C POSIX library
| C POSIX library |
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The C POSIX library is a language-independent library (using C calling conventions) that adds functions specific to POSIX systems. POSIX (and SUS) specifies a number of routines that should be available over and above those in the C standard library proper. It was developed at the same time as the ANSI C standard and is closely related to C. Some effort was made to make the C and POSIX libraries compatible, but there are a few POSIX functions that were never introduced into ANSI C.
Facilities are often implemented alongside the C standard library functionality, with varying degrees of closeness. For example, glibc implements functions such as fork within libc.so, but before NPTL was merged into glibc it constituted a separate library with its own linker flag. Often, this POSIX-specified functionality will be regarded as part of the library; the C library proper may be identified as the ANSI or ISO C library.
C POSIX library header files
| <cpio.h> | Magic numbers for the cpio archive format. |
| <dirent.h> | Allows the opening and listing of directories. |
| <fcntl.h> | File opening, locking and other operations. |
| <grp.h> | User group information and control. |
| <pwd.h> | passwd (user information) access and control. |
| <sys/ipc.h> | Inter-process communication (IPC). |
| <sys/msg.h> | POSIX message queues. |
| <sys/sem.h> | POSIX semaphores. |
| <sys/stat.h> | File information (stat et al). |
| <sys/time.h> | Time and date functions and structures. |
| <sys/types.h> | Various data types used elsewhere. |
| <sys/utsname.h> | uname and related structures. |
| <sys/wait.h> | Status of terminated child processes (see wait) |
| <tar.h> | Magic numbers for the tar archive format. |
| <termios.h> | Allows terminal I/O interfaces. |
| <unistd.h> | Various essential POSIX functions and constants. |
| <utime.h> | inode access and modification times. |