Update version.h and include/features.h for 2.18 release.
[glibc.git] / posix / unistd.h
blob178223d7555702d133a51eaf8deaff7bfc5327aa
1 /* Copyright (C) 1991-2013 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, see
16 <http://www.gnu.org/licenses/>. */
19 * POSIX Standard: 2.10 Symbolic Constants <unistd.h>
22 #ifndef _UNISTD_H
23 #define _UNISTD_H 1
25 #include <features.h>
27 __BEGIN_DECLS
29 /* These may be used to determine what facilities are present at compile time.
30 Their values can be obtained at run time from `sysconf'. */
32 #ifdef __USE_XOPEN2K8
33 /* POSIX Standard approved as ISO/IEC 9945-1 as of September 2008. */
34 # define _POSIX_VERSION 200809L
35 #elif defined __USE_XOPEN2K
36 /* POSIX Standard approved as ISO/IEC 9945-1 as of December 2001. */
37 # define _POSIX_VERSION 200112L
38 #elif defined __USE_POSIX199506
39 /* POSIX Standard approved as ISO/IEC 9945-1 as of June 1995. */
40 # define _POSIX_VERSION 199506L
41 #elif defined __USE_POSIX199309
42 /* POSIX Standard approved as ISO/IEC 9945-1 as of September 1993. */
43 # define _POSIX_VERSION 199309L
44 #else
45 /* POSIX Standard approved as ISO/IEC 9945-1 as of September 1990. */
46 # define _POSIX_VERSION 199009L
47 #endif
49 /* These are not #ifdef __USE_POSIX2 because they are
50 in the theoretically application-owned namespace. */
52 #ifdef __USE_XOPEN2K8
53 # define __POSIX2_THIS_VERSION 200809L
54 /* The utilities on GNU systems also correspond to this version. */
55 #elif defined __USE_XOPEN2K
56 /* The utilities on GNU systems also correspond to this version. */
57 # define __POSIX2_THIS_VERSION 200112L
58 #elif defined __USE_POSIX199506
59 /* The utilities on GNU systems also correspond to this version. */
60 # define __POSIX2_THIS_VERSION 199506L
61 #else
62 /* The utilities on GNU systems also correspond to this version. */
63 # define __POSIX2_THIS_VERSION 199209L
64 #endif
66 /* The utilities on GNU systems also correspond to this version. */
67 #define _POSIX2_VERSION __POSIX2_THIS_VERSION
69 /* If defined, the implementation supports the
70 C Language Bindings Option. */
71 #define _POSIX2_C_BIND __POSIX2_THIS_VERSION
73 /* If defined, the implementation supports the
74 C Language Development Utilities Option. */
75 #define _POSIX2_C_DEV __POSIX2_THIS_VERSION
77 /* If defined, the implementation supports the
78 Software Development Utilities Option. */
79 #define _POSIX2_SW_DEV __POSIX2_THIS_VERSION
81 /* If defined, the implementation supports the
82 creation of locales with the localedef utility. */
83 #define _POSIX2_LOCALEDEF __POSIX2_THIS_VERSION
85 /* X/Open version number to which the library conforms. It is selectable. */
86 #ifdef __USE_XOPEN2K8
87 # define _XOPEN_VERSION 700
88 #elif defined __USE_XOPEN2K
89 # define _XOPEN_VERSION 600
90 #elif defined __USE_UNIX98
91 # define _XOPEN_VERSION 500
92 #else
93 # define _XOPEN_VERSION 4
94 #endif
96 /* Commands and utilities from XPG4 are available. */
97 #define _XOPEN_XCU_VERSION 4
99 /* We are compatible with the old published standards as well. */
100 #define _XOPEN_XPG2 1
101 #define _XOPEN_XPG3 1
102 #define _XOPEN_XPG4 1
104 /* The X/Open Unix extensions are available. */
105 #define _XOPEN_UNIX 1
107 /* Encryption is present. */
108 #define _XOPEN_CRYPT 1
110 /* The enhanced internationalization capabilities according to XPG4.2
111 are present. */
112 #define _XOPEN_ENH_I18N 1
114 /* The legacy interfaces are also available. */
115 #define _XOPEN_LEGACY 1
118 /* Get values of POSIX options:
120 If these symbols are defined, the corresponding features are
121 always available. If not, they may be available sometimes.
122 The current values can be obtained with `sysconf'.
124 _POSIX_JOB_CONTROL Job control is supported.
125 _POSIX_SAVED_IDS Processes have a saved set-user-ID
126 and a saved set-group-ID.
127 _POSIX_REALTIME_SIGNALS Real-time, queued signals are supported.
128 _POSIX_PRIORITY_SCHEDULING Priority scheduling is supported.
129 _POSIX_TIMERS POSIX.4 clocks and timers are supported.
130 _POSIX_ASYNCHRONOUS_IO Asynchronous I/O is supported.
131 _POSIX_PRIORITIZED_IO Prioritized asynchronous I/O is supported.
132 _POSIX_SYNCHRONIZED_IO Synchronizing file data is supported.
133 _POSIX_FSYNC The fsync function is present.
134 _POSIX_MAPPED_FILES Mapping of files to memory is supported.
135 _POSIX_MEMLOCK Locking of all memory is supported.
136 _POSIX_MEMLOCK_RANGE Locking of ranges of memory is supported.
137 _POSIX_MEMORY_PROTECTION Setting of memory protections is supported.
138 _POSIX_MESSAGE_PASSING POSIX.4 message queues are supported.
139 _POSIX_SEMAPHORES POSIX.4 counting semaphores are supported.
140 _POSIX_SHARED_MEMORY_OBJECTS POSIX.4 shared memory objects are supported.
141 _POSIX_THREADS POSIX.1c pthreads are supported.
142 _POSIX_THREAD_ATTR_STACKADDR Thread stack address attribute option supported.
143 _POSIX_THREAD_ATTR_STACKSIZE Thread stack size attribute option supported.
144 _POSIX_THREAD_SAFE_FUNCTIONS Thread-safe functions are supported.
145 _POSIX_THREAD_PRIORITY_SCHEDULING
146 POSIX.1c thread execution scheduling supported.
147 _POSIX_THREAD_PRIO_INHERIT Thread priority inheritance option supported.
148 _POSIX_THREAD_PRIO_PROTECT Thread priority protection option supported.
149 _POSIX_THREAD_PROCESS_SHARED Process-shared synchronization supported.
150 _POSIX_PII Protocol-independent interfaces are supported.
151 _POSIX_PII_XTI XTI protocol-indep. interfaces are supported.
152 _POSIX_PII_SOCKET Socket protocol-indep. interfaces are supported.
153 _POSIX_PII_INTERNET Internet family of protocols supported.
154 _POSIX_PII_INTERNET_STREAM Connection-mode Internet protocol supported.
155 _POSIX_PII_INTERNET_DGRAM Connectionless Internet protocol supported.
156 _POSIX_PII_OSI ISO/OSI family of protocols supported.
157 _POSIX_PII_OSI_COTS Connection-mode ISO/OSI service supported.
158 _POSIX_PII_OSI_CLTS Connectionless ISO/OSI service supported.
159 _POSIX_POLL Implementation supports `poll' function.
160 _POSIX_SELECT Implementation supports `select' and `pselect'.
162 _XOPEN_REALTIME X/Open realtime support is available.
163 _XOPEN_REALTIME_THREADS X/Open realtime thread support is available.
164 _XOPEN_SHM Shared memory interface according to XPG4.2.
166 _XBS5_ILP32_OFF32 Implementation provides environment with 32-bit
167 int, long, pointer, and off_t types.
168 _XBS5_ILP32_OFFBIG Implementation provides environment with 32-bit
169 int, long, and pointer and off_t with at least
170 64 bits.
171 _XBS5_LP64_OFF64 Implementation provides environment with 32-bit
172 int, and 64-bit long, pointer, and off_t types.
173 _XBS5_LPBIG_OFFBIG Implementation provides environment with at
174 least 32 bits int and long, pointer, and off_t
175 with at least 64 bits.
177 If any of these symbols is defined as -1, the corresponding option is not
178 true for any file. If any is defined as other than -1, the corresponding
179 option is true for all files. If a symbol is not defined at all, the value
180 for a specific file can be obtained from `pathconf' and `fpathconf'.
182 _POSIX_CHOWN_RESTRICTED Only the super user can use `chown' to change
183 the owner of a file. `chown' can only be used
184 to change the group ID of a file to a group of
185 which the calling process is a member.
186 _POSIX_NO_TRUNC Pathname components longer than
187 NAME_MAX generate an error.
188 _POSIX_VDISABLE If defined, if the value of an element of the
189 `c_cc' member of `struct termios' is
190 _POSIX_VDISABLE, no character will have the
191 effect associated with that element.
192 _POSIX_SYNC_IO Synchronous I/O may be performed.
193 _POSIX_ASYNC_IO Asynchronous I/O may be performed.
194 _POSIX_PRIO_IO Prioritized Asynchronous I/O may be performed.
196 Support for the Large File Support interface is not generally available.
197 If it is available the following constants are defined to one.
198 _LFS64_LARGEFILE Low-level I/O supports large files.
199 _LFS64_STDIO Standard I/O supports large files.
202 #include <bits/posix_opt.h>
204 /* Get the environment definitions from Unix98. */
205 #if defined __USE_UNIX98 || defined __USE_XOPEN2K
206 # include <bits/environments.h>
207 #endif
209 /* Standard file descriptors. */
210 #define STDIN_FILENO 0 /* Standard input. */
211 #define STDOUT_FILENO 1 /* Standard output. */
212 #define STDERR_FILENO 2 /* Standard error output. */
215 /* All functions that are not declared anywhere else. */
217 #include <bits/types.h>
219 #ifndef __ssize_t_defined
220 typedef __ssize_t ssize_t;
221 # define __ssize_t_defined
222 #endif
224 #define __need_size_t
225 #define __need_NULL
226 #include <stddef.h>
228 #if defined __USE_XOPEN || defined __USE_XOPEN2K
229 /* The Single Unix specification says that some more types are
230 available here. */
231 # ifndef __gid_t_defined
232 typedef __gid_t gid_t;
233 # define __gid_t_defined
234 # endif
236 # ifndef __uid_t_defined
237 typedef __uid_t uid_t;
238 # define __uid_t_defined
239 # endif
241 # ifndef __off_t_defined
242 # ifndef __USE_FILE_OFFSET64
243 typedef __off_t off_t;
244 # else
245 typedef __off64_t off_t;
246 # endif
247 # define __off_t_defined
248 # endif
249 # if defined __USE_LARGEFILE64 && !defined __off64_t_defined
250 typedef __off64_t off64_t;
251 # define __off64_t_defined
252 # endif
254 # ifndef __useconds_t_defined
255 typedef __useconds_t useconds_t;
256 # define __useconds_t_defined
257 # endif
259 # ifndef __pid_t_defined
260 typedef __pid_t pid_t;
261 # define __pid_t_defined
262 # endif
263 #endif /* X/Open */
265 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
266 # ifndef __intptr_t_defined
267 typedef __intptr_t intptr_t;
268 # define __intptr_t_defined
269 # endif
270 #endif
272 #if defined __USE_BSD || defined __USE_XOPEN
273 # ifndef __socklen_t_defined
274 typedef __socklen_t socklen_t;
275 # define __socklen_t_defined
276 # endif
277 #endif
279 /* Values for the second argument to access.
280 These may be OR'd together. */
281 #define R_OK 4 /* Test for read permission. */
282 #define W_OK 2 /* Test for write permission. */
283 #define X_OK 1 /* Test for execute permission. */
284 #define F_OK 0 /* Test for existence. */
286 /* Test for access to NAME using the real UID and real GID. */
287 extern int access (const char *__name, int __type) __THROW __nonnull ((1));
289 #ifdef __USE_GNU
290 /* Test for access to NAME using the effective UID and GID
291 (as normal file operations use). */
292 extern int euidaccess (const char *__name, int __type)
293 __THROW __nonnull ((1));
295 /* An alias for `euidaccess', used by some other systems. */
296 extern int eaccess (const char *__name, int __type)
297 __THROW __nonnull ((1));
298 #endif
300 #ifdef __USE_ATFILE
301 /* Test for access to FILE relative to the directory FD is open on.
302 If AT_EACCESS is set in FLAG, then use effective IDs like `eaccess',
303 otherwise use real IDs like `access'. */
304 extern int faccessat (int __fd, const char *__file, int __type, int __flag)
305 __THROW __nonnull ((2)) __wur;
306 #endif /* Use GNU. */
309 /* Values for the WHENCE argument to lseek. */
310 #ifndef _STDIO_H /* <stdio.h> has the same definitions. */
311 # define SEEK_SET 0 /* Seek from beginning of file. */
312 # define SEEK_CUR 1 /* Seek from current position. */
313 # define SEEK_END 2 /* Seek from end of file. */
314 # ifdef __USE_GNU
315 # define SEEK_DATA 3 /* Seek to next data. */
316 # define SEEK_HOLE 4 /* Seek to next hole. */
317 # endif
318 #endif
320 #if defined __USE_BSD && !defined L_SET
321 /* Old BSD names for the same constants; just for compatibility. */
322 # define L_SET SEEK_SET
323 # define L_INCR SEEK_CUR
324 # define L_XTND SEEK_END
325 #endif
328 /* Move FD's file position to OFFSET bytes from the
329 beginning of the file (if WHENCE is SEEK_SET),
330 the current position (if WHENCE is SEEK_CUR),
331 or the end of the file (if WHENCE is SEEK_END).
332 Return the new file position. */
333 #ifndef __USE_FILE_OFFSET64
334 extern __off_t lseek (int __fd, __off_t __offset, int __whence) __THROW;
335 #else
336 # ifdef __REDIRECT_NTH
337 extern __off64_t __REDIRECT_NTH (lseek,
338 (int __fd, __off64_t __offset, int __whence),
339 lseek64);
340 # else
341 # define lseek lseek64
342 # endif
343 #endif
344 #ifdef __USE_LARGEFILE64
345 extern __off64_t lseek64 (int __fd, __off64_t __offset, int __whence)
346 __THROW;
347 #endif
349 /* Close the file descriptor FD.
351 This function is a cancellation point and therefore not marked with
352 __THROW. */
353 extern int close (int __fd);
355 /* Read NBYTES into BUF from FD. Return the
356 number read, -1 for errors or 0 for EOF.
358 This function is a cancellation point and therefore not marked with
359 __THROW. */
360 extern ssize_t read (int __fd, void *__buf, size_t __nbytes) __wur;
362 /* Write N bytes of BUF to FD. Return the number written, or -1.
364 This function is a cancellation point and therefore not marked with
365 __THROW. */
366 extern ssize_t write (int __fd, const void *__buf, size_t __n) __wur;
368 #if defined __USE_UNIX98 || defined __USE_XOPEN2K8
369 # ifndef __USE_FILE_OFFSET64
370 /* Read NBYTES into BUF from FD at the given position OFFSET without
371 changing the file pointer. Return the number read, -1 for errors
372 or 0 for EOF.
374 This function is a cancellation point and therefore not marked with
375 __THROW. */
376 extern ssize_t pread (int __fd, void *__buf, size_t __nbytes,
377 __off_t __offset) __wur;
379 /* Write N bytes of BUF to FD at the given position OFFSET without
380 changing the file pointer. Return the number written, or -1.
382 This function is a cancellation point and therefore not marked with
383 __THROW. */
384 extern ssize_t pwrite (int __fd, const void *__buf, size_t __n,
385 __off_t __offset) __wur;
386 # else
387 # ifdef __REDIRECT
388 extern ssize_t __REDIRECT (pread, (int __fd, void *__buf, size_t __nbytes,
389 __off64_t __offset),
390 pread64) __wur;
391 extern ssize_t __REDIRECT (pwrite, (int __fd, const void *__buf,
392 size_t __nbytes, __off64_t __offset),
393 pwrite64) __wur;
394 # else
395 # define pread pread64
396 # define pwrite pwrite64
397 # endif
398 # endif
400 # ifdef __USE_LARGEFILE64
401 /* Read NBYTES into BUF from FD at the given position OFFSET without
402 changing the file pointer. Return the number read, -1 for errors
403 or 0 for EOF. */
404 extern ssize_t pread64 (int __fd, void *__buf, size_t __nbytes,
405 __off64_t __offset) __wur;
406 /* Write N bytes of BUF to FD at the given position OFFSET without
407 changing the file pointer. Return the number written, or -1. */
408 extern ssize_t pwrite64 (int __fd, const void *__buf, size_t __n,
409 __off64_t __offset) __wur;
410 # endif
411 #endif
413 /* Create a one-way communication channel (pipe).
414 If successful, two file descriptors are stored in PIPEDES;
415 bytes written on PIPEDES[1] can be read from PIPEDES[0].
416 Returns 0 if successful, -1 if not. */
417 extern int pipe (int __pipedes[2]) __THROW __wur;
419 #ifdef __USE_GNU
420 /* Same as pipe but apply flags passed in FLAGS to the new file
421 descriptors. */
422 extern int pipe2 (int __pipedes[2], int __flags) __THROW __wur;
423 #endif
425 /* Schedule an alarm. In SECONDS seconds, the process will get a SIGALRM.
426 If SECONDS is zero, any currently scheduled alarm will be cancelled.
427 The function returns the number of seconds remaining until the last
428 alarm scheduled would have signaled, or zero if there wasn't one.
429 There is no return value to indicate an error, but you can set `errno'
430 to 0 and check its value after calling `alarm', and this might tell you.
431 The signal may come late due to processor scheduling. */
432 extern unsigned int alarm (unsigned int __seconds) __THROW;
434 /* Make the process sleep for SECONDS seconds, or until a signal arrives
435 and is not ignored. The function returns the number of seconds less
436 than SECONDS which it actually slept (thus zero if it slept the full time).
437 If a signal handler does a `longjmp' or modifies the handling of the
438 SIGALRM signal while inside `sleep' call, the handling of the SIGALRM
439 signal afterwards is undefined. There is no return value to indicate
440 error, but if `sleep' returns SECONDS, it probably didn't work.
442 This function is a cancellation point and therefore not marked with
443 __THROW. */
444 extern unsigned int sleep (unsigned int __seconds);
446 #if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \
447 || defined __USE_BSD
448 /* Set an alarm to go off (generating a SIGALRM signal) in VALUE
449 microseconds. If INTERVAL is nonzero, when the alarm goes off, the
450 timer is reset to go off every INTERVAL microseconds thereafter.
451 Returns the number of microseconds remaining before the alarm. */
452 extern __useconds_t ualarm (__useconds_t __value, __useconds_t __interval)
453 __THROW;
455 /* Sleep USECONDS microseconds, or until a signal arrives that is not blocked
456 or ignored.
458 This function is a cancellation point and therefore not marked with
459 __THROW. */
460 extern int usleep (__useconds_t __useconds);
461 #endif
464 /* Suspend the process until a signal arrives.
465 This always returns -1 and sets `errno' to EINTR.
467 This function is a cancellation point and therefore not marked with
468 __THROW. */
469 extern int pause (void);
472 /* Change the owner and group of FILE. */
473 extern int chown (const char *__file, __uid_t __owner, __gid_t __group)
474 __THROW __nonnull ((1)) __wur;
476 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
477 /* Change the owner and group of the file that FD is open on. */
478 extern int fchown (int __fd, __uid_t __owner, __gid_t __group) __THROW __wur;
481 /* Change owner and group of FILE, if it is a symbolic
482 link the ownership of the symbolic link is changed. */
483 extern int lchown (const char *__file, __uid_t __owner, __gid_t __group)
484 __THROW __nonnull ((1)) __wur;
486 #endif /* Use BSD || X/Open Unix. */
488 #ifdef __USE_ATFILE
489 /* Change the owner and group of FILE relative to the directory FD is open
490 on. */
491 extern int fchownat (int __fd, const char *__file, __uid_t __owner,
492 __gid_t __group, int __flag)
493 __THROW __nonnull ((2)) __wur;
494 #endif /* Use GNU. */
496 /* Change the process's working directory to PATH. */
497 extern int chdir (const char *__path) __THROW __nonnull ((1)) __wur;
499 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
500 /* Change the process's working directory to the one FD is open on. */
501 extern int fchdir (int __fd) __THROW __wur;
502 #endif
504 /* Get the pathname of the current working directory,
505 and put it in SIZE bytes of BUF. Returns NULL if the
506 directory couldn't be determined or SIZE was too small.
507 If successful, returns BUF. In GNU, if BUF is NULL,
508 an array is allocated with `malloc'; the array is SIZE
509 bytes long, unless SIZE == 0, in which case it is as
510 big as necessary. */
511 extern char *getcwd (char *__buf, size_t __size) __THROW __wur;
513 #ifdef __USE_GNU
514 /* Return a malloc'd string containing the current directory name.
515 If the environment variable `PWD' is set, and its value is correct,
516 that value is used. */
517 extern char *get_current_dir_name (void) __THROW;
518 #endif
520 #if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \
521 || defined __USE_BSD
522 /* Put the absolute pathname of the current working directory in BUF.
523 If successful, return BUF. If not, put an error message in
524 BUF and return NULL. BUF should be at least PATH_MAX bytes long. */
525 extern char *getwd (char *__buf)
526 __THROW __nonnull ((1)) __attribute_deprecated__ __wur;
527 #endif
530 /* Duplicate FD, returning a new file descriptor on the same file. */
531 extern int dup (int __fd) __THROW __wur;
533 /* Duplicate FD to FD2, closing FD2 and making it open on the same file. */
534 extern int dup2 (int __fd, int __fd2) __THROW;
536 #ifdef __USE_GNU
537 /* Duplicate FD to FD2, closing FD2 and making it open on the same
538 file while setting flags according to FLAGS. */
539 extern int dup3 (int __fd, int __fd2, int __flags) __THROW;
540 #endif
542 /* NULL-terminated array of "NAME=VALUE" environment variables. */
543 extern char **__environ;
544 #ifdef __USE_GNU
545 extern char **environ;
546 #endif
549 /* Replace the current process, executing PATH with arguments ARGV and
550 environment ENVP. ARGV and ENVP are terminated by NULL pointers. */
551 extern int execve (const char *__path, char *const __argv[],
552 char *const __envp[]) __THROW __nonnull ((1, 2));
554 #ifdef __USE_XOPEN2K8
555 /* Execute the file FD refers to, overlaying the running program image.
556 ARGV and ENVP are passed to the new program, as for `execve'. */
557 extern int fexecve (int __fd, char *const __argv[], char *const __envp[])
558 __THROW __nonnull ((2));
559 #endif
562 /* Execute PATH with arguments ARGV and environment from `environ'. */
563 extern int execv (const char *__path, char *const __argv[])
564 __THROW __nonnull ((1, 2));
566 /* Execute PATH with all arguments after PATH until a NULL pointer,
567 and the argument after that for environment. */
568 extern int execle (const char *__path, const char *__arg, ...)
569 __THROW __nonnull ((1, 2));
571 /* Execute PATH with all arguments after PATH until
572 a NULL pointer and environment from `environ'. */
573 extern int execl (const char *__path, const char *__arg, ...)
574 __THROW __nonnull ((1, 2));
576 /* Execute FILE, searching in the `PATH' environment variable if it contains
577 no slashes, with arguments ARGV and environment from `environ'. */
578 extern int execvp (const char *__file, char *const __argv[])
579 __THROW __nonnull ((1, 2));
581 /* Execute FILE, searching in the `PATH' environment variable if
582 it contains no slashes, with all arguments after FILE until a
583 NULL pointer and environment from `environ'. */
584 extern int execlp (const char *__file, const char *__arg, ...)
585 __THROW __nonnull ((1, 2));
587 #ifdef __USE_GNU
588 /* Execute FILE, searching in the `PATH' environment variable if it contains
589 no slashes, with arguments ARGV and environment from `environ'. */
590 extern int execvpe (const char *__file, char *const __argv[],
591 char *const __envp[])
592 __THROW __nonnull ((1, 2));
593 #endif
596 #if defined __USE_MISC || defined __USE_XOPEN
597 /* Add INC to priority of the current process. */
598 extern int nice (int __inc) __THROW __wur;
599 #endif
602 /* Terminate program execution with the low-order 8 bits of STATUS. */
603 extern void _exit (int __status) __attribute__ ((__noreturn__));
606 /* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf';
607 the `_SC_*' symbols for the NAME argument to `sysconf';
608 and the `_CS_*' symbols for the NAME argument to `confstr'. */
609 #include <bits/confname.h>
611 /* Get file-specific configuration information about PATH. */
612 extern long int pathconf (const char *__path, int __name)
613 __THROW __nonnull ((1));
615 /* Get file-specific configuration about descriptor FD. */
616 extern long int fpathconf (int __fd, int __name) __THROW;
618 /* Get the value of the system variable NAME. */
619 extern long int sysconf (int __name) __THROW;
621 #ifdef __USE_POSIX2
622 /* Get the value of the string-valued system variable NAME. */
623 extern size_t confstr (int __name, char *__buf, size_t __len) __THROW;
624 #endif
627 /* Get the process ID of the calling process. */
628 extern __pid_t getpid (void) __THROW;
630 /* Get the process ID of the calling process's parent. */
631 extern __pid_t getppid (void) __THROW;
633 /* Get the process group ID of the calling process.
634 This function is different on old BSD. */
635 #ifndef __FAVOR_BSD
636 extern __pid_t getpgrp (void) __THROW;
637 #else
638 # ifdef __REDIRECT_NTH
639 extern __pid_t __REDIRECT_NTH (getpgrp, (__pid_t __pid), __getpgid);
640 # else
641 # define getpgrp __getpgid
642 # endif
643 #endif
645 /* Get the process group ID of process PID. */
646 extern __pid_t __getpgid (__pid_t __pid) __THROW;
647 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
648 extern __pid_t getpgid (__pid_t __pid) __THROW;
649 #endif
652 /* Set the process group ID of the process matching PID to PGID.
653 If PID is zero, the current process's process group ID is set.
654 If PGID is zero, the process ID of the process is used. */
655 extern int setpgid (__pid_t __pid, __pid_t __pgid) __THROW;
657 #if defined __USE_SVID || defined __USE_BSD || defined __USE_XOPEN_EXTENDED
658 /* Both System V and BSD have `setpgrp' functions, but with different
659 calling conventions. The BSD function is the same as POSIX.1 `setpgid'
660 (above). The System V function takes no arguments and puts the calling
661 process in its on group like `setpgid (0, 0)'.
663 New programs should always use `setpgid' instead.
665 The default in GNU is to provide the System V function. The BSD
666 function is available under -D_BSD_SOURCE. */
668 # ifndef __FAVOR_BSD
670 /* Set the process group ID of the calling process to its own PID.
671 This is exactly the same as `setpgid (0, 0)'. */
672 extern int setpgrp (void) __THROW;
674 # else
676 /* Another name for `setpgid' (above). */
677 # ifdef __REDIRECT_NTH
678 extern int __REDIRECT_NTH (setpgrp, (__pid_t __pid, __pid_t __pgrp), setpgid);
679 # else
680 # define setpgrp setpgid
681 # endif
683 # endif /* Favor BSD. */
684 #endif /* Use SVID or BSD. */
686 /* Create a new session with the calling process as its leader.
687 The process group IDs of the session and the calling process
688 are set to the process ID of the calling process, which is returned. */
689 extern __pid_t setsid (void) __THROW;
691 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
692 /* Return the session ID of the given process. */
693 extern __pid_t getsid (__pid_t __pid) __THROW;
694 #endif
696 /* Get the real user ID of the calling process. */
697 extern __uid_t getuid (void) __THROW;
699 /* Get the effective user ID of the calling process. */
700 extern __uid_t geteuid (void) __THROW;
702 /* Get the real group ID of the calling process. */
703 extern __gid_t getgid (void) __THROW;
705 /* Get the effective group ID of the calling process. */
706 extern __gid_t getegid (void) __THROW;
708 /* If SIZE is zero, return the number of supplementary groups
709 the calling process is in. Otherwise, fill in the group IDs
710 of its supplementary groups in LIST and return the number written. */
711 extern int getgroups (int __size, __gid_t __list[]) __THROW __wur;
713 #ifdef __USE_GNU
714 /* Return nonzero iff the calling process is in group GID. */
715 extern int group_member (__gid_t __gid) __THROW;
716 #endif
718 /* Set the user ID of the calling process to UID.
719 If the calling process is the super-user, set the real
720 and effective user IDs, and the saved set-user-ID to UID;
721 if not, the effective user ID is set to UID. */
722 extern int setuid (__uid_t __uid) __THROW __wur;
724 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
725 /* Set the real user ID of the calling process to RUID,
726 and the effective user ID of the calling process to EUID. */
727 extern int setreuid (__uid_t __ruid, __uid_t __euid) __THROW __wur;
728 #endif
730 #if defined __USE_BSD || defined __USE_XOPEN2K
731 /* Set the effective user ID of the calling process to UID. */
732 extern int seteuid (__uid_t __uid) __THROW __wur;
733 #endif /* Use BSD. */
735 /* Set the group ID of the calling process to GID.
736 If the calling process is the super-user, set the real
737 and effective group IDs, and the saved set-group-ID to GID;
738 if not, the effective group ID is set to GID. */
739 extern int setgid (__gid_t __gid) __THROW __wur;
741 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
742 /* Set the real group ID of the calling process to RGID,
743 and the effective group ID of the calling process to EGID. */
744 extern int setregid (__gid_t __rgid, __gid_t __egid) __THROW __wur;
745 #endif
747 #if defined __USE_BSD || defined __USE_XOPEN2K
748 /* Set the effective group ID of the calling process to GID. */
749 extern int setegid (__gid_t __gid) __THROW __wur;
750 #endif /* Use BSD. */
752 #ifdef __USE_GNU
753 /* Fetch the real user ID, effective user ID, and saved-set user ID,
754 of the calling process. */
755 extern int getresuid (__uid_t *__ruid, __uid_t *__euid, __uid_t *__suid)
756 __THROW;
758 /* Fetch the real group ID, effective group ID, and saved-set group ID,
759 of the calling process. */
760 extern int getresgid (__gid_t *__rgid, __gid_t *__egid, __gid_t *__sgid)
761 __THROW;
763 /* Set the real user ID, effective user ID, and saved-set user ID,
764 of the calling process to RUID, EUID, and SUID, respectively. */
765 extern int setresuid (__uid_t __ruid, __uid_t __euid, __uid_t __suid)
766 __THROW __wur;
768 /* Set the real group ID, effective group ID, and saved-set group ID,
769 of the calling process to RGID, EGID, and SGID, respectively. */
770 extern int setresgid (__gid_t __rgid, __gid_t __egid, __gid_t __sgid)
771 __THROW __wur;
772 #endif
775 /* Clone the calling process, creating an exact copy.
776 Return -1 for errors, 0 to the new process,
777 and the process ID of the new process to the old process. */
778 extern __pid_t fork (void) __THROWNL;
780 #if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \
781 || defined __USE_BSD
782 /* Clone the calling process, but without copying the whole address space.
783 The calling process is suspended until the new process exits or is
784 replaced by a call to `execve'. Return -1 for errors, 0 to the new process,
785 and the process ID of the new process to the old process. */
786 extern __pid_t vfork (void) __THROW;
787 #endif /* Use BSD or XPG < 7. */
790 /* Return the pathname of the terminal FD is open on, or NULL on errors.
791 The returned storage is good only until the next call to this function. */
792 extern char *ttyname (int __fd) __THROW;
794 /* Store at most BUFLEN characters of the pathname of the terminal FD is
795 open on in BUF. Return 0 on success, otherwise an error number. */
796 extern int ttyname_r (int __fd, char *__buf, size_t __buflen)
797 __THROW __nonnull ((2)) __wur;
799 /* Return 1 if FD is a valid descriptor associated
800 with a terminal, zero if not. */
801 extern int isatty (int __fd) __THROW;
803 #if defined __USE_BSD \
804 || (defined __USE_XOPEN_EXTENDED && !defined __USE_UNIX98)
805 /* Return the index into the active-logins file (utmp) for
806 the controlling terminal. */
807 extern int ttyslot (void) __THROW;
808 #endif
811 /* Make a link to FROM named TO. */
812 extern int link (const char *__from, const char *__to)
813 __THROW __nonnull ((1, 2)) __wur;
815 #ifdef __USE_ATFILE
816 /* Like link but relative paths in TO and FROM are interpreted relative
817 to FROMFD and TOFD respectively. */
818 extern int linkat (int __fromfd, const char *__from, int __tofd,
819 const char *__to, int __flags)
820 __THROW __nonnull ((2, 4)) __wur;
821 #endif
823 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
824 /* Make a symbolic link to FROM named TO. */
825 extern int symlink (const char *__from, const char *__to)
826 __THROW __nonnull ((1, 2)) __wur;
828 /* Read the contents of the symbolic link PATH into no more than
829 LEN bytes of BUF. The contents are not null-terminated.
830 Returns the number of characters read, or -1 for errors. */
831 extern ssize_t readlink (const char *__restrict __path,
832 char *__restrict __buf, size_t __len)
833 __THROW __nonnull ((1, 2)) __wur;
834 #endif /* Use BSD. */
836 #ifdef __USE_ATFILE
837 /* Like symlink but a relative path in TO is interpreted relative to TOFD. */
838 extern int symlinkat (const char *__from, int __tofd,
839 const char *__to) __THROW __nonnull ((1, 3)) __wur;
841 /* Like readlink but a relative PATH is interpreted relative to FD. */
842 extern ssize_t readlinkat (int __fd, const char *__restrict __path,
843 char *__restrict __buf, size_t __len)
844 __THROW __nonnull ((2, 3)) __wur;
845 #endif
847 /* Remove the link NAME. */
848 extern int unlink (const char *__name) __THROW __nonnull ((1));
850 #ifdef __USE_ATFILE
851 /* Remove the link NAME relative to FD. */
852 extern int unlinkat (int __fd, const char *__name, int __flag)
853 __THROW __nonnull ((2));
854 #endif
856 /* Remove the directory PATH. */
857 extern int rmdir (const char *__path) __THROW __nonnull ((1));
860 /* Return the foreground process group ID of FD. */
861 extern __pid_t tcgetpgrp (int __fd) __THROW;
863 /* Set the foreground process group ID of FD set PGRP_ID. */
864 extern int tcsetpgrp (int __fd, __pid_t __pgrp_id) __THROW;
867 /* Return the login name of the user.
869 This function is a possible cancellation point and therefore not
870 marked with __THROW. */
871 extern char *getlogin (void);
872 #if defined __USE_REENTRANT || defined __USE_POSIX199506
873 /* Return at most NAME_LEN characters of the login name of the user in NAME.
874 If it cannot be determined or some other error occurred, return the error
875 code. Otherwise return 0.
877 This function is a possible cancellation point and therefore not
878 marked with __THROW. */
879 extern int getlogin_r (char *__name, size_t __name_len) __nonnull ((1));
880 #endif
882 #ifdef __USE_BSD
883 /* Set the login name returned by `getlogin'. */
884 extern int setlogin (const char *__name) __THROW __nonnull ((1));
885 #endif
888 #ifdef __USE_POSIX2
889 /* Get definitions and prototypes for functions to process the
890 arguments in ARGV (ARGC of them, minus the program name) for
891 options given in OPTS. */
892 # define __need_getopt
893 # include <getopt.h>
894 #endif
897 #if defined __USE_BSD || defined __USE_UNIX98 || defined __USE_XOPEN2K
898 /* Put the name of the current host in no more than LEN bytes of NAME.
899 The result is null-terminated if LEN is large enough for the full
900 name and the terminator. */
901 extern int gethostname (char *__name, size_t __len) __THROW __nonnull ((1));
902 #endif
905 #if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_UNIX98)
906 /* Set the name of the current host to NAME, which is LEN bytes long.
907 This call is restricted to the super-user. */
908 extern int sethostname (const char *__name, size_t __len)
909 __THROW __nonnull ((1)) __wur;
911 /* Set the current machine's Internet number to ID.
912 This call is restricted to the super-user. */
913 extern int sethostid (long int __id) __THROW __wur;
916 /* Get and set the NIS (aka YP) domain name, if any.
917 Called just like `gethostname' and `sethostname'.
918 The NIS domain name is usually the empty string when not using NIS. */
919 extern int getdomainname (char *__name, size_t __len)
920 __THROW __nonnull ((1)) __wur;
921 extern int setdomainname (const char *__name, size_t __len)
922 __THROW __nonnull ((1)) __wur;
925 /* Revoke access permissions to all processes currently communicating
926 with the control terminal, and then send a SIGHUP signal to the process
927 group of the control terminal. */
928 extern int vhangup (void) __THROW;
930 /* Revoke the access of all descriptors currently open on FILE. */
931 extern int revoke (const char *__file) __THROW __nonnull ((1)) __wur;
934 /* Enable statistical profiling, writing samples of the PC into at most
935 SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
936 is enabled, the system examines the user PC and increments
937 SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536]. If SCALE is zero,
938 disable profiling. Returns zero on success, -1 on error. */
939 extern int profil (unsigned short int *__sample_buffer, size_t __size,
940 size_t __offset, unsigned int __scale)
941 __THROW __nonnull ((1));
944 /* Turn accounting on if NAME is an existing file. The system will then write
945 a record for each process as it terminates, to this file. If NAME is NULL,
946 turn accounting off. This call is restricted to the super-user. */
947 extern int acct (const char *__name) __THROW;
950 /* Successive calls return the shells listed in `/etc/shells'. */
951 extern char *getusershell (void) __THROW;
952 extern void endusershell (void) __THROW; /* Discard cached info. */
953 extern void setusershell (void) __THROW; /* Rewind and re-read the file. */
956 /* Put the program in the background, and dissociate from the controlling
957 terminal. If NOCHDIR is zero, do `chdir ("/")'. If NOCLOSE is zero,
958 redirects stdin, stdout, and stderr to /dev/null. */
959 extern int daemon (int __nochdir, int __noclose) __THROW __wur;
960 #endif /* Use BSD || X/Open. */
963 #if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_XOPEN2K)
964 /* Make PATH be the root directory (the starting point for absolute paths).
965 This call is restricted to the super-user. */
966 extern int chroot (const char *__path) __THROW __nonnull ((1)) __wur;
968 /* Prompt with PROMPT and read a string from the terminal without echoing.
969 Uses /dev/tty if possible; otherwise stderr and stdin. */
970 extern char *getpass (const char *__prompt) __nonnull ((1));
971 #endif /* Use BSD || X/Open. */
974 /* Make all changes done to FD actually appear on disk.
976 This function is a cancellation point and therefore not marked with
977 __THROW. */
978 extern int fsync (int __fd);
981 #ifdef __USE_GNU
982 /* Make all changes done to all files on the file system associated
983 with FD actually appear on disk. */
984 extern int syncfs (int __fd) __THROW;
985 #endif
988 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
990 /* Return identifier for the current host. */
991 extern long int gethostid (void);
993 /* Make all changes done to all files actually appear on disk. */
994 extern void sync (void) __THROW;
997 # if defined __USE_BSD || !defined __USE_XOPEN2K
998 /* Return the number of bytes in a page. This is the system's page size,
999 which is not necessarily the same as the hardware page size. */
1000 extern int getpagesize (void) __THROW __attribute__ ((__const__));
1003 /* Return the maximum number of file descriptors
1004 the current process could possibly have. */
1005 extern int getdtablesize (void) __THROW;
1006 # endif
1008 #endif /* Use BSD || X/Open Unix. */
1011 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
1013 /* Truncate FILE to LENGTH bytes. */
1014 # ifndef __USE_FILE_OFFSET64
1015 extern int truncate (const char *__file, __off_t __length)
1016 __THROW __nonnull ((1)) __wur;
1017 # else
1018 # ifdef __REDIRECT_NTH
1019 extern int __REDIRECT_NTH (truncate,
1020 (const char *__file, __off64_t __length),
1021 truncate64) __nonnull ((1)) __wur;
1022 # else
1023 # define truncate truncate64
1024 # endif
1025 # endif
1026 # ifdef __USE_LARGEFILE64
1027 extern int truncate64 (const char *__file, __off64_t __length)
1028 __THROW __nonnull ((1)) __wur;
1029 # endif
1031 #endif /* Use BSD || X/Open Unix || POSIX 2008. */
1033 #if defined __USE_BSD || defined __USE_POSIX199309 \
1034 || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
1036 /* Truncate the file FD is open on to LENGTH bytes. */
1037 # ifndef __USE_FILE_OFFSET64
1038 extern int ftruncate (int __fd, __off_t __length) __THROW __wur;
1039 # else
1040 # ifdef __REDIRECT_NTH
1041 extern int __REDIRECT_NTH (ftruncate, (int __fd, __off64_t __length),
1042 ftruncate64) __wur;
1043 # else
1044 # define ftruncate ftruncate64
1045 # endif
1046 # endif
1047 # ifdef __USE_LARGEFILE64
1048 extern int ftruncate64 (int __fd, __off64_t __length) __THROW __wur;
1049 # endif
1051 #endif /* Use BSD || POSIX.1b || X/Open Unix || XPG6. */
1054 #if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K) \
1055 || defined __USE_MISC
1057 /* Set the end of accessible data space (aka "the break") to ADDR.
1058 Returns zero on success and -1 for errors (with errno set). */
1059 extern int brk (void *__addr) __THROW __wur;
1061 /* Increase or decrease the end of accessible data space by DELTA bytes.
1062 If successful, returns the address the previous end of data space
1063 (i.e. the beginning of the new space, if DELTA > 0);
1064 returns (void *) -1 for errors (with errno set). */
1065 extern void *sbrk (intptr_t __delta) __THROW;
1066 #endif
1069 #ifdef __USE_MISC
1070 /* Invoke `system call' number SYSNO, passing it the remaining arguments.
1071 This is completely system-dependent, and not often useful.
1073 In Unix, `syscall' sets `errno' for all errors and most calls return -1
1074 for errors; in many systems you cannot pass arguments or get return
1075 values for all system calls (`pipe', `fork', and `getppid' typically
1076 among them).
1078 In Mach, all system calls take normal arguments and always return an
1079 error code (zero for success). */
1080 extern long int syscall (long int __sysno, ...) __THROW;
1082 #endif /* Use misc. */
1085 #if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK
1086 /* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both
1087 files consistent. Some systems have them there and some here, and some
1088 software depends on the macros being defined without including both. */
1090 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
1091 LEN is always relative to the current file position.
1092 The CMD argument is one of the following.
1094 This function is a cancellation point and therefore not marked with
1095 __THROW. */
1097 # define F_ULOCK 0 /* Unlock a previously locked region. */
1098 # define F_LOCK 1 /* Lock a region for exclusive use. */
1099 # define F_TLOCK 2 /* Test and lock a region for exclusive use. */
1100 # define F_TEST 3 /* Test a region for other processes locks. */
1102 # ifndef __USE_FILE_OFFSET64
1103 extern int lockf (int __fd, int __cmd, __off_t __len) __wur;
1104 # else
1105 # ifdef __REDIRECT
1106 extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len),
1107 lockf64) __wur;
1108 # else
1109 # define lockf lockf64
1110 # endif
1111 # endif
1112 # ifdef __USE_LARGEFILE64
1113 extern int lockf64 (int __fd, int __cmd, __off64_t __len) __wur;
1114 # endif
1115 #endif /* Use misc and F_LOCK not already defined. */
1118 #ifdef __USE_GNU
1120 /* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno'
1121 set to EINTR. */
1123 # define TEMP_FAILURE_RETRY(expression) \
1124 (__extension__ \
1125 ({ long int __result; \
1126 do __result = (long int) (expression); \
1127 while (__result == -1L && errno == EINTR); \
1128 __result; }))
1129 #endif
1131 #if defined __USE_POSIX199309 || defined __USE_UNIX98
1132 /* Synchronize at least the data part of a file with the underlying
1133 media. */
1134 extern int fdatasync (int __fildes);
1135 #endif /* Use POSIX199309 */
1138 /* XPG4.2 specifies that prototypes for the encryption functions must
1139 be defined here. */
1140 #ifdef __USE_XOPEN
1141 /* Encrypt at most 8 characters from KEY using salt to perturb DES. */
1142 extern char *crypt (const char *__key, const char *__salt)
1143 __THROW __nonnull ((1, 2));
1145 /* Encrypt data in BLOCK in place if EDFLAG is zero; otherwise decrypt
1146 block in place. */
1147 extern void encrypt (char *__block, int __edflag) __THROW __nonnull ((1));
1150 /* Swab pairs bytes in the first N bytes of the area pointed to by
1151 FROM and copy the result to TO. The value of TO must not be in the
1152 range [FROM - N + 1, FROM - 1]. If N is odd the first byte in FROM
1153 is without partner. */
1154 extern void swab (const void *__restrict __from, void *__restrict __to,
1155 ssize_t __n) __THROW __nonnull ((1, 2));
1156 #endif
1159 /* The Single Unix specification demands this prototype to be here.
1160 It is also found in <stdio.h>. */
1161 #if defined __USE_XOPEN && !defined __USE_XOPEN2K
1162 /* Return the name of the controlling terminal. */
1163 extern char *ctermid (char *__s) __THROW;
1164 #endif
1167 /* Define some macros helping to catch buffer overflows. */
1168 #if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
1169 # include <bits/unistd.h>
1170 #endif
1172 __END_DECLS
1174 #endif /* unistd.h */