1 /* Copyright (C) 1991-2002,2003,2004,2005,2006 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
20 * POSIX Standard: 2.10 Symbolic Constants <unistd.h>
30 /* These may be used to determine what facilities are present at compile time.
31 Their values can be obtained at run time from `sysconf'. */
33 /* POSIX Standard approved as ISO/IEC 9945-1 as of December 2001. */
34 #define _POSIX_VERSION 200112L
36 /* These are not #ifdef __USE_POSIX2 because they are
37 in the theoretically application-owned namespace. */
39 /* The utilities on GNU systems also correspond to this version. */
40 #define _POSIX2_VERSION 200112L
42 /* If defined, the implementation supports the
43 C Language Bindings Option. */
44 #define _POSIX2_C_BIND 200112L
46 /* If defined, the implementation supports the
47 C Language Development Utilities Option. */
48 #define _POSIX2_C_DEV 200112L
50 /* If defined, the implementation supports the
51 Software Development Utilities Option. */
52 #define _POSIX2_SW_DEV 200112L
54 /* If defined, the implementation supports the
55 creation of locales with the localedef utility. */
56 #define _POSIX2_LOCALEDEF 200112L
58 /* X/Open version number to which the library conforms. It is selectable. */
60 # define _XOPEN_VERSION 500
62 # define _XOPEN_VERSION 4
65 /* Commands and utilities from XPG4 are available. */
66 #define _XOPEN_XCU_VERSION 4
68 /* We are compatible with the old published standards as well. */
73 /* The X/Open Unix extensions are available. */
76 /* Encryption is present. */
77 #define _XOPEN_CRYPT 1
79 /* The enhanced internationalization capabilities according to XPG4.2
81 #define _XOPEN_ENH_I18N 1
83 /* The legacy interfaces are also available. */
84 #define _XOPEN_LEGACY 1
87 /* Get values of POSIX options:
89 If these symbols are defined, the corresponding features are
90 always available. If not, they may be available sometimes.
91 The current values can be obtained with `sysconf'.
93 _POSIX_JOB_CONTROL Job control is supported.
94 _POSIX_SAVED_IDS Processes have a saved set-user-ID
95 and a saved set-group-ID.
96 _POSIX_REALTIME_SIGNALS Real-time, queued signals are supported.
97 _POSIX_PRIORITY_SCHEDULING Priority scheduling is supported.
98 _POSIX_TIMERS POSIX.4 clocks and timers are supported.
99 _POSIX_ASYNCHRONOUS_IO Asynchronous I/O is supported.
100 _POSIX_PRIORITIZED_IO Prioritized asynchronous I/O is supported.
101 _POSIX_SYNCHRONIZED_IO Synchronizing file data is supported.
102 _POSIX_FSYNC The fsync function is present.
103 _POSIX_MAPPED_FILES Mapping of files to memory is supported.
104 _POSIX_MEMLOCK Locking of all memory is supported.
105 _POSIX_MEMLOCK_RANGE Locking of ranges of memory is supported.
106 _POSIX_MEMORY_PROTECTION Setting of memory protections is supported.
107 _POSIX_MESSAGE_PASSING POSIX.4 message queues are supported.
108 _POSIX_SEMAPHORES POSIX.4 counting semaphores are supported.
109 _POSIX_SHARED_MEMORY_OBJECTS POSIX.4 shared memory objects are supported.
110 _POSIX_THREADS POSIX.1c pthreads are supported.
111 _POSIX_THREAD_ATTR_STACKADDR Thread stack address attribute option supported.
112 _POSIX_THREAD_ATTR_STACKSIZE Thread stack size attribute option supported.
113 _POSIX_THREAD_SAFE_FUNCTIONS Thread-safe functions are supported.
114 _POSIX_THREAD_PRIORITY_SCHEDULING
115 POSIX.1c thread execution scheduling supported.
116 _POSIX_THREAD_PRIO_INHERIT Thread priority inheritance option supported.
117 _POSIX_THREAD_PRIO_PROTECT Thread priority protection option supported.
118 _POSIX_THREAD_PROCESS_SHARED Process-shared synchronization supported.
119 _POSIX_PII Protocol-independent interfaces are supported.
120 _POSIX_PII_XTI XTI protocol-indep. interfaces are supported.
121 _POSIX_PII_SOCKET Socket protocol-indep. interfaces are supported.
122 _POSIX_PII_INTERNET Internet family of protocols supported.
123 _POSIX_PII_INTERNET_STREAM Connection-mode Internet protocol supported.
124 _POSIX_PII_INTERNET_DGRAM Connectionless Internet protocol supported.
125 _POSIX_PII_OSI ISO/OSI family of protocols supported.
126 _POSIX_PII_OSI_COTS Connection-mode ISO/OSI service supported.
127 _POSIX_PII_OSI_CLTS Connectionless ISO/OSI service supported.
128 _POSIX_POLL Implementation supports `poll' function.
129 _POSIX_SELECT Implementation supports `select' and `pselect'.
131 _XOPEN_REALTIME X/Open realtime support is available.
132 _XOPEN_REALTIME_THREADS X/Open realtime thread support is available.
133 _XOPEN_SHM Shared memory interface according to XPG4.2.
135 _XBS5_ILP32_OFF32 Implementation provides environment with 32-bit
136 int, long, pointer, and off_t types.
137 _XBS5_ILP32_OFFBIG Implementation provides environment with 32-bit
138 int, long, and pointer and off_t with at least
140 _XBS5_LP64_OFF64 Implementation provides environment with 32-bit
141 int, and 64-bit long, pointer, and off_t types.
142 _XBS5_LPBIG_OFFBIG Implementation provides environment with at
143 least 32 bits int and long, pointer, and off_t
144 with at least 64 bits.
146 If any of these symbols is defined as -1, the corresponding option is not
147 true for any file. If any is defined as other than -1, the corresponding
148 option is true for all files. If a symbol is not defined at all, the value
149 for a specific file can be obtained from `pathconf' and `fpathconf'.
151 _POSIX_CHOWN_RESTRICTED Only the super user can use `chown' to change
152 the owner of a file. `chown' can only be used
153 to change the group ID of a file to a group of
154 which the calling process is a member.
155 _POSIX_NO_TRUNC Pathname components longer than
156 NAME_MAX generate an error.
157 _POSIX_VDISABLE If defined, if the value of an element of the
158 `c_cc' member of `struct termios' is
159 _POSIX_VDISABLE, no character will have the
160 effect associated with that element.
161 _POSIX_SYNC_IO Synchronous I/O may be performed.
162 _POSIX_ASYNC_IO Asynchronous I/O may be performed.
163 _POSIX_PRIO_IO Prioritized Asynchronous I/O may be performed.
165 Support for the Large File Support interface is not generally available.
166 If it is available the following constants are defined to one.
167 _LFS64_LARGEFILE Low-level I/O supports large files.
168 _LFS64_STDIO Standard I/O supports large files.
171 #include <bits/posix_opt.h>
173 /* Get the environment definitions from Unix98. */
175 # include <bits/environments.h>
178 /* Standard file descriptors. */
179 #define STDIN_FILENO 0 /* Standard input. */
180 #define STDOUT_FILENO 1 /* Standard output. */
181 #define STDERR_FILENO 2 /* Standard error output. */
184 /* All functions that are not declared anywhere else. */
186 #include <bits/types.h>
188 #ifndef __ssize_t_defined
189 typedef __ssize_t ssize_t;
190 # define __ssize_t_defined
193 #define __need_size_t
197 #if defined __USE_XOPEN || defined __USE_XOPEN2K
198 /* The Single Unix specification says that some more types are
200 # ifndef __gid_t_defined
201 typedef __gid_t gid_t;
202 # define __gid_t_defined
205 # ifndef __uid_t_defined
206 typedef __uid_t uid_t;
207 # define __uid_t_defined
210 # ifndef __off_t_defined
211 # ifndef __USE_FILE_OFFSET64
212 typedef __off_t off_t;
214 typedef __off64_t off_t;
216 # define __off_t_defined
218 # if defined __USE_LARGEFILE64 && !defined __off64_t_defined
219 typedef __off64_t off64_t;
220 # define __off64_t_defined
223 # ifndef __useconds_t_defined
224 typedef __useconds_t useconds_t;
225 # define __useconds_t_defined
228 # ifndef __pid_t_defined
229 typedef __pid_t pid_t;
230 # define __pid_t_defined
234 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
235 # ifndef __intptr_t_defined
236 typedef __intptr_t intptr_t;
237 # define __intptr_t_defined
241 #if defined __USE_BSD || defined __USE_XOPEN
242 # ifndef __socklen_t_defined
243 typedef __socklen_t socklen_t;
244 # define __socklen_t_defined
248 /* Values for the second argument to access.
249 These may be OR'd together. */
250 #define R_OK 4 /* Test for read permission. */
251 #define W_OK 2 /* Test for write permission. */
252 #define X_OK 1 /* Test for execute permission. */
253 #define F_OK 0 /* Test for existence. */
255 /* Test for access to NAME using the real UID and real GID. */
256 extern int access (__const char *__name, int __type) __THROW __nonnull ((1));
259 /* Test for access to NAME using the effective UID and GID
260 (as normal file operations use). */
261 extern int euidaccess (__const char *__name, int __type)
262 __THROW __nonnull ((1));
264 /* An alias for `euidaccess', used by some other systems. */
265 extern int eaccess (__const char *__name, int __type)
266 __THROW __nonnull ((1));
270 /* Values for the WHENCE argument to lseek. */
271 #ifndef _STDIO_H /* <stdio.h> has the same definitions. */
272 # define SEEK_SET 0 /* Seek from beginning of file. */
273 # define SEEK_CUR 1 /* Seek from current position. */
274 # define SEEK_END 2 /* Seek from end of file. */
277 #if defined __USE_BSD && !defined L_SET
278 /* Old BSD names for the same constants; just for compatibility. */
279 # define L_SET SEEK_SET
280 # define L_INCR SEEK_CUR
281 # define L_XTND SEEK_END
285 /* Move FD's file position to OFFSET bytes from the
286 beginning of the file (if WHENCE is SEEK_SET),
287 the current position (if WHENCE is SEEK_CUR),
288 or the end of the file (if WHENCE is SEEK_END).
289 Return the new file position. */
290 #ifndef __USE_FILE_OFFSET64
291 extern __off_t lseek (int __fd, __off_t __offset, int __whence) __THROW;
293 # ifdef __REDIRECT_NTH
294 extern __off64_t __REDIRECT_NTH (lseek,
295 (int __fd, __off64_t __offset, int __whence),
298 # define lseek lseek64
301 #ifdef __USE_LARGEFILE64
302 extern __off64_t lseek64 (int __fd, __off64_t __offset, int __whence)
306 /* Close the file descriptor FD.
308 This function is a cancellation point and therefore not marked with
310 extern int close (int __fd);
312 /* Read NBYTES into BUF from FD. Return the
313 number read, -1 for errors or 0 for EOF.
315 This function is a cancellation point and therefore not marked with
317 extern ssize_t read (int __fd, void *__buf, size_t __nbytes) __wur;
319 /* Write N bytes of BUF to FD. Return the number written, or -1.
321 This function is a cancellation point and therefore not marked with
323 extern ssize_t write (int __fd, __const void *__buf, size_t __n) __wur;
326 # ifndef __USE_FILE_OFFSET64
327 /* Read NBYTES into BUF from FD at the given position OFFSET without
328 changing the file pointer. Return the number read, -1 for errors
331 This function is a cancellation point and therefore not marked with
333 extern ssize_t pread (int __fd, void *__buf, size_t __nbytes,
334 __off_t __offset) __wur;
336 /* Write N bytes of BUF to FD at the given position OFFSET without
337 changing the file pointer. Return the number written, or -1.
339 This function is a cancellation point and therefore not marked with
341 extern ssize_t pwrite (int __fd, __const void *__buf, size_t __n,
342 __off_t __offset) __wur;
345 extern ssize_t __REDIRECT (pread, (int __fd, void *__buf, size_t __nbytes,
348 extern ssize_t __REDIRECT (pwrite, (int __fd, __const void *__buf,
349 size_t __nbytes, __off64_t __offset),
352 # define pread pread64
353 # define pwrite pwrite64
357 # ifdef __USE_LARGEFILE64
358 /* Read NBYTES into BUF from FD at the given position OFFSET without
359 changing the file pointer. Return the number read, -1 for errors
361 extern ssize_t pread64 (int __fd, void *__buf, size_t __nbytes,
362 __off64_t __offset) __wur;
363 /* Write N bytes of BUF to FD at the given position OFFSET without
364 changing the file pointer. Return the number written, or -1. */
365 extern ssize_t pwrite64 (int __fd, __const void *__buf, size_t __n,
366 __off64_t __offset) __wur;
370 /* Create a one-way communication channel (pipe).
371 If successful, two file descriptors are stored in PIPEDES;
372 bytes written on PIPEDES[1] can be read from PIPEDES[0].
373 Returns 0 if successful, -1 if not. */
374 extern int pipe (int __pipedes[2]) __THROW __wur;
376 /* Schedule an alarm. In SECONDS seconds, the process will get a SIGALRM.
377 If SECONDS is zero, any currently scheduled alarm will be cancelled.
378 The function returns the number of seconds remaining until the last
379 alarm scheduled would have signaled, or zero if there wasn't one.
380 There is no return value to indicate an error, but you can set `errno'
381 to 0 and check its value after calling `alarm', and this might tell you.
382 The signal may come late due to processor scheduling. */
383 extern unsigned int alarm (unsigned int __seconds) __THROW;
385 /* Make the process sleep for SECONDS seconds, or until a signal arrives
386 and is not ignored. The function returns the number of seconds less
387 than SECONDS which it actually slept (thus zero if it slept the full time).
388 If a signal handler does a `longjmp' or modifies the handling of the
389 SIGALRM signal while inside `sleep' call, the handling of the SIGALRM
390 signal afterwards is undefined. There is no return value to indicate
391 error, but if `sleep' returns SECONDS, it probably didn't work.
393 This function is a cancellation point and therefore not marked with
395 extern unsigned int sleep (unsigned int __seconds);
397 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
398 /* Set an alarm to go off (generating a SIGALRM signal) in VALUE
399 microseconds. If INTERVAL is nonzero, when the alarm goes off, the
400 timer is reset to go off every INTERVAL microseconds thereafter.
401 Returns the number of microseconds remaining before the alarm. */
402 extern __useconds_t ualarm (__useconds_t __value, __useconds_t __interval)
405 /* Sleep USECONDS microseconds, or until a signal arrives that is not blocked
408 This function is a cancellation point and therefore not marked with
410 extern int usleep (__useconds_t __useconds);
414 /* Suspend the process until a signal arrives.
415 This always returns -1 and sets `errno' to EINTR.
417 This function is a cancellation point and therefore not marked with
419 extern int pause (void);
422 /* Change the owner and group of FILE. */
423 extern int chown (__const char *__file, __uid_t __owner, __gid_t __group)
424 __THROW __nonnull ((1)) __wur;
426 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
427 /* Change the owner and group of the file that FD is open on. */
428 extern int fchown (int __fd, __uid_t __owner, __gid_t __group) __THROW __wur;
431 /* Change owner and group of FILE, if it is a symbolic
432 link the ownership of the symbolic link is changed. */
433 extern int lchown (__const char *__file, __uid_t __owner, __gid_t __group)
434 __THROW __nonnull ((1)) __wur;
436 #endif /* Use BSD || X/Open Unix. */
439 /* Change the owner and group of FILE relative to the directory FD is open
441 extern int fchownat (int __fd, __const char *__file, __uid_t __owner,
442 __gid_t __group, int __flag)
443 __THROW __nonnull ((2)) __wur;
444 #endif /* Use GNU. */
446 /* Change the process's working directory to PATH. */
447 extern int chdir (__const char *__path) __THROW __nonnull ((1)) __wur;
449 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
450 /* Change the process's working directory to the one FD is open on. */
451 extern int fchdir (int __fd) __THROW __wur;
454 /* Get the pathname of the current working directory,
455 and put it in SIZE bytes of BUF. Returns NULL if the
456 directory couldn't be determined or SIZE was too small.
457 If successful, returns BUF. In GNU, if BUF is NULL,
458 an array is allocated with `malloc'; the array is SIZE
459 bytes long, unless SIZE == 0, in which case it is as
461 extern char *getcwd (char *__buf, size_t __size) __THROW __wur;
464 /* Return a malloc'd string containing the current directory name.
465 If the environment variable `PWD' is set, and its value is correct,
466 that value is used. */
467 extern char *get_current_dir_name (void) __THROW;
470 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
471 /* Put the absolute pathname of the current working directory in BUF.
472 If successful, return BUF. If not, put an error message in
473 BUF and return NULL. BUF should be at least PATH_MAX bytes long. */
474 extern char *getwd (char *__buf)
475 __THROW __nonnull ((1)) __attribute_deprecated__ __wur;
479 /* Duplicate FD, returning a new file descriptor on the same file. */
480 extern int dup (int __fd) __THROW __wur;
482 /* Duplicate FD to FD2, closing FD2 and making it open on the same file. */
483 extern int dup2 (int __fd, int __fd2) __THROW;
485 /* NULL-terminated array of "NAME=VALUE" environment variables. */
486 extern char **__environ;
488 extern char **environ;
492 /* Replace the current process, executing PATH with arguments ARGV and
493 environment ENVP. ARGV and ENVP are terminated by NULL pointers. */
494 extern int execve (__const char *__path, char *__const __argv[],
495 char *__const __envp[]) __THROW __nonnull ((1));
498 /* Execute the file FD refers to, overlaying the running program image.
499 ARGV and ENVP are passed to the new program, as for `execve'. */
500 extern int fexecve (int __fd, char *__const __argv[], char *__const __envp[])
505 /* Execute PATH with arguments ARGV and environment from `environ'. */
506 extern int execv (__const char *__path, char *__const __argv[])
507 __THROW __nonnull ((1));
509 /* Execute PATH with all arguments after PATH until a NULL pointer,
510 and the argument after that for environment. */
511 extern int execle (__const char *__path, __const char *__arg, ...)
512 __THROW __nonnull ((1));
514 /* Execute PATH with all arguments after PATH until
515 a NULL pointer and environment from `environ'. */
516 extern int execl (__const char *__path, __const char *__arg, ...)
517 __THROW __nonnull ((1));
519 /* Execute FILE, searching in the `PATH' environment variable if it contains
520 no slashes, with arguments ARGV and environment from `environ'. */
521 extern int execvp (__const char *__file, char *__const __argv[])
522 __THROW __nonnull ((1));
524 /* Execute FILE, searching in the `PATH' environment variable if
525 it contains no slashes, with all arguments after FILE until a
526 NULL pointer and environment from `environ'. */
527 extern int execlp (__const char *__file, __const char *__arg, ...)
528 __THROW __nonnull ((1));
531 #if defined __USE_MISC || defined __USE_XOPEN
532 /* Add INC to priority of the current process. */
533 extern int nice (int __inc) __THROW __wur;
537 /* Terminate program execution with the low-order 8 bits of STATUS. */
538 extern void _exit (int __status) __attribute__ ((__noreturn__));
541 /* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf';
542 the `_SC_*' symbols for the NAME argument to `sysconf';
543 and the `_CS_*' symbols for the NAME argument to `confstr'. */
544 #include <bits/confname.h>
546 /* Get file-specific configuration information about PATH. */
547 extern long int pathconf (__const char *__path, int __name)
548 __THROW __nonnull ((1));
550 /* Get file-specific configuration about descriptor FD. */
551 extern long int fpathconf (int __fd, int __name) __THROW;
553 /* Get the value of the system variable NAME. */
554 extern long int sysconf (int __name) __THROW __attribute__ ((__const__));
557 /* Get the value of the string-valued system variable NAME. */
558 extern size_t confstr (int __name, char *__buf, size_t __len) __THROW;
562 /* Get the process ID of the calling process. */
563 extern __pid_t getpid (void) __THROW;
565 /* Get the process ID of the calling process's parent. */
566 extern __pid_t getppid (void) __THROW;
568 /* Get the process group ID of the calling process.
569 This function is different on old BSD. */
571 extern __pid_t getpgrp (void) __THROW;
573 # ifdef __REDIRECT_NTH
574 extern __pid_t __REDIRECT_NTH (getpgrp, (__pid_t __pid), __getpgid);
576 # define getpgrp __getpgid
580 /* Get the process group ID of process PID. */
581 extern __pid_t __getpgid (__pid_t __pid) __THROW;
582 #ifdef __USE_XOPEN_EXTENDED
583 extern __pid_t getpgid (__pid_t __pid) __THROW;
587 /* Set the process group ID of the process matching PID to PGID.
588 If PID is zero, the current process's process group ID is set.
589 If PGID is zero, the process ID of the process is used. */
590 extern int setpgid (__pid_t __pid, __pid_t __pgid) __THROW;
592 #if defined __USE_SVID || defined __USE_BSD || defined __USE_XOPEN_EXTENDED
593 /* Both System V and BSD have `setpgrp' functions, but with different
594 calling conventions. The BSD function is the same as POSIX.1 `setpgid'
595 (above). The System V function takes no arguments and puts the calling
596 process in its on group like `setpgid (0, 0)'.
598 New programs should always use `setpgid' instead.
600 The default in GNU is to provide the System V function. The BSD
601 function is available under -D_BSD_SOURCE. */
605 /* Set the process group ID of the calling process to its own PID.
606 This is exactly the same as `setpgid (0, 0)'. */
607 extern int setpgrp (void) __THROW;
611 /* Another name for `setpgid' (above). */
612 # ifdef __REDIRECT_NTH
613 extern int __REDIRECT_NTH (setpgrp, (__pid_t __pid, __pid_t __pgrp), setpgid);
615 # define setpgrp setpgid
618 # endif /* Favor BSD. */
619 #endif /* Use SVID or BSD. */
621 /* Create a new session with the calling process as its leader.
622 The process group IDs of the session and the calling process
623 are set to the process ID of the calling process, which is returned. */
624 extern __pid_t setsid (void) __THROW;
626 #ifdef __USE_XOPEN_EXTENDED
627 /* Return the session ID of the given process. */
628 extern __pid_t getsid (__pid_t __pid) __THROW;
631 /* Get the real user ID of the calling process. */
632 extern __uid_t getuid (void) __THROW;
634 /* Get the effective user ID of the calling process. */
635 extern __uid_t geteuid (void) __THROW;
637 /* Get the real group ID of the calling process. */
638 extern __gid_t getgid (void) __THROW;
640 /* Get the effective group ID of the calling process. */
641 extern __gid_t getegid (void) __THROW;
643 /* If SIZE is zero, return the number of supplementary groups
644 the calling process is in. Otherwise, fill in the group IDs
645 of its supplementary groups in LIST and return the number written. */
646 extern int getgroups (int __size, __gid_t __list[]) __THROW __wur;
649 /* Return nonzero iff the calling process is in group GID. */
650 extern int group_member (__gid_t __gid) __THROW;
653 /* Set the user ID of the calling process to UID.
654 If the calling process is the super-user, set the real
655 and effective user IDs, and the saved set-user-ID to UID;
656 if not, the effective user ID is set to UID. */
657 extern int setuid (__uid_t __uid) __THROW;
659 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
660 /* Set the real user ID of the calling process to RUID,
661 and the effective user ID of the calling process to EUID. */
662 extern int setreuid (__uid_t __ruid, __uid_t __euid) __THROW;
665 #if defined __USE_BSD || defined __USE_XOPEN2K
666 /* Set the effective user ID of the calling process to UID. */
667 extern int seteuid (__uid_t __uid) __THROW;
668 #endif /* Use BSD. */
670 /* Set the group ID of the calling process to GID.
671 If the calling process is the super-user, set the real
672 and effective group IDs, and the saved set-group-ID to GID;
673 if not, the effective group ID is set to GID. */
674 extern int setgid (__gid_t __gid) __THROW;
676 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
677 /* Set the real group ID of the calling process to RGID,
678 and the effective group ID of the calling process to EGID. */
679 extern int setregid (__gid_t __rgid, __gid_t __egid) __THROW;
682 #if defined __USE_BSD || defined __USE_XOPEN2K
683 /* Set the effective group ID of the calling process to GID. */
684 extern int setegid (__gid_t __gid) __THROW;
685 #endif /* Use BSD. */
688 /* Fetch the effective user ID, real user ID, and saved-set user ID,
689 of the calling process. */
690 extern int getresuid (__uid_t *__euid, __uid_t *__ruid, __uid_t *__suid)
693 /* Fetch the effective group ID, real group ID, and saved-set group ID,
694 of the calling process. */
695 extern int getresgid (__gid_t *__egid, __gid_t *__rgid, __gid_t *__sgid)
698 /* Set the effective user ID, real user ID, and saved-set user ID,
699 of the calling process to EUID, RUID, and SUID, respectively. */
700 extern int setresuid (__uid_t __euid, __uid_t __ruid, __uid_t __suid)
703 /* Set the effective group ID, real group ID, and saved-set group ID,
704 of the calling process to EGID, RGID, and SGID, respectively. */
705 extern int setresgid (__gid_t __egid, __gid_t __rgid, __gid_t __sgid)
710 /* Clone the calling process, creating an exact copy.
711 Return -1 for errors, 0 to the new process,
712 and the process ID of the new process to the old process. */
713 extern __pid_t fork (void) __THROW;
715 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
716 /* Clone the calling process, but without copying the whole address space.
717 The calling process is suspended until the new process exits or is
718 replaced by a call to `execve'. Return -1 for errors, 0 to the new process,
719 and the process ID of the new process to the old process. */
720 extern __pid_t vfork (void) __THROW;
721 #endif /* Use BSD. */
724 /* Return the pathname of the terminal FD is open on, or NULL on errors.
725 The returned storage is good only until the next call to this function. */
726 extern char *ttyname (int __fd) __THROW;
728 /* Store at most BUFLEN characters of the pathname of the terminal FD is
729 open on in BUF. Return 0 on success, otherwise an error number. */
730 extern int ttyname_r (int __fd, char *__buf, size_t __buflen)
731 __THROW __nonnull ((2)) __wur;
733 /* Return 1 if FD is a valid descriptor associated
734 with a terminal, zero if not. */
735 extern int isatty (int __fd) __THROW;
737 #if defined __USE_BSD \
738 || (defined __USE_XOPEN_EXTENDED && !defined __USE_UNIX98)
739 /* Return the index into the active-logins file (utmp) for
740 the controlling terminal. */
741 extern int ttyslot (void) __THROW;
745 /* Make a link to FROM named TO. */
746 extern int link (__const char *__from, __const char *__to)
747 __THROW __nonnull ((1, 2)) __wur;
750 /* Like link but relative paths in TO and FROM are interpreted relative
751 to FROMFD and TOFD respectively. */
752 extern int linkat (int __fromfd, __const char *__from, int __tofd,
753 __const char *__to) __THROW __nonnull ((2, 4)) __wur;
756 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
757 /* Make a symbolic link to FROM named TO. */
758 extern int symlink (__const char *__from, __const char *__to)
759 __THROW __nonnull ((1, 2)) __wur;
761 /* Read the contents of the symbolic link PATH into no more than
762 LEN bytes of BUF. The contents are not null-terminated.
763 Returns the number of characters read, or -1 for errors. */
764 extern int readlink (__const char *__restrict __path, char *__restrict __buf,
765 size_t __len) __THROW __nonnull ((1, 2)) __wur;
766 #endif /* Use BSD. */
769 /* Like symlink but a relative path in TO is interpreted relative to TOFD. */
770 extern int symlinkat (__const char *__from, int __tofd,
771 __const char *__to) __THROW __nonnull ((1, 3)) __wur;
773 /* Like readlink but a relative PATH is interpreted relative to FD. */
774 extern int readlinkat (int __fd, __const char *__restrict __path,
775 char *__restrict __buf, size_t __len)
776 __THROW __nonnull ((2, 3)) __wur;
779 /* Remove the link NAME. */
780 extern int unlink (__const char *__name) __THROW __nonnull ((1));
783 /* Remove the link NAME relative to FD. */
784 extern int unlinkat (int __fd, __const char *__name, int __flag)
785 __THROW __nonnull ((2));
788 /* Remove the directory PATH. */
789 extern int rmdir (__const char *__path) __THROW __nonnull ((1));
792 /* Return the foreground process group ID of FD. */
793 extern __pid_t tcgetpgrp (int __fd) __THROW;
795 /* Set the foreground process group ID of FD set PGRP_ID. */
796 extern int tcsetpgrp (int __fd, __pid_t __pgrp_id) __THROW;
799 /* Return the login name of the user.
801 This function is a possible cancellation points and therefore not
802 marked with __THROW. */
803 extern char *getlogin (void);
804 #if defined __USE_REENTRANT || defined __USE_UNIX98
805 /* Return at most NAME_LEN characters of the login name of the user in NAME.
806 If it cannot be determined or some other error occurred, return the error
807 code. Otherwise return 0.
809 This function is a possible cancellation points and therefore not
810 marked with __THROW. */
811 extern int getlogin_r (char *__name, size_t __name_len) __nonnull ((1));
815 /* Set the login name returned by `getlogin'. */
816 extern int setlogin (__const char *__name) __THROW __nonnull ((1));
821 /* Get definitions and prototypes for functions to process the
822 arguments in ARGV (ARGC of them, minus the program name) for
823 options given in OPTS. */
824 # define __need_getopt
829 #if defined __USE_BSD || defined __USE_UNIX98
830 /* Put the name of the current host in no more than LEN bytes of NAME.
831 The result is null-terminated if LEN is large enough for the full
832 name and the terminator. */
833 extern int gethostname (char *__name, size_t __len) __THROW __nonnull ((1));
837 #if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_UNIX98)
838 /* Set the name of the current host to NAME, which is LEN bytes long.
839 This call is restricted to the super-user. */
840 extern int sethostname (__const char *__name, size_t __len)
841 __THROW __nonnull ((1)) __wur;
843 /* Set the current machine's Internet number to ID.
844 This call is restricted to the super-user. */
845 extern int sethostid (long int __id) __THROW __wur;
848 /* Get and set the NIS (aka YP) domain name, if any.
849 Called just like `gethostname' and `sethostname'.
850 The NIS domain name is usually the empty string when not using NIS. */
851 extern int getdomainname (char *__name, size_t __len)
852 __THROW __nonnull ((1)) __wur;
853 extern int setdomainname (__const char *__name, size_t __len)
854 __THROW __nonnull ((1)) __wur;
857 /* Revoke access permissions to all processes currently communicating
858 with the control terminal, and then send a SIGHUP signal to the process
859 group of the control terminal. */
860 extern int vhangup (void) __THROW;
862 /* Revoke the access of all descriptors currently open on FILE. */
863 extern int revoke (__const char *__file) __THROW __nonnull ((1)) __wur;
866 /* Enable statistical profiling, writing samples of the PC into at most
867 SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
868 is enabled, the system examines the user PC and increments
869 SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536]. If SCALE is zero,
870 disable profiling. Returns zero on success, -1 on error. */
871 extern int profil (unsigned short int *__sample_buffer, size_t __size,
872 size_t __offset, unsigned int __scale)
873 __THROW __nonnull ((1));
876 /* Turn accounting on if NAME is an existing file. The system will then write
877 a record for each process as it terminates, to this file. If NAME is NULL,
878 turn accounting off. This call is restricted to the super-user. */
879 extern int acct (__const char *__name) __THROW;
882 /* Successive calls return the shells listed in `/etc/shells'. */
883 extern char *getusershell (void) __THROW;
884 extern void endusershell (void) __THROW; /* Discard cached info. */
885 extern void setusershell (void) __THROW; /* Rewind and re-read the file. */
888 /* Put the program in the background, and dissociate from the controlling
889 terminal. If NOCHDIR is zero, do `chdir ("/")'. If NOCLOSE is zero,
890 redirects stdin, stdout, and stderr to /dev/null. */
891 extern int daemon (int __nochdir, int __noclose) __THROW __wur;
892 #endif /* Use BSD || X/Open. */
895 #if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_XOPEN2K)
896 /* Make PATH be the root directory (the starting point for absolute paths).
897 This call is restricted to the super-user. */
898 extern int chroot (__const char *__path) __THROW __nonnull ((1)) __wur;
900 /* Prompt with PROMPT and read a string from the terminal without echoing.
901 Uses /dev/tty if possible; otherwise stderr and stdin. */
902 extern char *getpass (__const char *__prompt) __nonnull ((1));
903 #endif /* Use BSD || X/Open. */
906 #if defined __USE_BSD || defined __USE_XOPEN
907 /* Make all changes done to FD actually appear on disk.
909 This function is a cancellation point and therefore not marked with
911 extern int fsync (int __fd);
912 #endif /* Use BSD || X/Open. */
915 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
917 /* Return identifier for the current host. */
918 extern long int gethostid (void);
920 /* Make all changes done to all files actually appear on disk. */
921 extern void sync (void) __THROW;
924 /* Return the number of bytes in a page. This is the system's page size,
925 which is not necessarily the same as the hardware page size. */
926 extern int getpagesize (void) __THROW __attribute__ ((__const__));
929 /* Return the maximum number of file descriptors
930 the current process could possibly have. */
931 extern int getdtablesize (void) __THROW;
934 /* Truncate FILE to LENGTH bytes. */
935 # ifndef __USE_FILE_OFFSET64
936 extern int truncate (__const char *__file, __off_t __length)
937 __THROW __nonnull ((1)) __wur;
939 # ifdef __REDIRECT_NTH
940 extern int __REDIRECT_NTH (truncate,
941 (__const char *__file, __off64_t __length),
942 truncate64) __nonnull ((1)) __wur;
944 # define truncate truncate64
947 # ifdef __USE_LARGEFILE64
948 extern int truncate64 (__const char *__file, __off64_t __length)
949 __THROW __nonnull ((1)) __wur;
952 #endif /* Use BSD || X/Open Unix. */
954 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
956 /* Truncate the file FD is open on to LENGTH bytes. */
957 # ifndef __USE_FILE_OFFSET64
958 extern int ftruncate (int __fd, __off_t __length) __THROW __wur;
960 # ifdef __REDIRECT_NTH
961 extern int __REDIRECT_NTH (ftruncate, (int __fd, __off64_t __length),
964 # define ftruncate ftruncate64
967 # ifdef __USE_LARGEFILE64
968 extern int ftruncate64 (int __fd, __off64_t __length) __THROW __wur;
971 #endif /* Use BSD || X/Open Unix || POSIX 2003. */
974 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
976 /* Set the end of accessible data space (aka "the break") to ADDR.
977 Returns zero on success and -1 for errors (with errno set). */
978 extern int brk (void *__addr) __THROW __wur;
980 /* Increase or decrease the end of accessible data space by DELTA bytes.
981 If successful, returns the address the previous end of data space
982 (i.e. the beginning of the new space, if DELTA > 0);
983 returns (void *) -1 for errors (with errno set). */
984 extern void *sbrk (intptr_t __delta) __THROW;
989 /* Invoke `system call' number SYSNO, passing it the remaining arguments.
990 This is completely system-dependent, and not often useful.
992 In Unix, `syscall' sets `errno' for all errors and most calls return -1
993 for errors; in many systems you cannot pass arguments or get return
994 values for all system calls (`pipe', `fork', and `getppid' typically
997 In Mach, all system calls take normal arguments and always return an
998 error code (zero for success). */
999 extern long int syscall (long int __sysno, ...) __THROW;
1001 #endif /* Use misc. */
1004 #if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK
1005 /* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both
1006 files consistent. Some systems have them there and some here, and some
1007 software depends on the macros being defined without including both. */
1009 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
1010 LEN is always relative to the current file position.
1011 The CMD argument is one of the following.
1013 This function is a cancellation point and therefore not marked with
1016 # define F_ULOCK 0 /* Unlock a previously locked region. */
1017 # define F_LOCK 1 /* Lock a region for exclusive use. */
1018 # define F_TLOCK 2 /* Test and lock a region for exclusive use. */
1019 # define F_TEST 3 /* Test a region for other processes locks. */
1021 # ifndef __USE_FILE_OFFSET64
1022 extern int lockf (int __fd, int __cmd, __off_t __len) __wur;
1025 extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len),
1028 # define lockf lockf64
1031 # ifdef __USE_LARGEFILE64
1032 extern int lockf64 (int __fd, int __cmd, __off64_t __len) __wur;
1034 #endif /* Use misc and F_LOCK not already defined. */
1039 /* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno'
1042 # define TEMP_FAILURE_RETRY(expression) \
1044 ({ long int __result; \
1045 do __result = (long int) (expression); \
1046 while (__result == -1L && errno == EINTR); \
1050 #if defined __USE_POSIX199309 || defined __USE_UNIX98
1051 /* Synchronize at least the data part of a file with the underlying
1053 extern int fdatasync (int __fildes) __THROW;
1054 #endif /* Use POSIX199309 */
1057 /* XPG4.2 specifies that prototypes for the encryption functions must
1060 /* Encrypt at most 8 characters from KEY using salt to perturb DES. */
1061 extern char *crypt (__const char *__key, __const char *__salt)
1062 __THROW __nonnull ((1, 2));
1064 /* Encrypt data in BLOCK in place if EDFLAG is zero; otherwise decrypt
1066 extern void encrypt (char *__block, int __edflag) __THROW __nonnull ((1));
1069 /* Swab pairs bytes in the first N bytes of the area pointed to by
1070 FROM and copy the result to TO. The value of TO must not be in the
1071 range [FROM - N + 1, FROM - 1]. If N is odd the first byte in FROM
1072 is without partner. */
1073 extern void swab (__const void *__restrict __from, void *__restrict __to,
1074 ssize_t __n) __THROW __nonnull ((1, 2));
1078 /* The Single Unix specification demands this prototype to be here.
1079 It is also found in <stdio.h>. */
1081 /* Return the name of the controlling terminal. */
1082 extern char *ctermid (char *__s) __THROW;
1086 /* Define some macros helping to catch buffer overflows. */
1087 #if __USE_FORTIFY_LEVEL > 0 && !defined __cplusplus
1088 # include <bits/unistd.h>
1093 #endif /* unistd.h */