 setttyent

Documentation:
man setttyent

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.118 Glibc Extensions to <unistd.h>

Next: , Up: Glibc Extensions to <unistd.h>   [Contents][Index]

13.118.1 _Fork

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Creating-a-Process.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.33, macOS 14, FreeBSD 13.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.3.0, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Next: , Previous: , Up: Glibc Extensions to <unistd.h>   [Contents][Index]

13.118.2 acct

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-acct-3.html

Documentation:
man acct

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Cygwin 2.9, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <unistd.h>   [Contents][Index]

13.118.3 brk

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 12.2/arm64, AIX 5.1, Cygwin 2.9, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <unistd.h>   [Contents][Index]

13.118.4 chroot

Documentation:
man chroot

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: AIX 5.1, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <unistd.h>   [Contents][Index]

13.118.5 closefrom

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Opening-and-Closing-Files.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.33, macOS 14, FreeBSD 7.2, Minix 3.3.0, AIX 7.1, HP-UX 11.31, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Note (quoted from man close): “The [POSIX] standard developers rejected a proposal to add closefrom() to the [POSIX] standard. Because the standard permits implementations to use inherited file descriptors as a means of providing a conforming environment for the child process, it is not possible to standardize an interface that closes arbitrary file descriptors above a certain value while still guaranteeing a conforming environment.”

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13.118.6 close_range

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: glibc 2.33, macOS 14, FreeBSD 12.4, NetBSD 10.0, OpenBSD 7.5, Minix 3.3.0, AIX 7.3.1, HP-UX 11.31, Solaris 11.4, Cygwin 3.4.6, mingw, MSVC 14, Android API level 33.

Next: , Previous: , Up: Glibc Extensions to <unistd.h>   [Contents][Index]

13.118.7 copy_file_range

Documentation:

Gnulib module: copy-file-range

Portability problems fixed by Gnulib:

  • This function exists only on Linux and FreeBSD and is therefore missing on many platforms: glibc 2.26, macOS 14, FreeBSD 12.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android API level 33. But the replacement function is only a stub: It always fails with error ENOSYS.
  • This function has many problems on Linux kernel versions before 5.3. On these kernel versions, the replacement function always fails with error ENOSYS.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc Extensions to <unistd.h>   [Contents][Index]

13.118.8 daemon

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-daemon-3.html

Documentation:
man daemon

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14.

Next: , Previous: , Up: Glibc Extensions to <unistd.h>   [Contents][Index]

13.118.9 dup3

Documentation:
man dup3

Gnulib module: dup3

Portability problems fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.8, macOS 14, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.1, mingw, MSVC 14, Android 4.4.
  • This function can crash on some platforms: Cygwin 1.7.25.
  • This function mistakenly succeeds when given two equal file descriptors on some platforms: NetBSD 10.0.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc Extensions to <unistd.h>   [Contents][Index]

13.118.10 eaccess

Documentation:
man eaccess

This function is an alias of euidaccess. See euidaccess.

Next: , Previous: , Up: Glibc Extensions to <unistd.h>   [Contents][Index]

13.118.11 endusershell

Documentation:
man endusershell

Gnulib module: getusershell

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 9.0.
  • This function is missing a declaration on some platforms: Solaris 9.

Portability problems not fixed by Gnulib:

Next: , Previous: , Up: Glibc Extensions to <unistd.h>   [Contents][Index]

13.118.12 euidaccess

Documentation:
man euidaccess

Gnulib module: euidaccess

Portability problems fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

Other problems of this function:

  • There is an inherent race between calling this function and performing some action based on the results; you should think twice before trusting this function, especially in a set-uid or set-gid program.
  • This function does not have an option for not following symbolic links (like stat versus lstat). If you need this option, use the Gnulib module faccessat with the AT_EACCESS flag.
  • On Solaris, for the root user, any file is X_OK even if the file does not have the x permission bit set.

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13.118.13 execveat

Documentation: man execveat.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: glibc 2.33/Linux, glibc 2.34/Hurd, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.3.0, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.118.14 execvpe

Documentation:
man execvpe

Gnulib module: execvpe

Portability problems fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.10, macOS 14, FreeBSD 14.0, NetBSD 7.1, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.5.x, mingw, Android 4.4.
  • This function is not declared on some platforms: AIX 7.1.
  • On Windows platforms (excluding Cygwin), this function does not pass command-line arguments correctly if they contain space, tab, backslash, or double-quote characters.
  • On Windows platforms (excluding Cygwin), this function spawns an asynchronous child process and then exits the current process immediately. As a consequence, the parent of the current process 1. may incorrectly proceed as if its child had exited, and 2. will never see the child’s exit status.
  • On Windows platforms (excluding Cygwin), the return type of this function is intptr_t, not int.

Portability problems not fixed by Gnulib:

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13.118.15 get_current_dir_name

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 1.7.9, mingw, MSVC 14, Android 9.0.

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13.118.16 getdomainname

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getdomainname.html

Documentation:

Gnulib module: getdomainname

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Solaris 11.3, mingw, MSVC 14, Android 7.1.
  • This function is declared in netdb.h, not in unistd.h, on some platforms: AIX 7.1.
  • The second argument is of type int, not size_t, on some platforms: macOS 14, FreeBSD 14.0, AIX 7.1.

Portability problems not fixed by Gnulib:

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13.118.17 getdtablesize

SUSv2 specification: https://pubs.opengroup.org/onlinepubs/7908799/xsh/getdtablesize.html

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getdtablesize.html

Documentation:
man getdtablesize

Gnulib module: getdtablesize

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Android LP64, mingw, MSVC 14, Android 9.0.
  • This function is not declared on some platforms: Android 13 (LP32?).
  • This function does not represent the true RLIMIT_NOFILE soft limit on some platforms: Android 13 (LP32?), Cygwin 1.7.25.

Portability problems not fixed by Gnulib:

  • On OpenVMS, this function returns the maximum number of open file descriptors in a process. The possible values of file descriptors are not constrained by this function.

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13.118.18 getpagesize

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getpagesize.html

Documentation:

Gnulib module: getpagesize

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: MSVC 14, Android 4.4.
  • This function is not declared on some platforms: HP-UX 11 with compiler option -D_XOPEN_SOURCE=600.
  • This function is broken on some platforms: mingw.

Portability problems not fixed by Gnulib:

  • The function has never been in POSIX and was removed from the Single UNIX Specification in SUSv3 (2001). Although portable programs are supposed to use sysconf (_SC_PAGESIZE) instead, in practice getpagesize can be a little faster.
  • On typical platforms this function’s API limits page sizes to at most 1 GiB, even though sysconf (_SC_PAGESIZE) does not have this limitation. However, this has not been a practical problem yet, and so many programs use getpagesize that it’s unlikely that new platforms would introduce larger page sizes any time soon.

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13.118.19 getpass

Documentation:

Gnulib module: getpass or getpass-gnu

Portability problems fixed by either Gnulib module getpass or getpass-gnu:

  • This function is missing on some platforms: mingw, MSVC 14, Android 9.0.
  • This function cannot be called from plain inline or extern inline functions on some platforms: Android 13.

Portability problems fixed by Gnulib module getpass-gnu:

  • The returned password is truncated to PASS_MAX characters on some platforms: uClibc (256), musl (128), macOS 14 (128), FreeBSD 14.0 (128), NetBSD 3.0 (128), OpenBSD 4.0 (128), AIX 5.1 (32), HP-UX 11 (8), Solaris 11 2010-11 (8, even less than PASS_MAX), Cygwin (128). The gnulib implementation returns the password untruncated.

Portability problems not fixed by Gnulib:

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13.118.20 getresgid

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1344

Documentation:
man getresgid

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, Minix 3.1.8, AIX 5.1, HP-UX 11.00, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.118.21 getresuid

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1344

Documentation:
man getresuid

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, Minix 3.1.8, AIX 5.1, HP-UX 11.00, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.118.22 gettid

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function exists only on Linux and is therefore missing on most non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.118.23 getusershell

Documentation:
man getusershell

Gnulib module: getusershell

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 9.0.
  • This function is missing a declaration on some platforms: Solaris 9.
  • This function mistakenly returns comments and empty lines on some platforms: musl libc 1.2.4

Portability problems not fixed by Gnulib:

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13.118.24 group_member

Documentation:
man group_member

Gnulib module: group-member

Portability problems fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

Portability problems not fixed by Gnulib:

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13.118.25 pipe2

Documentation:
man pipe2

Gnulib module: pipe2

Portability problems fixed by Gnulib:

  • This function is missing on many non-glibc platforms: glibc 2.8, macOS 14, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Cygwin 1.7.1, mingw, MSVC 14, Android 2.2. But the replacement function is not atomic; this matters in multi-threaded programs that spawn child processes.

Portability problems not fixed by Gnulib:

  • This function crashes rather than failing with EMFILE if no resources are left on some platforms: Cygwin 1.7.9.

Note: This function portably supports the O_NONBLOCK flag only if the gnulib module nonblocking is also used.

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13.118.26 profil

Documentation:
man profil

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.118.27 revoke

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, mingw, MSVC 14, Android 9.0.

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13.118.28 sbrk

Documentation:
man sbrk

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 12.2/arm64, AIX 5.1, mingw, MSVC 14.

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13.118.29 setlogin

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.118.30 setdomainname

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Cygwin 2.9, mingw, MSVC 14, Android 7.1.

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13.118.31 sethostid

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.118.32 sethostname

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-sethostname-2.html

Documentation:

Gnulib module: sethostname

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, Cygwin 1.7.x, mingw, MSVC 14, Android 5.1. Note that the Gnulib replacement may fail with ENOSYS on some platforms.
  • This function is not declared on some platforms: AIX 7.1, Solaris 10.

Portability problems not fixed by Gnulib:

  • The first parameter is char * instead of const char * on some platforms: Solaris 11 2010-11.
  • The second parameter is int instead of size_t on some platforms: macOS 14, FreeBSD 14.0, MidnightBSD 3.0, Solaris 11 2010-11, Solaris 11 OpenIndiana, Solaris 11 OmniOS.
  • This function does not reject a too long host name on some platforms: Cygwin 3.5.3.

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13.118.33 setresgid

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1344

Documentation:
man setresgid

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, Minix 3.1.8, AIX 5.1, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.118.34 setresuid

Specified in POSIX.1-2024. Draft specification:
https://www.austingroupbugs.net/view.php?id=1344

Documentation:
man setresuid

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, NetBSD 10.0, Minix 3.1.8, AIX 5.1, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14.

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13.118.35 setusershell

Documentation:
man setusershell

Gnulib module: getusershell

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, mingw, MSVC 14, Android 9.0.
  • This function is missing a declaration on some platforms: Solaris 9.

Portability problems not fixed by Gnulib:

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13.118.36 syncfs

Documentation:
man syncfs

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: glibc 2.13, macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 8.1.

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13.118.37 syscall

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, Cygwin 2.9, mingw, MSVC 14.

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13.118.38 ttyslot

Documentation:
man ttyslot

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14, Android 9.0.

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13.118.39 vhangup

Documentation:
man vhangup

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, mingw, MSVC 14, Android 9.0.

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13.119 Glibc <utmp.h>

Next: , Up: Glibc <utmp.h>   [Contents][Index]

13.119.1 endutent

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-endutent-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14.
  • This function is not declared on some platforms: Android before ca. 2015.

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13.119.2 getutent

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getutent-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14.

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13.119.3 getutent_r

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getutent-r-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.119.4 getutid

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14, Android 9.0.

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13.119.5 getutid_r

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.119.6 getutline

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14, Android 9.0.

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13.119.7 getutline_r

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.

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13.119.8 pututline

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14.

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13.119.9 setutent

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-setutent-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14.

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13.119.10 updwtmp

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, HP-UX 11, mingw, MSVC 14, Android 9.0.

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13.119.11 utmpname

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-utmpname-3.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, mingw, MSVC 14.

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13.119.12 login

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: FreeBSD 14.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 7.1, HP-UX 11.31, Solaris 11.4, mingw, MSVC 14, Android 9.0.

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13.119.13 login_tty

Documentation:

Gnulib module: login_tty

Portability problems fixed by Gnulib:

  • This function is missing on some platforms: Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.3, Android 5.1.
  • This function is declared in <utmp.h> on glibc, Cygwin, Android, in <util.h> on macOS 14, NetBSD 5.0, OpenBSD 3.8, in <libutil.h> on FreeBSD 14.0, Haiku, and in <termios.h> on Solaris 11.4.
  • This function requires linking with -lutil on some platforms: glibc 2.3.6, FreeBSD 14.0, NetBSD 5.0, OpenBSD 3.8. It is available without link options on other platforms: macOS 14, Cygwin.

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: mingw, MSVC 14.

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13.120 Glibc Extensions to <utmpx.h>

Next: , Up: Glibc Extensions to <utmpx.h>   [Contents][Index]

13.120.1 getutmp

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • On some platforms, this function does not support timestamps past the year 2038: glibc 2.38 on 32-bit platforms like x86 and ARM where time_t was historically 32 bits.
  • On some platforms, this function misbehaves if the year2038 or year2038-recommended modules are used and the program is configured without the --disable-year2038 option. The readutmp module works around this problem: glibc 2.38 on 32-bit platforms like x86 and ARM where time_t was historically 32 bits. See Avoiding the year 2038 problem.

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13.120.2 getutmpx

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • On some platforms, this function does not support timestamps past the year 2038: glibc 2.38 on 32-bit platforms like x86 and ARM where time_t was historically 32 bits.
  • On some platforms, this function misbehaves if the year2038 or year2038-recommended modules are used and the program is configured without the --disable-year2038 option. The readutmp module works around this problem: glibc 2.38 on 32-bit platforms like x86 and ARM where time_t was historically 32 bits. See Avoiding the year 2038 problem.

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13.120.3 updwtmpx

Documentation:
man updwtmpx

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Cygwin 1.5.x, mingw, MSVC 14, Android 9.0.

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13.120.4 utmpxname

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: FreeBSD 14.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, mingw, MSVC 14, Android 9.0.

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13.121 Glibc Extensions to <wchar.h>

Next: , Up: Glibc Extensions to <wchar.h>   [Contents][Index]

13.121.1 fgetwc_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fgetwc-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.2 fgetws_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fgetws-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.3 fputwc_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fputwc-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.4 fputws_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-fputws-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.5 getwc_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getwc-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.6 getwchar_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-getwchar-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on all non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.7 putwc_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-putwc-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on some platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.8 putwchar_unlocked

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-putwchar-unlocked-1.html

Documentation:

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 9.0.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.9 wcschrnul

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Search-Functions.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.10 wcsftime_l

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.11 wcstod_l

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 7.1, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.12 wcstof_l

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 7.1, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.13 wcstol_l

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.14 wcstold_l

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 7.1, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.15 wcstoll_l

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.16 wcstoq

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-wcstoq.html

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Parsing-of-Integers.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.17 wcstoul_l

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 8.1.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.18 wcstoull_l

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many platforms: FreeBSD 6.0, NetBSD 5.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 1.7.x, mingw, MSVC 14, Android 4.4.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.19 wcstouq

LSB specification:
https://refspecs.linuxbase.org/LSB_5.0.0/LSB-Core-generic/LSB-Core-generic/baselib-wcstouq.html

Documentation:
https://www.gnu.org/software/libc/manual/html_node/Parsing-of-Integers.html.

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 14.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 9.0.
  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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13.121.20 wmempcpy

Documentation:

Gnulib module: wmempcpy

Portability problems fixed by Gnulib:

  • This function is missing on many non-glibc platforms: macOS 14, FreeBSD 13.0, NetBSD 10.0, OpenBSD 6.7, Minix 3.1.8, AIX 5.1, HP-UX 11, Solaris 11.4, Cygwin 2.9, mingw, MSVC 14, Android 5.1.

Portability problems not fixed by Gnulib:

  • On Windows and 32-bit AIX platforms, wchar_t is a 16-bit type and therefore cannot accommodate all Unicode characters.

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14 Native Windows Support

There are three ways to create binaries that run on Microsoft Windows:

This chapter deals with the MinGW and MSVC platforms, commonly called “native Windows” platforms. Cygwin, on the other hand, is close enough to POSIX that it can be treated like any other Unix-like platform.

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14.1 Libtool and Windows

If you want it to be possible to compile your program for a native Windows platform and you use Libtool, you need to use the win32-dll option of LT_INIT. In other words, put: 

LT_INIT([win32-dll])

in your configure.ac. This sets the correct names for the OBJDUMP, DLLTOOL, and AS tools for the build.

If you are building a library, you will also need to pass -no-undefined to make sure Libtool produces a DLL for your library. From a Makefile.am: 

libgsasl_la_LDFLAGS += -no-undefined

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14.2 Large File Support

This module provides support for files 2 GiB and larger, or with device or inode numbers exceeding 32 bits. To this effect, it attempts to ensure that types like off_t and ino_t are 64-bit, at least on the following platforms: glibc, Mac OS X, FreeBSD, NetBSD, OpenBSD, AIX, HP-UX, Solaris, Cygwin, mingw, MSVC.

If the types cannot be made 64-bit, configure issues a warning and proceeds.

This module gives configure an option ‘--disable-largefile’ that suppresses support for large files. This may be useful if the package links to other libraries whose user-facing ABIs still require off_t or most other file-related types to be 32-bit on your platform.

This module also adds to configure an option --enable-year2038, needed on some platforms to access files with timestamps past the year 2038. See Avoiding the year 2038 problem.

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14.3 Inode numbers on Windows

The module ‘windows-stat-inodes’ ensures that, on native Windows platforms, struct stat contains st_dev, st_ino fields that are able to distinguish different inodes.

Note: Such values can only be provided for most files on the file system. For a few files (such as inaccessible files), st_dev and st_ino are set to 0. Therefore, you should test whether st_dev != 0 && st_ino != 0, before going to make inferences based on the file identity based on st_dev and st_ino.

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14.4 Precise file timestamps on Windows

The module ‘windows-stat-timespec’ ensures that, on native Windows platforms, struct stat contains st_atim, st_mtim, st_ctim fields of type struct timespec, providing 100 ns resolution for the timestamps of files.

Note: On some types of file systems, the timestamp resolution is limited by the file system. For example, on FAT file systems, st_mtim only has a resolution of 2 seconds. For more details, see https://docs.microsoft.com/en-us/windows/desktop/SysInfo/file-times.

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14.5 Avoiding the year 2038 problem

The year 2038 problem denotes unpredictable behaviour that will likely occur in the year 2038, for programs that use a 32-bit signed integer ‘time_t’ type that cannot represent timestamps on or after 2038-01-19 03:14:08 UTC. See Year 2038 problem for details.

The Gnulib module ‘year2038’ fixes this problem on some platforms, by making time_t wide enough to represent timestamps after 2038. This has no effect on most current platforms, which have timestamps that are already wide enough. However, ‘year2038’ by default arranges for builds on legacy 32-bit Linux kernels running glibc 2.34 and later to compile with ‘_TIME_BITS=64’ to get wider timestamps. On older platforms that do not support timestamps after the year 2038, ‘year2038’ causes configure to issue a warning but still proceed. On platforms that appear to support post-2038 timestamps but where something prevents this from working, configure fails.

The default behavior of ‘year2038’ can be overridden by using the configure option --disable-year2038, which suppresses support for post-2038 timestamps. This may be useful if the package links to other libraries whose user-facing ABIs still require time_t to be 32-bit on your platform.

The Gnulib module ‘year2038-recommended’ is like ‘year2038’, except it by default rejects platforms where time_t cannot represent timestamps after 2038. If this module is used and a 32-platform cannot support 64-bit time_t, one can still fix the year-2038 problem by using a 64-bit instead of a 32-bit build, as noted in the architecture list below. If all else fails one can configure with --disable-year2038; however, the resulting programs will mishandle timestamps after 2038.

The Gnulib module ‘year2038-recommended’ is designed for packages intended for use on 32-bit platforms after the year 2038. If your package is commonly built on 32-bit platforms that will not be used after the year 2038, you can use the ‘year2038’ module instead, to save builders the trouble of configuring with --disable-year2038.

If the Gnulib module ‘largefile’ is used but neither ‘year2038’ nor ‘year2038-recommended’ is used, configure will have an option --enable-year2038 that causes configure to behave as if ‘year2038’ was used. This is for packages that have long used ‘largefile’ but have not gotten around to upgrading their Gnulib module list to include ‘year2038’ or ‘year2038-recommended’. See Large File Support.

With the ‘year2038-recommended’ module, configure by default should work on the following 32-bit platforms (or 32-bit ABIs in bi-arch systems):

  • Linux kernel 5.1 (2019) and later with glibc 2.34 (2021) and later on x86, arm, mips (o32 or n32 ABI), powerpc32, sparc32, s390, hppa, m68k, sh, csky, microblaze, nios2,
  • Linux kernel 5.1 (2019) and later with musl libc 1.2 (2020) and later on x86,
  • Linux on arc, loong32, ork1, riscv32 and x86_64-x32,
  • NetBSD 6.0 (2012) and later on x86 and sparc,
  • OpenBSD 5.5 (2014) and later on x86,
  • FreeBSD/arm,
  • Minix 3.3 (2014).

Whereas with ‘year2038-recommended’, configure should by default fail on earlier versions of the abovementioned platforms if a version is listed, and it should also by default fail on all versions of the following older 32-bit platforms or ABIs:

  • Android on ARMv7 or x86,
  • Mac OS X 10.6 (2009) and earlier on x86 and powerpc,
  • GNU/Hurd/x86,
  • GNU/kFreeBSD/x86,
  • FreeBSD/x86 (this port demoted to Tier 2 in FreeBSD 13 [2021] and planned to never have 64-bit time_t),
  • MidnightBSD/x86,
  • AIX/powerpc (to fix, configure with ‘CC='gcc -maix64' AR='ar -X64'’),
  • Solaris 11.4 (2018) and earlier on x86 and sparc (to fix, configure with ‘CC='gcc -m64'’),
  • Cygwin 3.3.6 (2022) and earlier on x86,
  • Haiku/x86.

If you use the ‘year2038’ or ‘year2038-recommended’ modules, and configure to support timestamps after the year 2038, your code should not include ‘<utmp.h>’ or ‘<utmpx.h>’ directly, because these include files do not work with 64-bit timestamps if the platform’s time_t was traditionally 32 bits. Your code can instead use the ‘readutmp’ module, which works around this problem.

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14.6 Windows sockets

One of the portability problems for native Windows are sockets and networking functions.

14.6.1 Getaddrinfo and WINVER

This was written for the getaddrinfo module, but may be applicable to other functions too.

The getaddrinfo function exists in ws2tcpip.h and -lws2_32 on Windows XP. The function declaration is present if WINVER >= 0x0501. Windows 2000 does not have getaddrinfo in its WS2_32.DLL.

Thus, if you want to assume Windows XP or later, you can add AC_DEFINE([WINVER], [0x0501]) to avoid compiling the (partial) getaddrinfo implementation.

If you want to support Windows 2000, don’t do anything. The replacement function will open WS2_32.DLL during run-time to see if there is a getaddrinfo function available, and use it when available.

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14.7 Native Windows Support without MSVC Support

If your package does not desire to have MSVC support, that is, if MinGW shall be the only native Windows platform that you wish to get support for from Gnulib, and you wish to minimize the number of files imported from Gnulib accordingly, you can do so by passing the options ‘--avoid=msvc-inval --avoid=msvc-nothrow’ to gnulib-tool.

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14.8 Visual Studio Compatibility

The lib-msvc-compat module detects whether the linker supports --output-def when building a library. That parameter is used to generate a DEF file for a shared library (DLL). DEF files are useful for developers that use Visual Studio to develop programs that links to your library. See the GNU LD manual for more information.

There are other ways to create a DEF file, but we believe they are all sub-optimal to using --output-def during the build process. The variants we have considered include:

  • Use DUMPBIN /EXPORTS. This is explained in https://docs.microsoft.com/en-us/cpp/build/reference/dash-exports. The tool does not generate DEF files directly, so its output needs to be post processed manually: 
    $ { echo EXPORTS; \
    dumpbin /EXPORTS libfoo-0.dll | tail -n+20 | awk '{ print $4 }'; \
  } > libfoo-0.def
$ lib /def:libfoo-0.def
  • Use IMPDEF. There is a tool called IMPDEF that can generate DEF files. However, it is not part of a standard Visual Studio installation. Further, it is documented as being an unreliable process.
  • Use DLLTOOL. The dlltool is part of the MinGW suite, and thus not part of a standard Visual Studio installation. The documentation for the IMPDEF tool claims that DLLTOOL is the wrong tool for this job. Finally, DLLTOOL does not generate DEF files directly, so it requires post-processing of the output.

If you are using libtool to build your shared library, here is how to use this module. Import lib-msvc-compat to your project, and then add the following lines to the Makefile.am that builds the library: 

if HAVE_LD_OUTPUT_DEF
libfoo_la_LDFLAGS += -Wl,--output-def,libfoo-$(DLL_VERSION).def
libfoo-$(DLL_VERSION).def: libfoo.la
defexecdir = $(libdir)
defexec_DATA = libfoo-$(DLL_VERSION).def
DISTCLEANFILES += $(defexec_DATA)
endif

The DLL_VERSION variable needs to be defined. It should be the shared library version number used in the DLL filename. For Windows targets you compute this value from the values you pass to Libtool’s -version-info. Assuming you have variables LT_CURRENT and LT_AGE defined for the CURRENT and AGE libtool version integers, you compute DLL_VERSION as follows: 

DLL_VERSION=`expr ${LT_CURRENT} - ${LT_AGE}`
AC_SUBST(DLL_VERSION)

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15 Multithreading

Multithreading is a programming paradigm. In a multithreaded program, multiple threads execute concurrently (or quasi concurrently) at different places in the program.

There are three motivations for using multithreading in a program:

A multithreading API offers

Note: Programs that achieve multithreading through OpenMP (cf. the gnulib module ‘openmp’) don’t create and manage their threads themselves. Nevertheless, they need to use mutexes/locks in many cases.

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15.1 The three multithreading APIs

Three multithreading APIs are available to Gnulib users:

  • POSIX multithreading,
  • ISO C multithreading,
  • Gnulib multithreading.

They are supported on all platforms that have multithreading in one form or the other. Currently, these are all platforms supported by Gnulib, except for Minix.

The main differences are:

  • The exit code of a thread is a pointer in the POSIX and Gnulib APIs, but only an int in the ISO C API.
  • The POSIX API has additional facilities for detaching threads, setting the priority of a thread, assigning a thread to a certain set of processors, and much more.
  • In the POSIX and ISO C APIs, most functions have a return code, and you are supposed to check the return code; even locking and unlocking a lock can fail. In the Gnulib API, many functions don’t have a return code; if they cannot complete, the program aborts. This sounds harsh, but such aborts have not been reported in 12 years.
  • In the ISO C API, the initialization of a statically allocated lock is clumsy: You have to initialize it through a once-only function.

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15.2 Choosing the right multithreading API

Here are guidelines for determining which multithreading API is best for your code.

In programs that use advanced POSIX APIs, such as spin locks, detached threads (pthread_detach), signal blocking (pthread_sigmask), priorities (pthread_setschedparam), processor affinity (pthread_setaffinity_np), it is best to use the POSIX API. This is because you cannot convert an ISO C thrd_t or a Gnulib gl_thread_t to a POSIX pthread_t.

In code that is shared with glibc, it is best to use the POSIX API as well.

In libraries, it is best to use the Gnulib API. This is because it gives the person who builds the library an option ‘--enable-threads={isoc,posix,windows}’, that determines on which native multithreading API of the platform to rely. In other words, with this choice, you can minimize the amount of glue code that your library needs to contain.

In the other cases, the POSIX API and the Gnulib API are equally well suited.

The ISO C API is never the best choice, as of this writing (2020).

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15.3 The POSIX multithreading API

The POSIX multithreading API is documented in POSIX https://pubs.opengroup.org/onlinepubs/9699919799/.

To make use of POSIX multithreading, even on platforms that don’t support it natively (most prominently, native Windows), use the following Gnulib modules:

PurposeModule
For thread creation and management: pthread-thread
For simple and recursive locks: pthread-mutex
For read-write locks: pthread-rwlock
For once-only execution: pthread-once
For “condition variables” (wait queues): pthread-cond
For thread-local storage: pthread-tss
For relinquishing control: sched_yield
For spin locks: pthread-spin

There is also a convenience module named pthread which depends on all of these (except sched_yield); so you don’t need to enumerate these modules one by one.

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15.4 The ISO C multithreading API

The ISO C multithreading API is documented in ISO C 11 http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1570.pdf.

To make use of ISO C multithreading, even on platforms that don’t support it or have severe bugs, use the following Gnulib modules:

PurposeModule
For thread creation and management: thrd
For simple locks, recursive locks, and read-write locks: mtx
For once-only execution: mtx
For “condition variables” (wait queues): cnd
For thread-local storage: tss

There is also a convenience module named threads which depends on all of these; so you don’t need to enumerate these modules one by one.

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15.5 The Gnulib multithreading API

The Gnulib multithreading API is documented in the respective include files:

  • <glthread/thread.h>
  • <glthread/lock.h>
  • <glthread/cond.h>
  • <glthread/tls.h>
  • <glthread/yield.h>

To make use of Gnulib multithreading, use the following Gnulib modules:

PurposeModule
For thread creation and management: thread
For simple locks, recursive locks, and read-write locks: lock
For once-only execution: lock
For “condition variables” (wait queues): cond
For thread-local storage: tls
For relinquishing control: yield

The Gnulib multithreading supports a configure option ‘--enable-threads={isoc,posix,windows}’, that chooses the underlying thread implementation. Currently (2020):

  • --enable-threads=posix is supported and is the best choice on all platforms except for native Windows. It may also work, to a limited extent, on mingw with the winpthreads library, but is not recommended there.
  • --enable-threads=windows is supported and is the best choice on native Windows platforms (mingw and MSVC).
  • --enable-threads=isoc is supported on all platforms that have the ISO C multithreading API. However, --enable-threads=posix is always a better choice.

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15.6 Optimizations of multithreaded code

Despite all the optimizations of multithreading primitives that have been implemented over the years – from atomic operations in hardware, over futexes and restartable sequences in the Linux kernel, to lock elision [1] [2]) – single-threaded programs can still profit performance-wise from the assertion that they are single-threaded.

Gnulib defines four facilities that help optimizing for the single-threaded case.

  • The Gnulib multithreading API, when used on glibc ≤ 2.32 and *BSD systems, uses weak symbols to detect whether the program is linked with libpthread. If not, the program has no way to create additional threads and must therefore be single-threaded. This optimization applies to all the Gnulib multithreading API (locks, thread-local storage, and more).
  • The thread-optim module, on glibc ≥ 2.32 systems, allows your code to skip locking between threads (regardless which of the three multithreading APIs you use). You need extra code for this: include the "thread-optim.h" header file, and use the macro gl_multithreaded like this: 
    bool mt = gl_multithreaded ();
if (mt) gl_lock_lock (some_lock);
...
if (mt) gl_lock_unlock (some_lock);
  • You may use the unlocked-io module if you want the FILE stream functions getc, putc, etc. to use unlocked I/O if available, throughout the package. Unlocked I/O can improve performance, sometimes dramatically. But unlocked I/O is safe only in single-threaded programs, as well as in multithreaded programs for which you can guarantee that every FILE stream, including stdin, stdout, stderr, is used only in a single thread.

    You need extra code for this optimization to be effective: include the "unlocked-io.h" header file. Some Gnulib modules that do operations on FILE streams have these preparations already included.

  • You may define the C macro GNULIB_REGEX_SINGLE_THREAD, if all the programs in your package invoke the functions of the regex module only from a single thread.
  • You may define the C macro GNULIB_MBRTOWC_SINGLE_THREAD, if all the programs in your package invoke the functions mbrtowc, mbrtoc32, and the functions of the regex module only from a single thread. (The regex module uses mbrtowc under the hood.)
  • You may define the C macro GNULIB_WCHAR_SINGLE_LOCALE, if all the programs in your package set the locale early and
    • don’t change the locale after it has been initialized, and
    • don’t call locale sensitive functions (mbrtowc, wcwidth, etc.) before the locale has been initialized.

    This macro optimizes the functions mbrtowc, mbrtoc32, and wcwidth. You can get this macro defined by including the Gnulib module wchar-single.

  • You may define the C macro GNULIB_EXCLUDE_SINGLE_THREAD, if all the programs in your package invoke the functions of the exclude module only from a single thread.

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16 Strings and Characters

This chapter describes the APIs for strings and characters, provided by Gnulib.

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16.1 Strings

Several possible representations exist for the representation of strings in memory of a running C program.

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16.1.1 The C string representation

The classical representation of a string in C is a sequence of characters, where each character takes up one or more bytes, followed by a terminating NUL byte. This representation is used for strings that are passed by the operating system (in the argv argument of main, for example) and for strings that are passed to the operating system (in system calls such as open). The C type to hold such strings is ‘char *’ or, in places where the string shall not be modified, ‘const char *’. There are many C library functions, standardized by ISO C and POSIX, that assume this representation of strings.

A character encoding, or encoding for short, describes how the elements of a character set are represented as a sequence of bytes. For example, in the ASCII encoding, the UNDERSCORE character is represented by a single byte, with value 0x5F. As another example, the COPYRIGHT SIGN character is represented:

  • in the ISO-8859-1 encoding, by the single byte 0xA9,
  • in the UTF-8 encoding, by the two bytes 0xC2 0xA9,
  • in the GB18030 encoding, by the four bytes 0x81 0x30 0x84 0x38.

Note: The ‘char’ type may be signed or unsigned, depending on the platform. When we talk about the "byte 0xA9" we actually mean the char object whose value is (char) 0xA9; we omit the cast to char in this documentation, for brevity.

In POSIX, the character encoding is determined by the locale. The locale is some environmental attribute that the user can choose.

Depending on the encoding, in general, every character is represented by one or more bytes (up to 4 bytes in practice – but use MB_LEN_MAX instead of the number 4 in the code). When every character is represented by only 1 byte, we speak of an “unibyte locale”, otherwise of a “multibyte locale”.

It is important to realize that the majority of Unix installations nowadays use UTF-8 as locale encoding; therefore, the majority of users are using multibyte locales.

Three important facts to remember are:

A ‘char’ is a byte, not a character.

As a consequence:

  • The <ctype.h> API, that was designed only with unibyte encodings in mind, is useless nowadays for general text processing; it does not work in multibyte locales.
  • The strlen function does not return the number of characters in a string. Nor does it return the number of screen columns occupied by a string after it is output. It merely returns the number of bytes occupied by a string.
  • Truncating a string, for example, with strncpy, can have the effect of truncating it in the middle of a multibyte character. Such a string will, when output, have a garbled character at its end, often represented by a hollow box.

Multibyte does not imply UTF-8 encoding.

While UTF-8 is the most common multibyte encoding, GB18030 is also a supported locale encoding on GNU systems (mostly because it is a Chinese government standard, last revised in 2022).

Searching for a character in a string is not the same as searching for a byte in the string.

Take the above example of COPYRIGHT SIGN in the GB18030 encoding: A byte search will find the bytes '0' and '8' in this string. But a search for the character "0" or "8" in the string "©" must, of course, report “not found”.

As a consequence:

  • strchr and strrchr do not work with multibyte strings if the locale encoding is GB18030 and the character to be searched is a digit.
  • strstr does not work with multibyte strings if the locale encoding is different from UTF-8.
  • strcspn, strpbrk, strspn cannot work correctly in multibyte locales: they assume the second argument is a list of single-byte characters. Even in this simple case, they do not work with multibyte strings if the locale encoding is GB18030 and one of the characters to be searched is a digit.
  • strsep and strtok_r do not work with multibyte strings unless all of the delimiter characters are ASCII characters < 0x30.
  • The strcasecmp, strncasecmp, and strcasestr functions do not work with multibyte strings.

Workarounds can be found in Gnulib, in the form of mbs* API functions:

  • Gnulib has functions mbslen and mbswidth that can be used instead of strlen when the number of characters or the number of screen columns of a string is requested.
  • Gnulib has functions mbschr and mbsrrchr that are like strchr and strrchr, but work in multibyte locales.
  • Gnulib has a function mbsstr that is like strstr, but works in multibyte locales.
  • Gnulib has functions mbscspn, mbspbrk, mbsspn that are like strcspn, strpbrk, strspn, but work in multibyte locales.
  • Gnulib has functions mbssep and mbstok_r that are like strsep and strtok_r but work in multibyte locales.
  • Gnulib has functions mbscasecmp, mbsncasecmp, mbspcasecmp, and mbscasestr that are like strcasecmp, strncasecmp, and strcasestr, but work in multibyte locales. Still, the function ulc_casecmp is preferable to these functions.

A C string can contain encoding errors.

Not every NUL-terminated byte sequence represents a valid multibyte string. Byte sequences can contain encoding errors, that is, bytes or byte sequences that are invalid and do not represent characters.

String functions like mbscasecmp and strcoll whose behavior depends on encoding have unspecified behavior on strings containing encoding errors, unless the behavior is specifically documented. If an application needs a particular behavior on these strings it can iterate through them itself, as described in the next subsection.

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16.1.2 Iterating through strings

For complex string processing, string functions may not be enough, and you need to iterate through a string while processing each (possibly multibyte) character or encoding error in turn. Gnulib has several modules for iterating forward through a string in this way. Backward iteration, that is, from the string’s end to start, is not provided, as it is too hairy in general.

  • The mbiter module iterates through a string whose length is already known. The string can contain NULs and encoding errors.
  • The mbiterf module is like mbiter except it is more complex and typically faster.
  • The mbuiter module iterates through a C string whose length is not a-priori known. The string can contain encoding errors and is terminated by the first NUL.
  • The mbuiterf module is like mbuiter except it is more complex and typically faster.
  • The mcel module is simpler than mbiter and mbuiter and can be faster than even mbiterf and mbuiterf. It can iterate through either strings whose length is known, or C strings, or strings terminated by other ASCII characters < 0x30.
  • The mcel-prefer module is like mcel except that it causes some other modules to be based on mcel instead of on the mbiter family.

The choice of modules depends on the application’s needs. The mbiter module family is more suitable for applications that treat some sequences of two or more bytes as a single encoding error, and for applications that need to support obsolescent encodings on non-GNU platforms, such as CP864, EBCDIC, Johab, and Shift JIS. In this module family, mbuiter and mbuiterf are more suitable than mbiter and mbiterf when arguments are C strings, lengths are not already known, and it is highly likely that only the first few multibyte characters need to be inspected.

The mcel module is simpler and can be faster than the mbiter family, and is more suitable for applications that do not need the mbiter family’s special features.

The mcel-prefer module is like mcel except that it also causes some other modules, such as mbscasecmp, to use mcel rather than the mbiter family. This can be simpler and faster. However, it does not support the obsolescent encodings, and it may behave differently on data containing encoding errors where behavior is unspecified or undefined, because in mcel each encoding error is a single byte whereas in the mbiter family a single encoding error can contain two or more bytes.

If a package uses mcel-prefer, it may also want to give gnulib-tool one or more of the options --avoid=mbiter, --avoid=mbiterf, --avoid=mbuiter and --avoid=mbuiterf, to avoid packaging modules that are not needed.

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16.1.3 Strings with NUL characters

The GNU Coding Standards, section https://www.gnu.org/prep/standards/html_node/Semantics.html, specifies:

Utilities reading files should not drop NUL characters, or any other nonprinting characters.

When it is a requirement to store NUL characters in strings, a variant of the C strings is needed. Gnulib offers a “string descriptor” type for this purpose. See Handling strings with NUL characters.

All remarks regarding encodings and multibyte characters in the previous section apply to string descriptors as well.

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16.1.4 Character and String Functions in C Locale

The functions in this section are similar to the generic string functions from the standard C library, except that

  • They behave as if the locale was set to the "C" locale, even when the locale is different, and/or
  • They are specially optimized for the case where all characters are plain ASCII characters.

The functions are provided by the following modules.

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16.1.4.1 c-ctype

The c-ctype module contains functions operating on single-byte characters, like the functions in <ctype.h>, that operate as if the locale encoding was ASCII. (The "C" locale on many systems has the locale encoding "ASCII".)

The functions are: 

extern bool c_isascii (int c);

extern bool c_isalnum (int c);
extern bool c_isalpha (int c);
extern bool c_isblank (int c);
extern bool c_iscntrl (int c);
extern bool c_isdigit (int c);
extern bool c_islower (int c);
extern bool c_isgraph (int c);
extern bool c_isprint (int c);
extern bool c_ispunct (int c);
extern bool c_isspace (int c);
extern bool c_isupper (int c);
extern bool c_isxdigit (int c);

extern int c_tolower (int c);
extern int c_toupper (int c);

These functions assign properties only to ASCII characters.

The c argument can be a char or unsigned char value, whereas the corresponding functions in <ctype.h> take an argument that is actually an unsigned char value.

The c_is* functions return ‘bool’, where the corresponding functions in <ctype.h> return ‘int’ for historical reasons.

Note: The <ctype.h> functions support only unibyte locales.

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16.1.4.2 c-strcase

The c-strcase module contains case-insensitive string comparison functions operating on single-byte character strings, like the functions in <strings.h>, that operate as if the locale encoding was ASCII. (The "C" locale on many systems has the locale encoding "ASCII".)

The functions are: 

extern int c_strcasecmp (const char *s1, const char *s2);
extern int c_strncasecmp (const char *s1, const char *s2, size_t n);

For case conversion here, only ASCII characters are considered to be upper case or lower case.

Note: The functions strcasecmp, strncasecmp from <strings.h> support only unibyte locales; for multibyte locales, you need the functions mbscasecmp, mbsncasecmp, mbspcasecmp.

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16.1.4.3 c-strcaseeq

The c-strcaseeq module contains an optimized case-insensitive string comparison function operating on single-byte character strings, that operate as if the locale encoding was ASCII. (The "C" locale on many systems has the locale encoding "ASCII".)

The functions is actually implemented as a macro: 

extern int STRCASEEQ (const char *s1, const char *s2,
                      int s20, int s21, int s22, int s23, int s24, int s25,
                      int s26, int s27, int s28);

s2 should be a short literal ASCII string, and s20, s21, ... the individual characters of s2.

For case conversion here, only ASCII characters are considered to be upper case or lower case.

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16.1.4.4 c-strcasestr

The c-strcasestr module contains a case-insensitive string search function operating on single-byte character strings, that operate as if the locale encoding was ASCII. (The "C" locale on many systems has the locale encoding "ASCII".)

The function is: 

extern char *c_strcasestr (const char *haystack, const char *needle);

For case conversion here, only ASCII characters are considered to be upper case or lower case.

Note: The function strcasestr from <string.h> supports only unibyte locales; for multibyte locales, you need the function mbscasestr.

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16.1.4.5 c-strstr

The c-strstr module contains a substring search function operating on single-byte character strings, that operate as if the locale encoding was ASCII. (The "C" locale on many systems has the locale encoding "ASCII".)

The function is: 

extern char *c_strstr (const char *haystack, const char *needle);

Note: The function strstr from <string.h> supports only unibyte locales; for multibyte locales, you need the function mbsstr.

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16.1.4.6 c-strtod

The c-strtod module contains a string to number (‘double’) conversion function operating on single-byte character strings, that operates as if the locale encoding was ASCII. (The "C" locale on many systems has the locale encoding "ASCII".)

The function is: 

extern double c_strtod (const char *string, char **endp);

In particular, only a period ‘.’ is accepted as decimal point, even when the current locale’s notion of decimal point is a comma ‘,’, and no characters outside the basic character set are accepted.

On platforms without strtod_l, this function is not safe for use in multi-threaded applications since it calls setlocale.

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16.1.4.7 c-strtold

The c-strtold module contains a string to number (‘long double’) conversion function operating on single-byte character strings, that operates as if the locale encoding was ASCII. (The "C" locale on many systems has the locale encoding "ASCII".)

The function is: 

extern long double c_strtold (const char *string, char **endp);

In particular, only a period ‘.’ is accepted as decimal point, even when the current locale’s notion of decimal point is a comma ‘,’.

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16.1.5 Comparison of string APIs

This table summarizes the API functions available for strings, in POSIX and in Gnulib.

unibyte strings onlyassume C localemultibyte stringsmultibyte strings with NULswide character strings32-bit wide character strings
strlenstrlenmbslenstring_desc_lengthwcslenu32_strlen
strnlenstrnlenmbsnlen–wcsnlenu32_strnlen, u32_mbsnlen
strcmpstrcmpstrcmpstring_desc_cmpwcscmpu32_strcmp
strncmpstrncmpstrncmp–wcsncmpu32_strncmp
strcasecmpstrcasecmpmbscasecmp–wcscasecmpu32_casecmp
strncasecmpstrncasecmpmbsncasecmp, mbspcasecmp–wcsncasecmpu32_casecmp
strcollstrcmpstrcoll–wcscollu32_strcoll
strxfrm–strxfrm–wcsxfrm–
strchrstrchrmbschrstring_desc_indexwcschru32_strchr
strrchrstrrchrmbsrchrstring_desc_last_indexwcsrchru32_strrchr
strstrstrstrmbsstrstring_desc_containswcsstru32_strstr
strcasestrstrcasestrmbscasestr–––
strspnstrspnmbsspn–wcsspnu32_strspn
strcspnstrcspnmbscspn–wcscspnu32_strcspn
strpbrkstrpbrkmbspbrk–wcspbrku32_strpbrk
strtok_rstrtok_rmbstok_r–wcstoku32_strtok
strsepstrsepmbssep–––
strcpystrcpystrcpystring_desc_copywcscpyu32_strcpy
stpcpystpcpystpcpy–wcpcpyu32_stpcpy
strncpystrncpystrncpy–wcsncpyu32_strncpy
stpncpystpncpystpncpy–wcpncpyu32_stpncpy
strcatstrcatstrcatstring_desc_concatwcscatu32_strcat
strncatstrncatstrncat–wcsncatu32_strncat
freefreefreestring_desc_freefreefree
strdupstrdupstrdupstring_desc_copywcsdupu32_strdup
strndupstrndupstrndup–––
mbswidthmbswidthmbswidth–wcswidthc32swidth, u32_strwidth
strtolstrtolstrtol–––
strtoulstrtoulstrtoul–––
strtollstrtollstrtoll–––
strtoullstrtoullstrtoull–––
strtoimaxstrtoimaxstrtoimax–wcstoimax–
strtoumaxstrtoumaxstrtoumax–wcstoumax–
strtof–strtof–––
strtodc_strtodstrtod–––
strtoldc_strtoldstrtold–––
strfromf–strfromf–––
strfromd–strfromd–––
strfroml–strfroml–––
––––mbstowcsmbstoc32s
––––mbsrtowcsmbsrtoc32s
––––mbsnrtowcsmbsnrtoc32s
––––wcstombsc32stombs
––––wcsrtombsc32srtombs
––––wcsnrtombsc32snrtombs

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16.2 Characters

A character is the elementary unit that strings are made of.

What is a character? “A character is an element of a character set” is sort of a circular definition, but it highlights the fact that it is not merely a number. Although many characters are visually represented by a single glyph, there are characters that, for example, have a different glyph when used at the end of a word than when used inside a word. A character is also not the minimal rendered text processing unit; that is a grapheme cluster and in general consists of one or more characters. If you want to know more about the concept of character and various concepts associated with characters, refer to the Unicode standard.

For the representation in memory of a character, various types have been in use, and some of them were failures: char and wchar_t were invented for this purpose, but are not the right types. char32_t is the right type (successor of wchar_t); and mbchar_t (defined by Gnulib) is an alternative for specific kinds of processing.

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16.2.1 The char type

The char type is in the C language since the beginning in the 1970ies, but – due to its limitation of 256 possible values – is no longer the adequate type for storing a character.

Technically, it is still adequate in unibyte locales. But since most locales nowadays are multibyte locales, it makes no sense to write a program that runs only in unibyte locales.

ISO C and POSIX standardized an API for characters of type char, in <ctype.h>. This API is nowadays useless and obsolete, when it comes to general text processing.

The important lessons to remember are:

A ‘char’ is just the elementary storage unit for a string, not a character.

Never use <ctype.h>!

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16.2.2 The wchar_t type

The ISO C and POSIX standard creators made an attempt to overcome the dead end regarding the char type. They introduced

  • a type ‘wchar_t’, designed to encapsulate a character,
  • a “wide string” type ‘wchar_t *’, with some API functions declared in <wchar.h>, and
  • functions declared in <wctype.h> that were meant to supplant the ones in <ctype.h>.

Unfortunately, this API and its implementation has numerous problems:

  • On Windows platforms and on AIX in 32-bit mode, wchar_t is a 16-bit type. This means that it can never accommodate an entire Unicode character. Either the wchar_t * strings are limited to characters in UCS-2 (the “Basic Multilingual Plane” of Unicode), or – if wchar_t * strings are encoded in UTF-16 – a wchar_t represents only half of a character in the worst case, making the <wctype.h> functions pointless.
  • On Solaris and FreeBSD, the wchar_t encoding is locale dependent and undocumented. This means, if you want to know any property of a wchar_t character, other than the properties defined by <wctype.h> – such as whether it’s a dash, currency symbol, paragraph separator, or similar –, you have to convert it to char * encoding first, by use of the function wctomb.
  • When you read a stream of wide characters, through the functions fgetwc and fgetws, and when the input stream/file is not in the expected encoding, you have no way to determine the invalid byte sequence and do some corrective action. If you use these functions, your program becomes “garbage in - more garbage out” or “garbage in - abort”.

As a consequence, it is better to use multibyte strings. Such multibyte strings can bypass limitations of the wchar_t type, if you use functions defined in Gnulib and GNU libunistring for text processing. They can also faithfully transport malformed characters that were present in the input, without requiring the program to produce garbage or abort.

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16.2.3 The char32_t type

The ISO C and POSIX standard creators then introduced the char32_t type. In ISO C 11, it was conceptually a “32-bit wide character” type. In ISO C 23, its semantics has been further specified: A char32_t value is a Unicode code point.

Thus, the char32_t type is not affected the problems that plague the wchar_t type.

The char32_t type and its API are defined in the <uchar.h> header file.

ISO C and POSIX specify only the basic functions for the char32_t type, namely conversion of a single character (mbrtoc32 and c32rtomb). For convenience, Gnulib adds API for classification and case conversion of characters.

GNU libunistring can also be used on char32_t values. Since char32_t is the same as uint32_t, all u32_* functions of GNU libunistring are applicable to arrays of char32_t values.

On glibc systems, use of the 32-bit wide strings (char32_t[]) is exactly as efficient as the use of the older wide strings (wchar_t[]). This is possible because on glibc, wchar_t values already always were 32-bit and Unicode code points. mbrtoc32 is just an alias of mbrtowc. The Gnulib *c32* functions are optimized so that on glibc systems they immediately redirect to the corresponding *wc* functions.

Gnulib implements the ISO C 23 semantics of char32_t when you import the ‘uchar-c23’ module. Without this module, it implements only the ISO C 11 semantics; the effect is that on some platforms (macOS, FreeBSD, NetBSD, Solaris) a char32_t value is the same as a wchar_t value, not a Unicode code point. Thus, when you want to pass char32_t values to GNU libunistring or to some Unicode centric Gnulib functions, you need the ‘uchar-c23’ module in order to do so without portability problems.

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16.2.4 The mbchar_t type

Gnulib defines an alternate way to encode a multibyte character: mbchar_t. Its main feature is the ability to process a string or stream with some malformed characters without reporting an error.

The type mbchar_t, defined in "mbchar.h", holds a character in both the multibyte and the 32-bit wide character representation. In case of a malformed character only the multibyte representation is used.

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16.2.4.1 Reading multibyte strings

If you want to process (possibly multibyte) characters while reading them from a FILE * stream, without reading them into a string first, the mbfile module is made for this purpose.

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16.2.5 Comparison of character APIs

This table summarizes the API functions available for characters, in POSIX and in Gnulib.

unibyte characterassume C localewide character32-bit wide charactermbchar_t character
== '\0'== '\0'== L'\0'== 0mb_isnul
========mb_equal
isalnumc_isalnumiswalnumc32isalnummb_isalnum
isalphac_isalphaiswalphac32isalphamb_isalpha
isblankc_isblankiswblankc32isblankmb_isblank
iscntrlc_iscntrliswcntrlc32iscntrlmb_iscntrl
isdigitc_isdigitiswdigitc32isdigitmb_isdigit
isgraphc_isgraphiswgraphc32isgraphmb_isgraph
islowerc_isloweriswlowerc32islowermb_islower
isprintc_isprintiswprintc32isprintmb_isprint
ispunctc_ispunctiswpunctc32ispunctmb_ispunct
isspacec_isspaceiswspacec32isspacemb_isspace
isupperc_isupperiswupperc32isuppermb_isupper
isxdigitc_isxdigitiswxdigitc32isxdigitmb_isxdigit
––wctypec32_get_type_test–
––iswctypec32_apply_type_test–
tolowerc_tolowertowlowerc32tolower–
toupperc_touppertowupperc32toupper–
––wctransc32_get_mapping–
––towctransc32_apply_mapping–
––wcwidthc32widthmb_width

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17 Particular Modules

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17.1 alloca

The alloca module provides for a function alloca which allocates memory on the stack, where the system allows it. A memory block allocated with alloca exists only until the function that calls alloca returns or exits abruptly.

There are a few systems where this is not possible: HP-UX systems, and some other platforms when the C++ compiler is used. On these platforms the alloca module provides a malloc based emulation. This emulation will not free a memory block immediately when the calling function returns, but rather will wait until the next alloca call from a function with the same or a shorter stack length. Thus, in some cases, a few memory blocks will be kept although they are not needed any more.

The user can #include <alloca.h> and use alloca on all platforms. Note that the #include <alloca.h> must be the first one after the autoconf-generated config.h, for AIX 3 compatibility. Thanks to IBM for this nice restriction!

Note that GCC 3.1 and 3.2 can inline functions that call alloca. When this happens, the memory blocks allocated with alloca will not be freed until the end of the calling function. If this calling function runs a loop calling the function that uses alloca, the program easily gets a stack overflow and crashes. To protect against this compiler behaviour, you can mark the function that uses alloca with the following attribute: 

#ifdef __GNUC__
__attribute__ ((__noinline__))
#endif

An alternative to this module is the ‘alloca-opt’ module.

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17.2 alloca-opt

The alloca-opt module provides for a function alloca which allocates memory on the stack, where the system allows it. A memory block allocated with alloca exists only until the function that calls alloca returns or exits abruptly.

There are a few systems where this is not possible: HP-UX systems, and some other platforms when the C++ compiler is used. On these platforms the alloca-opt module provides no replacement, just a preprocessor macro HAVE_ALLOCA.

The user can #include <alloca.h> on all platforms, and use alloca on those platforms where the preprocessor macro HAVE_ALLOCA evaluates to true. If HAVE_ALLOCA is false, the code should use a heap-based memory allocation based on malloc or (in C++) new. Note that the #include <alloca.h> must be the first one after the autoconf-generated config.h, for AIX 3 compatibility. Thanks to IBM for this nice restriction!

Note that GCC 3.1 and 3.2 can inline functions that call alloca. When this happens, the memory blocks allocated with alloca will not be freed until the end of the calling function. If this calling function runs a loop calling the function that uses alloca, the program easily gets a stack overflow and crashes. To protect against this compiler behaviour, you can mark the function that uses alloca with the following attribute: 

#ifdef __GNUC__
__attribute__ ((__noinline__))
#endif

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17.3 Safe Allocation Macros

The standard C library malloc/realloc/calloc/free APIs are prone to a number of common coding errors. The safe-alloc module provides macros that make it easier to avoid many of them. It still uses the standard C allocation functions behind the scenes.

Some of the memory allocation mistakes that are commonly made are

  • passing the incorrect number of bytes to malloc, especially when allocating an array,
  • unchecked integer overflow when calculating array sizes,
  • fail to check the return value of malloc and realloc for errors,
  • forget to fully initialize memory just allocated with malloc,
  • duplicate calls to free by forgetting to set the pointer variable to NULL,
  • leaking memory in calls to realloc when that call fails.

The safe-alloc module addresses these problems in the following way:

  • It defines macros that wrap around the standard C allocation functions. That makes it possible to use the compiler’s knowledge of the size of objects for allocation; it also allows setting pointers passed in as arguments when appropriate.
  • It uses return values only for a success/failure error condition flag, and annotates them with GCC’s __warn_unused_result__ attribute.
  • When allocating a fresh array, it uses calloc instead of malloc so that the array’s contents are zeroed. However, memory added to an already-existing array is uninitialized.
Macro: int ALLOC (ptr)

Allocate sizeof *ptr bytes of memory and store the address of allocated memory in ptr. Fill the newly allocated memory with zeros.

Returns -1 on failure, 0 on success.

Macro: int ALLOC_N (ptr, count)

Allocate an array of count elements, each sizeof *ptr bytes long, and store the address of allocated memory in ptr. Fill the newly allocated memory with zeros.

Returns -1 on failure, 0 on success.

Macro: int ALLOC_N_UNINITIALIZED (ptr, count)

Allocate an array of count elements, each sizeof *ptr bytes long, and store the address of allocated memory in ptr. The allocated memory is not initialized.

Returns -1 on failure, 0 on success.

Macro: int REALLOC_N (ptr, count)

Reallocate the memory pointed to by ptr to be big enough to hold at least count elements, each sizeof *ptr bytes long, and store the address of allocated memory in ptr. If reallocation fails, the ptr variable is not modified. If the new array is smaller than the old one, discard excess contents; if larger, the newly added storage is not initialized.

Returns -1 on failure, 0 on success.

Macro: void FREE (ptr)

Free the memory stored in ptr and set ptr to NULL.

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17.4 Attributes

This module provides a header file attribute.h that defines macros related to C and C++ attributes and the GCC __attribute__ keyword.

Here is an example of its use: 

#include <attribute.h>

NODISCARD
extern char *crypt (char const *, char const *)
  ATTRIBUTE_NOTHROW ATTRIBUTE_LEAF ATTRIBUTE_NONNULL ((1, 2));

NODISCARD expands to [[nodiscard]] if the compiler supports this C23 syntax, otherwise to __attribute__ ((__warn_unused_result__)) if the compiler is a recent-enough GCC or GCC-like compiler, otherwise to nothing. ATTRIBUTE_NOTHROW expands to __attribute__ ((__nothrow__)) if the compiler is a recent-enough GCC or GCC-like compiler, and to nothing otherwise. Similarly for ATTRIBUTE_LEAF. ATTRIBUTE_NONNULL ((1, 2)) expands to __attribute__ ((__nonnull__ (1, 2))) if the compiler is recent-enough GCC, and to nothing otherwise.

Most of these attribute names begin with ATTRIBUTE_. A few do not, because they are part of C23 and their names are not likely to clash with other macro names. These macros are DEPRECATED, FALLTHROUGH, MAYBE_UNUSED, and NODISCARD, which can be defined to [[deprecated]] etc. on C23 platforms. Also, these exceptional macros should be placed at the start of function declarations, whereas the ATTRIBUTE_* macros can be placed at the end.

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17.5 Compile-time Assertions

This module provides a header file verify.h that defines macros related to compile-time verification.

Two of these macros are verify (V) and verify_expr (V, EXPR). Both accept an integer constant expression argument V and verify that it is nonzero. If not, a compile-time error results.

These two macros implement compile-time tests, as opposed to the standard assert macro which supports only runtime tests. Since the tests occur at compile-time, they are more reliable, and they require no runtime overhead.

verify (V); is a declaration; it can occur outside of functions. In contrast, verify_expr (V, EXPR) is an expression that returns the value of EXPR; it can be used in macros that expand to expressions. If EXPR is an integer constant expression, then verify_expr (V, EXPR) is also an integer constant expression. Although EXPR and verify_expr (V, EXPR) are guaranteed to have the same side effects and value and type (after integer promotion), they need not have the same type if EXPR’s type is an integer that is narrower than int or unsigned int.

V should be an integer constant expression in the sense of the C standard. Its leaf operands should be integer, enumeration, or character constants; or sizeof expressions that return constants; or floating constants that are the immediate operands of casts. Outside a sizeof subexpression, V should not contain any assignments, function calls, comma operators, casts to non-integer types, or subexpressions whose values are outside the representable ranges for their types. If V is not an integer constant expression, then a compiler might reject a usage like ‘verify (V);’ even when V is nonzero.

Although the standard assert macro is a runtime test, C23 and C++17 specify a builtin static_assert (V), which differs from verify in two major ways. First, it can also be used within a struct or union specifier, in place of an ordinary member declaration. Second, it allows the programmer to specify, as an optional second argument, a compile-time diagnostic as a string literal. If your program is not intended to be portable to compilers that lack C23 or C++17 static_assert, the only advantage of verify is that its name is a bit shorter.

The verify.h header defines one more macro, assume (E), which expands to an expression of type void that causes the compiler to assume that E yields a nonzero value. E should be a scalar expression, and should not have side effects; it may or may not be evaluated. The behavior is undefined if E would yield zero. The main use of assume is optimization, as the compiler may be able to generate better code if it assumes E. For best results, E should be simple enough that a compiler can determine that it has no side effects: if E calls an external function or accesses volatile storage the compiler may not be able to optimize E away and assume (E) may therefore slow down the program.

Here are some example uses of these macros. 

#include <verify.h>

#include <limits.h>
#include <time.h>

/* Verify that time_t is an integer type.  */
verify ((time_t) 1.5 == 1);

/* Verify that time_t is no smaller than int.  */
verify (sizeof (int) <= sizeof (time_t));

/* Verify that time_t is signed.  */
verify ((time_t) -1 < 0);

/* Verify that time_t uses two's complement representation.  */
verify (~ (time_t) -1 == 0);

/* Return the maximum value of the integer type T,
   verifying that T is an unsigned integer type.
   The cast to (T) is outside the call to verify_expr
   so that the result is of type T
   even when T is narrower than unsigned int.  */
#define MAX_UNSIGNED_VAL(t) \
   ((T) verify_expr (0 < (T) -1, -1))

/* Return T divided by CHAR_MAX + 1, where behavior is
   undefined if T < 0.  In the common case where CHAR_MAX
   is 127 the compiler can therefore implement the division
   by shifting T right 7 bits, an optimization that would
   not be valid if T were negative.  */
time_t
time_index (time_t t)
{
  assume (0 <= t);
  return t / (CHAR_MAX + 1);
}

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17.6 Non-returning Functions

A "non-returning" function is a function which cannot return normally. Instead of returning, it can loop forever, or it can transfer control via abort, execvp, exit, longjmp, throw (in C++), or similar mechanisms. Non-returning functions are declared with a void return type.

It helps the compiler’s ability to emit sensible warnings, following data-flow analysis, to declare which functions are non-returning. It can also help generate more-efficient code, as there is no need to save a return address when calling a non-returning function.

Gnulib has multiple ways to support such a declaration:

  • The _Noreturn keyword. No modules are needed, as Gnulib arranges for <config.h> to define _Noreturn to an appropriate replacement on platforms lacking it. Unfortunately, although this approach works for all current C versions, the _Noreturn keyword is obsolescent in C23.
  • The ‘noreturn’ module. It provides a way to put this declaration at function declarations, at function definitions, and in function pointer types. The identifiers to use are:
    • - _GL_NORETURN_FUNC for use in function declarations and function definitions.
    • - _GL_NORETURN_FUNCPTR for use on function pointers.

    The include file is <noreturn.h>.

Which of the approaches to use? If the non-returning functions you have to declare are unlikely to be accessed through function pointers, you should use _Noreturn; otherwise the module noreturn provides for better data-flow analysis and thus for better warnings.

There is also an obsolete stdnoreturn module, but its use is no longer recommended.

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17.7 Integer Properties

The intprops module consists of an include file <intprops.h> that defines several macros useful for testing properties of integer types.

Integer overflow is a common source of problems in programs written in C and other languages. In some cases, such as signed integer arithmetic in C programs, the resulting behavior is undefined, and practical platforms do not always behave as if integers wrap around reliably. In other cases, such as unsigned integer arithmetic in C, the resulting behavior is well-defined, but programs may still misbehave badly after overflow occurs.

Many techniques have been proposed to attack these problems. These include precondition testing, wraparound behavior where signed integer arithmetic is guaranteed to be modular, saturation semantics where overflow reliably yields an extreme value, undefined behavior sanitizers where overflow is guaranteed to trap, and various static analysis techniques.

Gnulib supports wraparound arithmetic and precondition testing, as these are relatively easy to support portably and efficiently. There are two families of precondition tests: the first, for integer types, is easier to use, while the second, for integer ranges, has a simple and straightforward portable implementation.

Like other Gnulib modules, the implementation of the intprops module assumes that integers use a two’s complement representation, but it does not assume that signed integer arithmetic wraps around. See Other portability assumptions made by Gnulib.

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17.7.1 Arithmetic Type Properties

TYPE_IS_INTEGER (t) is an arithmetic constant expression that yields 1 if the arithmetic type t is an integer type, 0 otherwise. bool counts as an integer type.

TYPE_SIGNED (t) is an arithmetic constant expression that yields 1 if the real type t is a signed integer type or a floating type, 0 otherwise. If t is an integer type, TYPE_SIGNED (t) is an integer constant expression.

EXPR_SIGNED (e) yields 1 if the real expression e has a signed integer type or a floating type, 0 otherwise. If e is an integer constant expression or an arithmetic constant expression, EXPR_SIGNED (e) is likewise. The expression e is not evaluated, and EXPR_SIGNED (e) is typically optimized to a constant.

Example usage: 

#include <intprops.h>
#include <sys/types.h>

enum
{
  clock_t_is_integer = TYPE_IS_INTEGER (clock_t),
  uid_t_is_signed = TYPE_SIGNED (uid_t)
};

int
CLOCKS_PER_SEC_is_signed (void)
{
  return EXPR_SIGNED (CLOCKS_PER_SEC);
}

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17.7.2 Integer Bounds

INT_BUFSIZE_BOUND (t) is an integer constant expression that is a bound on the size of the string representing an integer type or expression t in decimal notation, including the terminating null character and any leading - character. For example, if INT_BUFSIZE_BOUND (int) is 12, any value of type int can be represented in 12 bytes or less, including the terminating null. The bound is not necessarily tight.

Example usage: 

#include <intprops.h>
#include <stdio.h>
int
int_strlen (int i)
{
  char buf[INT_BUFSIZE_BOUND (int)];
  return sprintf (buf, "%d", i);
}

INT_STRLEN_BOUND (t) is an integer constant expression that is a bound on the length of the string representing an integer type or expression t in decimal notation, including any leading - character. This is one less than INT_BUFSIZE_BOUND (t).

TYPE_MINIMUM (t) and TYPE_MAXIMUM (t) are integer constant expressions equal to the minimum and maximum values of the integer type t. These expressions are of the type t.

Example usage: 

#include <sys/types.h>
#include <intprops.h>
bool
in_off_t_range (long long int a)
{
  return TYPE_MINIMUM (off_t) <= a && a <= TYPE_MAXIMUM (off_t);
}

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17.7.3 Checking Integer Overflow

Signed integer arithmetic has undefined behavior on overflow in C. Although almost all modern computers use two’s complement signed arithmetic that is well-defined to wrap around, C compilers routinely optimize assuming that signed integer overflow cannot occur, which means that a C program cannot easily get at the underlying machine arithmetic. For example: 

if ((a + b < b) == (a < 0))
  a += b;
else
  printf ("overflow\n");

might not work as expected if a and b are signed, because a compiler can assume that signed overflow cannot occur and treat the entire if expression as if it were true. And even if a is unsigned, the expression might not work as expected if b is negative or is wider than a.

The following macros work around this problem by yielding an overflow indication while computing the sum, difference, or product of two integers. For example, if i is of type int, INT_ADD_OK (INT_MAX - 1, 1, &i) sets i to INT_MAX and yields 1, whereas INT_ADD_OK (INT_MAX, 1, &i) yields 0.

Example usage: 

#include <intprops.h>
#include <stdio.h>

/* Compute A * B, reporting whether overflow occurred.  */
void
print_product (long int a, long int b)
{
  long int r;
  if (INT_MULTIPLY_OK (a, b, &r))
    printf ("result is %ld\n", r);
  else
    printf ("overflow\n");
}

These macros work for both signed and unsigned integers, so they can be used with integer types like time_t that may or may not be signed, depending on the platform.

These macros have the following restrictions:

  • Their first two arguments must be integer expressions.
  • Their last argument must be a non-null pointer to an integer.
  • They may evaluate their arguments zero or multiple times, so the arguments should not have side effects.
  • They are not necessarily constant expressions, even if all their arguments are constant expressions.
INT_ADD_OK (a, b, r)

Compute the sum of a and b. If it fits into *r, store it there and yield 1. Otherwise yield 0, possibly modifying *r to an unspecified value. See above for restrictions.

INT_SUBTRACT_OK (a, b, r)

Compute the difference between a and b. If it fits into *r, store it there and yield 1. Otherwise yield 0, possibly modifying *r to an unspecified value. See above for restrictions.

INT_MULTIPLY_OK (a, b, r)

Compute the product of a and b. If it fits into *r, store it there and yield 1. Otherwise yield 0, possibly modifying *r to an unspecified value. See above for restrictions.

Other macros are available if you need wrapped-around results when overflow occurs (see Wraparound Arithmetic with Integers), or if you need to check for overflow in operations other than addition, subtraction, and multiplication (see Integer Type Overflow).

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17.7.4 Wraparound Arithmetic with Integers

Signed integer arithmetic has undefined behavior on overflow in C. Although almost all modern computers use two’s complement signed arithmetic that is well-defined to wrap around, C compilers routinely optimize assuming that signed integer overflow cannot occur, which means that a C program cannot easily get at the underlying machine arithmetic. For example, on a typical machine with 32-bit two’s complement int the expression INT_MAX + 1 does not necessarily yield INT_MIN, because the compiler may do calculations with a 64-bit register, or may generate code that traps on signed integer overflow.

The following macros work around this problem by storing the wraparound value, i.e., the low-order bits of the correct answer, and by yielding an overflow indication. For example, if i is of type int, INT_ADD_WRAPV (INT_MAX, 1, &i) sets i to INT_MIN and yields 1 on a two’s complement machine. See Integer Type Overflow.

Example usage: 

#include <intprops.h>
#include <stdio.h>

/* Print the low order bits of A * B,
   reporting whether overflow occurred.  */
void
print_product (long int a, long int b)
{
  long int r;
  int overflow = INT_MULTIPLY_WRAPV (a, b, &r);
  printf ("result is %ld (%s)\n", r,
          (overflow
           ? "after overflow"
           : "no overflow"));
}

These macros work for both signed and unsigned integers, so they can be used with integer types like time_t that may or may not be signed, depending on the platform.

These macros have the following restrictions:

  • Their first two arguments must be integer expressions.
  • Their last argument must be a non-null pointer to an integer.
  • They may evaluate their arguments zero or multiple times, so the arguments should not have side effects.
  • They are not necessarily constant expressions, even if all their arguments are constant expressions.
INT_ADD_WRAPV (a, b, r)

Store the low-order bits of the sum of a and b into *r. Yield 1 if overflow occurred, 0 if the low-order bits are the mathematically-correct sum. See above for restrictions.

INT_SUBTRACT_WRAPV (a, b, r)

Store the low-order bits of the difference between a and b into *r. Yield 1 if overflow occurred, 0 if the low-order bits are the mathematically-correct difference. See above for restrictions.

INT_MULTIPLY_WRAPV (a, b, r)

Store the low-order bits of the product of a and b into *r. Yield 1 if overflow occurred, 0 if the low-order bits are the mathematically-correct product. See above for restrictions.

If your code includes <intprops.h> only for these _WRAPV macros, you may prefer to use Gnulib’s stdckdint module instead, as it supports similar macros that were standardized in C23 and are therefore independent of Gnulib if your code can assume C23 or later. See stdckdint.h.

Other macros are available if you do not need wrapped-around results when overflow occurs (see Checking Integer Overflow), or if you need to check for overflow in operations other than addition, subtraction, and multiplication (see Integer Type Overflow).

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17.7.5 Integer Type Overflow

Although unsigned integer arithmetic wraps around modulo a power of two, signed integer arithmetic has undefined behavior on overflow in C. Almost all modern computers use two’s complement signed arithmetic that is well-defined to wrap around, but C compilers routinely optimize based on the assumption that signed integer overflow cannot occur, which means that a C program cannot easily get at the underlying machine behavior. For example, the signed integer expression (a + b < b) != (a < 0) is not a reliable test for whether a + b overflows, because a compiler can assume that signed overflow cannot occur and treat the entire expression as if it were false.

These macros yield 1 if the corresponding C operators overflow, 0 otherwise. They work correctly on all known practical hosts, and do not rely on undefined behavior due to signed arithmetic overflow. They are integer constant expressions if their arguments are. They are typically easier to use than the integer range overflow macros (see Integer Range Overflow), and they support more operations and evaluation contexts than the integer overflow checking macros (see Checking Integer Overflow) or the wraparound macros (see Wraparound Arithmetic with Integers).

These macros can be tricky to use with arguments narrower than int. For example, in the common case with 16-bit short int and 32-bit int, if a and b are of type short int then INT_MULTIPLY_OVERFLOW (a, b) always yields 0, as a * b cannot overflow due to C’s rule that a and b are widened to int before multiplying. For this reason, often it is better to use the integer overflow checking macros (see Checking Integer Overflow) or the wraparound macros (see Wraparound Arithmetic with Integers) when checking for overflow in addition, subtraction, or multiplication.

Example usage: 

#include <intprops.h>
#include <limits.h>
#include <stdio.h>

/* Print A * B if in range, an overflow
   indicator otherwise.  */
void
print_product (long int a, long int b)
{
  if (INT_MULTIPLY_OVERFLOW (a, b))
    printf ("multiply would overflow");
  else
    printf ("product is %ld", a * b);
}

/* Does the product of two ints always fit
   in a long int?  */
enum {
  INT_PRODUCTS_FIT_IN_LONG
    = ! (INT_MULTIPLY_OVERFLOW
         ((long int) INT_MIN, INT_MIN))
};

These macros have the following restrictions:

  • Their arguments must be integer expressions.
  • They may evaluate their arguments zero or multiple times, so the arguments should not have side effects.

These macros are tuned for their last argument being a constant.

INT_ADD_OVERFLOW (a, b)

Yield 1 if a + b would overflow, 0 otherwise. See above for restrictions.

INT_SUBTRACT_OVERFLOW (a, b)

Yield 1 if a - b would overflow, 0 otherwise. See above for restrictions.

INT_NEGATE_OVERFLOW (a)

Yields 1 if -a would overflow, 0 otherwise. See above for restrictions.

INT_MULTIPLY_OVERFLOW (a, b)

Yield 1 if a * b would overflow, 0 otherwise. See above for restrictions.

INT_DIVIDE_OVERFLOW (a, b)

Yield 1 if a / b would overflow, 0 otherwise. See above for restrictions. Division overflow can happen on two’s complement hosts when dividing the most negative integer by -1. This macro does not check for division by zero.

INT_REMAINDER_OVERFLOW (a, b)

Yield 1 if a % b would overflow, 0 otherwise. See above for restrictions. Remainder overflow can happen on two’s complement hosts when dividing the most negative integer by -1; although the mathematical result is always 0, in practice some implementations trap, so this counts as an overflow. This macro does not check for division by zero.

INT_LEFT_SHIFT_OVERFLOW (a, b)

Yield 1 if a << b would overflow, 0 otherwise. See above for restrictions. The C standard says that behavior is undefined for shifts unless 0≤b<w where w is a’s word width, and that when a is negative then a << b has undefined behavior, but this macro does not check these other restrictions.

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17.7.6 Integer Range Overflow

These macros yield 1 if the corresponding C operators might not yield numerically correct answers due to arithmetic overflow, and 0 if if the operators do not overflow. They do not rely on undefined or implementation-defined behavior. They are integer constant expressions if their arguments are. Their implementations are simple and straightforward, but they are typically harder to use than the integer type overflow macros. See Integer Type Overflow.

Although the implementation of these macros is similar to that suggested in the SEI CERT C Secure Coding Standard, in its two sections “INT30-C. Ensure that unsigned integer operations do not wrap” and “INT32-C. Ensure that operations on signed integers do not result in overflow”, Gnulib’s implementation was derived independently of CERT’s suggestions.

Example usage: 

#include <intprops.h>
#include <limits.h>
#include <stdio.h>

void
print_product (long int a, long int b)
{
  if (INT_MULTIPLY_RANGE_OVERFLOW (a, b, LONG_MIN, LONG_MAX))
    printf ("multiply would overflow");
  else
    printf ("product is %ld", a * b);
}

/* Does the product of two ints always fit
   in a long int?  */
enum {
  INT_PRODUCTS_FIT_IN_LONG
    = ! (INT_MULTIPLY_RANGE_OVERFLOW
         ((long int) INT_MIN, (long int) INT_MIN,
          LONG_MIN, LONG_MAX))
};

These macros have the following restrictions:

  • Their arguments must be integer expressions.
  • They may evaluate their arguments zero or multiple times, so the arguments should not have side effects.
  • The arithmetic arguments (including the min and max arguments) must be of the same integer type after the usual arithmetic conversions, and the type must have minimum value min and maximum max. Unsigned values should use a zero min of the proper type, for example, (unsigned int) 0.

These macros are tuned for constant min and max. For commutative operations such as a + b, they are also tuned for constant b.

INT_ADD_RANGE_OVERFLOW (a, b, min, max)

Yield 1 if a + b would overflow in [min,max] integer arithmetic, 0 otherwise. See above for restrictions.

INT_SUBTRACT_RANGE_OVERFLOW (a, b, min, max)

Yield 1 if a - b would overflow in [min,max] integer arithmetic, 0 otherwise. See above for restrictions.

INT_NEGATE_RANGE_OVERFLOW (a, min, max)

Yield 1 if -a would overflow in [min,max] integer arithmetic, 0 otherwise. See above for restrictions.

INT_MULTIPLY_RANGE_OVERFLOW (a, b, min, max)

Yield 1 if a * b would overflow in [min,max] integer arithmetic, 0 otherwise. See above for restrictions.

INT_DIVIDE_RANGE_OVERFLOW (a, b, min, max)

Yield 1 if a / b would overflow in [min,max] integer arithmetic, 0 otherwise. See above for restrictions. Division overflow can happen on two’s complement hosts when dividing the most negative integer by -1. This macro does not check for division by zero.

INT_REMAINDER_RANGE_OVERFLOW (a, b, min, max)

Yield 1 if a % b would overflow in [min,max] integer arithmetic, 0 otherwise. See above for restrictions. Remainder overflow can happen on two’s complement hosts when dividing the most negative integer by -1; although the mathematical result is always 0, in practice some implementations trap, so this counts as an overflow. This macro does not check for division by zero.

INT_LEFT_SHIFT_RANGE_OVERFLOW (a, b, min, max)

Yield 1 if a << b would overflow in [min,max] integer arithmetic, 0 otherwise. See above for restrictions. Here, min and max are for a only, and b need not be of the same type as the other arguments. The C standard says that behavior is undefined for shifts unless 0≤b<w where w is a’s word width, and that when a is negative then a << b has undefined behavior, but this macro does not check these other restrictions.

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17.8 Static inline functions

In order to mark functions as static inline, the only prerequisite you need is an AC_REQUIRE([AC_C_INLINE]). No Gnulib module is needed.

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17.9 Extern inline functions

The extern-inline module supports the use of C99-style extern inline functions so that the code still runs on compilers that do not support this feature correctly.

C code ordinarily should not use inline. Typically it is better to let the compiler figure out whether to inline, as compilers are pretty good about optimization nowadays. In this sense, inline is like register, another keyword that is typically no longer needed.

Functions defined (not merely declared) in headers are an exception, as avoiding inline would commonly cause problems for these functions. Suppose aaa.h defines the function aaa_fun, and aaa.c, bbb.c and ccc.c all include aaa.h. If code is intended to portable to non-C99 compilers, aaa_fun cannot be declared with the C99 inline keyword. This problem cannot be worked around by making aaa_fun an ordinary function, as it would be defined three times with external linkage and the definitions would clash. Although aaa_fun could be a static function, with separate compilation if aaa_fun is not inlined its code will appear in the executable three times.

To avoid this code bloat, aaa.h can do this: 

/* aaa.h */
/* #include any other headers here */
#ifndef _GL_INLINE_HEADER_BEGIN
 #error "Please include config.h first."
#endif
_GL_INLINE_HEADER_BEGIN
#ifndef AAA_INLINE
# define AAA_INLINE _GL_INLINE
#endif
...
AAA_INLINE int
aaa_fun (int i)
{
  return i + 1;
}
...
_GL_INLINE_HEADER_END

and aaa.c can do this: 

/* aaa.c */
#include <config.h>
#define AAA_INLINE _GL_EXTERN_INLINE
#include <aaa.h>

whereas bbb.c and ccc.c can include aaa.h in the usual way. C99 compilers expand AAA_INLINE to C99-style inline usage, where aaa_fun is declared extern inline in aaa.c and plain inline in other modules. Non-C99 compilers that are compatible with GCC use GCC-specific syntax to accomplish the same ends. Other non-C99 compilers use static inline so they suffer from code bloat, but they are not mainline platforms and will die out eventually.

_GL_INLINE is a portable alternative to C99 plain inline.

_GL_EXTERN_INLINE is a portable alternative to C99 extern inline.

Invoke _GL_INLINE_HEADER_BEGIN before all uses of _GL_INLINE in an include file. This suppresses some bogus warnings in GCC versions before 5.1. If an include file includes other files, it is better to invoke this macro after including the other files.

Invoke _GL_INLINE_HEADER_END after all uses of _GL_INLINE in an include file.

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17.10 Handling closed standard file descriptors

Usually, when a program gets invoked, its file descriptors 0 (for standard input), 1 (for standard output), and 2 (for standard error) are open. But there are situations when some of these file descriptors are closed. These situations can arise when

  • The invoking process invokes close() on the file descriptor before exec, or
  • The invoking process invokes posix_spawn_file_actions_addclose() for the file descriptor before posix_spawn or posix_spawnp, or
  • The invoking process is a Bourne shell, and the shell script uses the POSIX syntax for closing the file descriptor: <&- for closing standard input, >&- for closing standard output, or 2>&- for closing standard error.

When a closed file descriptor is accessed through a system call, such as fcntl(), fstat(), read(), or write(), the system calls fails with error EBADF ("Bad file descriptor").

When a new file descriptor is allocated, the operating system chooses the smallest non-negative integer that does not yet correspond to an open file descriptor. So, when a given fd (0, 1, or 2) is closed, opening a new file descriptor may assign the new file descriptor to this fd. This can have unintended effects, because now standard input/output/error of your process is referring to a file that was not meant to be used in that role.

This situation is a security risk because the behaviour of the program in this situation was surely never tested, therefore anything can happen then – from overwriting precious files of the user to endless loops.

To deal with this situation, you first need to determine whether your program is affected by the problem.

  • Does your program invoke functions that allocate new file descriptors? These are the system calls
    • open(), openat(), creat()
    • dup()
    • fopen(), freopen()
    • pipe(), pipe2(), popen()
    • opendir()
    • tmpfile(), mkstemp(), mkstemps(), mkostemp(), mkostemps()

    Note that you also have to consider the libraries that your program uses.

  • If your program may open two or more file descriptors or FILE streams for reading at the same time, and some of them may reference standard input, your program is affected.
  • If your program may open two or more file descriptors or FILE streams for writing at the same time, and some of them may reference standard output or standard error, your program is affected.
  • If your program does not open new file descriptors or FILE streams, it is not affected.
  • If your program opens only one new file descriptor or FILE stream at a time, it is not affected. This is often the case for programs that are structured in simple phases: first a phase where input is read from a file into memory, then a phase of processing in memory, finally a phase where the result is written to a file.
  • If your program opens only two new file descriptors or FILE streams at a time, out of which one is for reading and the one is for writing, it is not affected. This is because if the first file descriptor is allocated and the second file descriptor is picked as 0, 1, or 2, and both happen to be the same, writing to the one opened in O_RDONLY mode will produce an error EBADF, as desired.

If your program is affected, what is the mitigation?

Some operating systems install open file descriptors in place of the closed ones, either in the exec system call or during program startup. When such a file descriptor is accessed through a system call, it behaves like an open file descriptor opened for the “wrong” direction: the system calls fcntl() and fstat() succeed, whereas read() from fd 0 and write() to fd 1 or 2 fail with error EBADF ("Bad file descriptor"). The important point here is that when your program allocates a new file descriptor, it will have a value greater than 2.

This mitigation is enabled on HP-UX, for all programs, and on glibc, FreeBSD, NetBSD, OpenBSD, but only for setuid or setgid programs. Since it is operating system dependent, it is not a complete mitigation.

For a complete mitigation, Gnulib provides two alternative sets of modules:

  • The xstdopen module.
  • The *-safer modules: fcntl-safer, openat-safer, unistd-safer, fopen-safer, freopen-safer, pipe2-safer, popen-safer, dirent-safer, tmpfile-safer, stdlib-safer.

The approach with the xstdopen module is simpler, but it adds three system calls to program startup. Whereas the approach with the *-safer modules is more complex, but adds no overhead (no additional system calls) in the normal case.

To use the approach with the xstdopen module:

  1. Import the module xstdopen from Gnulib.
  2. In the compilation unit that contains the main function, include "xstdopen.h".
  3. In the main function, near the beginning, namely right after the i18n related initializations (setlocale, bindtextdomain, textdomain invocations, if any) and the closeout initialization (if any), insert the invocation: 
    /* Ensure that stdin, stdout, stderr are open.  */
xstdopen ();

To use the approach with the *-safer modules:

  1. Import the relevant modules from Gnulib.
  2. In the compilation units that contain these function calls, include the replacement header file.

Do so according to this table:

FunctionModuleHeader file
open()fcntl-safer"fcntl--.h"
openat()openat-safer"fcntl--.h"
creat()fcntl-safer"fcntl--.h"
dup()unistd-safer"unistd--.h"
fopen()fopen-safer"stdio--.h"
freopen()freopen-safer"stdio--.h"
pipe()unistd-safer"unistd--.h"
pipe2()pipe2-safer"unistd--.h"
popen()popen-safer"stdio--.h"
opendir()dirent-safer"dirent--.h"
tmpfile()tmpfile-safer"stdio--.h"
mkstemp()stdlib-safer"stdlib--.h"
mkstemps()stdlib-safer"stdlib--.h"
mkostemp()stdlib-safer"stdlib--.h"
mkostemps()stdlib-safer"stdlib--.h"

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17.11 Handling strings with NUL characters

Strings in C are usually represented by a character sequence with a terminating NUL character. A ‘char *’, pointer to the first byte of this character sequence, is what gets passed around as function argument or return value.

The major restriction of this string representation is that it cannot handle strings that contain NUL characters: such strings will appear shorter than they were meant to be. In most application areas, this is not a problem, and the char * type is well usable.

In areas where strings with embedded NUL characters need to be handled, the common approach is to use a char *ptr pointer variable together with a size_t nbytes variable (or an idx_t nbytes variable, if you want to avoid problems due to integer overflow). This works fine in code that constructs or manipulates strings with embedded NUL characters. But when it comes to storing them, for example in an array or as key or value of a hash table, one needs a type that combines these two fields.

The Gnulib modules string-desc, xstring-desc, and string-desc-quotearg provide such a type. We call it a “string descriptor” and name it string_desc_t.

The type string_desc_t is a struct that contains a pointer to the first byte and the number of bytes of the memory region that make up the string. An additional terminating NUL byte, that may be present in memory, is not included in this byte count. This type implements the same concept as std::string_view in C++, or the String type in Java.

A string_desc_t can be passed to a function as an argument, or can be the return value of a function. This is type-safe: If, by mistake, a programmer passes a string_desc_t to a function that expects a char * argument, or vice versa, or assigns a string_desc_t value to a variable of type char *, or vice versa, the compiler will report an error.

Functions related to string descriptors are provided:

  • Side-effect-free operations in "string-desc.h",
  • Memory-allocating operations in "string-desc.h",
  • Memory-allocating operations with out-of-memory checking in "xstring-desc.h",
  • Operations with side effects in "string-desc.h".

For outputting a string descriptor, the *printf family of functions cannot be used directly. A format string directive such as "%.*s" would not work:

  • it would stop the output at the first encountered NUL character,
  • it would require to cast the number of bytes to int, and thus would not work for strings longer than INT_MAX bytes.

Therefore Gnulib offers

  • a function string_desc_fwrite that outputs a string descriptor to a FILE stream,
  • a function string_desc_write that outputs a string descriptor to a file descriptor,
  • and for those applications where the NUL characters should become visible as ‘\0’, a family of quotearg based functions, that allow to specify the escaping rules in detail.

The functionality is thus split across three modules as follows:

  • The module string-desc, under LGPL, defines the type and elementary functions.
  • The module xstring-desc, under GPL, defines the memory-allocating functions with out-of-memory checking.
  • The module string-desc-quotearg, under GPL, defines the quotearg based functions.

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17.12 Container data types

Gnulib provides several generic container data types. They can be used to organize collections of application-defined objects.

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17.12.1 Ordinary container data types

Data typeDetailsModuleMain include fileInclude file for operations with out-of-memory checking
Sequential listCan contain any number of objects in any given order. Duplicates are allowed, but can optionally be forbidden.list"gl_list.h""gl_xlist.h"
SetCan contain any number of objects; the order does not matter. Duplicates (in the sense of the comparator) are forbidden.set"gl_set.h""gl_xset.h"
Ordered setCan contain any number of objects in the order of a given comparator function. Duplicates (in the sense of the comparator) are forbidden.oset"gl_oset.h""gl_xoset.h"
MapCan contain any number of (key, value) pairs, where keys and values are objects; there are no (key, value1) and (key, value2) pairs with the same key (in the sense of a given comparator function).map"gl_map.h""gl_xmap.h"
Ordered mapCan contain any number of (key, value) pairs, where keys and values are objects; the (key, value) pairs are ordered by the key, in the order of a given comparator function; there are no (key, value1) and (key, value2) pairs with the same key (in the sense of the comparator function).omap"gl_omap.h""gl_xomap.h"

Operations without out-of-memory checking (suitable for use in libraries) are declared in the “main include file”. Whereas operations with out-of-memory checking (suitable only in programs) are declared in the “include file for operations with out-of-memory checking”.

For each of the data types, several implementations are available, with different performance profiles with respect to the available operations. This enables you to start with the simplest implementation (ARRAY) initially, and switch to a more suitable implementation after profiling your application. The implementation of each container instance is specified in a single place only: in the invocation of the function gl_*_create_empty that creates the instance.

The implementations and the guaranteed average performance for the operations for the “sequential list” data type are:

OperationARRAYCARRAYLINKEDTREELINKEDHASH with duplicatesLINKEDHASH without duplicatesTREEHASH with duplicatesTREEHASH without duplicates
gl_list_sizeO(1)O(1)O(1)O(1)O(1)O(1)O(1)O(1)
gl_list_node_valueO(1)O(1)O(1)O(1)O(1)O(1)O(1)O(1)
gl_list_node_set_valueO(1)O(1)O(1)O(1)O(1)O(1)O((log n)2)O(1)
gl_list_next_nodeO(1)O(1)O(1)O(log n)O(1)O(1)O(log n)O(log n)
gl_list_previous_nodeO(1)O(1)O(1)O(log n)O(1)O(1)O(log n)O(log n)
gl_list_first_nodeO(1)O(1)O(1)O(log n)O(1)O(1)O(log n)O(log n)
gl_list_last_nodeO(1)O(1)O(1)O(log n)O(1)O(1)O(log n)O(log n)
gl_list_get_atO(1)O(1)O(n)O(log n)O(n)O(n)O(log n)O(log n)
gl_list_get_firstO(1)O(1)O(1)O(log n)O(1)O(1)O(log n)O(log n)
gl_list_get_lastO(1)O(1)O(1)O(log n)O(1)O(1)O(log n)O(log n)
gl_list_set_atO(1)O(1)O(n)O(log n)O(n)O(n)O((log n)2)O(log n)
gl_list_set_firstO(1)O(1)O(1)O(log n)O(n)O(1)O((log n)2)O(log n)
gl_list_set_lastO(1)O(1)O(1)O(log n)O(n)O(1)O((log n)2)O(log n)
gl_list_searchO(n)O(n)O(n)O(n)O(n)O(1)O(log n)O(1)
gl_list_search_fromO(n)O(n)O(n)O(n)O(n)O(1)O((log n)2)O(log n)
gl_list_search_from_toO(n)O(n)O(n)O(n)O(n)O(1)O((log n)2)O(log n)
gl_list_indexofO(n)O(n)O(n)O(n)O(n)O(n)O(log n)O(log n)
gl_list_indexof_fromO(n)O(n)O(n)O(n)O(n)O(n)O((log n)2)O(log n)
gl_list_indexof_from_toO(n)O(n)O(n)O(n)O(n)O(n)O((log n)2)O(log n)
gl_list_add_firstO(n)O(1)O(1)O(log n)O(1)O(1)O((log n)2)O(log n)
gl_list_add_lastO(1)O(1)O(1)O(log n)O(1)O(1)O((log n)2)O(log n)
gl_list_add_beforeO(n)O(n)O(1)O(log n)O(1)O(1)O((log n)2)O(log n)
gl_list_add_afterO(n)O(n)O(1)O(log n)O(1)O(1)O((log n)2)O(log n)
gl_list_add_atO(n)O(n)O(n)O(log n)O(n)O(n)O((log n)2)O(log n)
gl_list_remove_nodeO(n)O(n)O(1)O(log n)O(n)O(1)O((log n)2)O(log n)
gl_list_remove_atO(n)O(n)O(n)O(log n)O(n)O(n)O((log n)2)O(log n)
gl_list_remove_firstO(n)O(1)O(1)O(log n)O(n)O(1)O((log n)2)O(log n)
gl_list_remove_lastO(1)O(1)O(1)O(log n)O(n)O(1)O((log n)2)O(log n)
gl_list_removeO(n)O(n)O(n)O(n)O(n)O(1)O((log n)2)O(log n)
gl_list_iteratorO(1)O(1)O(1)O(log n)O(1)O(1)O(log n)O(log n)
gl_list_iterator_from_toO(1)O(1)O(n)O(log n)O(n)O(n)O(log n)O(log n)
gl_list_iterator_nextO(1)O(1)O(1)O(log n)O(1)O(1)O(log n)O(log n)
gl_sortedlist_searchO(log n)O(log n)O(n)O(log n)O(n)O(n)O(log n)O(log n)
gl_sortedlist_search_fromO(log n)O(log n)O(n)O(log n)O(n)O(n)O(log n)O(log n)
gl_sortedlist_indexofO(log n)O(log n)O(n)O(log n)O(n)O(n)O(log n)O(log n)
gl_sortedlist_indexof_fromO(log n)O(log n)O(n)O(log n)O(n)O(n)O(log n)O(log n)
gl_sortedlist_addO(n)O(n)O(n)O(log n)O(n)O(n)O((log n)2)O(log n)
gl_sortedlist_removeO(n)O(n)O(n)O(log n)O(n)O(n)O((log n)2)O(log n)

The implementations and the guaranteed average performance for the operations for the “set” data type are:

OperationARRAYLINKEDHASH, HASH
gl_set_sizeO(1)O(1)
gl_set_addO(n)O(1)
gl_set_removeO(n)O(1)
gl_set_searchO(n)O(1)
gl_set_iteratorO(1)O(1)
gl_set_iterator_nextO(1)O(1)

The implementations and the guaranteed average performance for the operations for the “ordered set” data type are:

OperationARRAYTREE
gl_oset_sizeO(1)O(1)
gl_oset_addO(n)O(log n)
gl_oset_removeO(n)O(log n)
gl_oset_searchO(log n)O(log n)
gl_oset_search_atleastO(log n)O(log n)
gl_oset_iteratorO(1)O(log n)
gl_oset_iterator_nextO(1)O(log n)

The implementations and the guaranteed average performance for the operations for the “map” data type are:

OperationARRAYLINKEDHASH, HASH
gl_map_sizeO(1)O(1)
gl_map_getO(n)O(1)
gl_map_putO(n)O(1)
gl_map_removeO(n)O(1)
gl_map_searchO(n)O(1)
gl_map_iteratorO(1)O(1)
gl_map_iterator_nextO(1)O(1)

The implementations and the guaranteed average performance for the operations for the “ordered map” data type are:

OperationARRAYTREE
gl_omap_sizeO(1)O(1)
gl_omap_getO(log n)O(log n)
gl_omap_putO(n)O(log n)
gl_omap_removeO(n)O(log n)
gl_omap_searchO(log n)O(log n)
gl_omap_search_atleastO(log n)O(log n)
gl_omap_iteratorO(1)O(log n)
gl_omap_iterator_nextO(1)O(log n)

For C++, Gnulib provides a C++ template class for each of these container data types.

Data typeC++ classModuleInclude file
Sequential listgl_Listlist-c++"gl_list.hh"
Setgl_Setset-c++"gl_set.hh"
Ordered setgl_OSetoset-c++"gl_oset.hh"
Mapgl_Mapmap-c++"gl_map.hh"
Ordered mapgl_OMapomap-c++"gl_omap.hh"

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17.12.2 Specialized container data types

The hamt module implements the hash array mapped trie (HAMT) data structure. This is a data structure that contains (key, value) pairs. Lookup of a (key, value) pair given the key is on average an O(1) operation, assuming a good hash function for the keys is employed.

The HAMT data structure is useful when you want modifications (additions of pairs, removal, value changes) to be visible only to some part of your program, whereas other parts of the program continue to use the unmodified HAMT. The HAMT makes this possible in a space-efficient manner: the modified and the unmodified HAMT share most of their allocated memory. It is also time-efficient: Every such modification is O(1) on average, again assuming a good hash function for the keys.

A HAMT can be used whenever an ordinary hash table would be used. It does however, provide non-destructive updating operations without the need to copy the whole container. On the other hand, a hash table is simpler so that its performance may be better when non-destructive update operations are not needed.

For example, a HAMT can be used to model the dynamic environment in a LISP interpreter. Updating a value in the dynamic environment of one continuation frame would not modify values in earlier frames.

To use the module, include hamt.h in your code. The public interface is documented in that header file. You have to provide a hash function and an equivalence relation, which defines key equality. The module includes a test file test-hamt.c, which demonstrates how the API can be used.

In the current implementation, each inner node of the HAMT can store up to 32 = 2^5 entries and subtries. Whenever a collision between the initial bits of the hash values of two entries would happen, the next 5 bits of the hash values are examined and the two entries pushed down one level in the trie.

HAMTs have the same average access times as hash tables but grow and shrink dynamically, so they use memory more economically and do not have to be periodically resized.

They were described and analyzed in Phil Bagwell (2000). Ideal Hash Trees (Report). Infoscience Department, École Polytechnique Fédérale de Lausanne.

The persistence aspect of the HAMT data structure, which means that each updating operation (like inserting, replacing, or removing an entry) returns a new HAMT while leaving the original one intact, is achieved through structure sharing, which is even safe in the presence of multiple threads when the used C compiler supports atomics.

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17.13 Recognizing Option Arguments

The module ‘argmatch’ provides a simple textual user interface to a finite choice. It is for example well suited to recognize arguments of options or values of environment variables that accept a fixed set of valid choices.

These choices may be denoted by synonyms, such as ‘none’ and ‘off’ below. 

$ my_cp --backup=none foo bar
$ my_cp --backup=non foo bar
$ my_cp --backup=no foo bar
$ my_cp --backup=n foo bar
my_cp: ambiguous argument 'n' for 'backup type'
Valid arguments are:
  - 'no', 'none', 'off'
  - 'numbered', 't', 'newstyle'
  - 'existing', 'nil', 'numbered-existing'
  - 'simple', 'never', 'single'
Try 'my_cp --help' for more information.
$ my_cp --backup=num foo bar
$ my_cp --backup=true foo bar
my_cp: invalid argument 'true' for 'backup type'
Valid arguments are:
  - 'no', 'none', 'off'
  - 'numbered', 't', 'newstyle'
  - 'existing', 'nil', 'numbered-existing'
  - 'simple', 'never', 'single'
Try 'my_cp --help' for more information.

To set up argmatch, first call ‘ARGMATCH_DEFINE_GROUP (name, type)’ with the name of the argmatch group name, and the value type. For instance: 

enum backup_type
{
  no_backups,
  simple_backups,
  numbered_existing_backups,
  numbered_backups
};

ARGMATCH_DEFINE_GROUP (backup, enum backup_type);

This defines a few types and functions named argmatch_name_*. Introduce the array that defines the mapping from user-input to actual value, with a terminator: 

static const argmatch_backup_arg argmatch_backup_args[] =
{
  { "no",                no_backups },
  { "none",              no_backups },
  { "off",               no_backups },
  { "simple",            simple_backups },
  { "never",             simple_backups },
  { "single",            simple_backups },
  { "existing",          numbered_existing_backups },
  { "nil",               numbered_existing_backups },
  { "numbered-existing", numbered_existing_backups },
  { "numbered",          numbered_backups },
  { "t",                 numbered_backups },
  { "newstyle",          numbered_backups },
  { NULL, no_backups }
};

Then introduce the array that defines the values, also with a terminator. Document only once per group of synonyms: 

static const argmatch_backup_doc argmatch_backup_docs[] =
{
  { "no",       N_("never make backups (even if --backup is given)") },
  { "numbered", N_("make numbered backups") },
  { "existing", N_("numbered if numbered backups exist, simple otherwise") },
  { "simple",   N_("always make simple backups") },
  { NULL, NULL }
};

Finally, define the argmatch group: 

const argmatch_backup_group_type argmatch_backup_group =
{
  argmatch_backup_args,
  argmatch_backup_docs,
  N_("\
The backup suffix is '~', unless set with --suffix or SIMPLE_BACKUP_SUFFIX.\n\
The version control method may be selected via the --backup option or through\n\
the VERSION_CONTROL environment variable.  Here are the values:\n"),
  NULL
};

To use the argmatch group: 

ptrdiff_t i = argmatch_backup_choice ("--backup", "none");
// argmatch_backup_group.args[i].arg is "none", so its value
// is argmatch_backup_group.args[i].val.
// Return -1 on invalid argument, and -2 on ambiguity.

enum backup_type val = *argmatch_backup_value ("--backup", "none");
// Returns a pointer to the value, and exit on errors.
// So argmatch_backup_group.args[i].val == val.

const char *arg = argmatch_backup_argument (&no_backups);
// arg is "no".

// Print the documentation on stdout.
argmatch_backup_usage (stdout);
// Gives:
//
// The backup suffix is '~', unless set with --suffix or SIMPLE_BACKUP_SUFFIX.
// The version control method may be selected via the --backup option or through
// the VERSION_CONTROL environment variable.  Here are the values:
//
//   no, none, off  never make backups (even if --backup is given)
//   numbered, t, newstyle
//                  make numbered backups
//   existing, nil, numbered-existing
//                  numbered if numbered backups exist, simple otherwise
//   simple, never, single
//                  always make simple backups

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17.14 Quoting

Gnulib provides ‘quote’ and ‘quotearg’ modules to help with quoting text, such as file names, in messages to the user. Here’s an example of using ‘quote’: 

#include <quote.h>
 ...
  error (0, errno, _("cannot change owner of %s"), quote (fname));

This differs from 

  error (0, errno, _("cannot change owner of '%s'"), fname);

in that quote escapes unusual characters in fname, e.g., ‘'’ and control characters like ‘\n’.

However, a caveat: quote reuses the storage that it returns. Hence if you need more than one thing quoted at the same time, you need to use quote_n.

Also, the quote module is not suited for multithreaded applications. In that case, you have to use quotearg_alloc, defined in the ‘quotearg’ module, which is decidedly less convenient.

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17.15 progname and getprogname

Gnulib has two modules for retrieving the name of the currently executing program: progname and getprogname.

The progname module defines a variable program_name. It contains the name of the currently executing program, on all platforms. But it cannot be used implicitly: It requires that every main function be modified to invoke set_program_name (argv[0]) as one of its first actions.

The getprogname module defines a function getprogname(). It returns the name of the currently executing program, on most platforms. The advantage of this module is that it can be used without prior initializations. But it has limitations: In some rare situations, it cannot determine the name; then it returns "?" instead. And on some platforms, it returns a truncated program name.

The error function uses the getprogname module.

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17.16 gcd: greatest common divisor

The gcd function returns the greatest common divisor of two numbers a > 0 and b > 0. It is the caller’s responsibility to ensure that the arguments are non-zero.

If you need a gcd function for an integer type larger than ‘unsigned long’, you can include the gcd.c implementation file with parametrization. The parameters are:

  • WORD_T Define this to the unsigned integer type that you need this function for.
  • GCD Define this to the name of the function to be created.

The created function has the prototype 

WORD_T GCD (WORD_T a, WORD_T b);

If you need the least common multiple of two numbers, it can be computed like this: lcm(a,b) = (a / gcd(a,b)) * b or lcm(a,b) = a * (b / gcd(a,b)). Avoid the formula lcm(a,b) = (a * b) / gcd(a,b) because—although mathematically correct—it can yield a wrong result, due to integer overflow.

In some applications it is useful to have a function taking the gcd of two signed numbers. In this case, the gcd function result is usually normalized to be non-negative (so that two gcd results can be compared in magnitude or compared against 1, etc.). Note that in this case the prototype of the function has to be 

unsigned long gcd (long a, long b);

and not 

long gcd (long a, long b);

because gcd(LONG_MIN,LONG_MIN) = -LONG_MIN = LONG_MAX + 1 does not fit into a signed ‘long’.

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17.17 Profiling of program phases

The module ‘timevar’ provides a simple self-profiling facility, based on timers. 

Execution times (seconds)
read                  :   0.09 (19%) usr   0.08 (80%) sys   0.09 (18%) wall
read: scan            :   0.04 ( 9%) usr   0.08 (80%) sys   0.12 (26%) wall
read: parse           :   0.05 (10%) usr   0.00 ( 0%) sys   0.05 (10%) wall
work                  :   0.33 (70%) usr   0.00 ( 0%) sys   0.35 (71%) wall
work: phase 1         :   0.30 (64%) usr   0.00 ( 0%) sys   0.30 (64%) wall
work: phase 2         :   0.13 (28%) usr   0.00 ( 0%) sys   0.14 (29%) wall
output                :   0.04 ( 9%) usr   0.02 (20%) sys   0.04 ( 8%) wall
total time            :   0.47             0.10             0.49

To set up timevar, copy the stub file gnulib/lib/timevar.def next to where timevar.h and timevar.c were imported in your project, and define your timers there. For instance: 

/* The total execution time.  Mandatory.  */
DEFTIMEVAR (tv_total,      "total time")

/* Examples.  */
DEFTIMEVAR (tv_read,       "read")
DEFTIMEVAR (tv_work,       "work")
DEFTIMEVAR (tv_work_1,     "work: phase 1")
DEFTIMEVAR (tv_work_2,     "work: phase 2")
DEFTIMEVAR (tv_output,     "output")

Do not remove tv_total, it is mandatory. You may change its associated string.


Use timevar_push/timevar_pop to start/stop timers, as in the following example. 

#include <config.h>
#include "timevar.h"

#include <stdio.h>
#include "read.h"
#include "work.h"
#include "output.h"

int
main (void)
{
  timevar_enabled = true;
  timevar_init ();
  timevar_start (tv_total);

  timevar_push (tv_read);
  reader ();
  timevar_pop (tv_read);

  timevar_push (tv_work);
  work ();
  timevar_pop (tv_work);

  timevar_push (tv_output);
  output ();
  timevar_pop (tv_output);

  timevar_stop (tv_total);
  timevar_print (stderr);
}

with, for instance, in work.c 

#include <config.h>
#include "work.h"

void
work (void)
{
  timevar_push (tv_work_phase1);
  work1 ();
  timevar_pop (tv_work_phase1);

  timevar_push (tv_work_phase2);
  work2 ();
  timevar_pop (tv_work_phase2);
}

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17.18 Library version handling

The module ‘check-version’ can be useful when your gnulib application is a system library. You will typically wrap the call to the check_version function through a library API, your library header file may contain: 

#define STRINGPREP_VERSION "0.5.18"
...
  extern const char *stringprep_check_version (const char *req_version);

To avoid ELF symbol collisions with other libraries that use the ‘check-version’ module, add to config.h through a AC_DEFINE something like: 

AC_DEFINE(check_version, stringprep_check_version,
          [Rename check_version.])

The stringprep_check_version function will thus be implemented by the check_version module.

There are two uses of the interface. The first is a way to provide for applications to find out the version number of the library it uses. The application may contain diagnostic code such as: 

  printf ("Stringprep version: header %s library %s",
          STRINGPREP_VERSION,
          stringprep_check_version (NULL));

Separating the library and header file version can be useful when searching for version mismatch related problems.

The second uses is as a rudimentary test of proper library version, by making sure the application get a library version that is the same, or newer, than the header file used when building the application. This doesn’t catch all problems, libraries may change backwards incompatibly in later versions, but enable applications to require a certain minimum version before it may proceed.

Typical uses look like: 

       /* Check version of libgcrypt. */
       if (!gcry_check_version (GCRYPT_VERSION))
         die ("version mismatch\n");

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17.19 Supporting Relocation

It has been a pain for many users of GNU packages for a long time that packages are not relocatable. It means a user cannot copy a program, installed by another user on the same machine, to his home directory, and have it work correctly (including i18n). So many users need to go through configure; make; make install with all its dependencies, options, and hurdles.

Red Hat, Debian, and other binary distributions solve the “ease of installation” problem, but they hardwire path names, usually to /usr or /usr/local. This means that users need root privileges to install a binary package, and prevents installing two different versions of the same binary package.

A relocatable program can be moved or copied to a different location on the file system. It is possible to make symlinks to the installed and moved programs, and invoke them through the symlink. It is possible to do the same thing with a hard link only if the hard link file is in the same directory as the real program.

The relocatable-prog module aims to ease the process of making a GNU program relocatable. It helps overcome two obstacles. First, it aids with relocating the hard-coded references to absolute file names that GNU programs often contain. These references must be fixed up at runtime if a program is to be successfully relocated. The relocatable-prog module provides a function relocate that does this job.

Second, the loader must be able to find shared libraries linked to relocatable executables or referenced by other shared libraries linked to relocatable executables. The relocatable-prog module helps out here in a platform-specific way:

  • On most operating systems, it adds a linker option (-rpath) that causes the dynamic linker to search for libraries in a directory relative to the location of the invoked executable. This works on GNU/Linux and modern versions of GNU/Hurd, GNU/kFreeBSD, macOS, FreeBSD, NetBSD, OpenBSD, Solaris, Haiku.
  • On other Unix systems, it installs a trampoline executable. The trampoline sets the environment variable that controls shared library searching (usually LD_LIBRARY_PATH) and then invokes the real executable. This applies to operating systems such as AIX, HP-UX, or Minix.
  • On Windows, the executable’s own directory is searched for libraries, so installing shared libraries into the executable’s directory is sufficient.

You can make your program relocatable by following these steps:

  1. Import the relocatable-prog module. For libraries, use the relocatable-lib or relocatable-lib-lgpl module, if the libraries are independent. For installing multiple libraries, at least one of which depends on another one, use the relocatable-prog module. If you need more than one module, or you need to use them with different settings, you will need multiple copies of gnulib (see Using Gnulib for both a library and a program).
  2. In every program, add to main as the first statement (even before setting the locale or doing anything related to libintl): 
    set_program_name (argv[0]);

    The prototype for this function is in progname.h.

  3. If you want your code to be portable to platforms that do not support automatic initialization, call set_relocation_prefix.
  4. Everywhere where you use a constant pathname from installation-time, wrap it in relocate so it gets translated to the run-time situation. Example: 
    bindtextdomain (PACKAGE, LOCALEDIR);

    becomes: 

    bindtextdomain (PACKAGE, relocate (LOCALEDIR));

    The prototype for this function is in relocatable.h.

    There is also a variant of this function, named relocate2, that makes it easy to reclaim the memory allocated by the call.

  5. The set_program_name function can also configure some additional libraries to relocate files that they access, by defining corresponding C preprocessor symbols to 1. The libraries for which this is supported and the corresponding preprocessor symbols are:
    libcharset

    DEPENDS_ON_LIBCHARSET

    libiconv

    DEPENDS_ON_LIBICONV

    libintl

    DEPENDS_ON_LIBINTL

    Defining the symbol for a library makes every program in the package depend on that library, whether the program really uses the library or not, so this feature should be used with some caution.

  6. If your package installs shell scripts, also import the relocatable-script module. Then, near the beginning of each shell script that your package installs, add the following: 
    @relocatable_sh@

prefix="@prefix@"
exec_prefix="@exec_prefix@"   # usually needs $prefix.
datarootdir="@datarootdir@"   # usually needs $prefix.

if test "@RELOCATABLE@" = yes; then
  bindir="@bindir@"
  orig_installdir="$bindir" # see Makefile.am's *_SCRIPTS variables
  func_find_curr_installdir # determine curr_installdir
  func_find_prefixes
  relocate () {
    echo "$1/" \
    | sed -e "s%^${orig_installprefix}/%${curr_installprefix}/%" \
    | sed -e 's,/$,,'
  }
else
  relocate () {
    echo "$1"
  }
fi

# Get some relocated directory names.
sysconfdir=`relocate "@sysconfdir@"`          # usually needs $prefix.
some_datadir=`relocate "@datadir@/something"` # usually needs $datarootdir.
bindir=`relocate "@bindir@"`       # usually needs $exec_prefix, hence $prefix.

    You must adapt the definition of orig_installdir, depending on where the script gets installed. Also, at the end, instead of sysconfdir and some_datadir, transform those variables that you need.

  7. If your package installs Perl scripts, also import the relocatable-perl module. Then, near the beginning of each Perl script that your package installs, add the following: 
    @relocatable_pl@
if ("@RELOCATABLE@" eq "yes") {
  my $exec_prefix = "@exec_prefix@";
  my $orig_installdir = "@bindir@"; # see Makefile.am's *_SCRIPTS variables
  my ($orig_installprefix, $curr_installprefix) =
    find_prefixes($orig_installdir, find_curr_installdir());

  # the subroutine is defined whether or not the enclosing block is executed
  sub relocate {
    my ($dir) = @_;
    if ("@RELOCATABLE@" eq "yes") {
      $dir =~ s%^$orig_installprefix/%$curr_installprefix/%;
      $dir =~ s,/$,,;
    }
    return $dir;
  }
}

# Get some relocated directory names.
# (The gnulib module 'configmake' can help with this.)
$sysconfdir = relocate("@sysconfdir@");
$some_datadir = relocate(@datadir@/something");

    You must adapt the definition of $orig_installdir, depending on where the script gets installed. Also, at the end, instead of sysconfdir and some_datadir, transform those variables that you need.

  8. In your Makefile.am, for every program foo that gets installed in, say, $(bindir), you add: 
    foo_CPPFLAGS = -DINSTALLDIR=\"$(bindir)\"
if RELOCATABLE_VIA_LD
foo_LDFLAGS = `$(RELOCATABLE_LDFLAGS) $(bindir)`
endif

    When building gnulib to use with a relocatable library, you need to define the preprocessor symbol IN_LIBRARY. You may also want to build with ENABLE_COSTLY_RELOCATABLE, in which case you will also need to define INSTALLDIR. The following fragment can be added to an override Makefile.am used to build gnulib (see Modifying the build rules of a Gnulib import directory). 

    AM_CPPFLAGS += -DIN_LIBRARY -DENABLE_COSTLY_RELOCATABLE

if SHLIBS_IN_BINDIR
AM_CPPFLAGS += -DINSTALLDIR=\"$(bindir)\"
else
AM_CPPFLAGS += -DINSTALLDIR=\"$(libdir)\"
endif

    SHLIBS_IN_BINDIR is defined in configure.ac as follows: 

    AM_CONDITIONAL([SHLIBS_IN_BINDIR],
               [case "$host_os" in mingw* | cygwin*) true;; *) false;; esac])
  9. In your Makefile.am, for every library libfoo that gets installed in, say, $(libdir), you add: 
    if RELOCATABLE_VIA_LD
libfoo_la_LDFLAGS = `$(RELOCATABLE_LDFLAGS) $(libdir)`
endif
  10. Add a couple of variable assignments to your Makefile.am.

    If your package (or any package you rely on, e.g. gettext-runtime) will be relocated together with a set of installed shared libraries, then set RELOCATABLE_LIBRARY_PATH to a colon-separated list of those libraries’ directories, e.g. 

    RELOCATABLE_LIBRARY_PATH = $(libdir)

    If your config.h is not in $(top_builddir), then set RELOCATABLE_CONFIG_H_DIR to its directory, e.g. 

    RELOCATABLE_CONFIG_H_DIR = $(top_builddir)/src

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17.20 func

The func module makes sure that you can use the predefined identifier __func__ as defined by C99 in your code.

A small example is: 

#include <config.h>
#include <stdio.h> /* for printf */

int main (void)
{
    printf ("%s: hello world\n", __func__);
}

Note that sizeof cannot be applied to __func__: On SunPRO C compiler, sizeof __func__ evaluates to 0.

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17.21 stat-size

The stat-size module provides a small number of macros intended for interpreting the file size information in an instance of struct stat.

On POSIX systems, the st_blocks member of struct stat contains the number of disk blocks occupied by a file. The ST_NBLOCKS and STP_NBLOCKS macros estimate this quantity on systems which don’t actually have st_blocks. Each of these blocks contains ST_NBLOCKSIZE bytes.

The value of ST_NBLOCKSIZE is often quite small, small enough that performing I/O in chunks that size would be inefficient. The ST_BLKSIZE and STP_BLKSIZE macros give the I/O block size recommended for I/O to this file. This is not guaranteed to give optimum performance, but it should be reasonably efficient.

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18 Regular expressions

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18.1 Overview

A regular expression (or regexp, or pattern) is a text string that describes some (mathematical) set of strings. A regexp r matches a string s if s is in the set of strings described by r.

Using the Regex library, you can:

  • see if a string matches a specified pattern as a whole, and
  • search within a string for a substring matching a specified pattern.

Some regular expressions match only one string, i.e., the set they describe has only one member. For example, the regular expression ‘foo’ matches the string ‘foo’ and no others. Other regular expressions match more than one string, i.e., the set they describe has more than one member. For example, the regular expression ‘f*’ matches the set of strings made up of any number (including zero) of ‘f’s. As you can see, some characters in regular expressions match themselves (such as ‘f’) and some don’t (such as ‘*’); the ones that don’t match themselves instead let you specify patterns that describe many different strings.

To either match or search for a regular expression with the Regex library functions, you must first compile it with a Regex pattern compiling function. A compiled pattern is a regular expression converted to the internal format used by the library functions. Once you’ve compiled a pattern, you can use it for matching or searching any number of times.

The Regex library is used by including regex.h. Regex provides three groups of functions with which you can operate on regular expressions. One group—the GNU group—is more powerful but not completely compatible with the other two, namely the POSIX and Berkeley Unix groups; its interface was designed specifically for GNU.

We wrote this chapter with programmers in mind, not users of programs—such as Emacs—that use Regex. We describe the Regex library in its entirety, not how to write regular expressions that a particular program understands.

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18.2 Regular Expression Syntax

Characters are things you can type. Operators are things in a regular expression that match one or more characters. You compose regular expressions from operators, which in turn you specify using one or more characters.

Most characters represent what we call the match-self operator, i.e., they match themselves; we call these characters ordinary. Other characters represent either all or parts of fancier operators; e.g., ‘.’ represents what we call the match-any-character operator (which, no surprise, matches (almost) any character); we call these characters special. Two different things determine what characters represent what operators:

  1. the regular expression syntax your program has told the Regex library to recognize, and
  2. the context of the character in the regular expression.

In the following sections, we describe these things in more detail.

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18.2.1 Syntax Bits

In any particular syntax for regular expressions, some characters are always special, others are sometimes special, and others are never special. The particular syntax that Regex recognizes for a given regular expression depends on the current syntax (as set by re_set_syntax) when the pattern buffer of that regular expression was compiled.

You get a pattern buffer by compiling a regular expression. See GNU Pattern Buffers, for more information on pattern buffers. See GNU Regular Expression Compiling, and BSD Regular Expression Compiling, for more information on compiling.

Regex considers the current syntax to be a collection of bits; we refer to these bits as syntax bits. In most cases, they affect what characters represent what operators. We describe the meanings of the operators to which we refer in Common Operators and GNU Operators.

For reference, here is the complete list of syntax bits, in alphabetical order:

RE_BACKSLASH_ESCAPE_IN_LISTS

If this bit is set, then ‘\’ inside a list (see List Operators ([ … ] and [^ … ])) quotes (makes ordinary, if it’s special) the following character; if this bit isn’t set, then ‘\’ is an ordinary character inside lists. (See The Backslash Character, for what ‘\’ does outside of lists.)

RE_BK_PLUS_QM

If this bit is set, then ‘\+’ represents the match-one-or-more operator and ‘\?’ represents the match-zero-or-more operator; if this bit isn’t set, then ‘+’ represents the match-one-or-more operator and ‘?’ represents the match-zero-or-one operator. This bit is irrelevant if RE_LIMITED_OPS is set.

RE_CHAR_CLASSES

If this bit is set, then you can use character classes in lists; if this bit isn’t set, then you can’t.

RE_CONTEXT_INDEP_ANCHORS

If this bit is set, then ‘^’ and ‘$’ are special anywhere outside a list; if this bit isn’t set, then these characters are special only in certain contexts. See The Match-beginning-of-line Operator (^), and The Match-end-of-line Operator ($).

RE_CONTEXT_INDEP_OPS

If this bit is set, then certain characters are special anywhere outside a list; if this bit isn’t set, then those characters are special only in some contexts and are ordinary elsewhere. Specifically, if this bit isn’t set then ‘*’, and (if the syntax bit RE_LIMITED_OPS isn’t set) ‘+’ and ‘?’ (or ‘\+’ and ‘\?’, depending on the syntax bit RE_BK_PLUS_QM) represent repetition operators only if they’re not first in a regular expression or just after an open-group or alternation operator. The same holds for ‘{’ (or ‘\{’, depending on the syntax bit RE_NO_BK_BRACES) if it is the beginning of a valid interval and the syntax bit RE_INTERVALS is set.

RE_CONTEXT_INVALID_DUP

If this bit is set, then an open-interval operator cannot occur at the start of a regular expression, or immediately after an alternation, open-group or close-interval operator.

RE_CONTEXT_INVALID_OPS

If this bit is set, then repetition and alternation operators can’t be in certain positions within a regular expression. Specifically, the regular expression is invalid if it has:

  • a repetition operator first in the regular expression or just after a match-beginning-of-line, open-group, or alternation operator; or
  • an alternation operator first or last in the regular expression, just before a match-end-of-line operator, or just after an alternation or open-group operator.

If this bit isn’t set, then you can put the characters representing the repetition and alternation characters anywhere in a regular expression. Whether or not they will in fact be operators in certain positions depends on other syntax bits.

RE_DEBUG

If this bit is set, and the regex library was compiled with -DDEBUG, then internal debugging is turned on; if unset, then it is turned off.

RE_DOT_NEWLINE

If this bit is set, then the match-any-character operator matches a newline; if this bit isn’t set, then it doesn’t.

RE_DOT_NOT_NULL

If this bit is set, then the match-any-character operator doesn’t match a null character; if this bit isn’t set, then it does.

RE_HAT_LISTS_NOT_NEWLINE

If this bit is set, nonmatching lists ‘[^...]’ do not match newline; if not set, they do.

RE_ICASE

If this bit is set, then ignore case when matching; otherwise, case is significant.

RE_INTERVALS

If this bit is set, then Regex recognizes interval operators; if this bit isn’t set, then it doesn’t.

RE_INVALID_INTERVAL_ORD

If this bit is set, a syntactically invalid interval is treated as a string of ordinary characters. For example, the extended regular expression ‘a{1’ is treated as ‘a\{1’.

RE_LIMITED_OPS

If this bit is set, then Regex doesn’t recognize the match-one-or-more, match-zero-or-one or alternation operators; if this bit isn’t set, then it does.

RE_NEWLINE_ALT

If this bit is set, then newline represents the alternation operator; if this bit isn’t set, then newline is ordinary.

RE_NO_BK_BRACES

If this bit is set, then ‘{’ represents the open-interval operator and ‘}’ represents the close-interval operator; if this bit isn’t set, then ‘\{’ represents the open-interval operator and ‘\}’ represents the close-interval operator. This bit is relevant only if RE_INTERVALS is set.

RE_NO_BK_PARENS

If this bit is set, then ‘(’ represents the open-group operator and ‘)’ represents the close-group operator; if this bit isn’t set, then ‘\(’ represents the open-group operator and ‘\)’ represents the close-group operator.

RE_NO_BK_REFS

If this bit is set, then Regex doesn’t recognize ‘\’digit as the back-reference operator; if this bit isn’t set, then it does.

RE_NO_BK_VBAR

If this bit is set, then ‘|’ represents the alternation operator; if this bit isn’t set, then ‘\|’ represents the alternation operator. This bit is irrelevant if RE_LIMITED_OPS is set.

RE_NO_EMPTY_RANGES

If this bit is set, then a regular expression with a range whose ending point collates lower than its starting point is invalid; if this bit isn’t set, then Regex considers such a range to be empty.

RE_NO_GNU_OPS

If this bit is set, GNU regex operators are not recognized; otherwise, they are.

RE_NO_POSIX_BACKTRACKING

If this bit is set, succeed as soon as we match the whole pattern, without further backtracking. This means that a match may not be the leftmost longest; see What Gets Matched? for what this means.

RE_NO_SUB

If this bit is set, then no_sub will be set to one during re_compile_pattern. This causes matching and searching routines not to record substring match information.

RE_UNMATCHED_RIGHT_PAREN_ORD

If this bit is set and the regular expression has no matching open-group operator, then Regex considers what would otherwise be a close-group operator (based on how RE_NO_BK_PARENS is set) to match ‘)’.

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18.2.2 Predefined Syntaxes

If you’re programming with Regex, you can set a pattern buffer’s (see GNU Pattern Buffers) syntax either to an arbitrary combination of syntax bits (see Syntax Bits) or else to the configurations defined by Regex. These configurations define the syntaxes used by certain programs—GNU Emacs, POSIX Awk, traditional Awk, Grep, Egrep—in addition to syntaxes for POSIX basic and extended regular expressions.

The predefined syntaxes—taken directly from regex.h—are: 

#define RE_SYNTAX_EMACS 0

#define RE_SYNTAX_AWK                                                   \
  (RE_BACKSLASH_ESCAPE_IN_LISTS | RE_DOT_NOT_NULL                       \
   | RE_NO_BK_PARENS            | RE_NO_BK_REFS                         \
   | RE_NO_BK_VBAR               | RE_NO_EMPTY_RANGES                   \
   | RE_UNMATCHED_RIGHT_PAREN_ORD)

#define RE_SYNTAX_POSIX_AWK                                             \
  (RE_SYNTAX_POSIX_EXTENDED | RE_BACKSLASH_ESCAPE_IN_LISTS)

#define RE_SYNTAX_GREP                                                  \
  (RE_BK_PLUS_QM              | RE_CHAR_CLASSES                         \
   | RE_HAT_LISTS_NOT_NEWLINE | RE_INTERVALS                            \
   | RE_NEWLINE_ALT)

#define RE_SYNTAX_EGREP                                                 \
  (RE_CHAR_CLASSES        | RE_CONTEXT_INDEP_ANCHORS                    \
   | RE_CONTEXT_INDEP_OPS | RE_HAT_LISTS_NOT_NEWLINE                    \
   | RE_NEWLINE_ALT       | RE_NO_BK_PARENS                             \
   | RE_NO_BK_VBAR)

#define RE_SYNTAX_POSIX_EGREP                                           \
  (RE_SYNTAX_EGREP | RE_INTERVALS | RE_NO_BK_BRACES)

/* P1003.2/D11.2, section 4.20.7.1, lines 5078ff.  */
#define RE_SYNTAX_ED RE_SYNTAX_POSIX_BASIC

#define RE_SYNTAX_SED RE_SYNTAX_POSIX_BASIC

/* Syntax bits common to both basic and extended POSIX regex syntax.  */
#define _RE_SYNTAX_POSIX_COMMON                                         \
  (RE_CHAR_CLASSES | RE_DOT_NEWLINE      | RE_DOT_NOT_NULL              \
   | RE_INTERVALS  | RE_NO_EMPTY_RANGES)

#define RE_SYNTAX_POSIX_BASIC                                           \
  (_RE_SYNTAX_POSIX_COMMON | RE_BK_PLUS_QM)

/* Differs from ..._POSIX_BASIC only in that RE_BK_PLUS_QM becomes
   RE_LIMITED_OPS, i.e., \? \+ \| are not recognized.  Actually, this
   isn't minimal, since other operators, such as \`, aren't disabled.  */
#define RE_SYNTAX_POSIX_MINIMAL_BASIC                                   \
  (_RE_SYNTAX_POSIX_COMMON | RE_LIMITED_OPS)

#define RE_SYNTAX_POSIX_EXTENDED                                        \
  (_RE_SYNTAX_POSIX_COMMON | RE_CONTEXT_INDEP_ANCHORS                   \
   | RE_CONTEXT_INDEP_OPS  | RE_NO_BK_BRACES                            \
   | RE_NO_BK_PARENS       | RE_NO_BK_VBAR                              \
   | RE_UNMATCHED_RIGHT_PAREN_ORD)

/* Differs from ..._POSIX_EXTENDED in that RE_CONTEXT_INVALID_OPS
   replaces RE_CONTEXT_INDEP_OPS and RE_NO_BK_REFS is added.  */
#define RE_SYNTAX_POSIX_MINIMAL_EXTENDED                                \
  (_RE_SYNTAX_POSIX_COMMON  | RE_CONTEXT_INDEP_ANCHORS                  \
   | RE_CONTEXT_INVALID_OPS | RE_NO_BK_BRACES                           \
   | RE_NO_BK_PARENS        | RE_NO_BK_REFS                             \
   | RE_NO_BK_VBAR          | RE_UNMATCHED_RIGHT_PAREN_ORD)

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18.2.3 Collating Elements vs. Characters

POSIX generalizes the notion of a character to that of a collating element. It defines a collating element to be “a sequence of one or more bytes defined in the current collating sequence as a unit of collation.”

This generalizes the notion of a character in two ways. First, a single character can map into two or more collating elements. For example, the German “ß” collates as the collating element ‘s’ followed by another collating element ‘s’. Second, two or more characters can map into one collating element. For example, the Czech ‘ch’ collates after ‘h’ and before ‘i’.

Since POSIX’s “collating element” preserves the essential idea of a “character,” we use the latter, more familiar, term in this document.

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18.2.4 The Backslash Character

The ‘\’ character has one of four different meanings, depending on the context in which you use it and what syntax bits are set (see Syntax Bits). It can: 1) stand for itself, 2) quote the next character, 3) introduce an operator, or 4) do nothing.

  1. It stands for itself inside a list (see List Operators ([ … ] and [^ … ])) if the syntax bit RE_BACKSLASH_ESCAPE_IN_LISTS is not set. For example, ‘[\]’ would match ‘\’.
  2. It quotes (makes ordinary, if it’s special) the next character when you use it either:
    • outside a list,3 or
    • inside a list and the syntax bit RE_BACKSLASH_ESCAPE_IN_LISTS is set.
  3. It introduces an operator when followed by certain ordinary characters—sometimes only when certain syntax bits are set. See the cases RE_BK_PLUS_QM, RE_NO_BK_BRACES, RE_NO_BK_VAR, RE_NO_BK_PARENS, RE_NO_BK_REF in Syntax Bits. Also:
  4. In all other cases, Regex ignores ‘\’. For example, ‘\n’ matches ‘n’.

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18.3 Common Operators

You compose regular expressions from operators. In the following sections, we describe the regular expression operators specified by POSIX; GNU also uses these. Most operators have more than one representation as characters. See Regular Expression Syntax, for what characters represent what operators under what circumstances.

For most operators that can be represented in two ways, one representation is a single character and the other is that character preceded by ‘\’. For example, either ‘(’ or ‘\(’ represents the open-group operator. Which one does depends on the setting of a syntax bit, in this case RE_NO_BK_PARENS. Why is this so? Historical reasons dictate some of the varying representations, while POSIX dictates others.

Finally, almost all characters lose any special meaning inside a list (see List Operators ([ … ] and [^ … ])).

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18.3.1 The Match-self Operator (ordinary character)

This operator matches the character itself. All ordinary characters (see Regular Expression Syntax) represent this operator. For example, ‘f’ is always an ordinary character, so the regular expression ‘f’ matches only the string ‘f’. In particular, it does not match the string ‘ff’.

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18.3.2 The Match-any-character Operator (.)

This operator matches any single printing or nonprinting character except it won’t match a:

newline

if the syntax bit RE_DOT_NEWLINE isn’t set.

null

if the syntax bit RE_DOT_NOT_NULL is set.

The ‘.’ (period) character represents this operator. For example, ‘a.b’ matches any three-character string beginning with ‘a’ and ending with ‘b’.

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18.3.3 The Concatenation Operator

This operator concatenates two regular expressions a and b. No character represents this operator; you simply put b after a. The result is a regular expression that will match a string if a matches its first part and b matches the rest. For example, ‘xy’ (two match-self operators) matches ‘xy’.

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18.3.4 Repetition Operators

Repetition operators repeat the preceding regular expression a specified number of times.

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18.3.4.1 The Match-zero-or-more Operator (*)

This operator repeats the smallest possible preceding regular expression as many times as necessary (including zero) to match the pattern. ‘*’ represents this operator. For example, ‘o*’ matches any string made up of zero or more ‘o’s. Since this operator operates on the smallest preceding regular expression, ‘fo*’ has a repeating ‘o’, not a repeating ‘fo’. So, ‘fo*’ matches ‘f’, ‘fo’, ‘foo’, and so on.

Since the match-zero-or-more operator is a suffix operator, it may be useless as such when no regular expression precedes it. This is the case when it:

  • is first in a regular expression, or
  • follows a match-beginning-of-line, open-group, or alternation operator.

Three different things can happen in these cases:

  1. If the syntax bit RE_CONTEXT_INVALID_OPS is set, then the regular expression is invalid.
  2. If RE_CONTEXT_INVALID_OPS isn’t set, but RE_CONTEXT_INDEP_OPS is, then ‘*’ represents the match-zero-or-more operator (which then operates on the empty string).
  3. Otherwise, ‘*’ is ordinary.

The matcher processes a match-zero-or-more operator by first matching as many repetitions of the smallest preceding regular expression as it can. Then it continues to match the rest of the pattern.

If it can’t match the rest of the pattern, it backtracks (as many times as necessary), each time discarding one of the matches until it can either match the entire pattern or be certain that it cannot get a match. For example, when matching ‘ca*ar’ against ‘caaar’, the matcher first matches all three ‘a’s of the string with the ‘a*’ of the regular expression. However, it cannot then match the final ‘ar’ of the regular expression against the final ‘r’ of the string. So it backtracks, discarding the match of the last ‘a’ in the string. It can then match the remaining ‘ar’.

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18.3.4.2 The Match-one-or-more Operator (+ or \+)

If the syntax bit RE_LIMITED_OPS is set, then Regex doesn’t recognize this operator. Otherwise, if the syntax bit RE_BK_PLUS_QM isn’t set, then ‘+’ represents this operator; if it is, then ‘\+’ does.

This operator is similar to the match-zero-or-more operator except that it repeats the preceding regular expression at least once; see The Match-zero-or-more Operator (*), for what it operates on, how some syntax bits affect it, and how Regex backtracks to match it.

For example, supposing that ‘+’ represents the match-one-or-more operator; then ‘ca+r’ matches, e.g., ‘car’ and ‘caaaar’, but not ‘cr’.

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18.3.4.3 The Match-zero-or-one Operator (? or \?)

If the syntax bit RE_LIMITED_OPS is set, then Regex doesn’t recognize this operator. Otherwise, if the syntax bit RE_BK_PLUS_QM isn’t set, then ‘?’ represents this operator; if it is, then ‘\?’ does.

This operator is similar to the match-zero-or-more operator except that it repeats the preceding regular expression once or not at all; see The Match-zero-or-more Operator (*), to see what it operates on, how some syntax bits affect it, and how Regex backtracks to match it.

For example, supposing that ‘?’ represents the match-zero-or-one operator; then ‘ca?r’ matches both ‘car’ and ‘cr’, but nothing else.

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18.3.4.4 Interval Operators ({ … } or \{ … \})

If the syntax bit RE_INTERVALS is set, then Regex recognizes interval expressions. They repeat the smallest possible preceding regular expression a specified number of times.

If the syntax bit RE_NO_BK_BRACES is set, ‘{’ represents the open-interval operator and ‘}’ represents the close-interval operator ; otherwise, ‘\{’ and ‘\}’ do.

Specifically, supposing that ‘{’ and ‘}’ represent the open-interval and close-interval operators; then:

{count}

matches exactly count occurrences of the preceding regular expression.

{min,}

matches min or more occurrences of the preceding regular expression.

{min, max}

matches at least min but no more than max occurrences of the preceding regular expression.

The interval expression (but not necessarily the regular expression that contains it) is invalid if:

  • min is greater than max, or
  • any of count, min, or max are outside the range zero to RE_DUP_MAX (which symbol regex.h defines).

If the interval expression is invalid and the syntax bit RE_NO_BK_BRACES is set, then Regex considers all the characters in the would-be interval to be ordinary. If that bit isn’t set, then the regular expression is invalid.

If the interval expression is valid but there is no preceding regular expression on which to operate, then if the syntax bit RE_CONTEXT_INVALID_OPS is set, the regular expression is invalid. If that bit isn’t set, then Regex considers all the characters—other than backslashes, which it ignores—in the would-be interval to be ordinary.

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18.3.5 The Alternation Operator (| or \|)

If the syntax bit RE_LIMITED_OPS is set, then Regex doesn’t recognize this operator. Otherwise, if the syntax bit RE_NO_BK_VBAR is set, then ‘|’ represents this operator; otherwise, ‘\|’ does.

Alternatives match one of a choice of regular expressions: if you put the character(s) representing the alternation operator between any two regular expressions a and b, the result matches the union of the strings that a and b match. For example, supposing that ‘|’ is the alternation operator, then ‘foo|bar|quux’ would match any of ‘foo’, ‘bar’ or ‘quux’.

The alternation operator operates on the largest possible surrounding regular expressions. (Put another way, it has the lowest precedence of any regular expression operator.) Thus, the only way you can delimit its arguments is to use grouping. For example, if ‘(’ and ‘)’ are the open and close-group operators, then ‘fo(o|b)ar’ would match either ‘fooar’ or ‘fobar’. (‘foo|bar’ would match ‘foo’ or ‘bar’.)

The matcher usually tries all combinations of alternatives so as to match the longest possible string. For example, when matching ‘(fooq|foo)*(qbarquux|bar)’ against ‘fooqbarquux’, it cannot take, say, the first (“depth-first”) combination it could match, since then it would be content to match just ‘fooqbar’.

Note that since the default behavior is to return the leftmost longest match, when more than one of a series of alternatives matches the actual match will be the longest matching alternative, not necessarily the first in the list.

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18.3.6 List Operators ([ … ] and [^ … ])

Lists, also called bracket expressions, are a set of one or more items. An item is a character, a collating symbol, an equivalence class expression, a character class expression, or a range expression. The syntax bits affect which kinds of items you can put in a list. We explain the last four items in subsections below. Empty lists are invalid.

A matching list matches a single character represented by one of the list items. You form a matching list by enclosing one or more items within an open-matching-list operator (represented by ‘[’) and a close-list operator (represented by ‘]’).

For example, ‘[ab]’ matches either ‘a’ or ‘b’. ‘[ad]*’ matches the empty string and any string composed of just ‘a’s and ‘d’s in any order. Regex considers invalid a regular expression with a ‘[’ but no matching ‘]’.

Nonmatching lists are similar to matching lists except that they match a single character not represented by one of the list items. You use an open-nonmatching-list operator (represented by ‘[^’4) instead of an open-matching-list operator to start a nonmatching list.

For example, ‘[^ab]’ matches any character except ‘a’ or ‘b’.

If the syntax bit RE_HAT_LISTS_NOT_NEWLINE is set, then nonmatching lists do not match a newline.

Most characters lose any special meaning inside a list. The special characters inside a list follow.

‘]’

ends the list if it’s not the first list item. So, if you want to make the ‘]’ character a list item, you must put it first.

‘\’

quotes the next character if the syntax bit RE_BACKSLASH_ESCAPE_IN_LISTS is set.

‘[.’

represents the open-collating-symbol operator (see Collating Symbol Operators ([. … .])).

‘.]’

represents the close-collating-symbol operator.

‘[=’

represents the open-equivalence-class operator (see Equivalence Class Operators ([= … =])).

‘=]’

represents the close-equivalence-class operator.

‘[:’

represents the open-character-class operator (see Character Class Operators ([: … :])) if the syntax bit RE_CHAR_CLASSES is set and what follows is a valid character class expression.

‘:]’

represents the close-character-class operator if the syntax bit RE_CHAR_CLASSES is set and what precedes it is an open-character-class operator followed by a valid character class name.

‘-’

represents the range operator (see The Range Operator (-)) if it’s not first or last in a list or the ending point of a range.

All other characters are ordinary. For example, ‘[.*]’ matches ‘.’ and ‘*’.

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18.3.6.1 Collating Symbol Operators ([. … .])

Collating symbols can be represented inside lists. You form a collating symbol by putting a collating element between an open-collating-symbol operator and a close-collating-symbol operator. ‘[.’ represents the open-collating-symbol operator and ‘.]’ represents the close-collating-symbol operator. For example, if ‘ll’ is a collating element, then ‘[[.ll.]]’ would match ‘ll’.

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18.3.6.2 Equivalence Class Operators ([= … =])

Regex recognizes equivalence class expressions inside lists. A equivalence class expression is a set of collating elements which all belong to the same equivalence class. You form an equivalence class expression by putting a collating element between an open-equivalence-class operator and a close-equivalence-class operator. ‘[=’ represents the open-equivalence-class operator and ‘=]’ represents the close-equivalence-class operator. For example, if ‘a’ and ‘A’ were an equivalence class, then both ‘[[=a=]]’ and ‘[[=A=]]’ would match both ‘a’ and ‘A’. If the collating element in an equivalence class expression isn’t part of an equivalence class, then the matcher considers the equivalence class expression to be a collating symbol.

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18.3.6.3 Character Class Operators ([: … :])

If the syntax bit RE_CHAR_CLASSES is set, then Regex recognizes character class expressions inside lists. A character class expression matches one character from a given class. You form a character class expression by putting a character class name between an open-character-class operator (represented by ‘[:’) and a close-character-class operator (represented by ‘:]’). The character class names and their meanings are:

alnum

letters and digits

alpha

letters

blank

system-dependent; for GNU, a space or tab

cntrl

control characters (in the ASCII encoding, code 0177 and codes less than 040)

digit

digits

graph

same as print except omits space

lower

lowercase letters

print

printable characters (in the ASCII encoding, space tilde—codes 040 through 0176)

punct

neither control nor alphanumeric characters

space

space, carriage return, newline, vertical tab, and form feed

upper

uppercase letters

xdigit

hexadecimal digits: 0–9, a–f, A–F

These correspond to the definitions in the C library’s <ctype.h> facility. For example, ‘[:alpha:]’ corresponds to the standard facility isalpha. Regex recognizes character class expressions only inside of lists; so ‘[[:alpha:]]’ matches any letter, but ‘[:alpha:]’ outside of a bracket expression and not followed by a repetition operator matches just itself.

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18.3.6.4 The Range Operator (-)

Regex recognizes range expressions inside a list. They represent those characters that fall between two elements in the current collating sequence. You form a range expression by putting a range operator between two of any of the following: characters, collating elements, collating symbols, and equivalence class expressions. The starting point of the range and the ending point of the range don’t have to be the same kind of item, e.g., the starting point could be a collating element and the ending point could be an equivalence class expression. If a range’s ending point is an equivalence class, then all the collating elements in that class will be in the range.5 ‘-’ represents the range operator. For example, ‘a-f’ within a list represents all the characters from ‘a’ through ‘f’ inclusively.

If the syntax bit RE_NO_EMPTY_RANGES is set, then if the range’s ending point collates less than its starting point, the range (and the regular expression containing it) is invalid. For example, the regular expression ‘[z-a]’ would be invalid. If this bit isn’t set, then Regex considers such a range to be empty.

Since ‘-’ represents the range operator, if you want to make a ‘-’ character itself a list item, you must do one of the following:

  • Put the ‘-’ either first or last in the list.
  • Include a range whose starting point collates strictly lower than ‘-’ and whose ending point collates equal or higher. Unless a range is the first item in a list, a ‘-’ can’t be its starting point, but can be its ending point. That is because Regex considers ‘-’ to be the range operator unless it is preceded by another ‘-’. For example, in the ASCII encoding, ‘)’, ‘*’, ‘+’, ‘,’, ‘-’, ‘.’, and ‘/’ are contiguous characters in the collating sequence. You might think that ‘[)-+--/]’ has two ranges: ‘)-+’ and ‘--/’. Rather, it has the ranges ‘)-+’ and ‘+--’, plus the character ‘/’, so it matches, e.g., ‘,’, not ‘.’.
  • Put a range whose starting point is ‘-’ first in the list.

For example, ‘[-a-z]’ matches a lowercase letter or a hyphen (in English, in ASCII).

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18.3.7 Grouping Operators (( … ) or \( … \))

A group, also known as a subexpression, consists of an open-group operator, any number of other operators, and a close-group operator. Regex treats this sequence as a unit, just as mathematics and programming languages treat a parenthesized expression as a unit.

Therefore, using groups, you can:

If the syntax bit RE_NO_BK_PARENS is set, then ‘(’ represents the open-group operator and ‘)’ represents the close-group operator; otherwise, ‘\(’ and ‘\)’ do.

If the syntax bit RE_UNMATCHED_RIGHT_PAREN_ORD is set and a close-group operator has no matching open-group operator, then Regex considers it to match ‘)’.

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18.3.8 The Back-reference Operator (\digit)

If the syntax bit RE_NO_BK_REF isn’t set, then Regex recognizes back-references. A back-reference matches a specified preceding group. The back-reference operator is represented by ‘\digit’ anywhere after the end of a regular expression’s digit-th group (see Grouping Operators (( … ) or \( … \))).

digit must be between ‘1’ and ‘9’. The matcher assigns numbers 1 through 9 to the first nine groups it encounters. By using one of ‘\1’ through ‘\9’ after the corresponding group’s close-group operator, you can match a substring identical to the one that the group does.

Back-references match according to the following (in all examples below, ‘(’ represents the open-group, ‘)’ the close-group, ‘{’ the open-interval and ‘}’ the close-interval operator):

  • If the group matches a substring, the back-reference matches an identical substring. For example, ‘(a)\1’ matches ‘aa’ and ‘(bana)na\1bo\1’ matches ‘bananabanabobana’. Likewise, ‘(.*)\1’ matches any (newline-free if the syntax bit RE_DOT_NEWLINE isn’t set) string that is composed of two identical halves; the ‘(.*)’ matches the first half and the ‘\1’ matches the second half.
  • If the group matches more than once (as it might if followed by, e.g., a repetition operator), then the back-reference matches the substring the group last matched. For example, ‘((a*)b)*\1\2’ matches ‘aabababa’; first group 1 (the outer one) matches ‘aab’ and group 2 (the inner one) matches ‘aa’. Then group 1 matches ‘ab’ and group 2 matches ‘a’. So, ‘\1’ matches ‘ab’ and ‘\2’ matches ‘a’.
  • If the group doesn’t participate in a match, i.e., it is part of an alternative not taken or a repetition operator allows zero repetitions of it, then the back-reference makes the whole match fail. For example, ‘(one()|two())-and-(three\2|four\3)’ matches ‘one-and-three’ and ‘two-and-four’, but not ‘one-and-four’ or ‘two-and-three’. For example, if the pattern matches ‘one-and-’, then its group 2 matches the empty string and its group 3 doesn’t participate in the match. So, if it then matches ‘four’, then when it tries to back-reference group 3—which it will attempt to do because ‘\3’ follows the ‘four’—the match will fail because group 3 didn’t participate in the match.

You can use a back-reference as an argument to a repetition operator. For example, ‘(a(b))\2*’ matches ‘a’ followed by two or more ‘b’s. Similarly, ‘(a(b))\2{3}’ matches ‘abbbb’.

If there is no preceding digit-th subexpression, the regular expression is invalid.

Back-references can greatly slow down matching, as they can generate exponentially many matching possibilities that can consume both time and memory to explore. Also, the POSIX specification for back-references is at times unclear. Furthermore, many regular expression implementations have back-reference bugs that can cause programs to return incorrect answers or even crash, and fixing these bugs has often been low-priority: for example, as of 2020 the GNU C library bug database contained back-reference bugs 52, 10844, 11053, 24269 and 25322, with little sign of forthcoming fixes. Luckily, back-references are rarely useful and it should be little trouble to avoid them in practical applications.

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18.3.9 Anchoring Operators

These operators can constrain a pattern to match only at the beginning or end of the entire string or at the beginning or end of a line.

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18.3.9.1 The Match-beginning-of-line Operator (^)

This operator can match the empty string either at the beginning of the string or after a newline character. Thus, it is said to anchor the pattern to the beginning of a line.

In the cases following, ‘^’ represents this operator. (Otherwise, ‘^’ is ordinary.)

These rules imply that some valid patterns containing ‘^’ cannot be matched; for example, ‘foo^bar’ if RE_CONTEXT_INDEP_ANCHORS is set.

If the not_bol field is set in the pattern buffer (see GNU Pattern Buffers), then ‘^’ fails to match at the beginning of the string. This lets you match against pieces of a line, as you would need to if, say, searching for repeated instances of a given pattern in a line; it would work correctly for patterns both with and without match-beginning-of-line operators.

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18.3.9.2 The Match-end-of-line Operator ($)

This operator can match the empty string either at the end of the string or before a newline character in the string. Thus, it is said to anchor the pattern to the end of a line.

It is always represented by ‘$’. For example, ‘foo$’ usually matches, e.g., ‘foo’ and, e.g., the first three characters of ‘foo\nbar’.

Its interaction with the syntax bits and pattern buffer fields is exactly the dual of ‘^’’s; see the previous section. (That is, “‘^’” becomes “‘$’”, “beginning” becomes “end”, “next” becomes “previous”, “after” becomes “before”, and “not_bol” becomes “not_eol”.)

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18.4 GNU Operators

The following are operators that GNU defines (and POSIX doesn’t) that you can use unless the syntax bit RE_NO_GNU_OPS is set.

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18.4.1 Word Operators

The operators in this section require Regex to recognize parts of words. Characters that are part of words, which are called word-constituent, are letters, digits, and the underscore (‘_’); more precisely, any character in the POSIX class alnum in the current locale, or underscore.

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18.4.1.1 The Match-word-boundary Operator (\b)

This operator (represented by ‘\b’) matches the empty string at either the beginning or the end of a word. For example, ‘\brat\b’ matches the separate word ‘rat’.

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18.4.1.2 The Match-within-word Operator (\B)

This operator (represented by ‘\B’) matches the empty string within a word. For example, ‘c\Brat\Be’ matches ‘crate’, but ‘dirty \Brat’ doesn’t match ‘dirty rat’.

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18.4.1.3 The Match-beginning-of-word Operator (\<)

This operator (represented by ‘\<’) matches the empty string at the beginning of a word.

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18.4.1.4 The Match-end-of-word Operator (\>)

This operator (represented by ‘\>’) matches the empty string at the end of a word.

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18.4.1.5 The Match-word-constituent Operator (\w)

This operator (represented by ‘\w’) matches any word-constituent character.

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18.4.1.6 The Match-non-word-constituent Operator (\W)

This operator (represented by ‘\W’) matches any character that is not word-constituent.

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18.4.2 Space Operators

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18.4.2.1 The Match-space Operator (\s)

This operator (represented by ‘\s’) matches any space character (that is, in the POSIX class [:space:]).

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18.4.2.2 The Match-non-space Operator (\S)

This operator (represented by ‘\S’) matches any character that is not a space (that is, in the POSIX class [:space:]).

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18.4.3 Whole-string Operators

Following are operators which work on the whole string.

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18.4.3.1 The Match-beginning-of-string Operator (\`)

This operator (represented by ‘\`’) matches the empty string at the beginning of the string.

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18.4.3.2 The Match-end-of-string Operator (\')

This operator (represented by ‘\'’) matches the empty string at the end of the string.

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18.5 What Gets Matched?

Regex usually matches strings according to the “leftmost longest” rule; that is, it chooses the longest of the leftmost matches. This does not mean that for a regular expression containing subexpressions that it simply chooses the longest match for each subexpression, left to right; the overall match must also be the longest possible one.

For example, ‘(ac*)(c*d[ac]*)\1’ matches ‘acdacaaa’, not ‘acdac’, as it would if it were to choose the longest match for the first subexpression.

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18.6 Programming with Regex

Here we describe how you use the Regex data structures and functions in C programs. Regex has three interfaces: one designed for GNU, one compatible with POSIX (as specified by POSIX, draft 1003.2/D11.2), and one compatible with Berkeley Unix. The POSIX interface is not documented here; see the documentation of GNU libc, or the POSIX man pages. The Berkeley Unix interface is documented here for convenience, since its documentation is not otherwise readily available on GNU systems.

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18.6.1 GNU Regex Functions

If you’re writing code that doesn’t need to be compatible with either POSIX or Berkeley Unix, you can use these functions. They provide more options than the other interfaces.

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18.6.1.1 GNU Pattern Buffers

To compile, match, or search for a given regular expression, you must supply a pattern buffer. A pattern buffer holds one compiled regular expression.6

You can have several different pattern buffers simultaneously, each holding a compiled pattern for a different regular expression.

regex.h defines the pattern buffer struct with the following public fields: 

  unsigned char *buffer;
  unsigned long allocated;
  char *fastmap;
  char *translate;
  size_t re_nsub;
  unsigned no_sub : 1;
  unsigned not_bol : 1;
  unsigned not_eol : 1;

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18.6.1.2 GNU Regular Expression Compiling

In GNU, you can both match and search for a given regular expression. To do either, you must first compile it in a pattern buffer (see GNU Pattern Buffers).

Regular expressions match according to the syntax with which they were compiled; with GNU, you indicate what syntax you want by setting the variable re_syntax_options (declared in regex.h) before calling the compiling function, re_compile_pattern (see below). See Syntax Bits, and Predefined Syntaxes.

You can change the value of re_syntax_options at any time. Usually, however, you set its value once and then never change it.

re_compile_pattern takes a pattern buffer as an argument. You must initialize the following fields:

translate initialization
translate

Initialize this to point to a translate table if you want one, or to zero if you don’t. We explain translate tables in GNU Translate Tables.

fastmap

Initialize this to nonzero if you want a fastmap, or to zero if you don’t.

buffer
allocated

If you want re_compile_pattern to allocate memory for the compiled pattern, set both of these to zero. If you have an existing block of memory (allocated with malloc) you want Regex to use, set buffer to its address and allocated to its size (in bytes).

re_compile_pattern uses realloc to extend the space for the compiled pattern as necessary.

To compile a pattern buffer, use: 

char *
re_compile_pattern (const char *regex, const int regex_size,
                    struct re_pattern_buffer *pattern_buffer)

regex is the regular expression’s address, regex_size is its length, and pattern_buffer is the pattern buffer’s address.

If re_compile_pattern successfully compiles the regular expression, it returns zero and sets *pattern_buffer to the compiled pattern. It sets the pattern buffer’s fields as follows:

buffer

to the compiled pattern.

syntax

to the current value of re_syntax_options.

re_nsub

to the number of subexpressions in regex.

If re_compile_pattern can’t compile regex, it returns an error string corresponding to a POSIX error code.

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18.6.1.3 GNU Matching

Matching the GNU way means trying to match as much of a string as possible starting at a position within it you specify. Once you’ve compiled a pattern into a pattern buffer (see GNU Regular Expression Compiling), you can ask the matcher to match that pattern against a string using: 

int
re_match (struct re_pattern_buffer *pattern_buffer,
          const char *string, const int size,
          const int start, struct re_registers *regs)

pattern_buffer is the address of a pattern buffer containing a compiled pattern. string is the string you want to match; it can contain newline and null characters. size is the length of that string. start is the string index at which you want to begin matching; the first character of string is at index zero. See Using Registers, for an explanation of regs; you can safely pass zero.

re_match matches the regular expression in pattern_buffer against the string string according to the syntax of pattern_buffer. (See GNU Regular Expression Compiling, for how to set it.) The function returns -1 if the compiled pattern does not match any part of string and -2 if an internal error happens; otherwise, it returns how many (possibly zero) characters of string the pattern matched.

An example: suppose pattern_buffer points to a pattern buffer containing the compiled pattern for ‘a*’, and string points to ‘aaaaab’ (whereupon size should be 6). Then if start is 2, re_match returns 3, i.e., ‘a*’ would have matched the last three ‘a’s in string. If start is 0, re_match returns 5, i.e., ‘a*’ would have matched all the ‘a’s in string. If start is either 5 or 6, it returns zero.

If start is not between zero and size, then re_match returns -1.

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18.6.1.4 GNU Searching

Searching means trying to match starting at successive positions within a string. The function re_search does this.

Before calling re_search, you must compile your regular expression. See GNU Regular Expression Compiling.

Here is the function declaration: 

int
re_search (struct re_pattern_buffer *pattern_buffer,
           const char *string, const int size,
           const int start, const int range,
           struct re_registers *regs)

whose arguments are the same as those to re_match (see GNU Matching) except that the two arguments start and range replace re_match’s argument start.

If range is positive, then re_search attempts a match starting first at index start, then at start + 1 if that fails, and so on, up to start + range; if range is negative, then it attempts a match starting first at index start, then at start -1 if that fails, and so on.

If start is not between zero and size, then re_search returns -1. When range is positive, re_search adjusts range so that start + range - 1 is between zero and size, if necessary; that way it won’t search outside of string. Similarly, when range is negative, re_search adjusts range so that start + range + 1 is between zero and size, if necessary.

If the fastmap field of pattern_buffer is zero, re_search matches starting at consecutive positions; otherwise, it uses fastmap to make the search more efficient. See Searching with Fastmaps.

If no match is found, re_search returns -1. If a match is found, it returns the index where the match began. If an internal error happens, it returns -2.

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18.6.1.5 Matching and Searching with Split Data

Using the functions re_match_2 and re_search_2, you can match or search in data that is divided into two strings.

The function: 

int
re_match_2 (struct re_pattern_buffer *buffer,
            const char *string1, const int size1,
            const char *string2, const int size2,
            const int start,
            struct re_registers *regs,
            const int stop)

is similar to re_match (see GNU Matching) except that you pass two data strings and sizes, and an index stop beyond which you don’t want the matcher to try matching. As with re_match, if it succeeds, re_match_2 returns how many characters of string it matched. Regard string1 and string2 as concatenated when you set the arguments start and stop and use the contents of regs; re_match_2 never returns a value larger than size1 + size2.

The function: 

int
re_search_2 (struct re_pattern_buffer *buffer,
             const char *string1, const int size1,
             const char *string2, const int size2,
             const int start, const int range,
             struct re_registers *regs,
             const int stop)

is similarly related to re_search.

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18.6.1.6 Searching with Fastmaps

If you’re searching through a long string, you should use a fastmap. Without one, the searcher tries to match at consecutive positions in the string. Generally, most of the characters in the string could not start a match. It takes much longer to try matching at a given position in the string than it does to check in a table whether or not the character at that position could start a match. A fastmap is such a table.

More specifically, a fastmap is an array indexed by the characters in your character set. Under the ASCII encoding, therefore, a fastmap has 256 elements. If you want the searcher to use a fastmap with a given pattern buffer, you must allocate the array and assign the array’s address to the pattern buffer’s fastmap field. You either can compile the fastmap yourself or have re_search do it for you; when fastmap is nonzero, it automatically compiles a fastmap the first time you search using a particular compiled pattern.

By setting the buffer’s fastmap field before calling re_compile_pattern, you can reuse a buffer data structure across multiple searches with different patterns, and allocate the fastmap only once. Nonetheless, the fastmap must be recompiled each time the buffer has a new pattern compiled into it.

To compile a fastmap yourself, use: 

int
re_compile_fastmap (struct re_pattern_buffer *pattern_buffer)

pattern_buffer is the address of a pattern buffer. If the character c could start a match for the pattern, re_compile_fastmap makes pattern_buffer->fastmap[c] nonzero. It returns 0 if it can compile a fastmap and -2 if there is an internal error. For example, if ‘|’ is the alternation operator and pattern_buffer holds the compiled pattern for ‘a|b’, then re_compile_fastmap sets fastmap['a'] and fastmap['b'] (and no others).

re_search uses a fastmap as it moves along in the string: it checks the string’s characters until it finds one that’s in the fastmap. Then it tries matching at that character. If the match fails, it repeats the process. So, by using a fastmap, re_search doesn’t waste time trying to match at positions in the string that couldn’t start a match.

If you don’t want re_search to use a fastmap, store zero in the fastmap field of the pattern buffer before calling re_search.

Once you’ve initialized a pattern buffer’s fastmap field, you need never do so again—even if you compile a new pattern in it—provided the way the field is set still reflects whether or not you want a fastmap. re_search will still either do nothing if fastmap is null or, if it isn’t, compile a new fastmap for the new pattern.

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18.6.1.7 GNU Translate Tables

If you set the translate field of a pattern buffer to a translate table, then the GNU Regex functions to which you’ve passed that pattern buffer use it to apply a simple transformation to all the regular expression and string characters at which they look.

A translate table is an array indexed by the characters in your character set. Under the ASCII encoding, therefore, a translate table has 256 elements. The array’s elements are also characters in your character set. When the Regex functions see a character c, they use translate[c] in its place, with one exception: the character after a ‘\’ is not translated. (This ensures that, the operators, e.g., ‘\B’ and ‘\b’, are always distinguishable.)

For example, a table that maps all lowercase letters to the corresponding uppercase ones would cause the matcher to ignore differences in case.7 Such a table would map all characters except lowercase letters to themselves, and lowercase letters to the corresponding uppercase ones. Under the ASCII encoding, here’s how you could initialize such a table (we’ll call it case_fold): 

for (i = 0; i < 256; i++)
  case_fold[i] = i;
for (i = 'a'; i <= 'z'; i++)
  case_fold[i] = i - ('a' - 'A');

You tell Regex to use a translate table on a given pattern buffer by assigning that table’s address to the translate field of that buffer. If you don’t want Regex to do any translation, put zero into this field. You’ll get weird results if you change the table’s contents anytime between compiling the pattern buffer, compiling its fastmap, and matching or searching with the pattern buffer.

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18.6.1.8 Using Registers

A group in a regular expression can match a (possibly empty) substring of the string that regular expression as a whole matched. The matcher remembers the beginning and end of the substring matched by each group.

To find out what they matched, pass a nonzero regs argument to a GNU matching or searching function (see GNU Matching and GNU Searching), i.e., the address of a structure of this type, as defined in regex.h: 

struct re_registers
{
  unsigned num_regs;
  regoff_t *start;
  regoff_t *end;
};

Except for (possibly) the num_regs’th element (see below), the ith element of the start and end arrays records information about the ith group in the pattern. (They’re declared as C pointers, but this is only because not all C compilers accept zero-length arrays; conceptually, it is simplest to think of them as arrays.)

The start and end arrays are allocated in one of two ways. The simplest and perhaps most useful is to let the matcher (re)allocate enough space to record information for all the groups in the regular expression. If re_set_registers is not called before searching or matching, then the matcher allocates two arrays each of 1 + re_nsub elements (re_nsub is another field in the pattern buffer; see GNU Pattern Buffers). The extra element is set to -1. Then on subsequent calls with the same pattern buffer and regs arguments, the matcher reallocates more space if necessary.

The function: 

void
re_set_registers (struct re_pattern_buffer *buffer,
                  struct re_registers *regs,
                  size_t num_regs,
                  regoff_t *starts, regoff_t *ends)

sets regs to hold num_regs registers, storing them in starts and ends. Subsequent matches using buffer and regs will use this memory for recording register information. starts and ends must be allocated with malloc, and must each be at least num_regs * sizeof (regoff_t) bytes long.

If num_regs is zero, then subsequent matches should allocate their own register data.

Unless this function is called, the first search or match using buffer will allocate its own register data, without freeing the old data.

The following examples illustrate the information recorded in the re_registers structure. (In all of them, ‘(’ represents the open-group and ‘)’ the close-group operator. The first character in the string string is at index 0.)

  • If the regular expression has an i-th group that matches a substring of string, then the function sets regs->start[i] to the index in string where the substring matched by the i-th group begins, and regs->end[i] to the index just beyond that substring’s end. The function sets regs->start[0] and regs->end[0] to analogous information about the entire pattern.

    For example, when you match ‘((a)(b))’ against ‘ab’, you get:

    • 0 in regs->start[0] and 2 in regs->end[0]
    • 0 in regs->start[1] and 2 in regs->end[1]
    • 0 in regs->start[2] and 1 in regs->end[2]
    • 1 in regs->start[3] and 2 in regs->end[3]
  • If a group matches more than once (as it might if followed by, e.g., a repetition operator), then the function reports the information about what the group last matched.

    For example, when you match the pattern ‘(a)*’ against the string ‘aa’, you get:

    • 0 in regs->start[0] and 2 in regs->end[0]
    • 1 in regs->start[1] and 2 in regs->end[1]
  • If the i-th group does not participate in a successful match, e.g., it is an alternative not taken or a repetition operator allows zero repetitions of it, then the function sets regs->start[i] and regs->end[i] to -1.

    For example, when you match the pattern ‘(a)*b’ against the string ‘b’, you get:

    • 0 in regs->start[0] and 1 in regs->end[0]
    • -1 in regs->start[1] and -1 in regs->end[1]
  • If the i-th group matches a zero-length string, then the function sets regs->start[i] and regs->end[i] to the index just beyond that zero-length string.

    For example, when you match the pattern ‘(a*)b’ against the string ‘b’, you get:

    • 0 in regs->start[0] and 1 in regs->end[0]
    • 0 in regs->start[1] and 0 in regs->end[1]
  • If an i-th group contains a j-th group in turn not contained within any other group within group i and the function reports a match of the i-th group, then it records in regs->start[j] and regs->end[j] the last match (if it matched) of the j-th group.

    For example, when you match the pattern ‘((a*)b)*’ against the string ‘abb’, group 2 last matches the empty string, so you get what it previously matched:

    • 0 in regs->start[0] and 3 in regs->end[0]
    • 2 in regs->start[1] and 3 in regs->end[1]
    • 2 in regs->start[2] and 2 in regs->end[2]

    When you match the pattern ‘((a)*b)*’ against the string ‘abb’, group 2 doesn’t participate in the last match, so you get:

    • 0 in regs->start[0] and 3 in regs->end[0]
    • 2 in regs->start[1] and 3 in regs->end[1]
    • 0 in regs->start[2] and 1 in regs->end[2]
  • If an i-th group contains a j-th group in turn not contained within any other group within group i and the function sets regs->start[i] and regs->end[i] to -1, then it also sets regs->start[j] and regs->end[j] to -1.

    For example, when you match the pattern ‘((a)*b)*c’ against the string ‘c’, you get:

    • 0 in regs->start[0] and 1 in regs->end[0]
    • -1 in regs->start[1] and -1 in regs->end[1]
    • -1 in regs->start[2] and -1 in regs->end[2]

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18.6.1.9 Freeing GNU Pattern Buffers

To free any allocated fields of a pattern buffer, use the POSIX function regfree: 

void
regfree (regex_t *preg)

preg is the pattern buffer whose allocated fields you want freed; this works because since the type regex_t—the type for POSIX pattern buffers—is equivalent to the type re_pattern_buffer.

regfree also sets preg’s allocated field to zero. After a buffer has been freed, it must have a regular expression compiled in it before passing it to a matching or searching function.

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18.6.2 BSD Regex Functions

If you’re writing code that has to be Berkeley Unix compatible, you’ll need to use these functions whose interfaces are the same as those in Berkeley Unix.

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18.6.2.1 BSD Regular Expression Compiling

With Berkeley Unix, you can only search for a given regular expression; you can’t match one. To search for it, you must first compile it. Before you compile it, you must indicate the regular expression syntax you want it compiled according to by setting the variable re_syntax_options (declared in regex.h) to some syntax (see Regular Expression Syntax).

To compile a regular expression use: 

char *
re_comp (char *regex)

regex is the address of a null-terminated regular expression. re_comp uses an internal pattern buffer, so you can use only the most recently compiled pattern buffer. This means that if you want to use a given regular expression that you’ve already compiled—but it isn’t the latest one you’ve compiled—you’ll have to recompile it. If you call re_comp with the null string (not the empty string) as the argument, it doesn’t change the contents of the pattern buffer.

If re_comp successfully compiles the regular expression, it returns zero. If it can’t compile the regular expression, it returns an error string. re_comp’s error messages are identical to those of re_compile_pattern (see GNU Regular Expression Compiling).

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18.6.2.2 BSD Searching

Searching the Berkeley Unix way means searching in a string starting at its first character and trying successive positions within it to find a match. Once you’ve compiled a pattern using re_comp (see BSD Regular Expression Compiling), you can ask Regex to search for that pattern in a string using: 

int
re_exec (char *string)

string is the address of the null-terminated string in which you want to search.

re_exec returns either 1 for success or 0 for failure. It automatically uses a GNU fastmap (see Searching with Fastmaps).

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18.7 Regular expression syntaxes

Gnulib supports many different types of regular expressions; although the underlying features are the same or identical, the syntax used varies. The descriptions given here for the different types are generated automatically.

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18.7.1 ‘awk’ regular expression syntax

The character ‘.’ matches any single character except the null character.

‘+’

indicates that the regular expression should match one or more occurrences of the previous atom or regexp.

‘?’

indicates that the regular expression should match zero or one occurrence of the previous atom or regexp.

‘\+’

matches a ‘+’

‘\?’

matches a ‘?’.

Bracket expressions are used to match ranges of characters. Bracket expressions where the range is backward, for example ‘[z-a]’, are invalid. Within square brackets, ‘\’ can be used to quote the following character. Character classes are supported; for example ‘[[:digit:]]’ will match a single decimal digit.

GNU extensions are not supported and so ‘\w’, ‘\W’, ‘\<’, ‘\>’, ‘\b’, ‘\B’, ‘\`’, and ‘\'’ match ‘w’, ‘W’, ‘<’, ‘>’, ‘b’, ‘B’, ‘`’, and ‘'’ respectively.

Grouping is performed with parentheses ‘()’. An unmatched ‘)’ matches just itself. A backslash followed by a digit matches that digit.

The alternation operator is ‘|’.

The characters ‘^’ and ‘$’ always represent the beginning and end of a string respectively, except within square brackets. Within brackets, ‘^’ can be used to invert the membership of the character class being specified.

‘*’, ‘+’ and ‘?’ are special at any point in a regular expression except:

  1. At the beginning of a regular expression
  2. After an open-group, signified by ‘(’
  3. After the alternation operator ‘|’

The longest possible match is returned; this applies to the regular expression as a whole and (subject to this constraint) to subexpressions within groups.

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18.7.2 ‘egrep’ regular expression syntax

The character ‘.’ matches any single character.

‘+’

indicates that the regular expression should match one or more occurrences of the previous atom or regexp.

‘?’

indicates that the regular expression should match zero or one occurrence of the previous atom or regexp.

‘\+’

matches a ‘+’

‘\?’

matches a ‘?’.

Bracket expressions are used to match ranges of characters. Bracket expressions where the range is backward, for example ‘[z-a]’, are invalid. Within square brackets, ‘\’ is taken literally. Character classes are supported; for example ‘[[:digit:]]’ will match a single decimal digit.

GNU extensions are supported:

  1. ‘\w’ matches a character within a word
  2. ‘\W’ matches a character which is not within a word
  3. ‘\<’ matches the beginning of a word
  4. ‘\>’ matches the end of a word
  5. ‘\b’ matches a word boundary
  6. ‘\B’ matches characters which are not a word boundary
  7. ‘\`’ matches the beginning of the whole input
  8. ‘\'’ matches the end of the whole input

Grouping is performed with parentheses ‘()’. An unmatched ‘)’ matches just itself. A backslash followed by a digit acts as a back-reference and matches the same thing as the previous grouped expression indicated by that number. For example ‘\2’ matches the second group expression. The order of group expressions is determined by the position of their opening parenthesis ‘(’.

The alternation operator is ‘|’.

The characters ‘^’ and ‘$’ always represent the beginning and end of a string respectively, except within square brackets. Within brackets, ‘^’ can be used to invert the membership of the character class being specified.

The characters ‘*’, ‘+’ and ‘?’ are special anywhere in a regular expression.

Intervals are specified by ‘{’ and ‘}’. Invalid intervals are treated as literals, for example ‘a{1’ is treated as ‘a\{1’

The longest possible match is returned; this applies to the regular expression as a whole and (subject to this constraint) to subexpressions within groups.

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18.7.3 ‘ed’ regular expression syntax

The character ‘.’ matches any single character except the null character.

‘\+’

indicates that the regular expression should match one or more occurrences of the previous atom or regexp.

‘\?’

indicates that the regular expression should match zero or one occurrence of the previous atom or regexp.

‘+ and ?’

match themselves.

Bracket expressions are used to match ranges of characters. Bracket expressions where the range is backward, for example ‘[z-a]’, are invalid. Within square brackets, ‘\’ is taken literally. Character classes are supported; for example ‘[[:digit:]]’ will match a single decimal digit.

GNU extensions are supported:

  1. ‘\w’ matches a character within a word
  2. ‘\W’ matches a character which is not within a word
  3. ‘\<’ matches the beginning of a word
  4. ‘\>’ matches the end of a word
  5. ‘\b’ matches a word boundary
  6. ‘\B’ matches characters which are not a word boundary
  7. ‘\`’ matches the beginning of the whole input
  8. ‘\'’ matches the end of the whole input

Grouping is performed with backslashes followed by parentheses ‘\(’, ‘\)’. A backslash followed by a digit acts as a back-reference and matches the same thing as the previous grouped expression indicated by that number. For example ‘\2’ matches the second group expression. The order of group expressions is determined by the position of their opening parenthesis ‘\(’.

The alternation operator is ‘\|’.

The character ‘^’ only represents the beginning of a string when it appears:

  1. At the beginning of a regular expression
  2. After an open-group, signified by ‘\(’
  3. After the alternation operator ‘\|’

The character ‘$’ only represents the end of a string when it appears:

  1. At the end of a regular expression
  2. Before a close-group, signified by ‘\)’
  3. Before the alternation operator ‘\|’

‘\*’, ‘\+’ and ‘\?’ are special at any point in a regular expression except:

  1. At the beginning of a regular expression
  2. After an open-group, signified by ‘\(’
  3. After the alternation operator ‘\|’

Intervals are specified by ‘\{’ and ‘\}’. Invalid intervals such as ‘a\{1z’ are not accepted.

The longest possible match is returned; this applies to the regular expression as a whole and (subject to this constraint) to subexpressions within groups.

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18.7.4 ‘emacs’ regular expression syntax

The character ‘.’ matches any single character except newline.

‘+’

indicates that the regular expression should match one or more occurrences of the previous atom or regexp.

‘?’

indicates that the regular expression should match zero or one occurrence of the previous atom or regexp.

‘\+’

matches a ‘+’

‘\?’

matches a ‘?’.

Bracket expressions are used to match ranges of characters. Bracket expressions where the range is backward, for example ‘[z-a]’, are ignored. Within square brackets, ‘\’ is taken literally. Character classes are not supported, so for example you would need to use ‘[0-9]’ instead of ‘[[:digit:]]’.

GNU extensions are supported:

  1. ‘\w’ matches a character within a word
  2. ‘\W’ matches a character which is not within a word
  3. ‘\<’ matches the beginning of a word
  4. ‘\>’ matches the end of a word
  5. ‘\b’ matches a word boundary
  6. ‘\B’ matches characters which are not a word boundary
  7. ‘\`’ matches the beginning of the whole input
  8. ‘\'’ matches the end of the whole input

Grouping is performed with backslashes followed by parentheses ‘\(’, ‘\)’. A backslash followed by a digit acts as a back-reference and matches the same thing as the previous grouped expression indicated by that number. For example ‘\2’ matches the second group expression. The order of group expressions is determined by the position of their opening parenthesis ‘\(’.

The alternation operator is ‘\|’.

The character ‘^’ only represents the beginning of a string when it appears:

  1. At the beginning of a regular expression
  2. After an open-group, signified by ‘\(’
  3. After the alternation operator ‘\|’

The character ‘$’ only represents the end of a string when it appears:

  1. At the end of a regular expression
  2. Before a close-group, signified by ‘\)’
  3. Before the alternation operator ‘\|’

‘*’, ‘+’ and ‘?’ are special at any point in a regular expression except:

  1. At the beginning of a regular expression
  2. After an open-group, signified by ‘\(’
  3. After the alternation operator ‘\|’

The longest possible match is returned; this applies to the regular expression as a whole and (subject to this constraint) to subexpressions within groups.

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18.7.5 ‘gnu-awk’ regular expression syntax

The character ‘.’ matches any single character.

‘+’

indicates that the regular expression should match one or more occurrences of the previous atom or regexp.

‘?’

indicates that the regular expression should match zero or one occurrence of the previous atom or regexp.

‘\+’

matches a ‘+’

‘\?’

matches a ‘?’.

Bracket expressions are used to match ranges of characters. Bracket expressions where the range is backward, for example ‘[z-a]’, are invalid. Within square brackets, ‘\’ can be used to quote the following character. Character classes are supported; for example ‘[[:digit:]]’ will match a single decimal digit.

GNU extensions are supported:

  1. ‘\w’ matches a character within a word
  2. ‘\W’ matches a character which is not within a word
  3. ‘\<’ matches the beginning of a word
  4. ‘\>’ matches the end of a word
  5. ‘\b’ matches a word boundary
  6. ‘\B’ matches characters which are not a word boundary
  7. ‘\`’ matches the beginning of the whole input
  8. ‘\'’ matches the end of the whole input

Grouping is performed with parentheses ‘()’. An unmatched ‘)’ matches just itself. A backslash followed by a digit acts as a back-reference and matches the same thing as the previous grouped expression indicated by that number. For example ‘\2’ matches the second group expression. The order of group expressions is determined by the position of their opening parenthesis ‘(’.

The alternation operator is ‘|’.

The characters ‘^’ and ‘$’ always represent the beginning and end of a string respectively, except within square brackets. Within brackets, ‘^’ can be used to invert the membership of the character class being specified.

‘*’, ‘+’ and ‘?’ are special at any point in a regular expression except:

  1. At the beginning of a regular expression
  2. After an open-group, signified by ‘(’
  3. After the alternation operator ‘|’

Intervals are specified by ‘{’ and ‘}’. Invalid intervals are treated as literals, for example ‘a{1’ is treated as ‘a\{1’

The longest possible match is returned; this applies to the regular expression as a whole and (subject to this constraint) to subexpressions within groups.

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18.7.6 ‘grep’ regular expression syntax

The character ‘.’ matches any single character.

‘\+’

indicates that the regular expression should match one or more occurrences of the previous atom or regexp.

‘\?’

indicates that the regular expression should match zero or one occurrence of the previous atom or regexp.

‘+ and ?’

match themselves.

Bracket expressions are used to match ranges of characters. Bracket expressions where the range is backward, for example ‘[z-a]’, are invalid. Within square brackets, ‘\’ is taken literally. Character classes are supported; for example ‘[[:digit:]]’ will match a single decimal digit.

GNU extensions are supported:

  1. ‘\w’ matches a character within a word
  2. ‘\W’ matches a character which is not within a word
  3. ‘\<’ matches the beginning of a word
  4. ‘\>’ matches the end of a word
  5. ‘\b’ matches a word boundary
  6. ‘\B’ matches characters which are not a word boundary
  7. ‘\`’ matches the beginning of the whole input
  8. ‘\'’ matches the end of the whole input

Grouping is performed with backslashes followed by parentheses ‘\(’, ‘\)’. A backslash followed by a digit acts as a back-reference and matches the same thing as the previous grouped expression indicated by that number. For example ‘\2’ matches the second group expression. The order of group expressions is determined by the position of their opening parenthesis ‘\(’.

The alternation operator is ‘\|’.

The character ‘^’ only represents the beginning of a string when it appears:

  1. At the beginning of a regular expression
  2. After an open-group, signified by ‘\(’
  3. After a newline
  4. After the alternation operator ‘\|’

The character ‘$’ only represents the end of a string when it appears:

  1. At the end of a regular expression
  2. Before a close-group, signified by ‘\)’
  3. Before a newline
  4. Before the alternation operator ‘\|’

‘\*’, ‘\+’ and ‘\?’ are special at any point in a regular expression except:

  1. At the beginning of a regular expression
  2. After an open-group, signified by ‘\(’
  3. After a newline
  4. After the alternation operator ‘\|’

Intervals are specified by ‘\{’ and ‘\}’. Invalid intervals such as ‘a\{1z’ are not accepted.

The longest possible match is returned; this applies to the regular expression as a whole and (subject to this constraint) to subexpressions within groups.

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18.7.7 ‘posix-awk’ regular expression syntax

The character ‘.’ matches any single character except the null character.

‘+’

indicates that the regular expression should match one or more occurrences of the previous atom or regexp.

‘?’

indicates that the regular expression should match zero or one occurrence of the previous atom or regexp.

‘\+’

matches a ‘+’

‘\?’

matches a ‘?’.

Bracket expressions are used to match ranges of characters. Bracket expressions where the range is backward, for example ‘[z-a]’, are invalid. Within square brackets, ‘\’ can be used to quote the following character. Character classes are supported; for example ‘[[:digit:]]’ will match a single decimal digit.

GNU extensions are not supported and so ‘\w’, ‘\W’, ‘\<’, ‘\>’, ‘\b’, ‘\B’, ‘\`’, and ‘\'’ match ‘w’, ‘W’, ‘<’, ‘>’, ‘b’, ‘B’, ‘`’, and ‘'’ respectively.

Grouping is performed with parentheses ‘()’. An unmatched ‘)’ matches just itself. A backslash followed by a digit acts as a back-reference and matches the same thing as the previous grouped expression indicated by that number. For example ‘\2’ matches the second group expression. The order of group expressions is determined by the position of their opening parenthesis ‘(’.

The alternation operator is ‘|’.

The characters ‘^’ and ‘$’ always represent the beginning and end of a string respectively, except within square brackets. Within brackets, ‘^’ can be used to invert the membership of the character class being specified.

‘*’, ‘+’ and ‘?’ are special at any point in a regular expression except the following places, where they are not allowed:

  1. At the beginning of a regular expression
  2. After an open-group, signified by ‘(’
  3. After the alternation operator ‘|’

Intervals are specified by ‘{’ and ‘}’. Invalid intervals are treated as literals, for example ‘a{1’ is treated as ‘a\{1’

The longest possible match is returned; this applies to the regular expression as a whole and (subject to this constraint) to subexpressions within groups.

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18.7.8 ‘posix-basic’ regular expression syntax

This is a synonym for ed.

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18.7.9 ‘posix-egrep’ regular expression syntax

This is a synonym for egrep.

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18.7.10 ‘posix-extended’ regular expression syntax

The character ‘.’ matches any single character except the null character.

‘+’

indicates that the regular expression should match one or more occurrences of the previous atom or regexp.

‘?’

indicates that the regular expression should match zero or one occurrence of the previous atom or regexp.

‘\+’

matches a ‘+’

‘\?’

matches a ‘?’.

Bracket expressions are used to match ranges of characters. Bracket expressions where the range is backward, for example ‘[z-a]’, are invalid. Within square brackets, ‘\’ is taken literally. Character classes are supported; for example ‘[[:digit:]]’ will match a single decimal digit.

GNU extensions are supported:

  1. ‘\w’ matches a character within a word
  2. ‘\W’ matches a character which is not within a word
  3. ‘\<’ matches the beginning of a word
  4. ‘\>’ matches the end of a word
  5. ‘\b’ matches a word boundary
  6. ‘\B’ matches characters which are not a word boundary
  7. ‘\`’ matches the beginning of the whole input
  8. ‘\'’ matches the end of the whole input

Grouping is performed with parentheses ‘()’. An unmatched ‘)’ matches just itself. A backslash followed by a digit acts as a back-reference and matches the same thing as the previous grouped expression indicated by that number. For example ‘\2’ matches the second group expression. The order of group expressions is determined by the position of their opening parenthesis ‘(’.

The alternation operator is ‘|’.

The characters ‘^’ and ‘$’ always represent the beginning and end of a string respectively, except within square brackets. Within brackets, ‘^’ can be used to invert the membership of the character class being specified.

‘*’, ‘+’ and ‘?’ are special at any point in a regular expression except the following places, where they are not allowed:

  1. At the beginning of a regular expression
  2. After an open-group, signified by ‘(’
  3. After the alternation operator ‘|’

Intervals are specified by ‘{’ and ‘}’. Invalid intervals such as ‘a{1z’ are not accepted.

The longest possible match is returned; this applies to the regular expression as a whole and (subject to this constraint) to subexpressions within groups.

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18.7.11 ‘posix-minimal-basic’ regular expression syntax

The character ‘.’ matches any single character except the null character.

Bracket expressions are used to match ranges of characters. Bracket expressions where the range is backward, for example ‘[z-a]’, are invalid. Within square brackets, ‘\’ is taken literally. Character classes are supported; for example ‘[[:digit:]]’ will match a single decimal digit.

GNU extensions are supported:

  1. ‘\w’ matches a character within a word
  2. ‘\W’ matches a character which is not within a word
  3. ‘\<’ matches the beginning of a word
  4. ‘\>’ matches the end of a word
  5. ‘\b’ matches a word boundary
  6. ‘\B’ matches characters which are not a word boundary
  7. ‘\`’ matches the beginning of the whole input
  8. ‘\'’ matches the end of the whole input

Grouping is performed with backslashes followed by parentheses ‘\(’, ‘\)’. A backslash followed by a digit acts as a back-reference and matches the same thing as the previous grouped expression indicated by that number. For example ‘\2’ matches the second group expression. The order of group expressions is determined by the position of their opening parenthesis ‘\(’.

The character ‘^’ only represents the beginning of a string when it appears:

  1. At the beginning of a regular expression
  2. After an open-group, signified by ‘\(’

The character ‘$’ only represents the end of a string when it appears:

  1. At the end of a regular expression
  2. Before a close-group, signified by ‘\)’

Intervals are specified by ‘\{’ and ‘\}’. Invalid intervals such as ‘a\{1z’ are not accepted.

The longest possible match is returned; this applies to the regular expression as a whole and (subject to this constraint) to subexpressions within groups.

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18.7.12 ‘sed’ regular expression syntax

This is a synonym for ed.

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19 Build Infrastructure Modules

Gnulib has a couple of modules that don’t provide code, but rather extend the GNU Build System. That is, they are convenience facilities for use with GNU Automake (in particular).

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19.1 Searching for Libraries

The following macros check for the presence or location of certain C, C++, or Fortran library archive files.

Simple Library Tests

The macros AC_CHECK_LIB, AC_SEARCH_LIBS from GNU Autoconf check for the presence of certain C, C++, or Fortran library archive files. The libraries are looked up in the default linker path—a system dependent list of directories, that usually contains the /usr/lib directory—and those directories given by -L options in the LDFLAGS variable.

Locating Libraries

The following macros, defined in the Gnulib module havelib, search for the location of certain C, C++, or Fortran library archive files and make the found location available to the compilation process and to further Autoconf tests.

Macro: AC_LIB_LINKFLAGS(name, [dependencies])

Searches for lib<name> and the libraries corresponding to explicit and implicit dependencies. Sets and AC_SUBSTs the LIB<NAME> and LTLIB<NAME> variables (with <NAME> in upper case) and augments the CPPFLAGS variable by -I options.

This macro should be used when lib<name> is expected to be found.

Macro: AC_LIB_HAVE_LINKFLAGS(name, [dependencies], [includes], [testcode], [missing-message])

Searches for lib<name> and the libraries corresponding to explicit and implicit dependencies, together with the specified include files and the ability to compile and link the specified testcode. The missing-message defaults to no and may contain additional hints for the user. If found, it sets and AC_SUBSTs HAVE_LIB<NAME>=yes and the LIB<NAME> and LTLIB<NAME> variables (with <NAME> in upper case) and augments the CPPFLAGS variable by -I options, and #defines HAVE_LIB<NAME> to 1. Otherwise, it sets and AC_SUBSTs HAVE_LIB<NAME>=no and LIB<NAME> and LTLIB<NAME> to empty.

These macros assume that when a library is installed in some_directory/lib, its include files are installed in some_directory/include.

The complexities that AC_LIB_LINKFLAGS and AC_LIB_HAVE_LINKFLAGS deal with are the following:

  • The library is not necessarily already in the search path (CPPFLAGS for the include file search path, LDFLAGS for the library search path). The macro provides a ‘--with-lib<name>’ option. The user of the ‘configure’ script can use this option to indicate the location of the library and its include files. If not provided, the --prefix directory is searched as well.
  • The library is not necessarily already in the run time library search path. To avoid the need for setting an environment variable like LD_LIBRARY_PATH, the macro adds the appropriate run time search path options to the LIB<NAME> variable. This works on most systems. It can also be inhibited: The user of ‘configure’ can use the --disable-rpath option to force an installation that doesn’t contain hardcoded library search paths but instead may require the use of an environment variable like LD_LIBRARY_PATH.

The macros also set a variable LTLIB<NAME>, that should be used when linking with libtool. Both LTLIB<NAME> and LIB<NAME> contain essentially the same option, but where LIB<NAME> contains platform dependent flags like ‘-Wl,-rpath’, LTLIB<NAME> contains platform independent flags like ‘-R’.

If you, by mistake, use LIB<NAME> instead of LTLIB<NAME> when linking with libtool, you will observe that the binaries created in the build dir will prefer the shared libraries in the installation directories over the shared libraries in the build dir; this can lead to all sorts of build failures, test failures, or crashes!

If you, on the other hand, by mistake, use LTLIB<NAME> instead of LIB<NAME> when linking without libtool, you will observe build failures, because the ‘-R’ options contained in LTLIB<NAME> are not valid options to compilers such as GCC.

Example of using AC_LIB_LINKFLAGS

Suppose you want to use libz, the compression library.

  1. In configure.ac you add the line 
      AC_CONFIG_AUX_DIR([build-aux])
  AC_LIB_LINKFLAGS([z])

    Note that since the AC_LIB_LINKFLAGS invocation modifies the CPPFLAGS, it should precede all tests that check for header files, declarations, structures or types.

  2. To the package’s build-aux directory you add the file config.rpath, also part of the Gnulib havelib module. (gnulib-tool will usually do this for you automatically.)
  3. In Makefile.in you add @LIBZ@ to the link command line of your program. Or, if you are using Automake, you add $(LIBZ) to the LDADD variable that corresponds to your program.

Dependencies

The dependencies list is a space separated list of library names that libname is known to depend upon. Example: If libfooy depends on libfoox, and libfooz depends on libfoox and libfooy, you can write: 

AC_LIB_LINKFLAGS([foox])
AC_LIB_LINKFLAGS([fooy], [foox])
AC_LIB_LINKFLAGS([fooz], [foox fooy])

Explicit dependencies are necessary if you cannot assume that a .la file, created by libtool, is installed. If you can assume that libfooy.la is installed by libtool (and has not been omitted by the package distributor!), you can omit the explicit dependency and just write 

AC_LIB_LINKFLAGS([fooy])

This way, you don’t need to know in advance which libraries the needed library depends upon.

Static vs. shared

The macros find the libraries regardless whether they are installed as shared or static libraries.

CPPFLAGS vs. LDFLAGS

The macros determine the directories that should be added to the compiler preprocessor’s search path and to the linker’s search path. For the compiler preprocessor, -I options with the necessary directories are added to the CPPFLAGS variable, for use by the whole package. For the linker, appropriate options are added to the LIB<NAME> and LTLIB<NAME> variables, for use during linking by those programs and libraries that need the dependency on lib<name>. You need to use the value of LIB<NAME> or LTLIB<NAME> in the Makefiles. LTLIB<NAME> is for use with libtool, whereas LIB<NAME> is for when libtool is not involved in linking.

The macros do not check whether the include files and the library found match. If you want to verify this at configure time, one technique is to have a version number in the include files and a version number in the library, like this: 

  #define LIBNAME_VERSION 10203
  extern int libname_version; /* initialized to LIBNAME_VERSION */

and use a test like 

  AC_TRY_RUN([int main () { return libname_version != LIBNAME_VERSION; }])

Bi-arch systems

A bi-arch system is one where

  • the processor has a 32-bit execution mode and a 64-bit execution mode (for example, x86_64, ia64, sparc64, powerpc64), and
  • 32-bit mode libraries and executables and 64-bit mode libraries are both installed, and
  • 32-bit mode libraries and object files cannot be mixed with 64-bit mode ones.

On several types of such systems, for historical reasons, the 32-bit libraries are installed in prefix/lib, whereas the 64-bit libraries are installed in

  • prefix/lib64 on many glibc systems,
  • prefix/lib/64 on Solaris systems.

On such systems, in 64-bit mode, configure will search for the libraries in prefix/lib64 or prefix/lib/64, respectively, not in prefix/lib. A user can adhere to these system-wide conventions by using the ‘--libdir’ option when installing packages. When a user has already installed packages in 64-bit mode using the GNU default ‘--libdir=prefix/lib’, he can make this directory adhere to the system-wide convention by placing a symbolic link:

On glibc systems:

ln -s lib prefix/lib64

On Solaris systems:

ln -s . prefix/lib/64

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19.2 Controlling the Exported Symbols of Shared Libraries

The lib-symbol-visibility module allows precise control of the symbols exported by a shared library. This is useful because

  • It prevents abuse of undocumented APIs of your library. Symbols that are not exported from the library cannot be used. This eliminates the problem that when the maintainer of the library changes internals of the library, maintainers of other projects cry “breakage”. Instead, these maintainers are forced to negotiate the desired API from the maintainer of the library.
  • It reduces the risk of symbol collision between your library and other libraries. For example, the symbol ‘readline’ is defined in several libraries, most of which don’t have the same semantics and the same calling convention as the GNU readline library.
  • It reduces the startup time of programs linked to the library. This is because the dynamic loader has less symbols to process.
  • It allows the compiler to generate better code. Within a shared library, a call to a function that is a global symbol costs a “call” instruction to a code location in the so-called PLT (procedure linkage table) which contains a “jump” instruction to the actual function’s code. (This is needed so that the function can be overridden, for example by a function with the same name in the executable or in a shared library interposed with LD_PRELOAD.) Whereas a call to a function for which the compiler can assume that it is in the same shared library is just a direct “call” instructions. Similarly for variables: A reference to a global variable fetches a pointer in the so-called GOT (global offset table); this is a pointer to the variable’s memory. So the code to access it is two memory load instructions. Whereas for a variable which is known to reside in the same shared library, it is just a direct memory access: one memory load instruction.

There are traditionally three ways to specify the exported symbols of a shared library.

  • The programmer specifies the list of symbols to be exported when the shared library is created. Usually a command-line option is passed to the linker, with the name of a file containing the symbols.

    The upside of this approach is flexibility: it allows the same code to be used in different libraries with different export lists. The downsides are: 1. it’s a lot of maintenance overhead when the symbol list is platform dependent, 2. it doesn’t work well with C++, due to name mangling.

  • The programmer specifies a “hidden” attribute for every variable and function that shall not be exported.

    The drawbacks of this approach are: Symbols are still exported from the library by default. It’s a lot of maintenance work to mark every non- exported variable and function. But usually the exported API is quite small, compared to the internal API of the library. And it’s the wrong paradigm: It doesn’t force thinking when introducing new exported API.

  • The programmer specifies a “hidden” attribute for all files that make up the shared library, and an “exported” attribute for those symbols in these files that shall be exported.

    This is perfect: It burdens the maintainer only for exported API, not for library-internal API. And it keeps the annotations in the source code.

GNU libtool’s -export-symbols option implements the first approach. The script declared.sh from Gnulib can help to produce the list of symbols.

This gnulib module implements the third approach. For this it relies on GNU GCC 4.0 or newer, namely on its ‘-fvisibility=hidden’ command-line option and the “visibility” attribute. (The “visibility” attribute was already supported in GCC 3.4, but without the command line option, introduced in GCC 4.0, the third approach could not be used.)

More explanations on this subject can be found in https://gcc.gnu.org/wiki/Visibility, which contains more details on the GCC features and additional advice for C++ libraries, and in Ulrich Drepper’s paper https://www.akkadia.org/drepper/dsohowto.pdf, which also explains other tricks for reducing the startup time impact of shared libraries.

The gnulib autoconf macro gl_VISIBILITY tests for GCC 4.0 or newer. It defines a Makefile variable @CFLAG_VISIBILITY@ containing ‘-fvisibility=hidden’ or nothing. It also defines as a C macro and as a substituted variable: @HAVE_VISIBILITY@. Its value is 1 when symbol visibility control is supported, and 0 otherwise.

As of 2022, symbol visibility control is supported on

  • ELF platforms (glibc, Linux, *BSD, Solaris) with GCC or clang,
  • macOS,
  • AIX with gcc or xlclang.

It is not supported on

  • Other compilers on ELF platforms or AIX,
  • Windows.

To use this module in a library, say libfoo, you will do these steps:

  1. Add @CFLAG_VISIBILITY@ or (in a Makefile.am) $(CFLAG_VISIBILITY) to the CFLAGS for the compilation of the sources that make up the library.
  2. Add a C macro definition, say ‘-DBUILDING_LIBFOO’, to the CPPFLAGS for the compilation of the sources that make up the library.
  3. Define a macro specific to your library like this. 
    #if HAVE_VISIBILITY && BUILDING_LIBFOO
# define LIBFOO_SHLIB_EXPORTED __attribute__((__visibility__("default")))
#else
# define LIBFOO_SHLIB_EXPORTED
#endif

    This macro should be enabled in all public header files of your library.

  4. Annotate all variable, function and class declarations in all public header files of your library with ‘LIBFOO_SHLIB_EXPORTED’. This annotation can occur at different locations: between the ‘extern’ and the type or return type, or just before the entity being declared, or after the entire declarator. My preference is to put it right after ‘extern’, so that the declarations in the header files remain halfway readable.

Note that the precise control of the exported symbols will not work with other compilers than GCC >= 4.0, and will not work on systems where the assembler or linker lack the support of “hidden” visibility. Therefore, it’s good if, in order to reduce the risk of collisions with symbols in other libraries, you continue to use a prefix specific to your library for all non-static variables and functions and for all C++ classes in your library.

Note about other compilers: MSVC support can be added easily, by extending the definition of the macro mentioned above, to something like this: 

#if HAVE_VISIBILITY && BUILDING_LIBFOO
# define LIBFOO_SHLIB_EXPORTED __attribute__((__visibility__("default")))
#elif (defined _WIN32 && !defined __CYGWIN__) && @BUILDING_SHARED@ && BUILDING_LIBFOO
# if defined DLL_EXPORT
#  define LIBFOO_SHLIB_EXPORTED __declspec(dllexport)
# else
#  define LIBFOO_SHLIB_EXPORTED
# endif
#elif (defined _WIN32 && !defined __CYGWIN__) && @BUILDING_SHARED@
# define LIBFOO_SHLIB_EXPORTED __declspec(dllimport)
#else
# define LIBFOO_SHLIB_EXPORTED
#endif

Here BUILDING_SHARED is an Autoconf variable that you have to define. It ought to evaluate to 1 in a build configured with ‘--enable-shared’, or to 0 in a build configured with ‘--disable-shared’. You may use the following ‘configure.ac’ snippet: 

  if test "$enable_shared" = yes; then
    BUILDING_SHARED=1
  else
    BUILDING_SHARED=0
  fi
  AC_SUBST([BUILDING_SHARED])

And DLL_EXPORT is defined by Libtool, on Windows platforms, when compiling for a shared library (called DLL under Windows). It is not defined when Libtool compiles an object file meant to be linked statically into some executable.

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19.3 LD Version Scripts

The lib-symbol-versions module can be used to add shared library versioning support. Currently, only GNU LD and the Solaris linker supports this.

Version scripts provides information that can be used by GNU/Linux distribution packaging tools. For example, Debian has a tool dpkg-shlibdeps that can determine the minimal required version of each dependency (by looking at the symbol list) and stuff the information into the Debian specific packaging files.

For more information and other uses of version scripts, see Ulrich Drepper’s paper https://www.akkadia.org/drepper/dsohowto.pdf

You use the module by importing it to your library, and then add the following lines to the Makefile.am that builds the library: 

if HAVE_LD_VERSION_SCRIPT
libfoo_la_LDFLAGS += -Wl,--version-script=$(srcdir)/libfoo.map
endif

The version script file format is documented in the GNU LD manual, but a small example would be: 

LIBFOO_1.0 {
  global:
    libfoo_init; libfoo_doit; libfoo_done;

  local:
    *;
};

If you target platforms that do not support linker scripts (i.e., all platforms that doesn’t use GNU LD) you may want to consider a more portable but less powerful alternative: libtool -export-symbols. It will hide internal symbols from your library, but will not add ELF versioning symbols. Your usage would then be something like: 

if HAVE_LD_VERSION_SCRIPT
libfoo_la_LDFLAGS += -Wl,--version-script=$(srcdir)/libfoo.map
else
libfoo_la_LDFLAGS += -export-symbols $(srcdir)/libfoo.sym
endif

See the Libtool manual for the file syntax, but a small example would be: 

libfoo_init
libfoo_doit
libfoo_done

To avoid the need for a *.sym file if your symbols are easily expressed using a regular expression, you may use -export-symbols-regex: 

if HAVE_LD_VERSION_SCRIPT
libfoo_la_LDFLAGS += -Wl,--version-script=$(srcdir)/libfoo.map
else
libfoo_la_LDFLAGS += -export-symbols-regex '^libfoo_.*'
endif

For more discussions about symbol visibility, rather than shared library versioning, see the lib-symbol-visibility module (see Controlling the Exported Symbols of Shared Libraries).

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19.4 configmake

The configmake module builds a C include file named configmake.h containing the usual installation directory values; for example, those specified by --prefix or --libdir to configure. Each variable is given a #define with an all-uppercase macro name, such as PREFIX and LIBDIR. (Automake cannot create this file directly because the user might override directory values at make time.)

Specifically, the module retrieves values of the variables through configure followed by make, not directly through configure, so that a user who sets some of these variables consistently on the make command line gets correct results.

One advantage of this approach, compared to the classical approach of adding -DLIBDIR=\"$(libdir)\" etc. to AM_CPPFLAGS, is that it protects against the use of undefined variables. That is, if, say, $(libdir) is not set in the Makefile, LIBDIR is not defined by this module, and code using LIBDIR gives a compilation error.

Another advantage is that make output is shorter.

For the complete list of variables which are #defined this way, see the file gnulib/modules/configmake, or inspect your resulting gnulib Makefile.

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19.5 warnings

The warnings module allows to regularly build a package with more GCC warnings than the default warnings emitted by GCC. It is often used indirectly through the manywarnings module (see manywarnings).

It provides the following functionality:

  • You can select some warning options, such as ‘-Wall’, to be enabled whenever building with a GCC version that supports these options. The user can choose to override these warning options by providing the opposite options in the CFLAGS variable at configuration time.
  • You can make these warnings apply to selected directories only. In projects where subprojects are maintained by different people, or where parts of the source code are imported from external sources (for example from gnulib), it is useful to apply different warning options to different directories.
  • It lets you use ‘-Werror’ at ‘make distcheck’ time, to verify that on the maintainer’s system, no warnings remain. (Note that use of ‘-Werror’ in CFLAGS does not work in general, because it may break autoconfiguration.)
  • Similarly, it lets you use ‘-Werror’ when the builder runs configure with an option such as --enable-gcc-warnings.

To use this module, you need the following:

  1. In configure.ac, use for example 
    gl_WARN_ADD([-Wall], [WARN_CFLAGS])
gl_WARN_ADD([-Wpointer-arith], [WARN_CFLAGS])
  2. In the directories which shall use WARN_CFLAGS, use it in the definition of AM_CFLAGS, like this: 
    AM_CFLAGS = $(WARN_CFLAGS)

    Note that the AM_CFLAGS is used in combination with CFLAGS and before CFLAGS in build rules emitted by Automake. This allows the user to provide CFLAGS that override the WARN_CFLAGS.

‘gl_WARN_ADD([-Werror])’ is intended for developers, and should be avoided in contexts where it would affect ordinary installation builds. The warnings emitted by GCC depend, to some extent, on the contents of the system header files, on the size and signedness of built-in types, etc. Use of ‘-Werror’ would cause frustration to all users on platforms that the maintainer has not tested before the release. It is better if ‘-Werror’ is off by default, and is enabled only by developers. For example, ‘-Werror’ could affect ‘make distcheck’ or ‘configure --enable-gcc-warnings’ as mentioned above.

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19.6 manywarnings

The manywarnings module enables many GCC warnings for your package. Here is an example use: 

AC_ARG_ENABLE([gcc-warnings],
  [AS_HELP_STRING([[--enable-gcc-warnings[=TYPE]]],
    [control generation of GCC warnings.  The TYPE 'no' disables
     warnings; 'yes' (default) generates cheap warnings;
     'expensive' in addition generates expensive warnings.])])

AS_IF([test "$enable_gcc_warnings" != no],
  [
   # Set up the list of unwanted warning options.
   nw=
   if test "$enable_gcc_warnings" != expensive; then
     nw="$nw -fanalyzer"
   fi
   nw="$nw -Wbad-function-cast" # Casting a function's result is not more
                                # dangerous than casting any other value.
   nw="$nw -Winline"            # It's OK to not inline.
   nw="$nw -Wsign-compare"      # Too many false alarms.
   nw="$nw -Wstrict-overflow"   # It's OK to optimize strictly.
   nw="$nw -Wsystem-headers"    # Don't warn in system headers.

   # Setup the list of meaningful warning options for the C compiler.
   # The list comes from manywarnings.m4. Warning options that are not
   # generally meaningful have already been filtered out (cf.
   # build-aux/gcc-warning.spec).
   gl_MANYWARN_ALL_GCC([possible_warning_options])

   # Compute the list of warning options that are desired.
   gl_MANYWARN_COMPLEMENT([desired_warning_options],
                          [$possible_warning_options], [$nw])
   # Compute the list of remaining undesired warning options.
   # Namely those, that were not in manywarnings.m4 because they were
   # already listed in build-aux/gcc-warning.spec; this includes those
   # that are implied by -Wall.
   gl_MANYWARN_COMPLEMENT([remaining_undesired_warning_options],
                          [$nw], [$possible_warning_options])

   # Add the desired warning options to WARN_CFLAGS.
   for w in $desired_warning_options; do
     gl_WARN_ADD([$w])
   done

   # Add the opposites of the remaining undesired warning options to
   # WARN_CFLAGS.
   for w in `echo "$remaining_undesired_warning_options" | sed -e 's/-W/-Wno-/g'`; do
     gl_WARN_ADD([$w])
   done
])

This module sets up many GCC warning options.

When you use it for the first time, it is common practice to do it as follows:

  • Start with the newest major release of GCC. This will save you time, because some warning options produce many false alarms with older versions of GCC (such as -Wstrict-overflow or -Wunsafe-loop-optimizations).
  • Consider the platforms commonly used when enabling GCC warnings. This includes not only target architectures and operating systems, but also optimization options, which can greatly affect the warnings generated. Makefiles generated by configure default to -O2 optimization. If you also commonly build with -O0 or other optimization options, you can compile again with those options. Using more optimizations catches more bugs, because the compiler does a better static analysis of the program when optimizing more. Also, some warning options that diagnose suboptimal code generation, such as -Winline, are not effective when not optimizing. On the other hand, if it’s frequent to build the package with warnings but without optimizations, for debugging purposes, then you don’t want to see undesired warnings in these phases of development either.
  • Compile the package with an empty nw value, that is, with all possible warnings enabled.
  • Then you will go through the list of warnings. Since there are likely many warnings, the first time, it’s a good idea to sort them by warning option first: 
    $ grep warning: make-output.log \
  | sed -e 's/^\(.*\) \[\(-W.*\)\]$/\2  \1/' | sort -k1
  • You will likely deactivate warnings that occur often and don’t point to mistakes in the code, by adding them to the ‘nw’ variable, then reconfiguring and recompiling. When warnings point to real mistakes and bugs in the code, you will of course not disable them but fix your code to silence the warning instead.

    Many GCC warning options usually don’t point to mistakes in the code; these warnings enforce a certain programming style. It is a project management decision whether you want your code to follow any of these styles. Note that some of these programming styles are conflicting. You cannot have them all; you have to choose among them.

    When a warning option pinpoints real bugs occasionally, but it also whines about a few code locations which are fine, we recommend to leave the warning option enabled. Whether you then live with the remaining few warnings, or choose to disable them one-by-one through #pragma GCC diagnostic ignored "option" (see Diagnostic Pragmas in Using the GNU Compiler Collection, https://gcc.gnu.org/onlinedocs/gcc/Diagnostic-Pragmas.html), is again a project management decision.

When a new major version of GCC is released, the Gnulib maintainers add the newly available warning options into the gl_MANYWARN_ALL_GCC macro. You will then enjoy the benefits of the new warnings, simply by updating to the newest Gnulib. If some of the new warnings are undesired, you can add them to the ‘nw’ variable, as described above.

Comments on particular warning flags:

‘-fanalyzer’

The manywarnings module by default uses GCC’s -fanalyzer option, as this issues some useful warnings. (It can also help GCC generate better code.) However, -fanalyzer can greatly slow down compilation, and in programs with large modules it can be so slow as to be unusable, so it is common for configure to disable it unless configure is given an option like --enable-gcc-warnings=expensive.

‘-fstrict-aliasing’

Although the manywarnings module does not enable GCC’s -fstrict-aliasing option, it is enabled by default if you compile with -O2 or higher optimization, and can help GCC generate better warnings.

‘-Wanalyzer-malloc-leak’

The -fanalyzer option generates many false alarms about malloc leaks, which manywarnings suppresses by also using -Wno-analyzer-malloc-leak.

‘-fstrict-flex-arrays’

The manywarnings module by default uses GCC’s -fstrict-flex-arrays option if available, so that GCC can warn about nonportable usage of flexible array members. In a few cases this can help GCC generate better code, so it is not strictly a warning option.

‘-Wsign-compare’

GCC and Clang generate too many false alarms with -Wsign-compare, and we don’t recommend that warning. You can disable it by using gl_WARN_ADD([-Wno-sign-compare]) as illustrated above. Programs using Gnulib generally don’t enable that warning when compiling Gnulib code. If you happen to find a real bug with that warning we’d like to know it.

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19.7 Running self-tests under valgrind

For projects written in C or similar languages, running the self-tests under Valgrind can reveal hard to find memory issues. Gnulib supports two ways to make use of Valgrind: one that enables use of Valgrind at configure time, when configure found it to be present; and one at the discretion of the developer.

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19.7.1 Using valgrind without developer intervention

The valgrind-tests module searches for Valgrind at configure time and declares the LOG_VALGRIND automake variable for use with automake’s LOG_COMPILER.

After importing the valgrind-tests module to your project, you use it by adding the following to the Makefile.am that runs the self-tests: 

LOG_COMPILER = $(LOG_VALGRIND)

This will run all self-checks under valgrind.

Replace LOG_COMPILER with TESTS_ENVIRONMENT if you are using the old serial test harness. The parallel test harness has been the default in automake since version 1.11.3, but if you are using an older automake, or put ‘serial-tests’ in ‘AM_INIT_AUTOMAKE’/‘AUTOMAKE_OPTIONS’ you would still be using the serial test harness.

If you desire a project-wide decision that valgrind is not enabled by default, but still allow users to enable it with --enable-valgrind-tests you may put the following in configure.ac before gl_INIT. 

gl_VALGRIND_TESTS_DEFAULT_NO

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19.7.2 Valgrind options

The VALGRIND variable holds the name of the valgrind binary and some options passed to valgrind. You may provide additional options that are passed to valgrind using the ‘VALGRINDFLAGS’ variable, for example: 

./configure VALGRINDFLAGS="--suppressions=~/local.supp"

Alternatively during build phase: 

make check VALGRINDFLAGS="--suppressions=~/local.supp"

This is useful if you have a valgrind suppression files that are needed to avoid triggering errors for known errors, typically in system libraries.

The VALGRIND variable include options that are useful when valgrind is run non-interactively through the test harness. The default parameters are -q to silence the output, --error-exitcode=1 to cause valgrind errors to be treated as fatal errors, and --leak-check=full to check for memory leaks.

These options can be controlled through the DEFAULT_VALGRINDFLAGS variable. For example, when configuring the package: 

./configure DEFAULT_VALGRINDFLAGS="--quiet"

Alternatively, during the build phase: 

make check DEFAULT_VALGRINDFLAGS="--quiet"

That would have the effect of removing --error-exitcode=1 and --leak-check=full from the default options, thus causing any valgrind errors to be silently ignored, instead of causing fatal test failures.

As a developer you may use the variables in configure.ac before calling gl_INIT, like this if your program has deeply-nested call chains: 

gl_EARLY
...
VALGRINDFLAGS="$VALGRINDFLAGS --num-callers=42"
...
gl_INIT

Note that any user-supplied VALGRINDFLAGS value is preserved, which is usually what you want.

Finally, as a developer you may want to provide additional per-directory options to valgrind and the AM_VALGRINDFLAGS variable can be used for this. For example: 

AM_VALGRINDFLAGS = --suppressions=$(srcdir)/local-valgrind.supp
LOG_COMPILER = $(LOG_VALGRIND)

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19.7.3 Using valgrind at the developer’s discretion

In this approach, you define a Makefile.am variable ‘VALGRIND’ (or, more abstractly, ‘CHECKER’), that is usually set to empty. When you have configured and built the package and you decide that you want to run the tests with valgrind, you do so by modifying the definition of ‘VALGRIND’ in the Makefile.

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19.7.4 How to use Valgrind with shell scripts

It is not desirable to apply valgrind to shell scripts or other non-binaries, because

  • It is wasteful, and you usually don’t want to look for memory leaks in bash.
  • On a bi-arch system, you may get an error message such as "valgrind: wrong executable class (eg. 32-bit instead of 64-bit)".

There are two ways to avoid this:

  • Using the Automake parallel-tests feature, you can use the following instead: 
    TEST_EXTENSIONS = .pl .sh
LOG_COMPILER = $(LOG_VALGRIND)

    Then valgrind will only be used for the non-.sh and non-.pl tests.

    For old automake (before 1.11.3), you will need AUTOMAKE_OPTIONS = parallel-tests to enable the parallel test harness.

  • You can make use of the build-aux/run-test script from Gnulib. Add these lines to your Makefile.am: 
    LOG_COMPILER += $(SHELL) $(top_srcdir)/build-aux/run-test '$(LOG_VALGRIND)'

    Replace LOG_COMPILER with TESTS_ENVIRONMENT if you use the old serial test harness.

However, with this measure in place, binaries invoked through scripts will not be invoked under valgrind. This can be solved by defining environment variables in the TESTS_ENVIRONMENT variable that are then used by the shell scripts. For example, add the following: 

TESTS_ENVIRONMENT = VALGRIND='$(LOG_VALGRIND)'

And then modify the shell scripts to invoke the binary prefixed with $VALGRIND.

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19.8 VCS To ChangeLog

Gnulib provides the ‘vcs-to-changelog’ module to generate an output similar to the GNU ChangeLog format from metadata of source control software such as git. Here’s an example of using ‘vcs-to-changelog’: 

build-aux/vcs-to-changelog.py <from_ref> <to_ref>

where <from_ref> and <to_ref> refer to the range of commits to generate the output.

VCS To ChangeLog currently recognises changes in C source code and can traverse commits in git. Additional source frontends and source control backends may be added to the module. ‘vcs-to-changelog’ takes the following optional arguments:

  • -d: Run the parser debugger, used for debugging ‘vcs-to-changelog’
  • -q filename: Load filename as the quirks file for the project.

The quirks file is a python module that must minimally implement a get_project_quirks function that returns an object of type ProjectQuirks or its subclass. The subclass may override the following members of ProjectQuirks:

  • repo: Specify the project repo source control. The default value is git.
  • IGNORE_LIST: A list of files to ignore in the changesets, either because they are not needed (such as the ChangeLog) or because they are not parseable. For example, the GNU C Library has a header file that is only assembly code, which breaks the C parser.
  • MACRO_QUIRKS: A list of dictionary entries with indexes as orig and sub where orig is a Python regular expression pattern to match and sub is the substitution. These substitutions are used to work around C/C++ macros that are known to break parsing of C programs.
  • C_MACROS: This is a list of C preprocessor macro definitions that are extensively used and are known to break parsing due to some characteristic, mainly the lack of a semicolon at the end.

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19.9 gitlog-to-changelog

Gnulib have a module gitlog-to-changelog to parse git log output and generate ChangeLog files, see https://www.gnu.org/prep/standards/html_node/Change-Logs.html.

You would typically use it by extending the dist-hook in the top-level Makefile.am like this: 

dist-hook: gen-ChangeLog
...
.PHONY: gen-ChangeLog
gen-ChangeLog:
        $(AM_V_GEN)if test -e .git; then                               \
                $(top_srcdir)/build-aux/gitlog-to-changelog >          \
                        $(distdir)/cl-t &&                             \
                { rm -f $(distdir)/ChangeLog &&                        \
                  mv $(distdir)/cl-t $(distdir)/ChangeLog; }           \
        fi

See gitlog-to-changelog --help for complete documentation.

The tool prints timestamps using localtime, so its output may be different depending on what locale the developer that runs the tool is using. If your project desire reproducible ChangeLog files that doesn’t depend on locale settings, use something like the following. 

gen-ChangeLog:
        $(AM_V_GEN)if test -e .git; then                               \
                env LC_ALL=en_US.UTF-8 TZ=UTC=0                        \
                        $(top_srcdir)/build-aux/gitlog-to-changelog >  \
                        $(distdir)/cl-t &&                             \
                { rm -f $(distdir)/ChangeLog &&                        \
                  mv $(distdir)/cl-t $(distdir)/ChangeLog; }           \
        fi

If you wish to limit the ChangeLog entries (perhaps for size issues) to only contain entries since a particular git tag, use something like the following: 

dist-hook: gen-ChangeLog
...
gen_start_ver = 8.31
.PHONY: gen-ChangeLog
gen-ChangeLog:
        $(AM_V_GEN)if test -e .git; then                               \
          log_fix="$(srcdir)/build-aux/git-log-fix";                   \
          test -e "$$log_fix"                                          \
            && amend_git_log="--amend=$$log_fix"                       \
            || amend_git_log=;                                         \
          $(top_srcdir)/build-aux/gitlog-to-changelog $$amend_git_log  \
            -- v$(gen_start_ver)~.. > $(distdir)/cl-t &&               \
            { printf '\n\nSee the source repo for older entries\n'     \
              >> $(distdir)/cl-t &&                                    \
              rm -f $(distdir)/ChangeLog &&                            \
              mv $(distdir)/cl-t $(distdir)/ChangeLog; }               \
        fi

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20 Build Infrastructure Files

Gnulib contains also a small number of files that are not part of modules. They are meant to be imported into packages by means of ‘gnulib-tool --copy-file’, not ‘gnulib-tool --import’. For example, the commands to import the files config.guess and config.sub are 

for file in config.guess config.sub; do
  $GNULIB_TOOL --copy-file build-aux/$file \
    && chmod a+x build-aux/$file \
    || exit $?
done

Packages that don’t use Gnulib can get hold of these files through direct download from Gnulib’s git repository. The commands to do this look as follows: 

for file in config.guess config.sub; do
  echo "$0: getting $file..."
  wget -q --timeout=5 -O build-aux/$file.tmp "https://git.savannah.gnu.org/gitweb/?p=gnulib.git;a=blob_plain;f=build-aux/${file};hb=HEAD" \
    && mv build-aux/$file.tmp build-aux/$file \
    && chmod a+x build-aux/$file
  retval=$?
  rm -f build-aux/$file.tmp
  test $retval -eq 0 || exit $retval
done

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20.1 Recognizing platforms

build-aux/config.guess
build-aux/config.sub

These files are helper scripts, invoked by the ‘configure’ script. config.guess recognizes the platform on which the script is running, and produces a triplet of the form cpu-type-vendor-operating_system. config.sub receives a possibly abbreviated triplet and produces a canonical triplet for a platform. For more information, see https://www.gnu.org/prep/standards/html_node/Configuration.html.

It is important that you always include the newest versions of these two files in your tarball, because people who work on emerging platforms otherwise have a hard time building your package.

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20.2 Utilities for Makefiles

These programs can be used in Makefiles. Some of them are also described in https://www.gnu.org/software/automake/manual/html_node/Auxiliary-Programs.html.

build-aux/ar-lib
build-aux/compile

These two scripts are necessary for supporting portability to native Windows with the MSVC compiler. compile is a wrapper script that invokes the compiler and provides a command-line interface compatible with Unix compilers. Similarly, ar-lib is a wrapper script that provides a command-line interface compatible with Unix ar.

build-aux/depcomp

This is a helper script, used by Makefile rules generated by GNU Automake. It generates Makefile dependencies while compiling a file.

build-aux/install-sh

This is a helper script, used by Makefile rules generated by GNU Automake. It installs files during the make install phase. In the Makefile, don’t use this file directly; always use $(INSTALL_PROGRAM) or $(INSTALL_DATA) instead.

build-aux/mdate-sh

This script determines the modification time of a file and pretty-prints it. The typical use is to add a “Last modified” line to the documentation.

build-aux/mkinstalldirs

This is a helper script, used by Makefile rules generated by GNU Automake. It creates directories during the make install phase. It is roughly equivalent to ‘mkdir -p’ (except that the latter is not portable). In the Makefile, don’t use this file directly; always use $(MKDIR_P) instead.

build-aux/mktempd

This script creates a temporary directory. It is roughly equivalent to ‘mktemp -d’ (except that the latter is not portable).

build-aux/move-if-change

This script moves a freshly generated file to a destination file, with a special optimization for the case that both files are identical. In this case the freshly generated file is deleted, and the time stamp of the destination file is not changed. This is useful when updating a file that rarely actually changes and which many Makefile targets depend upon.

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20.3 Programs for developing in Git checkouts

These programs can help when developing in a Git checkout. The maintainer of the package copies these programs into the version control of the package, so that co-developers can use these tools right away.

top/gitsub.sh

This program manages the subdirectories of a Git checkout that come from other packages, including Gnulib.

top/bootstrap
top/autopull.sh
top/autogen.sh
top/bootstrap-funclib.sh

This is a set of three programs and a function library, that manage the source directory of a package, preparing for the state where ‘./configure’ can be used.

autopull.sh is a program for fetching dependencies that may require network accesses. It manages the Git submodules, including Gnulib – assuming that Gnulib is a Git submodule. It also can fetch the PO files for internationalized packages.

autogen.sh is a program that is meant to be run after autopull.sh. It generates all autogeneratable files that are omitted from version control. Usually this means that it invokes gnulib-tool and automake, that generate files from other files.

bootstrap is a wrapper around both: ./bootstrap --pull is equivalent to ./autopull.sh, ./bootstrap --gen is equivalent to ./autogen.sh. Plain ./bootstrap is equivalent to ./autopull.sh immediately followed by ./autogen.sh; however, because plain ./bootstrap mixes version control management and generation of files in non-obvious ways, it has a number of usability issues for the advanced developer.

bootstrap-funclib.sh is a function library for these three programs. It is not meant to be used directly.

All three programs make use of a configuration file, called bootstrap.conf.

build-aux/bootstrap

This acts like top/bootstrap, except it does not need the companion files autogen.sh, autopull.sh, and bootstrap-funclib.sh so it avoids some clutter in your project’s top level directory. With this approach, you update via ./bootstrap --pull and ./bootstrap --gen instead of via ./autopull.sh and ./autogen.sh. Otherwise this approach acts similarly, and uses the same bootstrap.conf file.

build-aux/bootstrap.conf

This is the template configuration file. After copying it into the top-level directory of your package, you need to customize it.

build-aux/po/Makefile.in.in
build-aux/po/remove-potcdate.sin

These are auxiliary files used by bootstrap. You don’t have to copy them yourself; bootstrap will do that.

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20.4 Utilities for building documentation

These are auxiliary files for building documentation.

build-aux/texinfo.tex

This file is needed for the conversion of Texinfo-format documentation to PDF, PostScript, or DVI formats. It implements the GNU Texinfo commands on top of plain TeX.

build-aux/x-to-1.in

This file, once processed, gives a program x-to-1, that produces a manual page for a program, by combining a skeleton with the program’s --help output.

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20.5 Utilities for building libraries

build-aux/declared.sh

This program extracts the declared global symbols of a C header file. It is useful when you want to control the set of symbols exported by a library. See Controlling the Exported Symbols of Shared Libraries.

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20.6 Utilities for running test suites

build-aux/run-test

This file is a test driver that supports running a test under valgrind.

build-aux/test-driver.diff

This is a patch, against Automake’s test driver, that supports running a test suite on Android.

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21 Release Management Files

Gnulib also contain a few scripts that are useful for the release management of a package. They can be used directly off the Gnulib checkout; they don’t need to copied first.

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21.1 Tools for releasing packages with shared libraries

build-aux/libtool-next-version

This program is a wizard that helps a maintainer update the libtool version of a shared library, without making mistakes in this process. For background documentation, see https://www.gnu.org/software/libtool/manual/html_node/Updating-version-info.html.

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21.2 Tools for uploading release tarballs

build-aux/gnupload

This program is a user-friendly way to upload a release tarball to one of the GNU servers (ftp.gnu.org or alpha.gnu.org). It implements the interface described in https://www.gnu.org/prep/maintain/html_node/Automated-FTP-Uploads.html.

build-aux/ncftpput-ftp

This is a helper program that mimics the ncftpput program used by gnupload. If you want to use gnupload but don’t have ncftp installed, copy this file into your $PATH, renaming it to ncftpput.

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Appendix A GNU Free Documentation License

Version 1.3, 3 November 2008 
Copyright © 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
https://fsf.org/

Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
  1. PREAMBLE

    The purpose of this License is to make a manual, textbook, or other functional and useful document free in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others.

    This License is a kind of “copyleft”, which means that derivative works of the document must themselves be free in the same sense. It complements the GNU General Public License, which is a copyleft license designed for free software.

    We have designed this License in order to use it for manuals for free software, because free software needs free documentation: a free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless of subject matter or whether it is published as a printed book. We recommend this License principally for works whose purpose is instruction or reference.

  2. APPLICABILITY AND DEFINITIONS

    This License applies to any manual or other work, in any medium, that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License. Such a notice grants a world-wide, royalty-free license, unlimited in duration, to use that work under the conditions stated herein. The “Document”, below, refers to any such manual or work. Any member of the public is a licensee, and is addressed as “you”. You accept the license if you copy, modify or distribute the work in a way requiring permission under copyright law.

    A “Modified Version” of the Document means any work containing the Document or a portion of it, either copied verbatim, or with modifications and/or translated into another language.

    A “Secondary Section” is a named appendix or a front-matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document’s overall subject (or to related matters) and contains nothing that could fall directly within that overall subject. (Thus, if the Document is in part a textbook of mathematics, a Secondary Section may not explain any mathematics.) The relationship could be a matter of historical connection with the subject or with related matters, or of legal, commercial, philosophical, ethical or political position regarding them.

    The “Invariant Sections” are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the Document is released under this License. If a section does not fit the above definition of Secondary then it is not allowed to be designated as Invariant. The Document may contain zero Invariant Sections. If the Document does not identify any Invariant Sections then there are none.

    The “Cover Texts” are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice that says that the Document is released under this License. A Front-Cover Text may be at most 5 words, and a Back-Cover Text may be at most 25 words.

    A “Transparent” copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, that is suitable for revising the document straightforwardly with generic text editors or (for images composed of pixels) generic paint programs or (for drawings) some widely available drawing editor, and that is suitable for input to text formatters or for automatic translation to a variety of formats suitable for input to text formatters. A copy made in an otherwise Transparent file format whose markup, or absence of markup, has been arranged to thwart or discourage subsequent modification by readers is not Transparent. An image format is not Transparent if used for any substantial amount of text. A copy that is not “Transparent” is called “Opaque”.

    Examples of suitable formats for Transparent copies include plain ASCII without markup, Texinfo input format, LaTeX input format, SGML or XML using a publicly available DTD, and standard-conforming simple HTML, PostScript or PDF designed for human modification. Examples of transparent image formats include PNG, XCF and JPG. Opaque formats include proprietary formats that can be read and edited only by proprietary word processors, SGML or XML for which the DTD and/or processing tools are not generally available, and the machine-generated HTML, PostScript or PDF produced by some word processors for output purposes only.

    The “Title Page” means, for a printed book, the title page itself, plus such following pages as are needed to hold, legibly, the material this License requires to appear in the title page. For works in formats which do not have any title page as such, “Title Page” means the text near the most prominent appearance of the work’s title, preceding the beginning of the body of the text.

    The “publisher” means any person or entity that distributes copies of the Document to the public.

    A section “Entitled XYZ” means a named subunit of the Document whose title either is precisely XYZ or contains XYZ in parentheses following text that translates XYZ in another language. (Here XYZ stands for a specific section name mentioned below, such as “Acknowledgements”, “Dedications”, “Endorsements”, or “History”.) To “Preserve the Title” of such a section when you modify the Document means that it remains a section “Entitled XYZ” according to this definition.

    The Document may include Warranty Disclaimers next to the notice which states that this License applies to the Document. These Warranty Disclaimers are considered to be included by reference in this License, but only as regards disclaiming warranties: any other implication that these Warranty Disclaimers may have is void and has no effect on the meaning of this License.

  3. VERBATIM COPYING

    You may copy and distribute the Document in any medium, either commercially or noncommercially, provided that this License, the copyright notices, and the license notice saying this License applies to the Document are reproduced in all copies, and that you add no other conditions whatsoever to those of this License. You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute. However, you may accept compensation in exchange for copies. If you distribute a large enough number of copies you must also follow the conditions in section 3.

    You may also lend copies, under the same conditions stated above, and you may publicly display copies.

  4. COPYING IN QUANTITY

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  5. MODIFICATIONS

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    1. Use in the Title Page (and on the covers, if any) a title distinct from that of the Document, and from those of previous versions (which should, if there were any, be listed in the History section of the Document). You may use the same title as a previous version if the original publisher of that version gives permission.
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    5. Add an appropriate copyright notice for your modifications adjacent to the other copyright notices.
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    7. Preserve in that license notice the full lists of Invariant Sections and required Cover Texts given in the Document’s license notice.
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    9. Preserve the section Entitled “History”, Preserve its Title, and add to it an item stating at least the title, year, new authors, and publisher of the Modified Version as given on the Title Page. If there is no section Entitled “History” in the Document, create one stating the title, year, authors, and publisher of the Document as given on its Title Page, then add an item describing the Modified Version as stated in the previous sentence.
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    13. Delete any section Entitled “Endorsements”. Such a section may not be included in the Modified Version.
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    15. Preserve any Warranty Disclaimers.

    If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as invariant. To do this, add their titles to the list of Invariant Sections in the Modified Version’s license notice. These titles must be distinct from any other section titles.

    You may add a section Entitled “Endorsements”, provided it contains nothing but endorsements of your Modified Version by various parties—for example, statements of peer review or that the text has been approved by an organization as the authoritative definition of a standard.

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  6. COMBINING DOCUMENTS

    You may combine the Document with other documents released under this License, under the terms defined in section 4 above for modified versions, provided that you include in the combination all of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice, and that you preserve all their Warranty Disclaimers.

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    In the combination, you must combine any sections Entitled “History” in the various original documents, forming one section Entitled “History”; likewise combine any sections Entitled “Acknowledgements”, and any sections Entitled “Dedications”. You must delete all sections Entitled “Endorsements.”

  7. COLLECTIONS OF DOCUMENTS

    You may make a collection consisting of the Document and other documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects.

    You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted document, and follow this License in all other respects regarding verbatim copying of that document.

  8. AGGREGATION WITH INDEPENDENT WORKS

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    If the Cover Text requirement of section 3 is applicable to these copies of the Document, then if the Document is less than one half of the entire aggregate, the Document’s Cover Texts may be placed on covers that bracket the Document within the aggregate, or the electronic equivalent of covers if the Document is in electronic form. Otherwise they must appear on printed covers that bracket the whole aggregate.

  9. TRANSLATION

    Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License, and all the license notices in the Document, and any Warranty Disclaimers, provided that you also include the original English version of this License and the original versions of those notices and disclaimers. In case of a disagreement between the translation and the original version of this License or a notice or disclaimer, the original version will prevail.

    If a section in the Document is Entitled “Acknowledgements”, “Dedications”, or “History”, the requirement (section 4) to Preserve its Title (section 1) will typically require changing the actual title.

  10. TERMINATION

    You may not copy, modify, sublicense, or distribute the Document except as expressly provided under this License. Any attempt otherwise to copy, modify, sublicense, or distribute it is void, and will automatically terminate your rights under this License.

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    Termination of your rights under this section does not terminate the licenses of parties who have received copies or rights from you under this License. If your rights have been terminated and not permanently reinstated, receipt of a copy of some or all of the same material does not give you any rights to use it.

  11. FUTURE REVISIONS OF THIS LICENSE

    The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See https://www.gnu.org/licenses/.

    Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License “or any later version” applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation. If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation. If the Document specifies that a proxy can decide which future versions of this License can be used, that proxy’s public statement of acceptance of a version permanently authorizes you to choose that version for the Document.

  12. RELICENSING

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    “Incorporate” means to publish or republish a Document, in whole or in part, as part of another Document.

    An MMC is “eligible for relicensing” if it is licensed under this License, and if all works that were first published under this License somewhere other than this MMC, and subsequently incorporated in whole or in part into the MMC, (1) had no cover texts or invariant sections, and (2) were thus incorporated prior to November 1, 2008.

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ADDENDUM: How to use this License for your documents

To use this License in a document you have written, include a copy of the License in the document and put the following copyright and license notices just after the title page: 

  Copyright (C)  year  your name.
  Permission is granted to copy, distribute and/or modify this document
  under the terms of the GNU Free Documentation License, Version 1.3
  or any later version published by the Free Software Foundation;
  with no Invariant Sections, no Front-Cover Texts, and no Back-Cover
  Texts.  A copy of the license is included in the section entitled ``GNU
  Free Documentation License''.

If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, replace the “with…Texts.” line with this: 

    with the Invariant Sections being list their titles, with
    the Front-Cover Texts being list, and with the Back-Cover Texts
    being list.

If you have Invariant Sections without Cover Texts, or some other combination of the three, merge those two alternatives to suit the situation.

If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.

Next: , Previous: , Up: GNU Gnulib   [Contents][Index]

Appendix B Gnulib history

In the beginning, Richard Stallman maintained the regular expression engine of GNU and made it available to other GNU packages, such as sed, awk, grep, so that they could use the same engine. Recall that there was no GNU C library at the time.

A couple of years later, Jim Meyering, who was maintaining the shell utilities, the file utilities, and the text processing utilities, collected the common parts of these three packages in the same repository. Paul Eggert joined in, with code coming from a few GNU packages that he maintained, and so did Bruno Haible, with reusable code from the GNU gettext package.

As they cared for portability, many changes in the C code were accompanied by changes in the build infrastructure. Copying these changes into packages — it was all done manually — became cumbersome. So they wrote a program, called ‘gnulib-tool’, that does this job of copying the requested shared code into a particular package. This was in 2002.

Providing a substitute / override for a system function was relatively easy. Providing a substitute / override for a system header file was significantly harder, but was done successively: for stdint.h in 2004, for stdarg.h, sys/socket.h, sys/stat.h in 2006, for sys/time.h, wchar.h in 2007, and the development of the corresponding idioms took until 2010.

Unicode string modules (that make up GNU libunistring) were added in 2007–2009.

Modules for numeric functions (<math.h>) were added in 2010–2011.

Modules for container data structures were added between 2006 and 2018.

Versatile bit-set modules were added in 2018.

POSIX threads on non-POSIX platforms, as well as ISO C threads on all platforms, were added in 2019.

The posix_spawn facility was brought to completion on native Windows in 2022, providing the world’s first posix_spawn implementation for this platform.

Support for Android was added in 2023 and immediately used by GNU Emacs for Android.

Functions for working with Unicode characters in multibyte representation, based on mbrtoc32, were added in 2023.

Modules for manipulating the floating-point environment (fenv.h) were added in 2023.

The ‘gnulib-tool’ rewrite in Python, that was started by Dmitry Selyutin in 2012 but lay unfinished for many years, was completed by Collin Funk and Bruno Haible in 2024.

Previous: , Up: GNU Gnulib   [Contents][Index]

Index

Jump to:   $   (   )   *   +   -   .   =   ?   [   \   ]   ^   _   {   |   }  
A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y  
Index Entry  Section
$
$: Match-end-of-line Operator
(
(: Grouping Operators
)
): Grouping Operators
*
‘*’: Match-zero-or-more Operator
+
‘+’: Match-one-or-more Operator
-
‘-’: List Operators
.
‘.’: Match-any-character Operator
=
‘=]’ in regex: Equivalence Class Operators
?
‘?’: Match-zero-or-one Operator
[
‘[’: List Operators
‘[=’ in regex: Equivalence Class Operators
‘[colon’ in regex: Character Class Operators
‘[^’: List Operators
\
\: The Backslash Character
‘\’: List Operators
‘\'’: Match-end-of-string Operator
\(: Grouping Operators
\): Grouping Operators
‘\<’: Match-beginning-of-word Operator
‘\>’: Match-end-of-word Operator
‘\b’: Match-word-boundary Operator
‘\B’: Match-within-word Operator
‘\s’: Match-space Operator
‘\S’: Match-non-space Operator
‘\w’: Match-word-constituent Operator
‘\W’: Match-non-word-constituent Operator
‘\`’: Match-beginning-of-string Operator
‘\{’: Interval Operators
\|: Alternation Operator
‘\}’: Interval Operators
]
‘]’: List Operators
^
^: Match-beginning-of-line Operator
‘^’: List Operators
_
_dl_find_object: _dl_find_object
_Exit: _Exit
_exit: _exit
_Fork: _Fork
_GL_EXTERN_INLINE: extern inline
_GL_INLINE: extern inline
_GL_INLINE_HEADER_BEGIN: extern inline
_GL_INLINE_HEADER_END: extern inline
_longjmp: _longjmp
_Noreturn: Non-returning Functions
_setjmp: _setjmp
_tolower: _tolower
_toupper: _toupper
__attribute__: Attributes
__libc_single_threaded: __libc_single_threaded
__VA_ARGS__: C99 features assumed
{
‘{’: Interval Operators
|
|: Alternation Operator
}
‘}’: Interval Operators
A
a64l: a64l
abort: abort
Aborting execution: Out of memory handling
abs: abs
accept: accept
accept4: accept4
access: access
acct: acct
acos: acos
acosf: acosf
acosh: acosh
acoshf: acoshf
acoshl: acoshl
acosl: acosl
AC_LIB_HAVE_LINKFLAGS(name, [dependencies], [includes], [testcode], [missing-message]): Searching for Libraries
AC_LIB_LINKFLAGS(name, [dependencies]): Searching for Libraries
addmntent: addmntent
addseverity: addseverity
adjtime: adjtime
adjtimex: adjtimex
advance: advance
aio_cancel: aio_cancel
aio_error: aio_error
aio_fsync: aio_fsync
aio_init: aio_init
aio_read: aio_read
aio_return: aio_return
aio_suspend: aio_suspend
aio_write: aio_write
alarm: alarm
aligned_alloc: aligned_alloc
ALLOC: Safe Allocation Macros
alloca: alloca
alloca: alloca-opt
allocated initialization: GNU Regular Expression Compiling
ALLOC_N: Safe Allocation Macros
ALLOC_N_UNINITIALIZED: Safe Allocation Macros
alphasort: alphasort
alternation operator: Alternation Operator
alternation operator and ‘^’: Match-beginning-of-line Operator
anchoring: Anchoring Operators
anchors: Match-beginning-of-line Operator
anchors: Match-end-of-line Operator
arc4random: arc4random
arc4random_buf: arc4random_buf
arc4random_uniform: arc4random_uniform
argp_error: argp_error
argp_err_exit_status: argp_err_exit_status
argp_failure: argp_failure
argp_help: argp_help
argp_parse: argp_parse
argp_program_bug_address: argp_program_bug_address
argp_program_version: argp_program_version
argp_program_version_hook: argp_program_version_hook
argp_state_help: argp_state_help
argp_usage: argp_usage
argz_add: argz_add
argz_add_sep: argz_add_sep
argz_append: argz_append
argz_count: argz_count
argz_create: argz_create
argz_create_sep: argz_create_sep
argz_delete: argz_delete
argz_extract: argz_extract
argz_insert: argz_insert
argz_next: argz_next
argz_replace: argz_replace
argz_stringify: argz_stringify
asctime: asctime
asctime_r: asctime_r
asin: asin
asinf: asinf
asinh: asinh
asinhf: asinhf
asinhl: asinhl
asinl: asinl
asprintf: asprintf
assert: assert
assertion: Compile-time Assertions
atan: atan
atan2: atan2
atan2f: atan2f
atan2l: atan2l
atanf: atanf
atanh: atanh
atanhf: atanhf
atanhl: atanhl
atanl: atanl
atexit: atexit
atof: atof
atoi: atoi
atol: atol
atoll: atoll
Attributes: Attributes
authdes_create: authdes_create
authdes_getucred: authdes_getucred
authdes_pk_create: authdes_pk_create
authnone_create: authnone_create
authunix_create: authunix_create
authunix_create_default: authunix_create_default
autopoint, caveat: gettextize and autopoint
Awk: Predefined Syntaxes
B
back-references: Back-reference Operator
backtrace: backtrace
backtrace_symbols: backtrace_symbols
backtrace_symbols_fd: backtrace_symbols_fd
backtracking: Match-zero-or-more Operator
backtracking: Alternation Operator
basename: basename
bcmp: bcmp
bcopy: bcopy
bdflush: bdflush
beginning-of-line operator: Match-beginning-of-line Operator
bind: bind
bindresvport: bindresvport
bindtextdomain: bindtextdomain
bind_textdomain_codeset: bind_textdomain_codeset
block size: stat-size
bracket expression: List Operators
brk: brk
bsd_signal: bsd_signal
bsearch: bsearch
bswap_16: bswap_16
bswap_32: bswap_32
bswap_64: bswap_64
btowc: btowc
buffer field, set by re_compile_pattern: GNU Regular Expression Compiling
buffer initialization: GNU Regular Expression Compiling
bzero: bzero
C
C++ header files: Header files
C++ tests modules: Extra tests modules
c16rtomb: c16rtomb
c32rtomb: c32rtomb
c8rtomb: c8rtomb
cabs: cabs
cabsf: cabsf
cabsl: cabsl
cacos: cacos
cacosf: cacosf
cacosh: cacosh
cacoshf: cacoshf
cacoshl: cacoshl
cacosl: cacosl
calloc: calloc
callrpc: callrpc
call_once: call_once
canonicalize: canonicalize
canonicalizef: canonicalizef
canonicalizel: canonicalizel
canonicalize_file_name: canonicalize_file_name
capget: capget
capset: capset
carg: carg
cargf: cargf
cargl: cargl
casin: casin
casinf: casinf
casinh: casinh
casinhf: casinhf
casinhl: casinhl
casinl: casinl
catan: catan
catanf: catanf
catanh: catanh
catanhf: catanhf
catanhl: catanhl
catanl: catanl
catclose: catclose
catgets: catgets
catopen: catopen
cbrt: cbrt
cbrtf: cbrtf
cbrtl: cbrtl
ccos: ccos
ccosf: ccosf
ccosh: ccosh
ccoshf: ccoshf
ccoshl: ccoshl
ccosl: ccosl
ceil: ceil
ceilf: ceilf
ceill: ceill
cexp: cexp
cexpf: cexpf
cexpl: cexpl
cfgetispeed: cfgetispeed
cfgetospeed: cfgetospeed
cfmakeraw: cfmakeraw
cfree: cfree
cfsetispeed: cfsetispeed
cfsetospeed: cfsetospeed
cfsetspeed: cfsetspeed
changelog: gitlog-to-changelog
character classes: Character Class Operators
chdir: chdir
chmod: chmod
chown: chown
chroot: chroot
cimag: cimag
cimagf: cimagf
cimagl: cimagl
clearenv: clearenv
clearerr: clearerr
clearerr_unlocked: clearerr_unlocked
clntraw_create: clntraw_create
clnttcp_create: clnttcp_create
clntudp_bufcreate: clntudp_bufcreate
clntudp_create: clntudp_create
clntunix_create: clntunix_create
clnt_broadcast: clnt_broadcast
clnt_create: clnt_create
clnt_pcreateerror: clnt_pcreateerror
clnt_perrno: clnt_perrno
clnt_perror: clnt_perror
clnt_spcreateerror: clnt_spcreateerror
clnt_sperrno: clnt_sperrno
clnt_sperror: clnt_sperror
clock: clock
clock_adjtime: clock_adjtime
clock_getcpuclockid: clock_getcpuclockid
clock_getres: clock_getres
clock_gettime: clock_gettime
clock_nanosleep: clock_nanosleep
clock_settime: clock_settime
clog: clog
clog10: clog10
clog10f: clog10f
clog10l: clog10l
clogf: clogf
clogl: clogl
clone: clone
close: close
closedir: closedir
closefrom: closefrom
closelog: closelog
close_range: close_range
cnd_broadcast: cnd_broadcast
cnd_destroy: cnd_destroy
cnd_init: cnd_init
cnd_signal: cnd_signal
cnd_timedwait: cnd_timedwait
cnd_wait: cnd_wait
‘colon]’ in regex: Character Class Operators
comments describing functions: Specification
conditional dependencies: Conditional dependencies
configmake module: configmake
configmake.h, module for updating: configmake
confstr: confstr
conj: conj
conjf: conjf
conjl: conjl
connect: connect
copysign: copysign
copysignf: copysignf
copysignl: copysignl
copy_file_range: copy_file_range
cos: cos
cosf: cosf
cosh: cosh
coshf: coshf
coshl: coshl
cosl: cosl
cpow: cpow
cpowf: cpowf
cpowl: cpowl
cproj: cproj
cprojf: cprojf
cprojl: cprojl
creal: creal
crealf: crealf
creall: creall
creat: creat
crypt: crypt
csin: csin
csinf: csinf
csinh: csinh
csinhf: csinhf
csinhl: csinhl
csinl: csinl
csqrt: csqrt
csqrtf: csqrtf
csqrtl: csqrtl
ctan: ctan
ctanf: ctanf
ctanh: ctanh
ctanhf: ctanhf
ctanhl: ctanhl
ctanl: ctanl
ctermid: ctermid
ctime: ctime
ctime_r: ctime_r
cuserid: cuserid
D
daddl: daddl
daemon: daemon
daylight: daylight
dbm_clearerr: dbm_clearerr
dbm_close: dbm_close
dbm_delete: dbm_delete
dbm_error: dbm_error
dbm_fetch: dbm_fetch
dbm_firstkey: dbm_firstkey
dbm_nextkey: dbm_nextkey
dbm_open: dbm_open
dbm_store: dbm_store
dcgettext: dcgettext
dcngettext: dcngettext
ddivl: ddivl
DEF files: Visual Studio Compatibility
describing functions, locating: Specification
dfmal: dfmal
dgettext: dgettext
difftime: difftime
dirent-safer: Closed standard fds
dirfd: dirfd
dirname: dirname
div: div
dladdr: dladdr
dladdr1: dladdr1
dlclose: dlclose
dlerror: dlerror
dlinfo: dlinfo
dlmopen: dlmopen
dlopen: dlopen
dlsym: dlsym
dlvsym: dlvsym
dl_iterate_phdr: dl_iterate_phdr
dmull: dmull
dngettext: dngettext
dn_comp: dn_comp
dn_expand: dn_expand
dn_skipname: dn_skipname
double inclusion of header files: Header files
dprintf: dprintf
drand48: drand48
drand48_r: drand48_r
drem: drem
dremf: dremf
dreml: dreml
dsqrtl: dsqrtl
dsubl: dsubl
dup: dup
dup2: dup2
dup3: dup3
duplocale: duplocale
dysize: dysize
E
eaccess: eaccess
ecvt: ecvt
ecvt_r: ecvt_r
Egrep: Predefined Syntaxes
Emacs: Predefined Syntaxes
encrypt: encrypt
end in struct re_registers: Using Registers
end-of-line operator: Match-end-of-line Operator
endaliasent: endaliasent
endfsent: endfsent
endgrent: endgrent
endhostent: endhostent
endmntent: endmntent
endnetent: endnetent
endnetgrent: endnetgrent
endprotoent: endprotoent
endpwent: endpwent
endrpcent: endrpcent
endservent: endservent
endsgent: endsgent
endspent: endspent
endttyent: endttyent
endusershell: endusershell
endutent: endutent
endutxent: endutxent
environ: environ
envz_add: envz_add
envz_entry: envz_entry
envz_get: envz_get
envz_merge: envz_merge
envz_remove: envz_remove
envz_strip: envz_strip
epoll_create: epoll_create
epoll_create1: epoll_create1
epoll_ctl: epoll_ctl
epoll_pwait: epoll_pwait
epoll_pwait2: epoll_pwait2
epoll_wait: epoll_wait
equivalence class expression in regex: Equivalence Class Operators
erand48: erand48
erand48_r: erand48_r
erf: erf
erfc: erfc
erfcf: erfcf
erfcl: erfcl
erff: erff
erfl: erfl
err: err
errno: errno
error: error
error: progname and getprogname
error_at_line: error_at_line
error_message_count: error_message_count
error_one_per_line: error_one_per_line
error_print_progname: error_print_progname
errx: errx
ether_aton: ether_aton
ether_aton_r: ether_aton_r
ether_hostton: ether_hostton
ether_line: ether_line
ether_ntoa: ether_ntoa
ether_ntoa_r: ether_ntoa_r
ether_ntohost: ether_ntohost
euidaccess: euidaccess
eventfd: eventfd
eventfd_read: eventfd_read
eventfd_write: eventfd_write
execl: execl
execle: execle
execlp: execlp
execv: execv
execve: execve
execveat: execveat
execvp: execvp
execvpe: execvpe
exit: exit
exp: exp
exp10: exp10
exp10f: exp10f
exp10l: exp10l
exp2: exp2
exp2f: exp2f
exp2l: exp2l
expf: expf
expl: expl
explicit_bzero: explicit_bzero
expm1: expm1
expm1f: expm1f
expm1l: expm1l
EXPR_SIGNED: Arithmetic Type Properties
extern inline: extern inline
Extra tests modules: Extra tests modules
F
fabs: fabs
fabsf: fabsf
fabsl: fabsl
faccessat: faccessat
fadd: fadd
faddl: faddl
fallocate: fallocate
fanotify_init: fanotify_init
fanotify_mark: fanotify_mark
fastmap initialization: GNU Regular Expression Compiling
fastmaps: Searching with Fastmaps
fattach: fattach
fchdir: fchdir
fchmod: fchmod
fchmodat: fchmodat
fchown: fchown
fchownat: fchownat
fclose: fclose
fcloseall: fcloseall
fcntl: fcntl
fcntl-safer: Closed standard fds
fcvt: fcvt
fcvt_r: fcvt_r
fdatasync: fdatasync
fdetach: fdetach
fdim: fdim
fdimf: fdimf
fdiml: fdiml
fdiv: fdiv
fdivl: fdivl
fdopen: fdopen
fdopendir: fdopendir
FD_CLR: FD_CLR
FD_ISSET: FD_ISSET
FD_SET: FD_SET
FD_ZERO: FD_ZERO
feclearexcept: feclearexcept
fedisableexcept: fedisableexcept
feenableexcept: feenableexcept
fegetenv: fegetenv
fegetexcept: fegetexcept
fegetexceptflag: fegetexceptflag
fegetmode: fegetmode
fegetround: fegetround
feholdexcept: feholdexcept
feof: feof
feof_unlocked: feof_unlocked
feraiseexcept: feraiseexcept
ferror: ferror
ferror_unlocked: ferror_unlocked
fesetenv: fesetenv
fesetexcept: fesetexcept
fesetexceptflag: fesetexceptflag
fesetmode: fesetmode
fesetround: fesetround
fetestexcept: fetestexcept
fetestexceptflag: fetestexceptflag
feupdateenv: feupdateenv
fexecve: fexecve
fflush: fflush
fflush_unlocked: fflush_unlocked
ffma: ffma
ffmal: ffmal
ffs: ffs
ffsl: ffsl
ffsll: ffsll
fgetc: fgetc
fgetc_unlocked: fgetc_unlocked
fgetfilecon: fgetfilecon
fgetgrent: fgetgrent
fgetgrent_r: fgetgrent_r
fgetpos: fgetpos
fgetpwent: fgetpwent
fgetpwent_r: fgetpwent_r
fgets: fgets
fgetsgent: fgetsgent
fgetsgent_r: fgetsgent_r
fgetspent: fgetspent
fgetspent_r: fgetspent_r
fgets_unlocked: fgets_unlocked
fgetwc: fgetwc
fgetwc_unlocked: fgetwc_unlocked
fgetws: fgetws
fgetws_unlocked: fgetws_unlocked
fgetxattr: fgetxattr
fileno: fileno
fileno_unlocked: fileno_unlocked
Finding modules: Which modules?
finite: finite
finitef: finitef
finitel: finitel
flistxattr: flistxattr
flock: flock
flockfile: flockfile
floor: floor
floorf: floorf
floorl: floorl
fma: fma
fmaf: fmaf
fmal: fmal
fmax: fmax
fmaxf: fmaxf
fmaximum: fmaximum
fmaximumf: fmaximumf
fmaximuml: fmaximuml
fmaximum_mag: fmaximum_mag
fmaximum_magf: fmaximum_magf
fmaximum_magl: fmaximum_magl
fmaximum_mag_num: fmaximum_mag_num
fmaximum_mag_numf: fmaximum_mag_numf
fmaximum_mag_numl: fmaximum_mag_numl
fmaximum_num: fmaximum_num
fmaximum_numf: fmaximum_numf
fmaximum_numl: fmaximum_numl
fmaxl: fmaxl
fmaxmag: fmaxmag
fmaxmagf: fmaxmagf
fmaxmagl: fmaxmagl
fmemopen: fmemopen
fmin: fmin
fminf: fminf
fminimum: fminimum
fminimumf: fminimumf
fminimuml: fminimuml
fminimum_mag: fminimum_mag
fminimum_magf: fminimum_magf
fminimum_magl: fminimum_magl
fminimum_mag_num: fminimum_mag_num
fminimum_mag_numf: fminimum_mag_numf
fminimum_mag_numl: fminimum_mag_numl
fminimum_num: fminimum_num
fminimum_numf: fminimum_numf
fminimum_numl: fminimum_numl
fminl: fminl
fminmag: fminmag
fminmagf: fminmagf
fminmagl: fminmagl
fmod: fmod
fmodf: fmodf
fmodl: fmodl
fmtmsg: fmtmsg
fmul: fmul
fmull: fmull
fnmatch: fnmatch
fopen: fopen
fopen-safer: Closed standard fds
fopencookie: fopencookie
fork: fork
forkpty: forkpty
fpathconf: fpathconf
fpclassify: fpclassify
fprintf: fprintf
fputc: fputc
fputc_unlocked: fputc_unlocked
fputs: fputs
fputs_unlocked: fputs_unlocked
fputwc: fputwc
fputwc_unlocked: fputwc_unlocked
fputws: fputws
fputws_unlocked: fputws_unlocked
fread: fread
fread_unlocked: fread_unlocked
free: free
FREE: Safe Allocation Macros
freeaddrinfo: freeaddrinfo
freeifaddrs: freeifaddrs
freelocale: freelocale
fremovexattr: fremovexattr
freopen: freopen
freopen-safer: Closed standard fds
frexp: frexp
frexpf: frexpf
frexpl: frexpl
fromfp: fromfp
fromfpf: fromfpf
fromfpl: fromfpl
fromfpx: fromfpx
fromfpxf: fromfpxf
fromfpxl: fromfpxl
fscanf: fscanf
fsconfig: fsconfig
fseek: fseek
fseeko: fseeko
fsetpos: fsetpos
fsetxattr: fsetxattr
fsmount: fsmount
fsopen: fsopen
fspick: fspick
fsqrt: fsqrt
fsqrtl: fsqrtl
fstat: fstat
fstatat: fstatat
fstatfs: fstatfs
fstatvfs: fstatvfs
fsub: fsub
fsubl: fsubl
fsync: fsync
ftell: ftell
ftello: ftello
ftime: ftime
ftok: ftok
ftruncate: ftruncate
ftrylockfile: ftrylockfile
fts_children: fts_children
fts_close: fts_close
fts_open: fts_open
fts_read: fts_read
fts_set: fts_set
ftw: ftw
funlockfile: funlockfile
futimens: futimens
futimes: futimes
futimesat: futimesat
fwide: fwide
fwprintf: fwprintf
fwrite: fwrite
fwrite_unlocked: fwrite_unlocked
fwscanf: fwscanf
G
gai_strerror: gai_strerror
gamma: gamma
gammaf: gammaf
gammal: gammal
gcd: gcd
gcvt: gcvt
getaddrinfo: getaddrinfo
getaliasbyname: getaliasbyname
getaliasbyname_r: getaliasbyname_r
getaliasent: getaliasent
getaliasent_r: getaliasent_r
getauxval: getauxval
getc: getc
getchar: getchar
getchar_unlocked: getchar_unlocked
getcontext: getcontext
getcpu: getcpu
getcwd: getcwd
getc_unlocked: getc_unlocked
getdate: getdate
getdate_err: getdate_err
getdate_r: getdate_r
getdelim: getdelim
getdirentries: getdirentries
getdomainname: getdomainname
getdtablesize: getdtablesize
getegid: getegid
getentropy: getentropy
getenv: getenv
geteuid: geteuid
getfilecon: getfilecon
getfsent: getfsent
getfsfile: getfsfile
getfsspec: getfsspec
getgid: getgid
getgrent: getgrent
getgrent_r: getgrent_r
getgrgid: getgrgid
getgrgid_r: getgrgid_r
getgrnam: getgrnam
getgrnam_r: getgrnam_r
getgrouplist: getgrouplist
getgroups: getgroups
gethostbyaddr: gethostbyaddr
gethostbyaddr_r: gethostbyaddr_r
gethostbyname: gethostbyname
gethostbyname2: gethostbyname2
gethostbyname2_r: gethostbyname2_r
gethostbyname_r: gethostbyname_r
gethostent: gethostent
gethostent_r: gethostent_r
gethostid: gethostid
gethostname: gethostname
getifaddrs: getifaddrs
getipv4sourcefilter: getipv4sourcefilter
getitimer: getitimer
getline: getline
getloadavg: getloadavg
getlogin: getlogin
getlogin_r: getlogin_r
getmntent: getmntent
getmntent_r: getmntent_r
getmsg: getmsg
getnameinfo: getnameinfo
getnetbyaddr: getnetbyaddr
getnetbyaddr_r: getnetbyaddr_r
getnetbyname: getnetbyname
getnetbyname_r: getnetbyname_r
getnetent: getnetent
getnetent_r: getnetent_r
getnetgrent: getnetgrent
getnetgrent_r: getnetgrent_r
getnetname: getnetname
getopt: getopt
getopt_long: getopt_long
getopt_long_only: getopt_long_only
getpagesize: getpagesize
getpass: getpass
getpayload: getpayload
getpayloadf: getpayloadf
getpayloadl: getpayloadl
getpeername: getpeername
getpgid: getpgid
getpgrp: getpgrp
getpid: getpid
getpmsg: getpmsg
getppid: getppid
getpriority: getpriority
getprogname: progname and getprogname
getprotobyname: getprotobyname
getprotobyname_r: getprotobyname_r
getprotobynumber: getprotobynumber
getprotobynumber_r: getprotobynumber_r
getprotoent: getprotoent
getprotoent_r: getprotoent_r
getpt: getpt
getpublickey: getpublickey
getpw: getpw
getpwent: getpwent
getpwent_r: getpwent_r
getpwnam: getpwnam
getpwnam_r: getpwnam_r
getpwuid: getpwuid
getpwuid_r: getpwuid_r
getrandom: getrandom
getresgid: getresgid
getresuid: getresuid
getrlimit: getrlimit
getrpcbyname: getrpcbyname
getrpcbyname_r: getrpcbyname_r
getrpcbynumber: getrpcbynumber
getrpcbynumber_r: getrpcbynumber_r
getrpcent: getrpcent
getrpcent_r: getrpcent_r
getrpcport: getrpcport
getrusage: getrusage
gets: gets
getsecretkey: getsecretkey
getservbyname: getservbyname
getservbyname_r: getservbyname_r
getservbyport: getservbyport
getservbyport_r: getservbyport_r
getservent: getservent
getservent_r: getservent_r
getsgent: getsgent
getsgent_r: getsgent_r
getsgnam: getsgnam
getsgnam_r: getsgnam_r
getsid: getsid
getsockname: getsockname
getsockopt: getsockopt
getsourcefilter: getsourcefilter
getspent: getspent
getspent_r: getspent_r
getspnam: getspnam
getspnam_r: getspnam_r
getsubopt: getsubopt
gettext: gettext
gettextize, caveat: gettextize and autopoint
gettid: gettid
gettimeofday: gettimeofday
getttyent: getttyent
getttynam: getttynam
getuid: getuid
getumask: getumask
getusershell: getusershell
getutent: getutent
getutent_r: getutent_r
getutid: getutid
getutid_r: getutid_r
getutline: getutline
getutline_r: getutline_r
getutmp: getutmp
getutmpx: getutmpx
getutxent: getutxent
getutxid: getutxid
getutxline: getutxline
getw: getw
getwc: getwc
getwchar: getwchar
getwchar_unlocked: getwchar_unlocked
getwc_unlocked: getwc_unlocked
getwd: getwd
getxattr: getxattr
get_avphys_pages: get_avphys_pages
get_current_dir_name: get_current_dir_name
get_myaddress: get_myaddress
get_nprocs: get_nprocs
get_nprocs_conf: get_nprocs_conf
get_phys_pages: get_phys_pages
gitlog: gitlog-to-changelog
glob: glob
globfree: globfree
glob_pattern_p: glob_pattern_p
gmtime: gmtime
gmtime_r: gmtime_r
gnulib-tool: Invoking gnulib-tool
gnu_dev_major: gnu_dev_major
gnu_dev_makedev: gnu_dev_makedev
gnu_dev_minor: gnu_dev_minor
gnu_get_libc_release: gnu_get_libc_release
gnu_get_libc_version: gnu_get_libc_version
grantpt: grantpt
Grep: Predefined Syntaxes
grouping: Grouping Operators
group_member: group_member
gsignal: gsignal
H
hasmntopt: hasmntopt
hcreate: hcreate
hcreate_r: hcreate_r
hdestroy: hdestroy
hdestroy_r: hdestroy_r
header file include protection: Header files
Header files and C++: Header files
herror: herror
host2netname: host2netname
hsearch: hsearch
hsearch_r: hsearch_r
hstrerror: hstrerror
htonl: htonl
htons: htons
hypot: hypot
hypotf: hypotf
hypotl: hypotl
h_errno: h_errno
I
iconv: iconv
iconv_close: iconv_close
iconv_open: iconv_open
if_freenameindex: if_freenameindex
if_indextoname: if_indextoname
if_nameindex: if_nameindex
if_nametoindex: if_nametoindex
ilogb: ilogb
ilogbf: ilogbf
ilogbl: ilogbl
imaxabs: imaxabs
imaxdiv: imaxdiv
in6addr_any: in6addr_any
in6addr_loopback: in6addr_loopback
index: _index
inet6_option_alloc: inet6_option_alloc
inet6_option_append: inet6_option_append
inet6_option_find: inet6_option_find
inet6_option_init: inet6_option_init
inet6_option_next: inet6_option_next
inet6_option_space: inet6_option_space
inet6_opt_append: inet6_opt_append
inet6_opt_find: inet6_opt_find
inet6_opt_finish: inet6_opt_finish
inet6_opt_get_val: inet6_opt_get_val
inet6_opt_init: inet6_opt_init
inet6_opt_next: inet6_opt_next
inet6_opt_set_val: inet6_opt_set_val
inet6_rth_add: inet6_rth_add
inet6_rth_getaddr: inet6_rth_getaddr
inet6_rth_init: inet6_rth_init
inet6_rth_reverse: inet6_rth_reverse
inet6_rth_segments: inet6_rth_segments
inet6_rth_space: inet6_rth_space
inet_addr: inet_addr
inet_aton: inet_aton
inet_lnaof: inet_lnaof
inet_makeaddr: inet_makeaddr
inet_netof: inet_netof
inet_network: inet_network
inet_net_ntop: inet_net_ntop
inet_net_pton: inet_net_pton
inet_nsap_addr: inet_nsap_addr
inet_nsap_ntoa: inet_nsap_ntoa
inet_ntoa: inet_ntoa
inet_ntop: inet_ntop
inet_pton: inet_pton
initgroups: initgroups
initial import: Initial import
initstate: initstate
initstate_r: initstate_r
inline: static inline
inline: extern inline
innetgr: innetgr
inotify_add_watch: inotify_add_watch
inotify_init: inotify_init
inotify_init1: inotify_init1
inotify_rm_watch: inotify_rm_watch
insque: insque
int: Safe Allocation Macros
int: Safe Allocation Macros
int: Safe Allocation Macros
int: Safe Allocation Macros
integer arithmetic portability: Unsupported Platforms
integer bounds: Integer Bounds
integer overflow: Integer Properties
integer overflow checking: Checking Integer Overflow
integer properties: Integer Properties
integer range overflow: Integer Range Overflow
integer type overflow: Integer Type Overflow
interval expression: Interval Operators
INT_ADD_OK: Checking Integer Overflow
INT_ADD_OVERFLOW: Integer Type Overflow
INT_ADD_RANGE_OVERFLOW: Integer Range Overflow
INT_ADD_WRAPV: Wraparound Arithmetic
INT_BUFSIZE_BOUND: Integer Bounds
INT_DIVIDE_OVERFLOW: Integer Type Overflow
INT_DIVIDE_RANGE_OVERFLOW: Integer Range Overflow
INT_LEFT_SHIFT_OVERFLOW: Integer Type Overflow
INT_LEFT_SHIFT_RANGE_OVERFLOW: Integer Range Overflow
INT_MULTIPLY_OK: Checking Integer Overflow
INT_MULTIPLY_OVERFLOW: Integer Type Overflow
INT_MULTIPLY_RANGE_OVERFLOW: Integer Range Overflow
INT_MULTIPLY_WRAPV: Wraparound Arithmetic
INT_NEGATE_OVERFLOW: Integer Type Overflow
INT_NEGATE_RANGE_OVERFLOW: Integer Range Overflow
INT_REMAINDER_OVERFLOW: Integer Type Overflow
INT_REMAINDER_RANGE_OVERFLOW: Integer Range Overflow
INT_STRLEN_BOUND: Integer Bounds
INT_SUBTRACT_OK: Checking Integer Overflow
INT_SUBTRACT_OVERFLOW: Integer Type Overflow
INT_SUBTRACT_RANGE_OVERFLOW: Integer Range Overflow
INT_SUBTRACT_WRAPV: Wraparound Arithmetic
invoking gnulib-tool: Invoking gnulib-tool
ioctl: ioctl
ioperm: ioperm
iopl: iopl
isalnum: isalnum
isalnum_l: isalnum_l
isalpha: isalpha
isalpha_l: isalpha_l
isascii: isascii
isastream: isastream
isatty: isatty
isblank: isblank
isblank_l: isblank_l
iscntrl: iscntrl
iscntrl_l: iscntrl_l
isctype: isctype
isdigit: isdigit
isdigit_l: isdigit_l
isfdtype: isfdtype
isfinite: isfinite
isgraph: isgraph
isgraph_l: isgraph_l
isgreater: isgreater
isgreaterequal: isgreaterequal
isinf: isinf
isinff: isinff
isinfl: isinfl
isless: isless
islessequal: islessequal
islessgreater: islessgreater
islower: islower
islower_l: islower_l
isnan: isnan
isnanf: isnanf
isnanl: isnanl
isnormal: isnormal
isprint: isprint
isprint_l: isprint_l
ispunct: ispunct
ispunct_l: ispunct_l
isspace: isspace
isspace_l: isspace_l
isunordered: isunordered
isupper: isupper
isupper_l: isupper_l
iswalnum: iswalnum
iswalnum_l: iswalnum_l
iswalpha: iswalpha
iswalpha_l: iswalpha_l
iswblank: iswblank
iswblank_l: iswblank_l
iswcntrl: iswcntrl
iswcntrl_l: iswcntrl_l
iswctype: iswctype
iswctype_l: iswctype_l
iswdigit: iswdigit
iswdigit_l: iswdigit_l
iswgraph: iswgraph
iswgraph_l: iswgraph_l
iswlower: iswlower
iswlower_l: iswlower_l
iswprint: iswprint
iswprint_l: iswprint_l
iswpunct: iswpunct
iswpunct_l: iswpunct_l
iswspace: iswspace
iswspace_l: iswspace_l
iswupper: iswupper
iswupper_l: iswupper_l
iswxdigit: iswxdigit
iswxdigit_l: iswxdigit_l
isxdigit: isxdigit
isxdigit_l: isxdigit_l
J
j0: j0
j0f: j0f
j0l: j0l
j1: j1
j1f: j1f
j1l: j1l
jn: jn
jnf: jnf
jnl: jnl
jrand48: jrand48
jrand48_r: jrand48_r
K
key_decryptsession: key_decryptsession
key_decryptsession_pk: key_decryptsession_pk
key_encryptsession: key_encryptsession
key_encryptsession_pk: key_encryptsession_pk
key_gendes: key_gendes
key_get_conv: key_get_conv
key_secretkey_is_set: key_secretkey_is_set
key_setsecret: key_setsecret
kill: kill
killpg: killpg
klogctl: klogctl
L
l64a: l64a
labs: labs
lchmod: lchmod
lchown: lchown
lckpwdf: lckpwdf
lcong48: lcong48
lcong48_r: lcong48_r
LD DEF files: Visual Studio Compatibility
ldexp: ldexp
ldexpf: ldexpf
ldexpl: ldexpl
ldiv: ldiv
lfind: lfind
lgamma: lgamma
lgammaf: lgammaf
lgammaf_r: lgammaf_r
lgammal: lgammal
lgammal_r: lgammal_r
lgamma_r: lgamma_r
lgetfilecon: lgetfilecon
lgetxattr: lgetxattr
link: link
linkat: linkat
lio_listio: lio_listio
listen: listen
listxattr: listxattr
llabs: llabs
lldiv: lldiv
llistxattr: llistxattr
llogb: llogb
llogbf: llogbf
llogbl: llogbl
llrint: llrint
llrintf: llrintf
llrintl: llrintl
llround: llround
llroundf: llroundf
llroundl: llroundl
loc1: loc1
loc2: loc2
localeconv: localeconv
localtime: localtime
localtime_r: localtime_r
lockf: lockf
locs: locs
log: log
log10: log10
log10f: log10f
log10l: log10l
log1p: log1p
log1pf: log1pf
log1pl: log1pl
log2: log2
log2f: log2f
log2l: log2l
logb: logb
logbf: logbf
logbl: logbl
logf: logf
login: login
login_tty: login_tty
logl: logl
long-running tests modules: Extra tests modules
longjmp: longjmp
lrand48: lrand48
lrand48_r: lrand48_r
lremovexattr: lremovexattr
lrint: lrint
lrintf: lrintf
lrintl: lrintl
lround: lround
lroundf: lroundf
lroundl: lroundl
lsearch: lsearch
lseek: lseek
lsetxattr: lsetxattr
lstat: lstat
lutimes: lutimes
M
madvise: madvise
makecontext: makecontext
mallinfo: mallinfo
mallinfo2: mallinfo2
malloc: malloc
malloc: GNU Regular Expression Compiling
malloc_info: malloc_info
malloc_stats: malloc_stats
malloc_trim: malloc_trim
malloc_usable_size: malloc_usable_size
mallopt: mallopt
matching list: List Operators
matching newline: List Operators
matching with GNU functions: GNU Matching
matherr: matherr
mblen: mblen
mbrlen: mbrlen
mbrtoc16: mbrtoc16
mbrtoc32: mbrtoc32
mbrtoc8: mbrtoc8
mbrtowc: mbrtowc
mbsinit: mbsinit
mbsnrtowcs: mbsnrtowcs
mbsrtowcs: mbsrtowcs
mbstowcs: mbstowcs
mbtowc: mbtowc
mcheck: mcheck
mcheck_check_all: mcheck_check_all
mcheck_pedantic: mcheck_pedantic
memalign: memalign
memccpy: memccpy
memchr: memchr
memcmp: memcmp
memcpy: memcpy
memfd_create: memfd_create
memfrob: memfrob
memmem: memmem
memmove: memmove
Memory allocation failure: Out of memory handling
mempcpy: mempcpy
memrchr: memrchr
memset: memset
memset_explicit: memset_explicit
mincore: mincore
mkdir: mkdir
mkdirat: mkdirat
mkdtemp: mkdtemp
mkfifo: mkfifo
mkfifoat: mkfifoat
mknod: mknod
mknodat: mknodat
mkostemp: mkostemp
mkostemps: mkostemps
mkstemp: mkstemp
mkstemps: mkstemps
mktemp: mktemp
mktime: mktime
mlock: mlock
mlock2: mlock2
mlockall: mlockall
mmap: mmap
modf: modf
modff: modff
modfl: modfl
monstartup: monstartup
mount: mount
mount_setattr: mount_setattr
move_mount: move_mount
mprobe: mprobe
mprotect: mprotect
mq_close: mq_close
mq_getattr: mq_getattr
mq_notify: mq_notify
mq_open: mq_open
mq_receive: mq_receive
mq_send: mq_send
mq_setattr: mq_setattr
mq_timedreceive: mq_timedreceive
mq_timedsend: mq_timedsend
mq_unlink: mq_unlink
mrand48: mrand48
mrand48_r: mrand48_r
mremap: mremap
msgctl: msgctl
msgget: msgget
msgrcv: msgrcv
msgsnd: msgsnd
msync: msync
mtrace: mtrace
mtx_destroy: mtx_destroy
mtx_init: mtx_init
mtx_lock: mtx_lock
mtx_timedlock: mtx_timedlock
mtx_trylock: mtx_trylock
mtx_unlock: mtx_unlock
multibyte locale: C strings
munlock: munlock
munlockall: munlockall
munmap: munmap
muntrace: muntrace
N
name_to_handle_at: name_to_handle_at
nan: nan
nanf: nanf
nanl: nanl
nanosleep: nanosleep
nearbyint: nearbyint
nearbyintf: nearbyintf
nearbyintl: nearbyintl
netname2host: netname2host
netname2user: netname2user
newlocale: newlocale
nextafter: nextafter
nextafterf: nextafterf
nextafterl: nextafterl
nextdown: nextdown
nextdownf: nextdownf
nextdownl: nextdownl
nexttoward: nexttoward
nexttowardf: nexttowardf
nexttowardl: nexttowardl
nextup: nextup
nextupf: nextupf
nextupl: nextupl
nftw: nftw
ngettext: ngettext
nice: nice
nis_add: nis_add
nis_addmember: nis_addmember
nis_add_entry: nis_add_entry
nis_checkpoint: nis_checkpoint
nis_clone_object: nis_clone_object
nis_creategroup: nis_creategroup
nis_destroygroup: nis_destroygroup
nis_destroy_object: nis_destroy_object
nis_dir_cmp: nis_dir_cmp
nis_domain_of: nis_domain_of
nis_domain_of_r: nis_domain_of_r
nis_first_entry: nis_first_entry
nis_freenames: nis_freenames
nis_freeresult: nis_freeresult
nis_freeservlist: nis_freeservlist
nis_freetags: nis_freetags
nis_getnames: nis_getnames
nis_getservlist: nis_getservlist
nis_ismember: nis_ismember
nis_leaf_of: nis_leaf_of
nis_leaf_of_r: nis_leaf_of_r
nis_lerror: nis_lerror
nis_list: nis_list
nis_local_directory: nis_local_directory
nis_local_group: nis_local_group
nis_local_host: nis_local_host
nis_local_principal: nis_local_principal
nis_lookup: nis_lookup
nis_mkdir: nis_mkdir
nis_modify: nis_modify
nis_modify_entry: nis_modify_entry
nis_name_of: nis_name_of
nis_name_of_r: nis_name_of_r
nis_next_entry: nis_next_entry
nis_perror: nis_perror
nis_ping: nis_ping
nis_print_directory: nis_print_directory
nis_print_entry: nis_print_entry
nis_print_group: nis_print_group
nis_print_group_entry: nis_print_group_entry
nis_print_link: nis_print_link
nis_print_object: nis_print_object
nis_print_result: nis_print_result
nis_print_rights: nis_print_rights
nis_print_table: nis_print_table
nis_remove: nis_remove
nis_removemember: nis_removemember
nis_remove_entry: nis_remove_entry
nis_rmdir: nis_rmdir
nis_servstate: nis_servstate
nis_sperrno: nis_sperrno
nis_sperror: nis_sperror
nis_sperror_r: nis_sperror_r
nis_stats: nis_stats
nis_verifygroup: nis_verifygroup
nl_langinfo: nl_langinfo
nl_langinfo_l: nl_langinfo_l
nonmatching list: List Operators
noreturn: Non-returning Functions
not_bol field in pattern buffer: Match-beginning-of-line Operator
nrand48: nrand48
nrand48_r: nrand48_r
ns_name_compress: ns_name_compress
ns_name_ntop: ns_name_ntop
ns_name_pack: ns_name_pack
ns_name_pton: ns_name_pton
ns_name_skip: ns_name_skip
ns_name_uncompress: ns_name_uncompress
ns_name_unpack: ns_name_unpack
ntohl: ntohl
ntohs: ntohs
ntp_adjtime: ntp_adjtime
ntp_gettime: ntp_gettime
ntp_gettimex: ntp_gettimex
null pointer: nullptr
null pointer type: stddef.h
num_regs in struct re_registers: Using Registers
O
Obsolete modules: Obsolete modules
obstack_alloc_failed_handler: obstack_alloc_failed_handler
obstack_exit_failure: obstack_exit_failure
obstack_free: obstack_free
obstack_printf: obstack_printf
obstack_vprintf: obstack_vprintf
on_exit: on_exit
open: open
open-group operator and ‘^’: Match-beginning-of-line Operator
openat: openat
openat-safer: Closed standard fds
opendir: opendir
openlog: openlog
openpty: openpty
open_by_handle_at: open_by_handle_at
open_memstream: open_memstream
open_tree: open_tree
open_wmemstream: open_wmemstream
optarg: optarg
opterr: opterr
optind: optind
optopt: optopt
or operator: Alternation Operator
Out of Memory handling: Out of memory handling
overflow, integer: Integer Properties
overflow, integer range: Integer Range Overflow
overflow, integer type: Integer Type Overflow
P
parenthesizing: Grouping Operators
parse_printf_format: parse_printf_format
pathconf: pathconf
pattern buffer initialization: GNU Regular Expression Compiling
pattern buffer, definition of: GNU Pattern Buffers
pause: pause
pclose: pclose
perror: perror
personality: personality
pidfd_getfd: pidfd_getfd
pidfd_getpid: pidfd_getpid
pidfd_open: pidfd_open
pidfd_send_signal: pidfd_send_signal
pidfd_spawn: pidfd_spawn
pidfd_spawnp: pidfd_spawnp
pipe: pipe
pipe2: pipe2
pipe2-safer: Closed standard fds
pkey_alloc: pkey_alloc
pkey_free: pkey_free
pkey_get: pkey_get
pkey_mprotect: pkey_mprotect
pkey_set: pkey_set
pmap_getmaps: pmap_getmaps
pmap_getport: pmap_getport
pmap_rmtcall: pmap_rmtcall
pmap_set: pmap_set
pmap_unset: pmap_unset
poll: poll
popen: popen
popen-safer: Closed standard fds
portability, integer arithmetic: Unsupported Platforms
POSIX Awk: Predefined Syntaxes
posix_fadvise: posix_fadvise
posix_fallocate: posix_fallocate
posix_madvise: posix_madvise
posix_memalign: posix_memalign
posix_mem_offset: posix_mem_offset
posix_openpt: posix_openpt
posix_spawn: posix_spawn
posix_spawnattr_destroy: posix_spawnattr_destroy
posix_spawnattr_getcgroup_np: posix_spawnattr_getcgroup_np
posix_spawnattr_getflags: posix_spawnattr_getflags
posix_spawnattr_getpgroup: posix_spawnattr_getpgroup
posix_spawnattr_getschedparam: posix_spawnattr_getschedparam
posix_spawnattr_getschedpolicy: posix_spawnattr_getschedpolicy
posix_spawnattr_getsigdefault: posix_spawnattr_getsigdefault
posix_spawnattr_getsigmask: posix_spawnattr_getsigmask
posix_spawnattr_init: posix_spawnattr_init
posix_spawnattr_setcgroup_np: posix_spawnattr_setcgroup_np
posix_spawnattr_setflags: posix_spawnattr_setflags
posix_spawnattr_setpgroup: posix_spawnattr_setpgroup
posix_spawnattr_setschedparam: posix_spawnattr_setschedparam
posix_spawnattr_setschedpolicy: posix_spawnattr_setschedpolicy
posix_spawnattr_setsigdefault: posix_spawnattr_setsigdefault
posix_spawnattr_setsigmask: posix_spawnattr_setsigmask
posix_spawnp: posix_spawnp
posix_spawn_file_actions_addchdir_np: posix_spawn_file_actions_addchdir_np
posix_spawn_file_actions_addclose: posix_spawn_file_actions_addclose
posix_spawn_file_actions_addclosefrom_np: posix_spawn_file_actions_addclosefrom_np
posix_spawn_file_actions_adddup2: posix_spawn_file_actions_adddup2
posix_spawn_file_actions_addfchdir_np: posix_spawn_file_actions_addfchdir_np
posix_spawn_file_actions_addopen: posix_spawn_file_actions_addopen
posix_spawn_file_actions_addtcsetpgrp_np: posix_spawn_file_actions_addtcsetpgrp_np
posix_spawn_file_actions_destroy: posix_spawn_file_actions_destroy
posix_spawn_file_actions_init: posix_spawn_file_actions_init
posix_trace_attr_destroy: posix_trace_attr_destroy
posix_trace_attr_getclockres: posix_trace_attr_getclockres
posix_trace_attr_getcreatetime: posix_trace_attr_getcreatetime
posix_trace_attr_getgenversion: posix_trace_attr_getgenversion
posix_trace_attr_getinherited: posix_trace_attr_getinherited
posix_trace_attr_getlogfullpolicy: posix_trace_attr_getlogfullpolicy
posix_trace_attr_getlogsize: posix_trace_attr_getlogsize
posix_trace_attr_getmaxdatasize: posix_trace_attr_getmaxdatasize
posix_trace_attr_getmaxsystemeventsize: posix_trace_attr_getmaxsystemeventsize
posix_trace_attr_getmaxusereventsize: posix_trace_attr_getmaxusereventsize
posix_trace_attr_getname: posix_trace_attr_getname
posix_trace_attr_getstreamfullpolicy: posix_trace_attr_getstreamfullpolicy
posix_trace_attr_getstreamsize: posix_trace_attr_getstreamsize
posix_trace_attr_init: posix_trace_attr_init
posix_trace_attr_setinherited: posix_trace_attr_setinherited
posix_trace_attr_setlogfullpolicy: posix_trace_attr_setlogfullpolicy
posix_trace_attr_setlogsize: posix_trace_attr_setlogsize
posix_trace_attr_setmaxdatasize: posix_trace_attr_setmaxdatasize
posix_trace_attr_setname: posix_trace_attr_setname
posix_trace_attr_setstreamfullpolicy: posix_trace_attr_setstreamfullpolicy
posix_trace_attr_setstreamsize: posix_trace_attr_setstreamsize
posix_trace_clear: posix_trace_clear
posix_trace_close: posix_trace_close
posix_trace_create: posix_trace_create
posix_trace_create_withlog: posix_trace_create_withlog
posix_trace_event: posix_trace_event
posix_trace_eventid_equal: posix_trace_eventid_equal
posix_trace_eventid_get_name: posix_trace_eventid_get_name
posix_trace_eventid_open: posix_trace_eventid_open
posix_trace_eventset_add: posix_trace_eventset_add
posix_trace_eventset_del: posix_trace_eventset_del
posix_trace_eventset_empty: posix_trace_eventset_empty
posix_trace_eventset_fill: posix_trace_eventset_fill
posix_trace_eventset_ismember: posix_trace_eventset_ismember
posix_trace_eventtypelist_getnext_id: posix_trace_eventtypelist_getnext_id
posix_trace_eventtypelist_rewind: posix_trace_eventtypelist_rewind
posix_trace_flush: posix_trace_flush
posix_trace_getnext_event: posix_trace_getnext_event
posix_trace_get_attr: posix_trace_get_attr
posix_trace_get_filter: posix_trace_get_filter
posix_trace_get_status: posix_trace_get_status
posix_trace_open: posix_trace_open
posix_trace_rewind: posix_trace_rewind
posix_trace_set_filter: posix_trace_set_filter
posix_trace_shutdown: posix_trace_shutdown
posix_trace_start: posix_trace_start
posix_trace_stop: posix_trace_stop
posix_trace_timedgetnext_event: posix_trace_timedgetnext_event
posix_trace_trid_eventid_open: posix_trace_trid_eventid_open
posix_trace_trygetnext_event: posix_trace_trygetnext_event
posix_typed_mem_get_info: posix_typed_mem_get_info
posix_typed_mem_open: posix_typed_mem_open
pow: pow
pow10: pow10
pow10f: pow10f
pow10l: pow10l
powf: powf
powl: powl
ppoll: ppoll
prctl: prctl
pread: pread
preadv: preadv
preadv2: preadv2
printf: printf
printf_size: printf_size
printf_size_info: printf_size_info
privileged tests modules: Extra tests modules
prlimit: prlimit
process_madvise: process_madvise
process_mrelease: process_mrelease
process_vm_readv: process_vm_readv
process_vm_writev: process_vm_writev
profil: profil
progname: progname and getprogname
program_invocation_name: program_invocation_name
program_invocation_short_name: program_invocation_short_name
program_name: progname and getprogname
pselect: pselect
psiginfo: psiginfo
psignal: psignal
pthread_atfork: pthread_atfork
pthread_attr_destroy: pthread_attr_destroy
pthread_attr_getaffinity_np: pthread_attr_getaffinity_np
pthread_attr_getdetachstate: pthread_attr_getdetachstate
pthread_attr_getguardsize: pthread_attr_getguardsize
pthread_attr_getinheritsched: pthread_attr_getinheritsched
pthread_attr_getschedparam: pthread_attr_getschedparam
pthread_attr_getschedpolicy: pthread_attr_getschedpolicy
pthread_attr_getscope: pthread_attr_getscope
pthread_attr_getsigmask_np: pthread_attr_getsigmask_np
pthread_attr_getstack: pthread_attr_getstack
pthread_attr_getstackaddr: pthread_attr_getstackaddr
pthread_attr_getstacksize: pthread_attr_getstacksize
pthread_attr_init: pthread_attr_init
pthread_attr_setaffinity_np: pthread_attr_setaffinity_np
pthread_attr_setdetachstate: pthread_attr_setdetachstate
pthread_attr_setguardsize: pthread_attr_setguardsize
pthread_attr_setinheritsched: pthread_attr_setinheritsched
pthread_attr_setschedparam: pthread_attr_setschedparam
pthread_attr_setschedpolicy: pthread_attr_setschedpolicy
pthread_attr_setscope: pthread_attr_setscope
pthread_attr_setsigmask_np: pthread_attr_setsigmask_np
pthread_attr_setstack: pthread_attr_setstack
pthread_attr_setstackaddr: pthread_attr_setstackaddr
pthread_attr_setstacksize: pthread_attr_setstacksize
pthread_barrierattr_destroy: pthread_barrierattr_destroy
pthread_barrierattr_getpshared: pthread_barrierattr_getpshared
pthread_barrierattr_init: pthread_barrierattr_init
pthread_barrierattr_setpshared: pthread_barrierattr_setpshared
pthread_barrier_destroy: pthread_barrier_destroy
pthread_barrier_init: pthread_barrier_init
pthread_barrier_wait: pthread_barrier_wait
pthread_cancel: pthread_cancel
pthread_cleanup_pop: pthread_cleanup_pop
pthread_cleanup_push: pthread_cleanup_push
pthread_clockjoin_np: pthread_clockjoin_np
pthread_condattr_destroy: pthread_condattr_destroy
pthread_condattr_getclock: pthread_condattr_getclock
pthread_condattr_getpshared: pthread_condattr_getpshared
pthread_condattr_init: pthread_condattr_init
pthread_condattr_setclock: pthread_condattr_setclock
pthread_condattr_setpshared: pthread_condattr_setpshared
pthread_cond_broadcast: pthread_cond_broadcast
pthread_cond_clockwait: pthread_cond_clockwait
pthread_cond_destroy: pthread_cond_destroy
pthread_cond_init: pthread_cond_init
pthread_cond_signal: pthread_cond_signal
pthread_cond_timedwait: pthread_cond_timedwait
pthread_cond_wait: pthread_cond_wait
pthread_create: pthread_create
pthread_detach: pthread_detach
pthread_equal: pthread_equal
pthread_exit: pthread_exit
pthread_getaffinity_np: pthread_getaffinity_np
pthread_getattr_default_np: pthread_getattr_default_np
pthread_getattr_np: pthread_getattr_np
pthread_getconcurrency: pthread_getconcurrency
pthread_getcpuclockid: pthread_getcpuclockid
pthread_getname_np: pthread_getname_np
pthread_getschedparam: pthread_getschedparam
pthread_getspecific: pthread_getspecific
pthread_join: pthread_join
pthread_key_create: pthread_key_create
pthread_key_delete: pthread_key_delete
pthread_kill: pthread_kill
pthread_kill_other_threads_np: pthread_kill_other_threads_np
pthread_mutexattr_destroy: pthread_mutexattr_destroy
pthread_mutexattr_getprioceiling: pthread_mutexattr_getprioceiling
pthread_mutexattr_getprotocol: pthread_mutexattr_getprotocol
pthread_mutexattr_getpshared: pthread_mutexattr_getpshared
pthread_mutexattr_getrobust: pthread_mutexattr_getrobust
pthread_mutexattr_gettype: pthread_mutexattr_gettype
pthread_mutexattr_init: pthread_mutexattr_init
pthread_mutexattr_setprioceiling: pthread_mutexattr_setprioceiling
pthread_mutexattr_setprotocol: pthread_mutexattr_setprotocol
pthread_mutexattr_setpshared: pthread_mutexattr_setpshared
pthread_mutexattr_setrobust: pthread_mutexattr_setrobust
pthread_mutexattr_settype: pthread_mutexattr_settype
pthread_mutex_clocklock: pthread_mutex_clocklock
pthread_mutex_consistent: pthread_mutex_consistent
pthread_mutex_destroy: pthread_mutex_destroy
pthread_mutex_getprioceiling: pthread_mutex_getprioceiling
pthread_mutex_init: pthread_mutex_init
pthread_mutex_lock: pthread_mutex_lock
pthread_mutex_setprioceiling: pthread_mutex_setprioceiling
pthread_mutex_timedlock: pthread_mutex_timedlock
pthread_mutex_trylock: pthread_mutex_trylock
pthread_mutex_unlock: pthread_mutex_unlock
pthread_once: pthread_once
pthread_rwlockattr_destroy: pthread_rwlockattr_destroy
pthread_rwlockattr_getkind_np: pthread_rwlockattr_getkind_np
pthread_rwlockattr_getpshared: pthread_rwlockattr_getpshared
pthread_rwlockattr_init: pthread_rwlockattr_init
pthread_rwlockattr_setkind_np: pthread_rwlockattr_setkind_np
pthread_rwlockattr_setpshared: pthread_rwlockattr_setpshared
pthread_rwlock_clockrdlock: pthread_rwlock_clockrdlock
pthread_rwlock_clockwrlock: pthread_rwlock_clockwrlock
pthread_rwlock_destroy: pthread_rwlock_destroy
pthread_rwlock_init: pthread_rwlock_init
pthread_rwlock_rdlock: pthread_rwlock_rdlock
pthread_rwlock_timedrdlock: pthread_rwlock_timedrdlock
pthread_rwlock_timedwrlock: pthread_rwlock_timedwrlock
pthread_rwlock_tryrdlock: pthread_rwlock_tryrdlock
pthread_rwlock_trywrlock: pthread_rwlock_trywrlock
pthread_rwlock_unlock: pthread_rwlock_unlock
pthread_rwlock_wrlock: pthread_rwlock_wrlock
pthread_self: pthread_self
pthread_setaffinity_np: pthread_setaffinity_np
pthread_setattr_default_np: pthread_setattr_default_np
pthread_setcancelstate: pthread_setcancelstate
pthread_setcanceltype: pthread_setcanceltype
pthread_setconcurrency: pthread_setconcurrency
pthread_setname_np: pthread_setname_np
pthread_setschedparam: pthread_setschedparam
pthread_setschedprio: pthread_setschedprio
pthread_setspecific: pthread_setspecific
pthread_sigmask: pthread_sigmask
pthread_sigqueue: pthread_sigqueue
pthread_spin_destroy: pthread_spin_destroy
pthread_spin_init: pthread_spin_init
pthread_spin_lock: pthread_spin_lock
pthread_spin_trylock: pthread_spin_trylock
pthread_spin_unlock: pthread_spin_unlock
pthread_testcancel: pthread_testcancel
pthread_timedjoin_np: pthread_timedjoin_np
pthread_tryjoin_np: pthread_tryjoin_np
ptrace: ptrace
ptsname: ptsname
ptsname_r: ptsname_r
putc: putc
putchar: putchar
putchar_unlocked: putchar_unlocked
putc_unlocked: putc_unlocked
putenv: putenv
putgrent: putgrent
putmsg: putmsg
putpmsg: putpmsg
putpwent: putpwent
puts: puts
putsgent: putsgent
putspent: putspent
pututline: pututline
pututxline: pututxline
putw: putw
putwc: putwc
putwchar: putwchar
putwchar_unlocked: putwchar_unlocked
putwc_unlocked: putwc_unlocked
pvalloc: pvalloc
pwrite: pwrite
pwritev: pwritev
pwritev2: pwritev2
Q
qecvt: qecvt
qecvt_r: qecvt_r
qfcvt: qfcvt
qfcvt_r: qfcvt_r
qgcvt: qgcvt
qsort: qsort
qsort_r: qsort_r
quick_exit: quick_exit
quotactl: quotactl
quote: Quoting
quotearg: Quoting
quotearg_alloc: Quoting
quote_n: Quoting
Quoting: Quoting
R
raise: raise
rand: rand
random: random
random_r: random_r
rand_r: rand_r
range argument to re_search: GNU Searching
rawmemchr: rawmemchr
rcmd: rcmd
rcmd_af: rcmd_af
read: read
readahead: readahead
readdir: readdir
readdir_r: readdir_r
readlink: readlink
readlinkat: readlinkat
readv: readv
realloc: realloc
REALLOC_N: Safe Allocation Macros
realpath: realpath
reboot: reboot
recv: recv
recvfrom: recvfrom
recvmmsg: recvmmsg
recvmsg: recvmsg
regcomp: regcomp
regerror: regerror
regex.h: Overview
regexec: regexec
regexp anchoring: Anchoring Operators
regfree: regfree
regfree: Freeing GNU Pattern Buffers
register_printf_function: register_printf_function
register_printf_modifier: register_printf_modifier
register_printf_specifier: register_printf_specifier
register_printf_type: register_printf_type
regular expressions, syntax of: Regular Expression Syntax
remainder: remainder
remainderf: remainderf
remainderl: remainderl
remap_file_pages: remap_file_pages
remove: remove
removexattr: removexattr
remque: remque
remquo: remquo
remquof: remquof
remquol: remquol
rename: rename
renameat: renameat
renameat2: renameat2
res_dnok: res_dnok
res_hnok: res_hnok
res_init: res_init
res_mailok: res_mailok
res_mkquery: res_mkquery
res_nmkquery: res_nmkquery
res_nquery: res_nquery
res_nquerydomain: res_nquerydomain
res_nsearch: res_nsearch
res_nsend: res_nsend
res_ownok: res_ownok
res_query: res_query
res_querydomain: res_querydomain
res_search: res_search
res_send: res_send
revoke: revoke
rewind: rewind
rewinddir: rewinddir
rexec: rexec
rexec_af: rexec_af
RE_BACKSLASH_ESCAPE_IN_LIST: Syntax Bits
RE_BK_PLUS_QM: Syntax Bits
RE_CHAR_CLASSES: Syntax Bits
re_comp: re_comp
re_comp: BSD Regular Expression Compiling
re_compile_fastmap: re_compile_fastmap
re_compile_fastmap: Searching with Fastmaps
re_compile_pattern: re_compile_pattern
re_compile_pattern: GNU Regular Expression Compiling
RE_CONTEXT_INDEP_ANCHORS: Syntax Bits
RE_CONTEXT_INDEP_ANCHORS (and ‘^’): Match-beginning-of-line Operator
RE_CONTEXT_INDEP_OPS: Syntax Bits
RE_CONTEXT_INVALID_DUP: Syntax Bits
RE_CONTEXT_INVALID_OPS: Syntax Bits
RE_DEBUG: Syntax Bits
RE_DOT_NEWLINE: Syntax Bits
RE_DOT_NOT_NULL: Syntax Bits
re_exec: re_exec
re_exec: BSD Searching
RE_HAT_LISTS_NOT_NEWLINE: Syntax Bits
RE_ICASE: Syntax Bits
RE_INTERVALS: Syntax Bits
RE_INVALID_INTERVAL_ORD: Syntax Bits
RE_LIMITED_OPS: Syntax Bits
re_match: re_match
re_match: GNU Matching
re_match_2: re_match_2
re_match_2: Matching/Searching with Split Data
RE_NEWLINE_ALT: Syntax Bits
RE_NO_BK_BRACES: Syntax Bits
RE_NO_BK_PARENS: Syntax Bits
RE_NO_BK_REFS: Syntax Bits
RE_NO_BK_VBAR: Syntax Bits
RE_NO_EMPTY_RANGES: Syntax Bits
RE_NO_GNU_OPS: Syntax Bits
RE_NO_POSIX_BACKTRACKING: Syntax Bits
RE_NO_SUB: Syntax Bits
re_nsub field, set by re_compile_pattern: GNU Regular Expression Compiling
re_pattern_buffer definition: GNU Pattern Buffers
re_registers: Using Registers
re_search: re_search
re_search: GNU Searching
re_search_2: re_search_2
re_search_2: Matching/Searching with Split Data
re_set_registers: re_set_registers
re_set_registers: Using Registers
re_set_syntax: re_set_syntax
re_syntax_options: re_syntax_options
re_syntax_options initialization: GNU Regular Expression Compiling
RE_UNMATCHED_RIGHT_PAREN_ORD: Syntax Bits
rindex: rindex
rint: rint
rintf: rintf
rintl: rintl
rmdir: rmdir
round: round
roundeven: roundeven
roundevenf: roundevenf
roundevenl: roundevenl
roundf: roundf
roundl: roundl
rpc_createerr: rpc_createerr
rpmatch: rpmatch
rresvport: rresvport
rresvport_af: rresvport_af
rtime: rtime
ruserok: ruserok
ruserok_af: ruserok_af
S
sbrk: sbrk
scalb: scalb
scalbf: scalbf
scalbl: scalbl
scalbln: scalbln
scalblnf: scalblnf
scalblnl: scalblnl
scalbn: scalbn
scalbnf: scalbnf
scalbnl: scalbnl
scandir: scandir
scandirat: scandirat
scanf: scanf
sched_getaffinity: sched_getaffinity
sched_getcpu: sched_getcpu
sched_getparam: sched_getparam
sched_getscheduler: sched_getscheduler
sched_get_priority_max: sched_get_priority_max
sched_get_priority_min: sched_get_priority_min
sched_rr_get_interval: sched_rr_get_interval
sched_setaffinity: sched_setaffinity
sched_setparam: sched_setparam
sched_setscheduler: sched_setscheduler
sched_yield: sched_yield
searching with GNU functions: GNU Searching
secure_getenv: secure_getenv
seed48: seed48
seed48_r: seed48_r
seekdir: seekdir
select: select
semctl: semctl
semget: semget
semop: semop
semtimedop: semtimedop
sem_clockwait: sem_clockwait
sem_close: sem_close
sem_destroy: sem_destroy
sem_getvalue: sem_getvalue
sem_init: sem_init
sem_open: sem_open
sem_post: sem_post
sem_timedwait: sem_timedwait
sem_trywait: sem_trywait
sem_unlink: sem_unlink
sem_wait: sem_wait
send: send
sendfile: sendfile
sendmmsg: sendmmsg
sendmsg: sendmsg
sendto: sendto
setaliasent: setaliasent
setbuf: setbuf
setbuffer: setbuffer
setcontext: setcontext
setdomainname: setdomainname
setegid: setegid
setenv: setenv
seteuid: seteuid
setfsent: setfsent
setfsgid: setfsgid
setfsuid: setfsuid
setgid: setgid
setgrent: setgrent
setgroups: setgroups
sethostent: sethostent
sethostid: sethostid
sethostname: sethostname
setipv4sourcefilter: setipv4sourcefilter
setitimer: setitimer
setjmp: setjmp
setkey: setkey
setlinebuf: setlinebuf
setlocale: setlocale
setlogin: setlogin
setlogmask: setlogmask
setmntent: setmntent
setnetent: setnetent
setnetgrent: setnetgrent
setns: setns
setpayload: setpayload
setpayloadf: setpayloadf
setpayloadl: setpayloadl
setpayloadsig: setpayloadsig
setpayloadsigf: setpayloadsigf
setpayloadsigl: setpayloadsigl
setpgid: setpgid
setpgrp: setpgrp
setpriority: setpriority
setprotoent: setprotoent
setpwent: setpwent
setregid: setregid
setresgid: setresgid
setresuid: setresuid
setreuid: setreuid
setrlimit: setrlimit
setrpcent: setrpcent
setservent: setservent
setsgent: setsgent
setsid: setsid
setsockopt: setsockopt
setsourcefilter: setsourcefilter
setspent: setspent
setstate: setstate
setstate_r: setstate_r
settimeofday: settimeofday
setttyent: setttyent
setuid: setuid
setusershell: setusershell
setutent: setutent
setutxent: setutxent
setvbuf: setvbuf
setxattr: setxattr
sgetsgent: sgetsgent
sgetsgent_r: sgetsgent_r
sgetspent: sgetspent
sgetspent_r: sgetspent_r
shmat: shmat
shmctl: shmctl
shmdt: shmdt
shmget: shmget
shm_open: shm_open
shm_unlink: shm_unlink
shutdown: shutdown
sigabbrev_np: sigabbrev_np
sigaction: sigaction
sigaddset: sigaddset
sigaltstack: sigaltstack
sigandset: sigandset
sigblock: sigblock
sigdelset: sigdelset
sigdescr_np: sigdescr_np
sigemptyset: sigemptyset
sigfillset: sigfillset
siggetmask: siggetmask
sighold: sighold
sigignore: sigignore
siginterrupt: siginterrupt
sigisemptyset: sigisemptyset
sigismember: sigismember
siglongjmp: siglongjmp
signal: signal
signalfd: signalfd
signbit: signbit
signgam: signgam
significand: significand
significandf: significandf
significandl: significandl
sigorset: sigorset
sigpause: sigpause
sigpending: sigpending
sigprocmask: sigprocmask
sigqueue: sigqueue
sigrelse: sigrelse
sigreturn: sigreturn
sigset: sigset
sigsetjmp: sigsetjmp
sigsetmask: sigsetmask
sigstack: sigstack
sigsuspend: sigsuspend
sigtimedwait: sigtimedwait
sigvec: sigvec
sigwait: sigwait
sigwaitinfo: sigwaitinfo
sin: sin
sincos: sincos
sincosf: sincosf
sincosl: sincosl
sinf: sinf
sinh: sinh
sinhf: sinhf
sinhl: sinhl
sinl: sinl
sleep: sleep
snprintf: snprintf
sockatmark: sockatmark
socket: socket
socketpair: socketpair
specification: Specification
sprintf: sprintf
sprofil: sprofil
sqrt: sqrt
sqrtf: sqrtf
sqrtl: sqrtl
srand: srand
srand48: srand48
srand48_r: srand48_r
srandom: srandom
srandom_r: srandom_r
sscanf: sscanf
ssignal: ssignal
start argument to re_search: GNU Searching
start in struct re_registers: Using Registers
stat: stat
statfs: statfs
static inline: static inline
statvfs: statvfs
statx: statx
stdc_bit_ceil: stdc_bit_ceil
stdc_bit_floor: stdc_bit_floor
stdc_bit_width: stdc_bit_width
stdc_count_ones: stdc_count_ones
stdc_count_zeros: stdc_count_zeros
stdc_first_leading_one: stdc_first_leading_one
stdc_first_leading_zero: stdc_first_leading_zero
stdc_first_trailing_one: stdc_first_trailing_one
stdc_first_trailing_zero: stdc_first_trailing_zero
stdc_has_single_bit: stdc_has_single_bit
stdc_leading_ones: stdc_leading_ones
stdc_leading_zeros: stdc_leading_zeros
stdc_trailing_ones: stdc_trailing_ones
stdc_trailing_zeros: stdc_trailing_zeros
stderr: stderr
stdin: stdin
stdlib-safer: Closed standard fds
stdnoreturn: Non-returning Functions
stdopen: Closed standard fds
stdout: stdout
step: step
stime: stime
stpcpy: stpcpy
stpncpy: stpncpy
STP_BLKSIZE: stat-size
STP_NBLOCKS: stat-size
strcasecmp: strcasecmp
strcasecmp_l: strcasecmp_l
strcasestr: strcasestr
strcat: strcat
strchr: strchr
strchrnul: strchrnul
strcmp: strcmp
strcoll: strcoll
strcoll_l: strcoll_l
strcpy: strcpy
strcspn: strcspn
strdup: strdup
strerror: strerror
strerrordesc_np: strerrordesc_np
strerrorname_np: strerrorname_np
strerror_l: strerror_l
strerror_r: strerror_r
strfmon: strfmon
strfmon_l: strfmon_l
strfromd: strfromd
strfromf: strfromf
strfroml: strfroml
strfry: strfry
strftime: strftime
strftime_l: strftime_l
strlcat: strlcat
strlcpy: strlcpy
strlen: strlen
strncasecmp: strncasecmp
strncasecmp_l: strncasecmp_l
strncat: strncat
strncmp: strncmp
strncpy: strncpy
strndup: strndup
strnlen: strnlen
strpbrk: strpbrk
strptime: strptime
strptime_l: strptime_l
strrchr: strrchr
strsep: strsep
strsignal: strsignal
strspn: strspn
strstr: strstr
strtod: strtod
strtod_l: strtod_l
strtof: strtof
strtof_l: strtof_l
strtoimax: strtoimax
strtok: strtok
strtok_r: strtok_r
strtol: strtol
strtold: strtold
strtold_l: strtold_l
strtoll: strtoll
strtoll_l: strtoll_l
strtol_l: strtol_l
strtoq: strtoq
strtoul: strtoul
strtoull: strtoull
strtoull_l: strtoull_l
strtoul_l: strtoul_l
strtoumax: strtoumax
strtouq: strtouq
struct re_pattern_buffer definition: GNU Pattern Buffers
strverscmp: strverscmp
strxfrm: strxfrm
strxfrm_l: strxfrm_l
ST_BLKSIZE: stat-size
ST_NBLOCKS: stat-size
ST_NBLOCKSIZE: stat-size
subexpressions: Grouping Operators
svcerr_auth: svcerr_auth
svcerr_decode: svcerr_decode
svcerr_noproc: svcerr_noproc
svcerr_noprog: svcerr_noprog
svcerr_progvers: svcerr_progvers
svcerr_systemerr: svcerr_systemerr
svcerr_weakauth: svcerr_weakauth
svcraw_create: svcraw_create
svctcp_create: svctcp_create
svcudp_bufcreate: svcudp_bufcreate
svcudp_create: svcudp_create
svcunix_create: svcunix_create
svc_exit: svc_exit
svc_fdset: svc_fdset
svc_getreq: svc_getreq
svc_getreqset: svc_getreqset
svc_getreq_common: svc_getreq_common
svc_getreq_poll: svc_getreq_poll
svc_max_pollfd: svc_max_pollfd
svc_pollfd: svc_pollfd
svc_register: svc_register
svc_run: svc_run
svc_sendreply: svc_sendreply
svc_unregister: svc_unregister
swab: swab
swapcontext: swapcontext
swapoff: swapoff
swapon: swapon
swprintf: swprintf
swscanf: swscanf
symlink: symlink
symlinkat: symlinkat
sync: sync
syncfs: syncfs
sync_file_range: sync_file_range
syntax bits: Syntax Bits
syntax field, set by re_compile_pattern: GNU Regular Expression Compiling
syntax initialization: GNU Regular Expression Compiling
syntax of regular expressions: Regular Expression Syntax
syscall: syscall
sysconf: sysconf
sysctl: sysctl
sysinfo: sysinfo
syslog: syslog
system: system
sysv_signal: sysv_signal
sys_errlist: sys_errlist
sys_nerr: sys_nerr
sys_siglist: sys_siglist
T
tan: tan
tanf: tanf
tanh: tanh
tanhf: tanhf
tanhl: tanhl
tanl: tanl
tcdrain: tcdrain
tcflow: tcflow
tcflush: tcflush
tcgetattr: tcgetattr
tcgetpgrp: tcgetpgrp
tcgetsid: tcgetsid
tcsendbreak: tcsendbreak
tcsetattr: tcsetattr
tcsetpgrp: tcsetpgrp
tdelete: tdelete
tdestroy: tdestroy
telldir: telldir
tempnam: tempnam
tests modules, C++: Extra tests modules
tests modules, long-running: Extra tests modules
tests modules, privileged: Extra tests modules
tests modules, unportable: Extra tests modules
textdomain: textdomain
tfind: tfind
tgamma: tgamma
tgammaf: tgammaf
tgammal: tgammal
tgkill: tgkill
thrd_create: thrd_create
thrd_current: thrd_current
thrd_detach: thrd_detach
thrd_equal: thrd_equal
thrd_exit: thrd_exit
thrd_join: thrd_join
thrd_sleep: thrd_sleep
thrd_yield: thrd_yield
time: time
timegm: timegm
timelocal: timelocal
timerfd_create: timerfd_create
timerfd_gettime: timerfd_gettime
timerfd_settime: timerfd_settime
timer_create: timer_create
timer_delete: timer_delete
timer_getoverrun: timer_getoverrun
timer_gettime: timer_gettime
timer_settime: timer_settime
times: times
timespec_get: timespec_get
timespec_getres: timespec_getres
timezone: timezone
tmpfile: tmpfile
tmpfile-safer: Closed standard fds
tmpnam: tmpnam
tmpnam_r: tmpnam_r
toascii: toascii
tolower: tolower
tolower_l: tolower_l
totalorder: totalorder
totalorderf: totalorderf
totalorderl: totalorderl
totalordermag: totalordermag
totalordermagf: totalordermagf
totalordermagl: totalordermagl
toupper: toupper
toupper_l: toupper_l
towctrans: towctrans
towctrans_l: towctrans_l
towlower: towlower
towlower_l: towlower_l
towupper: towupper
towupper_l: towupper_l
translate initialization: GNU Regular Expression Compiling
trunc: trunc
truncate: truncate
truncf: truncf
truncl: truncl
tsearch: tsearch
tss_create: tss_create
tss_delete: tss_delete
tss_get: tss_get
tss_set: tss_set
ttyname: ttyname
ttyname_r: ttyname_r
ttyslot: ttyslot
twalk: twalk
twalk_r: twalk_r
TYPE_IS_INTEGER: Arithmetic Type Properties
TYPE_MAXIMUM: Integer Bounds
TYPE_MINIMUM: Integer Bounds
TYPE_SIGNED: Arithmetic Type Properties
tzname: tzname
tzset: tzset
U
ualarm: ualarm
ufromfp: ufromfp
ufromfpf: ufromfpf
ufromfpl: ufromfpl
ufromfpx: ufromfpx
ufromfpxf: ufromfpxf
ufromfpxl: ufromfpxl
ulckpwdf: ulckpwdf
ulimit: ulimit
umask: umask
umount: umount
umount2: umount2
uname: uname
ungetc: ungetc
ungetwc: ungetwc
unibyte locale: C strings
unistd-safer: Closed standard fds
unlink: unlink
unlinkat: unlinkat
unlockpt: unlockpt
unportable tests modules: Extra tests modules
unsetenv: unsetenv
updwtmp: updwtmp
updwtmpx: updwtmpx
uselocale: uselocale
user2netname: user2netname
usleep: usleep
ustat: ustat
utime: utime
utimensat: utimensat
utimes: utimes
utmpname: utmpname
utmpxname: utmpxname
V
valgrind: Running self-tests under valgrind
valloc: valloc
vasprintf: vasprintf
va_arg: va_arg
va_copy: va_copy
va_end: va_end
va_start: va_start
VCS To ChangeLog: VCS To ChangeLog
vcs-to-changelog: VCS To ChangeLog
vdprintf: vdprintf
verify: Compile-time Assertions
verify_expr: Compile-time Assertions
verr: verr
verrx: verrx
versionsort: versionsort
vfork: vfork
vfprintf: vfprintf
vfscanf: vfscanf
vfwprintf: vfwprintf
vfwscanf: vfwscanf
vhangup: vhangup
vlimit: vlimit
void: Safe Allocation Macros
vprintf: vprintf
vscanf: vscanf
vsnprintf: vsnprintf
vsprintf: vsprintf
vsscanf: vsscanf
vswprintf: vswprintf
vswscanf: vswscanf
vsyslog: vsyslog
vwarn: vwarn
vwarnx: vwarnx
vwprintf: vwprintf
vwscanf: vwscanf
W
wait: wait
wait3: wait3
wait4: wait4
waitid: waitid
waitpid: waitpid
warn: warn
warnx: warnx
wcpcpy: wcpcpy
wcpncpy: wcpncpy
wcrtomb: wcrtomb
wcscasecmp: wcscasecmp
wcscasecmp_l: wcscasecmp_l
wcscat: wcscat
wcschr: wcschr
wcschrnul: wcschrnul
wcscmp: wcscmp
wcscoll: wcscoll
wcscoll_l: wcscoll_l
wcscpy: wcscpy
wcscspn: wcscspn
wcsdup: wcsdup
wcsftime: wcsftime
wcsftime_l: wcsftime_l
wcslen: wcslen
wcsncasecmp: wcsncasecmp
wcsncasecmp_l: wcsncasecmp_l
wcsncat: wcsncat
wcsncmp: wcsncmp
wcsncpy: wcsncpy
wcsnlen: wcsnlen
wcsnrtombs: wcsnrtombs
wcspbrk: wcspbrk
wcsrchr: wcsrchr
wcsrtombs: wcsrtombs
wcsspn: wcsspn
wcsstr: wcsstr
wcstod: wcstod
wcstod_l: wcstod_l
wcstof: wcstof
wcstof_l: wcstof_l
wcstoimax: wcstoimax
wcstok: wcstok
wcstol: wcstol
wcstold: wcstold
wcstold_l: wcstold_l
wcstoll: wcstoll
wcstoll_l: wcstoll_l
wcstol_l: wcstol_l
wcstombs: wcstombs
wcstoq: wcstoq
wcstoul: wcstoul
wcstoull: wcstoull
wcstoull_l: wcstoull_l
wcstoul_l: wcstoul_l
wcstoumax: wcstoumax
wcstouq: wcstouq
wcswcs: wcswcs
wcswidth: wcswidth
wcsxfrm: wcsxfrm
wcsxfrm_l: wcsxfrm_l
wctob: wctob
wctomb: wctomb
wctrans: wctrans
wctrans_l: wctrans_l
wctype: wctype
wctype_l: wctype_l
wcwidth: wcwidth
wmemchr: wmemchr
wmemcmp: wmemcmp
wmemcpy: wmemcpy
wmemmove: wmemmove
wmempcpy: wmempcpy
wmemset: wmemset
word boundaries, matching: Match-word-boundary Operator
wordexp: wordexp
wordfree: wordfree
wprintf: wprintf
wraparound integer arithmetic: Wraparound Arithmetic
write: write
writev: writev
wscanf: wscanf
X
xalloc_die: Out of memory handling
xdrmem_create: xdrmem_create
xdrrec_create: xdrrec_create
xdrrec_endofrecord: xdrrec_endofrecord
xdrrec_eof: xdrrec_eof
xdrrec_skiprecord: xdrrec_skiprecord
xdrstdio_create: xdrstdio_create
xdr_array: xdr_array
xdr_authunix_parms: xdr_authunix_parms
xdr_bool: xdr_bool
xdr_bytes: xdr_bytes
xdr_callhdr: xdr_callhdr
xdr_callmsg: xdr_callmsg
xdr_cback_data: xdr_cback_data
xdr_char: xdr_char
xdr_cryptkeyarg: xdr_cryptkeyarg
xdr_cryptkeyarg2: xdr_cryptkeyarg2
xdr_cryptkeyres: xdr_cryptkeyres
xdr_des_block: xdr_des_block
xdr_domainname: xdr_domainname
xdr_double: xdr_double
xdr_enum: xdr_enum
xdr_float: xdr_float
xdr_free: xdr_free
xdr_getcredres: xdr_getcredres
xdr_hyper: xdr_hyper
xdr_int: xdr_int
xdr_int16_t: xdr_int16_t
xdr_int32_t: xdr_int32_t
xdr_int64_t: xdr_int64_t
xdr_int8_t: xdr_int8_t
xdr_keybuf: xdr_keybuf
xdr_keydat: xdr_keydat
xdr_keystatus: xdr_keystatus
xdr_key_netstarg: xdr_key_netstarg
xdr_key_netstres: xdr_key_netstres
xdr_long: xdr_long
xdr_longlong_t: xdr_longlong_t
xdr_netnamestr: xdr_netnamestr
xdr_netobj: xdr_netobj
xdr_obj_p: xdr_obj_p
xdr_opaque: xdr_opaque
xdr_opaque_auth: xdr_opaque_auth
xdr_pmap: xdr_pmap
xdr_pmaplist: xdr_pmaplist
xdr_pointer: xdr_pointer
xdr_quad_t: xdr_quad_t
xdr_reference: xdr_reference
xdr_replymsg: xdr_replymsg
xdr_rmtcallres: xdr_rmtcallres
xdr_rmtcall_args: xdr_rmtcall_args
xdr_short: xdr_short
xdr_sizeof: xdr_sizeof
xdr_string: xdr_string
xdr_uint16_t: xdr_uint16_t
xdr_uint32_t: xdr_uint32_t
xdr_uint64_t: xdr_uint64_t
xdr_uint8_t: xdr_uint8_t
xdr_union: xdr_union
xdr_unixcred: xdr_unixcred
xdr_u_char: xdr_u_char
xdr_u_hyper: xdr_u_hyper
xdr_u_int: xdr_u_int
xdr_u_long: xdr_u_long
xdr_u_longlong_t: xdr_u_longlong_t
xdr_u_quad_t: xdr_u_quad_t
xdr_u_short: xdr_u_short
xdr_valdat: xdr_valdat
xdr_vector: xdr_vector
xdr_void: xdr_void
xdr_wrapstring: xdr_wrapstring
xdr_ypbind_resptype: xdr_ypbind_resptype
xdr_ypmaplist: xdr_ypmaplist
xdr_ypmap_parms: xdr_ypmap_parms
xdr_yppushresp_xfr: xdr_yppushresp_xfr
xdr_ypreq_key: xdr_ypreq_key
xdr_ypreq_nokey: xdr_ypreq_nokey
xdr_ypreq_xfr: xdr_ypreq_xfr
xdr_ypresp_all: xdr_ypresp_all
xdr_ypresp_key_val: xdr_ypresp_key_val
xdr_ypresp_maplist: xdr_ypresp_maplist
xdr_ypresp_master: xdr_ypresp_master
xdr_ypresp_order: xdr_ypresp_order
xdr_ypresp_val: xdr_ypresp_val
xdr_ypresp_xfr: xdr_ypresp_xfr
xdr_ypstat: xdr_ypstat
xdr_ypxfrstat: xdr_ypxfrstat
xprt_register: xprt_register
xprt_unregister: xprt_unregister
xstdopen: Closed standard fds
Y
y0: y0
y0f: y0f
y0l: y0l
y1: y1
y1f: y1f
y1l: y1l
yn: yn
ynf: ynf
ynl: ynl
ypbinderr_string: ypbinderr_string
yperr_string: yperr_string
ypprot_err: ypprot_err
yp_all: yp_all
yp_bind: yp_bind
yp_first: yp_first
yp_get_default_domain: yp_get_default_domain
yp_master: yp_master
yp_match: yp_match
yp_next: yp_next
yp_order: yp_order
yp_unbind: yp_unbind
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Footnotes

(1)

Ristenpart T, Yilek S. When good randomness goes bad: virtual machine vulnerabilities and hedging deployed cryptography. NDSS 2010.

(2)

Ristenpart T, Yilek S. When good randomness goes bad: virtual machine vulnerabilities and hedging deployed cryptography. NDSS 2010.

(3)

Sometimes you don’t have to explicitly quote special characters to make them ordinary. For instance, most characters lose any special meaning inside a list (see List Operators ([ … ] and [^ … ])). In addition, if the syntax bits RE_CONTEXT_INVALID_OPS and RE_CONTEXT_INDEP_OPS aren’t set, then (for historical reasons) the matcher considers special characters ordinary if they are in contexts where the operations they represent make no sense; for example, then the match-zero-or-more operator (represented by ‘*’) matches itself in the regular expression ‘*foo’ because there is no preceding expression on which it can operate. It is poor practice, however, to depend on this behavior; if you want a special character to be ordinary outside a list, it’s better to always quote it, regardless.

(4)

Regex therefore doesn’t consider the ‘^’ to be the first character in the list. If you put a ‘^’ character first in (what you think is) a matching list, you’ll turn it into a nonmatching list.

(5)

You can’t use a character class for the starting or ending point of a range, since a character class is not a single character.

(6)

Regular expressions are also referred to as “patterns,” hence the name “pattern buffer.”

(7)

A table that maps all uppercase letters to the corresponding lowercase ones would work just as well for this purpose.