C POSIX library

The C POSIX library is a specification of a C standard library for POSIX systems. It was developed at the same time as the ANSI C standard. Some effort was made to make POSIX compatible with standard C; POSIX includes additional functions to those introduced in standard C.

C POSIX library header files

Header file	Description	First released
`<aio.h>`	Asynchronous input and output	Issue 5
`<arpa/inet.h>`	Functions for manipulating numeric IP addresses (part of Berkeley sockets)	Issue 6
`<assert.h>`	Verify assumptions	??
`<complex.h>`	Complex Arithmetic, see C mathematical functions	??
`<cpio.h>`	Magic numbers for the cpio archive format	Issue 3
`<ctype.h>`	Character types
`<dirent.h>`	Allows the opening and listing of directories	Issue 2
`<dlfcn.h>`	Dynamic linking	Issue 5
`<errno.h>`	Retrieving Error Number	??
`<fcntl.h>`	File opening, locking and other operations	Issue 1
`<fenv.h>`	Floating-Point Environment (FPE), see C mathematical functions	??
`<float.h>`	Floating-point types, see C data types	??
`<fmtmsg.h>`	Message display structures	Issue 4
`<fnmatch.h>`	Filename matching	Issue 4
`<ftw.h>`	File tree traversal	Issue 1
`<glob.h>`	Pathname "globbing" (pattern-matching)	Issue 4
`<grp.h>`	User group information and control	Issue 1
`<iconv.h>`	Codeset conversion facility	Issue 4
`<inttypes.h>`	Fixed sized integer types, see C data types	??
`<iso646.h>`	Alternative spellings, see C alternative tokens	??
`<langinfo.h>`	Language information constants – builds on C localization functions	Issue 2
`<libgen.h>`	Pathname manipulation	Issue 4
`<limits.h>`	Implementation-defined constants, see C data types	??
`<locale.h>`	Category macros, see C localization functions	??
`<math.h>`	Mathematical declarations, see C mathematical functions	??
`<monetary.h>`	String formatting of monetary units	Issue 4
`<mqueue.h>`	Message queue	Issue 5
`<ndbm.h>`	NDBM database operations	Issue 4
`<net/if.h>`	Listing of local network interfaces	Issue 6
`<netdb.h>`	Translating protocol and host names into numeric addresses (part of Berkeley sockets)	Issue 6
`<netinet/in.h>`	Defines Internet protocol and address family (part of Berkeley sockets)	Issue 6
`<netinet/tcp.h>`	Additional TCP control options (part of Berkeley sockets)	Issue 6
`<nl_types.h>`	Localization message catalog functions	Issue 2
`<poll.h>`	Asynchronous file descriptor multiplexing	Issue 4
`<pthread.h>`	Defines an API for creating and manipulating POSIX threads	Issue 5
`<pwd.h>`	passwd (user information) access and control	Issue 1
`<regex.h>`	Regular expression matching	Issue 4
`<sched.h>`	Execution scheduling	Issue 5
`<search.h>`	Search tables	Issue 1
`<semaphore.h>`	POSIX semaphores	Issue 5
`<setjmp.h>`	Stack environment declarations	??
`<signal.h>`	Signals, see C signal handling	??
`<spawn.h>`	Process spawning	Issue 6
`<stdarg.h>`	Handle Variable Argument List	??
`<stdbool.h>`	Boolean type and values, see C data types	??
`<stddef.h>`	Standard type definitions, see C data types	??
`<stdint.h>`	Integer types, see C data types	??
`<stdio.h>`	Standard buffered input/output, see C file input/output	??
`<stdlib.h>`	Standard library definitions, see C standard library	??
`<string.h>`	Several String Operations, see C string handling	??
`<strings.h>`	Case-insensitive string comparisons	Issue 4
`<stropts.h>`	Stream manipulation, including ioctl	Issue 4
`<sys/ipc.h>`	Inter-process communication (IPC)	Issue 2
`<sys/mman.h>`	Memory management, including POSIX shared memory and memory mapped files	Issue 4
`<sys/msg.h>`	POSIX message queues	Issue 2
`<sys/resource.h>`	Resource usage, priorities, and limiting	Issue 4
`<sys/select.h>`	Synchronous I/O multiplexing	Issue 6
`<sys/sem.h>`	XSI (SysV style) semaphores	Issue 2
`<sys/shm.h>`	XSI (SysV style) shared memory	Issue 2
`<sys/socket.h>`	Main Berkley sockets header	Issue 6
`<sys/stat.h>`	File information (stat et al.)	Issue 1
`<sys/statvfs.h>`	File System information	Issue 4
`<sys/time.h>`	Time and date functions and structures	Issue 4
`<sys/times.h>`	File access and modification times	Issue 1
`<sys/types.h>`	Various data types used elsewhere	Issue 1
`<sys/uio.h>`	Vectored I/O operations	Issue 4
`<sys/un.h>`	Unix domain sockets	Issue 6
`<sys/utsname.h>`	Operating system information, including uname	Issue 1
`<sys/wait.h>`	Status of terminated child processes (see wait)	Issue 3
`<syslog.h>`	System error logging	Issue 4
`<tar.h>`	Magic numbers for the tar archive format	Issue 3
`<termios.h>`	Allows terminal I/O interfaces	Issue 3
`<tgmath.h>`	Type-Generic Macros, see C mathematical functions	??
`<time.h>`	Type-Generic Macros, see C date and time functions	??
`<trace.h>`	Tracing of runtime behavior (DEPRECATED)	Issue 6
`<ulimit.h>`	Resource limiting (DEPRECATED in favor of <sys/resource.h>)	Issue 1
`<unistd.h>`	Various essential POSIX functions and constants	Issue 1
`<utime.h>`	inode access and modification times	Issue 3
`<utmpx.h>`	User accounting database functions	Issue 4
`<wchar.h>`	Wide-Character Handling, see C string handling	??
`<wctype.h>`	Wide-Character Classification and Mapping Utilities, see C character classification	??
`<wordexp.h>`	Word-expansion like the shell would perform	Issue 4

References

Official List of headers in the POSIX library on opengroup.org
Lists headers in the POSIX library at the Wayback Machine (archived July 24, 2010)
Description of the posix library from the Flux OSKit

C POSIX library header files

References

Further reading