GNU Gnulib

GNU Gnulib

This manual is for GNU Gnulib (updated $Date: 2007-09-09 13:20:45 $), which is a library of common routines intended to be shared at the source level.

Copyright © 2004, 2005, 2006, 2007 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 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License.”

• Introduction
• Invoking gnulib-tool
• Miscellaneous Notes
• POSIX Substitutes Library: Building as a separate substitutes library.
• Header File Substitutes: Overriding system headers.
• Function Substitutes: Replacing system functions.
• Particular Modules: Documentation of individual modules.
• GNU Free Documentation License: Copying and sharing this manual.
• Index

1 Introduction

Gnulib is a source code library. It provides basic functionalities to programs and libraries. Currently (as of October 2006) more than 30 packages make use of Gnulib.

Resources:

• Gnulib is hosted at Savannah: http://savannah.gnu.org/projects/gnulib. Get the sources through git or CVS from there.
• The Gnulib home page: http://www.gnu.org/software/gnulib/.

• Library vs. Reusable Code
• Portability and Application Code
• Modules
• Various Kinds of Modules
• Collaborative Development
• Copyright
• Steady Development
• Openness

1.1 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.

1.2 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 C99, POSIX:2001) 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() 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.

1.3 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.

1.4 Various Kinds of Modules

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

1.4.1 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 stdbool.h or 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 an added underscore, so that on systems which do provide a correct header file the system's one is used.

1.4.2 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.

1.4.3 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 Woe32 requires a different API than the classical POSIX basename function.

1.4.4 Reusable application code

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

1.4.5 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.

1.4.6 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.

1.4.7 Build / maintenance infrastructure

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

1.5 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 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.

1.6 Copyright

Most modules are under the GPL. Some, mostly modules which can reasonably be used in libraries, are under LGPL. The source files always say "GPL", but the real license specification is in the module description file. If the module description file says "GPL", it currently means "GPLv2+" (GPLv2 or newer, at the licensee's choice); if it says "LGPL", it currently means "LGPLv2+" (LGPLv2 or newer, at the licensee's choice).

More precisely, the license specification in the module description file applies to the files in lib/ and build-aux/. Different licenses apply to files in special directories:

modules/

Module description files are under this copyright:

Copyright © 200X-200Y Free Software Foundation, Inc.
Copying and distribution of this file, with or without modification, in any medium, are permitted without royalty provided the copyright notice and this notice are preserved.

m4/

Autoconf macro files are under this copyright:

Copyright © 200X-200Y Free Software Foundation, Inc.
This file is free software; the Free Software Foundation gives unlimited permission to copy and/or distribute it, with or without modifications, as long as this notice is preserved.

tests/

If a license statement is not present in a test module, the test files are under GPL. Even if the corresponding source module is under LGPL, this is not a problem, since compiled tests are not installed by “make install”.

doc/

Documentation files are under this copyright:

Copyright © 200X-200Y 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 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts.

If you want to use some Gnulib modules under LGPL, you can do so by passing the option `--lgpl' to gnulib-tool. This will replace the GPL header with an LGPL header while copying the source files to your package.

Keep in mind that when you submit patches to files in Gnulib, you should license them under a compatible license. This means that sometimes the contribution will have to be LGPL, if the original file is available under LGPL. You can find out about it by looking for a "License: LGPL" information in the corresponding module description.

1.7 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. We don't make releases, but instead recommend to use the newest version of Gnulib from the CVS, except in periods of major changes.

1.8 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.

2 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.

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.

• Initial import: First import of Gnulib modules.
• Modified imports: Changing the import specification.
• Simple update: Tracking Gnulib development.
• CVS Issues: Integration with CVS.

2.1 Initial import

Gnulib assumes your project uses Autoconf and Automake. 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 C89 and C99 (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_.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_.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,
       - 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 pre-existing files, in particular Makefile.am. Unfortunately, separating the generated Makefile.am content (for building the gnulib library) into a separate file, say gnulib.mk, that could be included by your handwritten Makefile.am is not possible, due to how variable assignments are handled by Automake.

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

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$(top_srcdir)/lib -I$(top_builddir)/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 pre-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.

A final word of warning: Gnulib currently assumes it will be responsible for all functions that end up in the Autoconf @LIBOBJS@ variables (and/or @LTLIBOBJS@ if using Libtool), e.g., those specified in AC_REPLACE_FUNCS in your configure.ac. Therefore, if you have any functions which are not covered by Gnulib which need that treatment, you have to essentially reimplement AC_REPLACE_FUNCS using different names; for an example, see the Findutils sources. Perhaps this will be improved in the future.

2.2 Modified imports

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

If you only want to use more Gnulib modules, simply invoke gnulib-tool --import new-modules. gnulib-tool remembers which modules were used last time. The list of modules that you pass after `--import' is added to the previous list of modules.

For most changes, such as added or removed modules, or even different choices of `--lib', `--source-base' or `--aux-dir', there are two ways to perform the change.

The standard way is to modify manually the file gnulib-cache.m4 in the M4 macros directory, then launch `gnulib-tool --import'.

The other way is to call gnulib-tool again, with the changed command-line options. Note that this doesn't let you remove modules, because as you just learned, the list of modules is always cumulated. Also this way is often impractical, because you don't remember the way you invoked gnulib-tool last time.

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, the macros have the following meaning:

gl_MODULES

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

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_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_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 corresponds to the `--lgpl' 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.

2.3 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 --import

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

2.4 CVS Issues

All files created by gnulib-tool, except gnulib-cache.m4, should be treated like generated source files, like for example a parser.c file is generated from parser.y.

• In projects which commit all source files, whether generated or not, into CVS, the gnulib-tool generated files should all be committed.

  Gnulib also contains files generated by make (and removed by make clean), using information determined by configure They should not be checked into CVS, but instead added to .cvsignore. When you have a Gnulib source file of the form lib/foo_.h, the corresponding lib/foo.h is such a file.

• In projects which customarily omit from the CVS all files that generated from other source files, all these files and directories would not be added into CVS. The only file that must be added to CVS is gnulib-cache.m4 in the M4 macros directory. Also, the script for restoring files not in CVS, customarily called autogen.sh or bootstrap.sh, will typically contain the statement for restoring the omitted files:

            $ gnulib-tool --update
       

  The `--update' option operates much like the `--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.

The same holds for other version control systems than CVS, such as `git' or `svn'.

3 Miscellaneous Notes

• Comments
• Header files
• Out of memory handling
• Library version handling
• Windows sockets
• Libtool and Windows
• License Texinfo sources
• Build robot for gnulib

3.1 Comments

Where to put comments describing functions: Because of risk of divergence, we prefer to keep most function describing comments in only one place: just above the actual function definition. Some people prefer to put that documentation in the .h file. In any case, it should appear in just one place unless you can ensure that the multiple copies will always remain identical.

3.2 Header files

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 C89 and C99 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.

Include ordering

When writing a gnulib module, or even in general, a good way to order the `#include' directives is the following.

• First 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 private headers, in arbitrary order.

3.3 Out of memory handling

The GSS API does not have a standard error code for the out of memory error condition. Instead of adding a non-standard error code, this library 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.

However, we realize that some applications may not want to have the GSS library abort execution in any situation. The GSS library 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_fail_func to that function. The variable should be declared as follows.

     extern void (*xalloc_fail_func) (void);

The GSS library will invoke this function if an out of memory error occurs. Note that after this the GSS library is in an undefined state, so you must unload or restart the application to continue call GSS library functions. The hook is only intended to allow the application to log the situation in a special way. Of course, care must be taken to not allocate more memory, as that will likely also fail.

3.4 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");

3.5 Windows sockets

There are several issues when building applications that should work under Windows. The most problematic part is for applications that use sockets.

Hopefully, we can add helpful notes to this section that will help you port your application to Windows using gnulib.

3.5.1 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 to (partial) getaddrinfo implementation.

If you want to support Windows 2000, don't do anything, but be aware that gnulib will use its own (partial) getaddrinfo implementation even on Windows XP. Currently the code does not attempt to determine if the getaddrinfo function is available during runtime.

Todo: Make getaddrinfo.c open the WS2_32.DLL and check for the getaddrinfo symbol and use it if present, otherwise fall back to our own implementation.

3.6 Libtool and Windows

If you want it to be possible to cross-compile your program to MinGW and you use Libtool, you need to put:

     AC_LIBTOOL_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

3.7 License Texinfo sources

Gnulib provides copies of the GNU GPL, GNU LGPL, and GNU FDL licenses in Texinfo form. (The master location is http://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.

3.8 Build robot for gnulib

To simplify testing on a wide set of platforms, gnulib is built on many platforms every day and the results are uploaded to:

http://autobuild.josefsson.org/gnulib/

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

1. Create gnulib directory

   On a machine with recent automake, autoconf, m4 installed and with a gnulib git or cvs checkout (typically a Linux machine), use

             gnulib-tool --create-megatestdir --with-tests --dir=..."
        

   Note: The created directory uses ca. 512 MB on disk.

2. 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.

3. 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.

4. Submit build logs

   Submit each log file to Simon's site, either through a

             mail `echo gnulib__at__autobuild.josefsson.org | sed -e s/__at__/@/`
        

   or through netcat

             autobuild-submit logs/*
        

4 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).

5 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.

• aio.h
• arpa/inet.h
• assert.h
• complex.h
• cpio.h
• ctype.h
• dirent.h
• dlfcn.h
• errno.h
• fcntl.h
• fenv.h
• float.h
• fmtmsg.h
• fnmatch.h
• ftw.h
• glob.h
• grp.h
• iconv.h
• inttypes.h
• iso646.h
• langinfo.h
• libgen.h
• limits.h
• locale.h
• math.h
• monetary.h
• mqueue.h
• ndbm.h
• net/if.h
• netdb.h
• netinet/in.h
• netinet/tcp.h
• nl_types.h
• poll.h
• pthread.h
• pwd.h
• regex.h
• sched.h
• search.h
• semaphore.h
• setjmp.h
• signal.h
• spawn.h
• stdarg.h
• stdbool.h
• stddef.h
• stdint.h
• stdio.h
• stdlib.h
• string.h
• strings.h
• stropts.h
• sys/ipc.h
• sys/mman.h
• sys/msg.h
• sys/resource.h
• sys/select.h
• sys/sem.h
• sys/shm.h
• sys/socket.h
• sys/stat.h
• sys/statvfs.h
• sys/time.h
• sys/timeb.h
• sys/times.h
• sys/types.h
• sys/uio.h
• sys/un.h
• sys/utsname.h
• sys/wait.h
• syslog.h
• tar.h
• termios.h
• tgmath.h
• time.h
• trace.h
• ucontext.h
• ulimit.h
• unistd.h
• utime.h
• utmpx.h
• wchar.h
• wctype.h
• wordexp.h

5.1 aio.h

POSIX specification: http://www.opengroup.org/susv3xbd/aio.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

• This header file is missing on some platforms: MacOS X 10.3, NetBSD 3.0, OpenBSD 3.8, Cygwin, mingw, Interix 3.5, BeOS.

5.2 arpa/inet.h

POSIX specification: http://www.opengroup.org/susv3xbd/arpa/inet.h.html

Gnulib module: arpa_inet

Portability problems fixed by Gnulib:

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

Portability problems not fixed by Gnulib:

5.3 assert.h

POSIX specification: http://www.opengroup.org/susv3xbd/assert.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

5.4 complex.h

POSIX specification: http://www.opengroup.org/susv3xbd/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, AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Cygwin, mingw, Interix 3.5, BeOS.

5.5 cpio.h

POSIX specification: http://www.opengroup.org/susv3xbd/cpio.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

• This header file is missing on some platforms: MacOS X 10.3, Cygwin, mingw, BeOS.

5.6 ctype.h

POSIX specification: http://www.opengroup.org/susv3xbd/ctype.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

5.7 dirent.h

POSIX specification: http://www.opengroup.org/susv3xbd/dirent.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

5.8 dlfcn.h

POSIX specification: http://www.opengroup.org/susv3xbd/dlfcn.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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

5.9 errno.h

POSIX specification: http://www.opengroup.org/susv3xbd/errno.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

5.10 fcntl.h

POSIX specification: http://www.opengroup.org/susv3xbd/fcntl.h.html

Gnulib module: fcntl

Portability problems fixed by Gnulib:

• `O_NOCTTY', `O_DSYNC', `O_NONBLOCK', `O_RSYNC', `O_SYNC' are not defined on some platforms.
• `O_BINARY', `O_TEXT' (not specified by POSIX, but essential for portability to Woe32 platforms) are defined on some platforms but not on others.
• `O_DIRECT', `O_DIRECTORY', `O_NDELAY', `O_NOATIME', `O_NOFOLLOW', `O_NOLINKS' (not specified by POSIX) are defined on some platforms but not on others.

Portability problems not fixed by Gnulib:

5.11 fenv.h

POSIX specification: http://www.opengroup.org/susv3xbd/fenv.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, OpenBSD 3.8, AIX 5.1, IRIX 6.5, OSF/1 5.1, Cygwin, Interix 3.5, BeOS.

5.12 float.h

POSIX specification: http://www.opengroup.org/susv3xbd/float.h.html

Gnulib module: float

Portability problems fixed by Gnulib:

• The values of LDBL_* macros are incorrect on some platforms: On BeOS, they are the same as the values of the DBL_* macros, although `long double' is a larger type than `double'.

Portability problems not fixed by Gnulib:

5.13 fmtmsg.h

POSIX specification: http://www.opengroup.org/susv3xbd/fmtmsg.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

• This header file is missing on some platforms: MacOS X 10.3, OpenBSD 3.8, Cygwin, mingw, Interix 3.5, BeOS.

5.14 fnmatch.h

POSIX specification: http://www.opengroup.org/susv3xbd/fnmatch.h.html

Gnulib module: fnmatch-posix or fnmatch-gnu

Portability problems fixed by Gnulib:

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

Portability problems not fixed by Gnulib:

5.15 ftw.h

POSIX specification: http://www.opengroup.org/susv3xbd/ftw.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

• This header file is missing on some platforms: MacOS X 10.3, FreeBSD 5.2.1, NetBSD 3.0, mingw, BeOS.

5.16 glob.h

POSIX specification: http://www.opengroup.org/susv3xbd/glob.h.html

Gnulib module: glob

Portability problems fixed by Gnulib:

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

Portability problems not fixed by Gnulib:

5.17 grp.h

POSIX specification: http://www.opengroup.org/susv3xbd/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.

5.18 iconv.h

POSIX specification: http://www.opengroup.org/susv3xbd/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 3.8, mingw, BeOS, when GNU libiconv is not installed.

5.19 inttypes.h

POSIX specification: http://www.opengroup.org/susv3xbd/inttypes.h.html

Gnulib module: inttypes

Portability problems fixed by Gnulib:

• This header file is missing on some platforms: OSF/1 4.0, Interix 3.5.
• This header file is very incomplete on some platforms.
• The PRI* macros are defined to non-string values on AIX 4.3.3.
• The declarations of imaxabs and imaxdiv are missing on some platforms: NetBSD 3.0, OpenBSD 3.8, AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, BeOS.
• The declarations of strtoimax and strtoumax are missing on some platforms: OpenBSD 3.8, AIX 4.3.2, AIX 5.1 (missing only strtoumax), OSF/1 5.1.

Portability problems not fixed by Gnulib:

5.20 iso646.h

POSIX specification: http://www.opengroup.org/susv3xbd/iso646.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

• This header file is missing on some platforms: HP-UX 11, IRIX 6.5, OSF/1 4.0, Cygwin, mingw, BeOS.

5.21 langinfo.h

POSIX specification: http://www.opengroup.org/susv3xbd/langinfo.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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

5.22 libgen.h

POSIX specification: http://www.opengroup.org/susv3xbd/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, BeOS.

5.23 limits.h

POSIX specification: http://www.opengroup.org/susv3xbd/limits.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

5.24 locale.h

POSIX specification: http://www.opengroup.org/susv3xbd/locale.h.html

Gnulib module: locale

Portability problems fixed by Gnulib:

• The definition of `LC_MESSAGES' is missing on some platforms: mingw.

Portability problems not fixed by Gnulib:

5.25 math.h

POSIX specification: http://www.opengroup.org/susv3xbd/math.h.html

Gnulib module: math

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

5.26 monetary.h

POSIX specification: http://www.opengroup.org/susv3xbd/monetary.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, Cygwin, mingw, BeOS.

5.27 mqueue.h

POSIX specification: http://www.opengroup.org/susv3xbd/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 X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Cygwin, mingw, Interix 3.5, BeOS.

5.28 ndbm.h

POSIX specification: http://www.opengroup.org/susv3xbd/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, BeOS.

5.29 net/if.h

POSIX specification: http://www.opengroup.org/susv3xbd/net/if.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

• This header file is missing on some platforms: mingw, Interix 3.5, BeOS.

5.30 netdb.h

POSIX specification: http://www.opengroup.org/susv3xbd/netdb.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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

5.31 netinet/in.h

POSIX specification: http://www.opengroup.org/susv3xbd/netinet/in.h.html

Gnulib module: netinet_in

Portability problems fixed by Gnulib:

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

Portability problems not fixed by Gnulib:

5.32 netinet/tcp.h

POSIX specification: http://www.opengroup.org/susv3xbd/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, BeOS.

5.33 nl_types.h

POSIX specification: http://www.opengroup.org/susv3xbd/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: MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 10, Cygwin, mingw, BeOS.

5.34 poll.h

POSIX specification: http://www.opengroup.org/susv3xbd/poll.h.html

Gnulib module: poll

Portability problems fixed by Gnulib:

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

Portability problems not fixed by Gnulib:

5.35 pthread.h

POSIX specification: http://www.opengroup.org/susv3xbd/pthread.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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

5.36 pwd.h

POSIX specification: http://www.opengroup.org/susv3xbd/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.

5.37 regex.h

POSIX specification: http://www.opengroup.org/susv3xbd/regex.h.html

Gnulib module: regex

Portability problems fixed by Gnulib:

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

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.

5.38 sched.h

POSIX specification: http://www.opengroup.org/susv3xbd/sched.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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

5.39 search.h

POSIX specification: http://www.opengroup.org/susv3xbd/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: BeOS.

5.40 semaphore.h

POSIX specification: http://www.opengroup.org/susv3xbd/semaphore.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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

5.41 setjmp.h

POSIX specification: http://www.opengroup.org/susv3xbd/setjmp.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

5.42 signal.h

POSIX specification: http://www.opengroup.org/susv3xbd/signal.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

5.43 spawn.h

POSIX specification: http://www.opengroup.org/susv3xbd/spawn.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

• This header file is missing on some platforms: MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Cygwin, mingw, Interix 3.5, BeOS.

5.44 stdarg.h

POSIX specification: http://www.opengroup.org/susv3xbd/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:

5.45 stdbool.h

POSIX specification: http://www.opengroup.org/susv3xbd/stdbool.h.html

Gnulib module: stdbool

Portability problems fixed by Gnulib:

• This header file is missing on some platforms: AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1.
• Some compilers have bugs relating to `bool'.

Portability problems not fixed by Gnulib:

• <stdbool.h> must be #included before `_Bool' can be used.
• You cannot assume that _Bool is a typedef; it might 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 casted value is known to be equal to 0 or 1.

5.46 stddef.h

POSIX specification: http://www.opengroup.org/susv3xbd/stddef.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

5.47 stdint.h

POSIX specification: http://www.opengroup.org/susv3xbd/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, IRIX 6.5, OSF/1 5.1, Interix 3.5, BeOS.
• 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.
• The value of WINT_MAX is incorrect on some platforms: mingw.

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.
• Macros are used instead of typedefs.

The stdint.h 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

5.48 stdio.h

POSIX specification: http://www.opengroup.org/susv3xbd/stdio.h.html

Gnulib module: stdio

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

5.49 stdlib.h

POSIX specification: http://www.opengroup.org/susv3xbd/stdlib.h.html

Gnulib module: stdlib

Portability problems fixed by Gnulib:

• The macros EXIT_SUCCESS and EXIT_FAILURE are not defined on some platforms.
• The macro EXIT_FAILURE is incorrectly defined on Tandem/NSK.

Portability problems not fixed by Gnulib:

5.50 string.h

POSIX specification: http://www.opengroup.org/susv3xbd/string.h.html

Gnulib module: string

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

5.51 strings.h

POSIX specification: http://www.opengroup.org/susv3xbd/strings.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

• This header file defines symbols, such as `index', often used for variables, making debugging harder.

5.52 stropts.h

POSIX specification: http://www.opengroup.org/susv3xbd/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 X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, Cygwin, mingw, BeOS.

5.53 sys/ipc.h

POSIX specification: http://www.opengroup.org/susv3xbd/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, BeOS.

5.54 sys/mman.h

POSIX specification: http://www.opengroup.org/susv3xbd/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, BeOS.

5.55 sys/msg.h

POSIX specification: http://www.opengroup.org/susv3xbd/sys/msg.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

• This header file is missing on some platforms: MacOS X 10.3, mingw, BeOS.

5.56 sys/resource.h

POSIX specification: http://www.opengroup.org/susv3xbd/sys/resource.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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

5.57 sys/select.h

POSIX specification: http://www.opengroup.org/susv3xbd/sys/select.h.html

Gnulib module: sys_select

Portability problems fixed by Gnulib:

• This header file is missing on some platforms: HP-UX 11, mingw, BeOS.
• This header file is not self-contained on some platforms: it requires <sys/types.h> to be included first.

Portability problems not fixed by Gnulib:

5.58 sys/sem.h

POSIX specification: http://www.opengroup.org/susv3xbd/sys/sem.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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

5.59 sys/shm.h

POSIX specification: http://www.opengroup.org/susv3xbd/sys/shm.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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

5.60 sys/socket.h

POSIX specification: http://www.opengroup.org/susv3xbd/sys/socket.h.html

Gnulib module: sys_socket

Portability problems fixed by Gnulib:

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

Portability problems not fixed by Gnulib:

5.61 sys/stat.h

POSIX specification: http://www.opengroup.org/susv3xbd/sys/stat.h.html

Gnulib module: sys_stat

Portability problems fixed by Gnulib:

• Some macros, such as S_IFMT, 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 mingw.

Portability problems not fixed by Gnulib:

5.62 sys/statvfs.h

POSIX specification: http://www.opengroup.org/susv3xbd/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: MacOS X 10.3, OpenBSD 3.8, mingw.

5.63 sys/time.h

POSIX specification: http://www.opengroup.org/susv3xbd/sys/time.h.html

Gnulib module: sys_time

Portability problems fixed by Gnulib:

• This header file is missing on some platforms.
• `struct timeval' is not defined on some platforms.

Portability problems not fixed by Gnulib:

5.64 sys/timeb.h

POSIX specification: http://www.opengroup.org/susv3xbd/sys/timeb.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

5.65 sys/times.h

POSIX specification: http://www.opengroup.org/susv3xbd/sys/times.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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

5.66 sys/types.h

POSIX specification: http://www.opengroup.org/susv3xbd/sys/types.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

5.67 sys/uio.h

POSIX specification: http://www.opengroup.org/susv3xbd/sys/uio.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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

5.68 sys/un.h

POSIX specification: http://www.opengroup.org/susv3xbd/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, BeOS.

5.69 sys/utsname.h

POSIX specification: http://www.opengroup.org/susv3xbd/sys/utsname.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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

5.70 sys/wait.h

POSIX specification: http://www.opengroup.org/susv3xbd/sys/wait.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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

5.71 syslog.h

POSIX specification: http://www.opengroup.org/susv3xbd/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, BeOS.

5.72 tar.h

POSIX specification: http://www.opengroup.org/susv3xbd/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, mingw, BeOS.

5.73 termios.h

POSIX specification: http://www.opengroup.org/susv3xbd/termios.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

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

5.74 tgmath.h

POSIX specification: http://www.opengroup.org/susv3xbd/tgmath.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

• This header file is missing on some platforms: MacOS X 10.3, FreeBSD 5.2.1, NetBSD 3.0, OpenBSD 3.8, AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Cygwin, mingw, Interix 3.5, BeOS.

5.75 time.h

POSIX specification: http://www.opengroup.org/susv3xbd/time.h.html

Gnulib module: time

Portability problems fixed by Gnulib:

• `struct timespec' is not defined on some platforms.

Portability problems not fixed by Gnulib:

5.76 trace.h

POSIX specification: http://www.opengroup.org/susv3xbd/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 X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, AIX 5.1, HP-UX 11, IRIX 6.5, OSF/1 5.1, Solaris 10, Cygwin, mingw, Interix 3.5, BeOS.

5.77 ucontext.h

POSIX specification: http://www.opengroup.org/susv3xbd/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 3.8, Cygwin, mingw, BeOS.

5.78 ulimit.h

POSIX specification: http://www.opengroup.org/susv3xbd/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 3.8, Cygwin, mingw, BeOS.

5.79 unistd.h

POSIX specification: http://www.opengroup.org/susv3xbd/unistd.h.html

Gnulib module: unistd

Portability problems fixed by Gnulib:

• This header file is missing on some platforms: msvc.
• The SEEK_* macros are not defined in this file on some platforms: mingw.
• The _exit function is not declared in this file on some platforms: mingw.

Portability problems not fixed by Gnulib:

5.80 utime.h

POSIX specification: http://www.opengroup.org/susv3xbd/utime.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

• This header file is missing on some platforms. Use <sys/utime.h> if <utime.h> is missing.

5.81 utmpx.h

POSIX specification: http://www.opengroup.org/susv3xbd/utmpx.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

• This header file is missing on some platforms: MacOS X 10.3, FreeBSD 6.0, OpenBSD 3.8, mingw, BeOS.

5.82 wchar.h

POSIX specification: http://www.opengroup.org/susv3xbd/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.
• This header file is not self-contained on some platforms: OSF/1 with Desktop Toolkit C, BSD/OS 4.0.1.

Portability problems not fixed by Gnulib:

5.83 wctype.h

POSIX specification: http://www.opengroup.org/susv3xbd/wctype.h.html

Gnulib module: wctype

Portability problems fixed by Gnulib:

• This header file is missing on some platforms: HP-UX 11.00, BeOS.
• This header file is not self-contained on some platforms: Solaris 2.5, OSF/1 with Desktop Toolkit C, BSD/OS 4.0.1.
• The functions isw* are missing on some platforms: FreeBSD 4.11.
• The functions isw* are actually defined as macros that don't work, on IRIX 5.3.

Portability problems not fixed by Gnulib:

5.84 wordexp.h

POSIX specification: http://www.opengroup.org/susv3xbd/wordexp.h.html

Gnulib module: —

Portability problems fixed by Gnulib:

Portability problems not fixed by Gnulib:

• This header file is missing on some platforms: MacOS X 10.3, OpenBSD 3.8, Cygwin, mingw, Interix 3.5, BeOS.

6 ISO C and POSIX Function Substitutes

This chapter describes which functions and function-like macros 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.

• FD_CLR
• FD_ISSET
• FD_SET
• FD_ZERO
• _Exit
• _exit
• _longjmp
• _setjmp
• _tolower
• _toupper
• a64l
• abort
• abs
• accept
• access
• acos
• acosf
• acosh
• acoshf
• acoshl
• acosl
• aio_cancel
• aio_error
• aio_fsync
• aio_read
• aio_return
• aio_suspend
• aio_write
• alarm
• asctime
• asctime_r
• asin
• asinf
• asinh
• asinhf
• asinhl
• asinl
• assert
• atan
• atan2
• atan2f
• atan2l
• atanf
• atanh
• atanhf
• atanhl
• atanl
• atexit
• atof
• atoi
• atol
• atoll
• basename
• bcmp
• bcopy
• bind
• bsd_signal
• bsearch
• btowc
• bzero
• cabs
• cabsf
• cabsl
• cacos
• cacosf
• cacosh
• cacoshf
• cacoshl
• cacosl
• calloc
• carg
• cargf
• cargl
• casin
• casinf
• casinh
• casinhf
• casinhl
• casinl
• catan
• catanf
• catanh
• catanhf
• catanhl
• catanl
• catclose
• catgets
• catopen
• cbrt
• cbrtf
• cbrtl
• ccos
• ccosf
• ccosh
• ccoshf
• ccoshl
• ccosl
• ceil
• ceilf
• ceill
• cexp
• cexpf
• cexpl
• cfgetispeed
• cfgetospeed
• cfsetispeed
• cfsetospeed
• chdir
• chmod
• chown
• cimag
• cimagf
• cimagl
• clearerr
• clock
• clock_getcpuclockid
• clock_getres
• clock_gettime
• clock_nanosleep
• clock_settime
• clog
• clogf
• clogl
• close
• closedir
• closelog
• confstr
• conj
• conjf
• conjl
• connect
• copysign
• copysignf
• copysignl
• cos
• cosf
• cosh
• coshf
• coshl
• cosl
• cpow
• cpowf
• cpowl
• cproj
• cprojf
• cprojl
• creal
• crealf
• creall
• creat
• crypt
• csin
• csinf
• csinh
• csinhf
• csinhl
• csinl
• csqrt
• csqrtf
• csqrtl
• ctan
• ctanf
• ctanh
• ctanhf
• ctanhl
• ctanl
• ctermid
• ctime
• ctime_r
• daylight
• dbm_clearerr
• dbm_close
• dbm_delete
• dbm_error
• dbm_fetch
• dbm_firstkey
• dbm_nextkey
• dbm_open
• dbm_store
• difftime
• dirname
• div
• dlclose
• dlerror
• dlopen
• dlsym
• drand48
• dup
• dup2
• ecvt
• encrypt
• endgrent
• endhostent
• endnetent
• endprotoent
• endpwent
• endservent
• endutxent
• environ
• erand48
• erf
• erfc
• erfcf
• erfcl
• erff
• erfl
• errno
• execl
• execle
• execlp
• execv
• execve
• execvp
• exit
• exp
• exp2
• exp2f
• exp2l
• expf
• expl
• expm1
• expm1f
• expm1l
• fabs
• fabsf
• fabsl
• fattach
• fchdir
• fchmod
• fchown
• fclose
• fcntl
• fcvt
• fdatasync
• fdetach
• fdim
• fdimf
• fdiml
• fdopen
• feclearexcept
• fegetenv
• fegetexceptflag
• fegetround
• feholdexcept
• feof
• feraiseexcept
• ferror
• fesetenv
• fesetexceptflag
• fesetround
• fetestexcept
• feupdateenv
• fflush
• ffs
• fgetc
• fgetpos
• fgets
• fgetwc
• fgetws
• fileno
• flockfile
• floor
• floorf
• floorl
• fma
• fmaf
• fmal
• fmax
• fmaxf
• fmaxl
• fmin
• fminf
• fminl
• fmod
• fmodf
• fmodl
• fmtmsg
• fnmatch
• fopen
• fork
• fpathconf
• fpclassify
• fprintf
• fputc
• fputs
• fputwc
• fputws
• fread
• free
• freeaddrinfo
• freopen
• frexp
• frexpf
• frexpl
• fscanf
• fseek
• fseeko
• fsetpos
• fstat
• fstatvfs
• fsync
• ftell
• ftello
• ftime
• ftok
• ftruncate
• ftrylockfile
• ftw
• funlockfile
• fwide
• fwprintf
• fwrite
• fwscanf
• gai_strerror
• gcvt
• getaddrinfo
• getc
• getc_unlocked
• getchar
• getchar_unlocked
• getcontext
• getcwd
• getdate
• getdelim
• getegid
• getenv
• geteuid
• getgid
• getgrent
• getgrgid
• getgrgid_r
• getgrnam
• getgrnam_r
• getgroups
• gethostbyaddr
• gethostbyname
• gethostent
• gethostid
• gethostname
• getitimer
• getline
• getlogin
• getlogin_r
• getmsg
• getnameinfo
• getnetbyaddr
• getnetbyname
• getnetent
• getopt
• getpeername
• getpgid
• getpgrp
• getpid
• getpmsg
• getppid
• getpriority
• getprotobyname
• getprotobynumber
• getprotoent
• getpwent
• getpwnam
• getpwnam_r
• getpwuid
• getpwuid_r
• getrlimit
• getrusage
• gets
• getservbyname
• getservbyport
• getservent
• getsid
• getsockname
• getsockopt
• getsubopt
• gettimeofday
• getuid
• getutxent
• getutxid
• getutxline
• getwc
• getwchar
• getwd
• glob
• globfree
• gmtime
• gmtime_r
• grantpt
• h_errno
• hcreate
• hdestroy
• hsearch
• htonl
• htons
• hypot
• hypotf
• hypotl
• iconv
• iconv_close
• iconv_open
• if_freenameindex
• if_indextoname
• if_nameindex
• if_nametoindex
• ilogb
• ilogbf
• ilogbl
• imaxabs
• imaxdiv
• index
• inet_addr
• inet_ntoa
• inet_ntop
• inet_pton
• initstate
• insque
• ioctl
• isalnum
• isalpha
• isascii
• isastream
• isatty
• isblank
• iscntrl
• isdigit
• isfinite
• isgraph
• isgreater
• isgreaterequal
• isinf
• isless
• islessequal
• islessgreater
• islower
• isnan
• isnormal
• isprint
• ispunct
• isspace
• isunordered
• isupper
• iswalnum
• iswalpha
• iswblank
• iswcntrl
• iswctype
• iswdigit
• iswgraph
• iswlower
• iswprint
• iswpunct
• iswspace
• iswupper
• iswxdigit
• isxdigit
• j0
• j1
• jn
• jrand48
• kill
• killpg
• l64a
• labs
• lchown
• lcong48
• ldexp
• ldexpf
• ldexpl
• ldiv
• lfind
• lgamma
• lgammaf
• lgammal
• link
• lio_listio
• listen
• llabs
• lldiv
• llrint
• llrintf
• llrintl
• llround
• llroundf
• llroundl
• localeconv
• localtime
• localtime_r
• lockf
• log
• log10
• log10f
• log10l
• log1p
• log1pf
• log1pl
• log2
• log2f
• log2l
• logb
• logbf
• logbl
• logf
• logl
• longjmp
• lrand48
• lrint
• lrintf
• lrintl
• lround
• lroundf
• lroundl
• lsearch
• lseek
• lstat
• makecontext
• malloc
• mblen
• mbrlen
• mbrtowc
• mbsinit
• mbsrtowcs
• mbstowcs
• mbtowc
• memccpy
• memchr
• memcmp
• memcpy
• memmove
• memset
• mkdir
• mkfifo
• mknod
• mkstemp
• mktemp
• mktime
• mlock
• mlockall
• mmap
• modf
• modff
• modfl
• mprotect
• mq_close
• mq_getattr
• mq_notify
• mq_open
• mq_receive
• mq_send
• mq_setattr
• mq_timedreceive
• mq_timedsend
• mq_unlink
• mrand48
• msgctl
• msgget
• msgrcv
• msgsnd
• msync
• munlock
• munlockall
• munmap
• nan
• nanf
• nanl
• nanosleep
• nearbyint
• nearbyintf
• nearbyintl
• nextafter
• nextafterf
• nextafterl
• nexttoward
• nexttowardf
• nexttowardl
• nftw
• nice
• nl_langinfo
• nrand48
• ntohl
• ntohs
• open
• opendir
• openlog
• optarg
• pathconf
• pause
• pclose
• perror
• pipe
• poll
• popen
• posix_fadvise
• posix_fallocate
• posix_madvise
• posix_mem_offset
• posix_memalign
• posix_openpt
• posix_spawn
• posix_spawn_file_actions_addclose
• posix_spawn_file_actions_adddup2
• posix_spawn_file_actions_addopen
• posix_spawn_file_actions_destroy
• posix_spawn_file_actions_init
• posix_spawnattr_destroy
• posix_spawnattr_getflags
• posix_spawnattr_getpgroup
• posix_spawnattr_getschedparam
• posix_spawnattr_getschedpolicy
• posix_spawnattr_getsigdefault
• posix_spawnattr_getsigmask
• posix_spawnattr_init
• posix_spawnattr_setflags
• posix_spawnattr_setpgroup
• posix_spawnattr_setschedparam
• posix_spawnattr_setschedpolicy
• posix_spawnattr_setsigdefault
• posix_spawnattr_setsigmask
• posix_spawnp
• posix_trace_attr_destroy
• posix_trace_attr_getclockres
• posix_trace_attr_getcreatetime
• posix_trace_attr_getgenversion
• posix_trace_attr_getinherited
• posix_trace_attr_getlogfullpolicy
• posix_trace_attr_getlogsize
• posix_trace_attr_getmaxdatasize
• posix_trace_attr_getmaxsystemeventsize
• posix_trace_attr_getmaxusereventsize
• posix_trace_attr_getname
• posix_trace_attr_getstreamfullpolicy
• posix_trace_attr_getstreamsize
• posix_trace_attr_init
• posix_trace_attr_setinherited
• posix_trace_attr_setlogfullpolicy
• posix_trace_attr_setlogsize
• posix_trace_attr_setmaxdatasize
• posix_trace_attr_setname
• posix_trace_attr_setstreamfullpolicy
• posix_trace_attr_setstreamsize
• posix_trace_clear
• posix_trace_close
• posix_trace_create
• posix_trace_create_withlog
• posix_trace_event
• posix_trace_eventid_equal
• posix_trace_eventid_get_name
• posix_trace_eventid_open
• posix_trace_eventset_add
• posix_trace_eventset_del
• posix_trace_eventset_empty
• posix_trace_eventset_fill
• posix_trace_eventset_ismember
• posix_trace_eventtypelist_getnext_id
• posix_trace_eventtypelist_rewind
• posix_trace_flush
• posix_trace_get_attr
• posix_trace_get_filter
• posix_trace_get_status
• posix_trace_getnext_event
• posix_trace_open
• posix_trace_rewind
• posix_trace_set_filter
• posix_trace_shutdown
• posix_trace_start
• posix_trace_stop
• posix_trace_timedgetnext_event
• posix_trace_trid_eventid_open
• posix_trace_trygetnext_event
• posix_typed_mem_get_info
• posix_typed_mem_open
• pow
• powf
• powl
• pread
• printf
• pselect
• pthread_atfork
• pthread_attr_destroy
• pthread_attr_getdetachstate
• pthread_attr_getguardsize
• pthread_attr_getinheritsched
• pthread_attr_getschedparam
• pthread_attr_getschedpolicy
• pthread_attr_getscope
• pthread_attr_getstack
• pthread_attr_getstackaddr
• pthread_attr_getstacksize
• pthread_attr_init
• pthread_attr_setdetachstate
• pthread_attr_setguardsize
• pthread_attr_setinheritsched
• pthread_attr_setschedparam
• pthread_attr_setschedpolicy
• pthread_attr_setscope
• pthread_attr_setstack
• pthread_attr_setstackaddr
• pthread_attr_setstacksize
• pthread_barrier_destroy
• pthread_barrier_init
• pthread_barrier_wait
• pthread_barrierattr_destroy
• pthread_barrierattr_getpshared
• pthread_barrierattr_init
• pthread_barrierattr_setpshared
• pthread_cancel
• pthread_cleanup_pop
• pthread_cleanup_push
• pthread_cond_broadcast
• pthread_cond_destroy
• pthread_cond_init
• pthread_cond_signal
• pthread_cond_timedwait
• pthread_cond_wait
• pthread_condattr_destroy
• pthread_condattr_getclock
• pthread_condattr_getpshared
• pthread_condattr_init
• pthread_condattr_setclock
• pthread_condattr_setpshared
• pthread_create
• pthread_detach
• pthread_equal
• pthread_exit
• pthread_getconcurrency
• pthread_getcpuclockid
• pthread_getschedparam
• pthread_getspecific
• pthread_join
• pthread_key_create
• pthread_key_delete
• pthread_kill
• pthread_mutex_destroy
• pthread_mutex_getprioceiling
• pthread_mutex_init
• pthread_mutex_lock
• pthread_mutex_setprioceiling
• pthread_mutex_timedlock
• pthread_mutex_trylock
• pthread_mutex_unlock
• pthread_mutexattr_destroy
• pthread_mutexattr_getprioceiling
• pthread_mutexattr_getprotocol
• pthread_mutexattr_getpshared
• pthread_mutexattr_gettype
• pthread_mutexattr_init
• pthread_mutexattr_setprioceiling
• pthread_mutexattr_setprotocol
• pthread_mutexattr_setpshared
• pthread_mutexattr_settype
• pthread_once
• pthread_rwlock_destroy
• pthread_rwlock_init
• pthread_rwlock_rdlock
• pthread_rwlock_timedrdlock
• pthread_rwlock_timedwrlock
• pthread_rwlock_tryrdlock
• pthread_rwlock_trywrlock
• pthread_rwlock_unlock
• pthread_rwlock_wrlock
• pthread_rwlockattr_destroy
• pthread_rwlockattr_getpshared
• pthread_rwlockattr_init
• pthread_rwlockattr_setpshared
• pthread_self
• pthread_setcancelstate
• pthread_setcanceltype
• pthread_setconcurrency
• pthread_setschedparam
• pthread_setschedprio
• pthread_setspecific
• pthread_sigmask
• pthread_spin_destroy
• pthread_spin_init
• pthread_spin_lock
• pthread_spin_trylock
• pthread_spin_unlock
• pthread_testcancel
• ptsname
• putc
• putc_unlocked
• putchar
• putchar_unlocked
• putenv
• putmsg
• putpmsg
• puts
• pututxline
• putwc
• putwchar
• pwrite
• qsort
• raise
• rand
• rand_r
• random
• read
• readdir
• readdir_r
• readlink
• readv
• realloc
• realpath
• recv
• recvfrom
• recvmsg
• regcomp
• regerror
• regexec
• regfree
• remainder
• remainderf
• remainderl
• remove
• remque
• remquo
• remquof
• remquol
• rename
• rewind
• rewinddir
• rindex
• rint
• rintf
• rintl
• rmdir
• round
• roundf
• roundl
• scalb
• scalbln
• scalblnf
• scalblnl
• scalbn
• scalbnf
• scalbnl
• scanf
• sched_get_priority_max
• sched_getparam
• sched_getscheduler
• sched_rr_get_interval
• sched_setparam
• sched_setscheduler
• sched_yield
• seed48
• seekdir
• select
• sem_close
• sem_destroy
• sem_getvalue
• sem_init
• sem_open
• sem_post
• sem_timedwait
• sem_trywait
• sem_unlink
• sem_wait
• semctl
• semget
• semop
• send
• sendmsg
• sendto
• setbuf
• setcontext
• setegid
• setenv
• seteuid
• setgid
• setgrent
• sethostent
• setitimer
• setjmp
• setkey
• setlocale
• setlogmask
• setnetent
• setpgid
• setpgrp
• setpriority
• setprotoent
• setpwent
• setregid
• setreuid
• setrlimit
• setservent
• setsid
• setsockopt
• setstate
• setuid
• setutxent
• setvbuf
• shm_open
• shm_unlink
• shmat
• shmctl
• shmdt
• shmget
• shutdown
• sigaction
• sigaddset
• sigaltstack
• sigdelset
• sigemptyset
• sigfillset
• sighold
• sigignore
• siginterrupt
• sigismember
• siglongjmp
• signal
• signbit
• sigpause
• sigpending
• sigprocmask
• sigqueue
• sigrelse
• sigset
• sigsetjmp
• sigsuspend
• sigtimedwait
• sigwait
• sigwaitinfo
• sin
• sinf
• sinh
• sinhf
• sinhl
• sinl
• sleep
• snprintf
• sockatmark
• socket
• socketpair
• sprintf
• sqrt
• sqrtf
• sqrtl
• srand
• srand48
• srandom
• sscanf
• stat
• statvfs
• stderr
• stdin
• stdout
• strcasecmp
• strcat
• strchr
• strcmp
• strcoll
• strcpy
• strcspn
• strdup
• strerror
• strerror_r
• strfmon
• strftime
• strlen
• strncasecmp
• strncat
• strncmp
• strncpy
• strpbrk
• strptime
• strrchr
• strspn
• strstr
• strtod
• strtof
• strtoimax
• strtok
• strtok_r
• strtol
• strtold
• strtoll
• strtoul
• strtoull
• strtoumax
• strxfrm
• swab
• swapcontext
• swprintf
• swscanf
• symlink
• sync
• sysconf
• syslog
• system
• tan
• tanf
• tanh
• tanhf
• tanhl
• tanl
• tcdrain
• tcflow
• tcflush
• tcgetattr
• tcgetpgrp
• tcgetsid
• tcsendbreak
• tcsetattr
• tcsetpgrp
• tdelete
• telldir
• tempnam
• tfind
• tgamma
• tgammaf
• tgammal
• time
• timer_create
• timer_delete
• timer_getoverrun
• timer_settime
• times
• timezone
• tmpfile
• tmpnam
• toascii
• tolower
• toupper
• towctrans
• towlower
• towupper
• trunc
• truncate
• truncf
• truncl
• tsearch
• ttyname
• ttyname_r
• twalk
• tzname
• tzset
• ualarm
• ulimit
• umask
• uname
• ungetc
• ungetwc
• unlink
• unlockpt
• unsetenv
• usleep
• utime
• utimes
• va_arg
• va_copy
• va_end
• va_start
• vfork
• vfprintf
• vfscanf
• vfwprintf
• vfwscanf
• vprintf
• vscanf
• vsnprintf
• vsprintf
• vsscanf
• vswprintf
• vswscanf
• vwprintf
• vwscanf
• wait
• waitid
• waitpid
• wcrtomb
• wcscat
• wcschr
• wcscmp
• wcscoll
• wcscpy
• wcscspn
• wcsftime
• wcslen
• wcsncat
• wcsncmp
• wcsncpy
• wcspbrk
• wcsrchr
• wcsrtombs
• wcsspn
• wcsstr
• wcstod
• wcstof
• wcstoimax
• wcstok
• wcstol
• wcstold
• wcstoll
• wcstombs
• wcstoul
• wcstoull
• wcstoumax
• wcswcs
• wcswidth
• wcsxfrm
• wctob
• wctomb
• wctrans
• wctype
• wcwidth
• wmemchr
• wmemcmp
• wmemcpy
• wmemmove
• wmemset
• wordexp
• wordfree
• wprintf
• write
• writev
• wscanf
• y0
• y1
• yn