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1 /* Copyright (C) 1991,92,93,94,95,96,97,98 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 Library General Public License as
6 published by the Free Software Foundation; either version 2 of the
7 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 Library General Public License for more details.
14 You should have received a copy of the GNU Library General Public
15 License along with the GNU C Library; see the file COPYING.LIB. If not,
16 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 Boston, MA 02111-1307, USA. */
20 * POSIX Standard: 2.10 Symbolic Constants <unistd.h>
23 #ifndef _UNISTD_H
24 #define _UNISTD_H 1
26 #include <features.h>
28 __BEGIN_DECLS
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 August, 1988 and
34 extended by POSIX-1b (aka POSIX-4) and POSIX-1c (aka POSIX threads). */
35 #define _POSIX_VERSION 199506L
37 /* These are not #ifdef __USE_POSIX2 because they are
38 in the theoretically application-owned namespace. */
40 /* POSIX Standard approved as ISO/IEC 9945-2 as of December, 1993. */
41 #define _POSIX2_C_VERSION 199209L
43 /* The utilities on GNU systems also correspond to this version. */
44 #define _POSIX2_VERSION 199209L
46 /* If defined, the implementation supports the
47 C Language Bindings Option. */
48 #define _POSIX2_C_BIND 1
50 /* If defined, the implementation supports the
51 C Language Development Utilities Option. */
52 #define _POSIX2_C_DEV 1
54 /* If defined, the implementation supports the
55 Software Development Utilities Option. */
56 #define _POSIX2_SW_DEV 1
58 /* If defined, the implementation supports the
59 creation of locales with the localedef utility. */
60 #define _POSIX2_LOCALEDEF 1
62 /* X/Open version number to which the library conforms. It is selectable. */
63 #ifdef __USE_UNIX98
64 # define _XOPEN_VERSION 500
65 #else
66 # define _XOPEN_VERSION 4
67 #endif
69 /* Commands and utilities from XPG4 are available. */
70 #define _XOPEN_XCU_VERSION 4
72 /* We are compatible with the old published standards as well. */
73 #define _XOPEN_XPG2 1
74 #define _XOPEN_XPG3 1
75 #define _XOPEN_XPG4 1
77 /* The X/Open Unix extensions are available. */
78 #define _XOPEN_UNIX 1
80 /* Encryption is present. */
81 #define _XOPEN_CRYPT 1
83 /* The enhanced internationalization capabilities according to XPG4.2
84 are present. */
85 #define _XOPEN_ENH_I18N 1
87 /* The legacy interfaces are also available. */
88 #define _XOPEN_LEGACY 1
91 /* Get values of POSIX options:
93 If these symbols are defined, the corresponding features are
94 always available. If not, they may be available sometimes.
95 The current values can be obtained with `sysconf'.
97 _POSIX_JOB_CONTROL Job control is supported.
98 _POSIX_SAVED_IDS Processes have a saved set-user-ID
99 and a saved set-group-ID.
100 _POSIX_REALTIME_SIGNALS Real-time, queued signals are supported.
101 _POSIX_PRIORITY_SCHEDULING Priority scheduling is supported.
102 _POSIX_TIMERS POSIX.4 clocks and timers are supported.
103 _POSIX_ASYNCHRONOUS_IO Asynchronous I/O is supported.
104 _POSIX_PRIORITIZED_IO Prioritized asynchronous I/O is supported.
105 _POSIX_SYNCHRONIZED_IO Synchronizing file data is supported.
106 _POSIX_FSYNC The fsync function is present.
107 _POSIX_MAPPED_FILES Mapping of files to memory is supported.
108 _POSIX_MEMLOCK Locking of all memory is supported.
109 _POSIX_MEMLOCK_RANGE Locking of ranges of memory is supported.
110 _POSIX_MEMORY_PROTECTION Setting of memory protections is supported.
111 _POSIX_MESSAGE_PASSING POSIX.4 message queues are supported.
112 _POSIX_SEMAPHORES POSIX.4 counting semaphores are supported.
113 _POSIX_SHARED_MEMORY_OBJECTS POSIX.4 shared memory objects are supported.
114 _POSIX_THREADS POSIX.1c pthreads are supported.
115 _POSIX_THREAD_ATTR_STACKADDR Thread stack address attribute option supported.
116 _POSIX_THREAD_ATTR_STACKSIZE Thread stack size attribute option supported.
117 _POSIX_THREAD_SAFE_FUNCTIONS Thread-safe functions are supported.
118 _POSIX_THREAD_PRIORITY_SCHEDULING
119 POSIX.1c thread execution scheduling supported.
120 _POSIX_THREAD_PRIO_INHERIT Thread priority inheritance option supported.
121 _POSIX_THREAD_PRIO_PROTECT Thread priority protection option supported.
122 _POSIX_THREAD_PROCESS_SHARED Process-shared synchronization supported.
123 _POSIX_PII Protocol-independent interfaces are supported.
124 _POSIX_PII_XTI XTI protocol-indep. interfaces are supported.
125 _POSIX_PII_SOCKET Socket protocol-indep. interfaces are supported.
126 _POSIX_PII_INTERNET Internet family of protocols supported.
127 _POSIX_PII_INTERNET_STREAM Connection-mode Internet protocol supported.
128 _POSIX_PII_INTERNET_DGRAM Connectionless Internet protocol supported.
129 _POSIX_PII_OSI ISO/OSI family of protocols supported.
130 _POSIX_PII_OSI_COTS Connection-mode ISO/OSI service supported.
131 _POSIX_PII_OSI_CLTS Connectionless ISO/OSI service supported.
132 _POSIX_POLL Implementation supports `poll' function.
133 _POSIX_SELECT Implementation supports `select' and `pselect'.
135 _XOPEN_REALTIME X/Open realtime support is available.
136 _XOPEN_REALTIME_THREADS X/Open realtime thread support is available.
137 _XOPEN_SHM Shared memory interface according to XPG4.2.
139 _XBS5_ILP32_OFF32 Implementation provides environment with 32-bit
140 int, long, pointer, and off_t types.
141 _XBS5_ILP32_OFFBIG Implementation provides environment with 32-bit
142 int, long, and pointer and off_t with at least
143 64 bits.
144 _XBS5_LP64_OFF64 Implementation provides environment with 32-bit
145 int, and 64-bit long, pointer, and off_t types.
146 _XBS5_LPBIG_OFFBIG Implementation provides environment with at
147 least 32 bits int and long, pointer, and off_t
148 with at least 64 bits.
150 If any of these symbols is defined as -1, the corresponding option is not
151 true for any file. If any is defined as other than -1, the corresponding
152 option is true for all files. If a symbol is not defined at all, the value
153 for a specific file can be obtained from `pathconf' and `fpathconf'.
155 _POSIX_CHOWN_RESTRICTED Only the super user can use `chown' to change
156 the owner of a file. `chown' can only be used
157 to change the group ID of a file to a group of
158 which the calling process is a member.
159 _POSIX_NO_TRUNC Pathname components longer than
160 NAME_MAX generate an error.
161 _POSIX_VDISABLE If defined, if the value of an element of the
162 `c_cc' member of `struct termios' is
163 _POSIX_VDISABLE, no character will have the
164 effect associated with that element.
165 _POSIX_SYNC_IO Synchronous I/O may be performed.
166 _POSIX_ASYNC_IO Asynchronous I/O may be performed.
167 _POSIX_PRIO_IO Prioritized Asynchronous I/O may be performed.
169 Support for the Large File Support interface is not generally available.
170 If it is available the following constants are defined to one.
171 _LFS64_LARGEFILE Low-level I/O supports large files.
172 _LFS64_STDIO Standard I/O supports large files.
175 #include <bits/posix_opt.h>
177 /* Get the environment definitions from Unix98. */
178 #ifdef __USE_UNIX98
179 # include <bits/environments.h>
180 #endif
182 /* Standard file descriptors. */
183 #define STDIN_FILENO 0 /* Standard input. */
184 #define STDOUT_FILENO 1 /* Standard output. */
185 #define STDERR_FILENO 2 /* Standard error output. */
188 /* All functions that are not declared anywhere else. */
190 #include <bits/types.h>
192 #ifndef ssize_t
193 typedef __ssize_t ssize_t;
194 # define ssize_t ssize_t
195 #endif
197 #define __need_size_t
198 #define __need_NULL
199 #include <stddef.h>
201 #ifdef __USE_XOPEN
202 /* The Single Unix specification says that some more types are
203 available here. */
204 # ifndef gid_t
205 typedef __gid_t gid_t;
206 # define gid_t gid_t
207 # endif
209 # ifndef uid_t
210 typedef __uid_t uid_t;
211 # define uid_t uid_t
212 # endif
214 # ifndef off_t
215 # ifndef __USE_FILE_OFFSET64
216 typedef __off_t off_t;
217 # else
218 typedef __off64_t off_t;
219 # endif
220 # define off_t off_t
221 # endif
222 # if defined __USE_LARGEFILE64 && !defined off64_t
223 typedef __off64_t off64_t;
224 # define off64_t off64_t
225 # endif
227 # ifndef pid_t
228 typedef __pid_t pid_t;
229 # define pid_t pid_t
230 # endif
231 #endif /* X/Open */
233 #ifdef __USE_UNIX98
234 # ifndef intptr_t
235 typedef __intptr_t intptr_t;
236 # define intptr_t intptr_t
237 # endif
238 #endif /* Unix98 */
240 /* Values for the second argument to access.
241 These may be OR'd together. */
242 #define R_OK 4 /* Test for read permission. */
243 #define W_OK 2 /* Test for write permission. */
244 #define X_OK 1 /* Test for execute permission. */
245 #define F_OK 0 /* Test for existence. */
247 /* Test for access to NAME using the real UID and real GID. */
248 extern int access __P ((__const char *__name, int __type));
250 #ifdef __USE_GNU
251 /* Test for access to NAME using the effective UID and GID
252 (as normal file operations use). */
253 extern int euidaccess __P ((__const char *__name, int __type));
254 #endif
257 /* Values for the WHENCE argument to lseek. */
258 #ifndef _STDIO_H /* <stdio.h> has the same definitions. */
259 # define SEEK_SET 0 /* Seek from beginning of file. */
260 # define SEEK_CUR 1 /* Seek from current position. */
261 # define SEEK_END 2 /* Seek from end of file. */
262 #endif
264 #if defined __USE_BSD && !defined L_SET
265 /* Old BSD names for the same constants; just for compatibility. */
266 # define L_SET SEEK_SET
267 # define L_INCR SEEK_CUR
268 # define L_XTND SEEK_END
269 #endif
272 /* Move FD's file position to OFFSET bytes from the
273 beginning of the file (if WHENCE is SEEK_SET),
274 the current position (if WHENCE is SEEK_CUR),
275 or the end of the file (if WHENCE is SEEK_END).
276 Return the new file position. */
277 extern __off_t __lseek __P ((int __fd, __off_t __offset, int __whence));
278 #ifndef __USE_FILE_OFFSET64
279 extern __off_t lseek __P ((int __fd, __off_t __offset, int __whence));
280 #else
281 # ifdef __REDIRECT
282 extern __off64_t __REDIRECT (lseek,
283 __P ((int __fd, __off64_t __offset,
284 int __whence)),
285 lseek64);
286 # else
287 # define lseek lseek64
288 # endif
289 #endif
290 #ifdef __USE_LARGEFILE64
291 extern __off64_t lseek64 __P ((int __fd, __off64_t __offset, int __whence));
292 #endif
294 /* Close the file descriptor FD. */
295 extern int __close __P ((int __fd));
296 extern int close __P ((int __fd));
298 /* Read NBYTES into BUF from FD. Return the
299 number read, -1 for errors or 0 for EOF. */
300 extern ssize_t __read __P ((int __fd, __ptr_t __buf, size_t __nbytes));
301 extern ssize_t read __P ((int __fd, __ptr_t __buf, size_t __nbytes));
303 /* Write N bytes of BUF to FD. Return the number written, or -1. */
304 extern ssize_t __write __P ((int __fd, __const __ptr_t __buf, size_t __n));
305 extern ssize_t write __P ((int __fd, __const __ptr_t __buf, size_t __n));
307 #ifdef __USE_UNIX98
308 /* Read NBYTES into BUF from FD at the given position OFFSET without
309 changing the file pointer. Return the number read, -1 for errors
310 or 0 for EOF. */
311 extern ssize_t __pread64 __P ((int __fd, __ptr_t __buf, size_t __nbytes,
312 __off64_t __offset));
313 /* Write N bytes of BUF to FD at the given position OFFSET without
314 changing the file pointer. Return the number written, or -1. */
315 extern ssize_t __pwrite64 __P ((int __fd, __const __ptr_t __buf, size_t __n,
316 __off64_t __offset));
318 # ifndef __USE_FILE_OFFSET64
319 extern ssize_t pread __P ((int __fd, __ptr_t __buf, size_t __nbytes,
320 __off_t __offset));
321 extern ssize_t pwrite __P ((int __fd, __const __ptr_t __buf, size_t __n,
322 __off_t __offset));
323 # else
324 # ifdef __REDIRECT
325 extern ssize_t __REDIRECT (pread, __P ((int __fd, __ptr_t __buf,
326 size_t __nbytes,__off64_t __offset)),
327 pread64);
328 extern ssize_t __REDIRECT (pwrite, __P ((int __fd, __const __ptr_t __buf,
329 size_t __nbytes, __off64_t __offset)),
330 pwrite64);
331 # else
332 # define pread pread64
333 # define pwrite pwrite64
334 # endif
335 # endif
337 # ifdef __USE_LARGEFILE64
338 extern ssize_t pread64 __P ((int __fd, __ptr_t __buf, size_t __nbytes,
339 __off64_t __offset));
340 extern ssize_t pwrite64 __P ((int __fd, __const __ptr_t __buf, size_t __n,
341 __off64_t __offset));
342 # endif
343 #endif
345 /* Create a one-way communication channel (pipe).
346 If successful, two file descriptors are stored in PIPEDES;
347 bytes written on PIPEDES[1] can be read from PIPEDES[0].
348 Returns 0 if successful, -1 if not. */
349 extern int pipe __P ((int __pipedes[2]));
351 /* Schedule an alarm. In SECONDS seconds, the process will get a SIGALRM.
352 If SECONDS is zero, any currently scheduled alarm will be cancelled.
353 The function returns the number of seconds remaining until the last
354 alarm scheduled would have signaled, or zero if there wasn't one.
355 There is no return value to indicate an error, but you can set `errno'
356 to 0 and check its value after calling `alarm', and this might tell you.
357 The signal may come late due to processor scheduling. */
358 extern unsigned int alarm __P ((unsigned int __seconds));
360 /* Make the process sleep for SECONDS seconds, or until a signal arrives
361 and is not ignored. The function returns the number of seconds less
362 than SECONDS which it actually slept (thus zero if it slept the full time).
363 If a signal handler does a `longjmp' or modifies the handling of the
364 SIGALRM signal while inside `sleep' call, the handling of the SIGALRM
365 signal afterwards is undefined. There is no return value to indicate
366 error, but if `sleep' returns SECONDS, it probably didn't work. */
367 extern unsigned int sleep __P ((unsigned int __seconds));
369 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
370 /* Set an alarm to go off (generating a SIGALRM signal) in VALUE
371 microseconds. If INTERVAL is nonzero, when the alarm goes off, the
372 timer is reset to go off every INTERVAL microseconds thereafter.
373 Returns the number of microseconds remaining before the alarm. */
374 extern unsigned int ualarm __P ((unsigned int __value,
375 unsigned int __interval));
377 /* Sleep USECONDS microseconds, or until a signal arrives that is not blocked
378 or ignored. */
379 extern void usleep __P ((unsigned int __useconds));
380 #endif
383 /* Suspend the process until a signal arrives.
384 This always returns -1 and sets `errno' to EINTR. */
385 extern int pause __P ((void));
388 /* Change the owner and group of FILE. */
389 extern int chown __P ((__const char *__file, __uid_t __owner,
390 __gid_t __group));
392 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
393 /* Change the owner and group of the file that FD is open on. */
394 extern int fchown __P ((int __fd, __uid_t __owner, __gid_t __group));
397 /* Change owner and group of FILE, if it is a symbolic
398 link the ownership of the symbolic link is changed. */
399 extern int lchown __P ((__const char *__file, __uid_t __owner,
400 __gid_t __group));
402 #endif /* Use BSD || X/Open Unix. */
404 /* Change the process's working directory to PATH. */
405 extern int __chdir __P ((__const char *__path));
406 extern int chdir __P ((__const char *__path));
408 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
409 /* Change the process's working directory to the one FD is open on. */
410 extern int fchdir __P ((int __fd));
411 #endif
413 /* Get the pathname of the current working directory,
414 and put it in SIZE bytes of BUF. Returns NULL if the
415 directory couldn't be determined or SIZE was too small.
416 If successful, returns BUF. In GNU, if BUF is NULL,
417 an array is allocated with `malloc'; the array is SIZE
418 bytes long, unless SIZE == 0, in which case it is as
419 big as necessary. */
420 extern char *getcwd __P ((char *__buf, size_t __size));
422 #ifdef __USE_GNU
423 /* Return a malloc'd string containing the current directory name.
424 If the environment variable `PWD' is set, and its value is correct,
425 that value is used. */
426 extern char *get_current_dir_name __P ((void));
427 #endif
429 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
430 /* Put the absolute pathname of the current working directory in BUF.
431 If successful, return BUF. If not, put an error message in
432 BUF and return NULL. BUF should be at least PATH_MAX bytes long. */
433 extern char *getwd __P ((char *__buf));
434 #endif
437 /* Duplicate FD, returning a new file descriptor on the same file. */
438 extern int dup __P ((int __fd));
440 /* Duplicate FD to FD2, closing FD2 and making it open on the same file. */
441 extern int dup2 __P ((int __fd, int __fd2));
443 /* NULL-terminated array of "NAME=VALUE" environment variables. */
444 extern char **__environ;
445 #ifdef __USE_GNU
446 extern char **environ;
447 #endif
450 /* Replace the current process, executing PATH with arguments ARGV and
451 environment ENVP. ARGV and ENVP are terminated by NULL pointers. */
452 extern int execve __P ((__const char *__path, char *__const __argv[],
453 char *__const __envp[]));
455 #ifdef __USE_GNU
456 /* Execute the file FD refers to, overlaying the running program image.
457 ARGV and ENVP are passed to the new program, as for `execve'. */
458 extern int fexecve __P ((int __fd,
459 char *__const __argv[], char *__const __envp[]));
461 #endif
464 /* Execute PATH with arguments ARGV and environment from `environ'. */
465 extern int execv __P ((__const char *__path, char *__const __argv[]));
467 /* Execute PATH with all arguments after PATH until a NULL pointer,
468 and the argument after that for environment. */
469 extern int execle __P ((__const char *__path, __const char *__arg, ...));
471 /* Execute PATH with all arguments after PATH until
472 a NULL pointer and environment from `environ'. */
473 extern int execl __P ((__const char *__path, __const char *__arg, ...));
475 /* Execute FILE, searching in the `PATH' environment variable if it contains
476 no slashes, with arguments ARGV and environment from `environ'. */
477 extern int execvp __P ((__const char *__file, char *__const __argv[]));
479 /* Execute FILE, searching in the `PATH' environment variable if
480 it contains no slashes, with all arguments after FILE until a
481 NULL pointer and environment from `environ'. */
482 extern int execlp __P ((__const char *__file, __const char *__arg, ...));
485 #if defined __USE_MISC || defined __USE_XOPEN
486 /* Add INC to priority of the current process. */
487 extern int nice __P ((int __inc));
488 #endif
491 /* Terminate program execution with the low-order 8 bits of STATUS. */
492 extern void _exit __P ((int __status)) __attribute__ ((__noreturn__));
495 /* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf';
496 the `_SC_*' symbols for the NAME argument to `sysconf';
497 and the `_CS_*' symbols for the NAME argument to `confstr'. */
498 #include <bits/confname.h>
500 /* Get file-specific configuration information about PATH. */
501 extern long int pathconf __P ((__const char *__path, int __name));
503 /* Get file-specific configuration about descriptor FD. */
504 extern long int fpathconf __P ((int __fd, int __name));
506 /* Get the value of the system variable NAME. */
507 extern long int sysconf __P ((int __name));
509 #ifdef __USE_POSIX2
510 /* Get the value of the string-valued system variable NAME. */
511 extern size_t confstr __P ((int __name, char *__buf, size_t __len));
512 #endif
515 /* Get the process ID of the calling process. */
516 extern __pid_t __getpid __P ((void));
517 extern __pid_t getpid __P ((void));
519 /* Get the process ID of the calling process's parent. */
520 extern __pid_t getppid __P ((void));
522 /* Get the process group ID of the calling process.
523 This function is different on old BSD. */
524 #ifndef __FAVOR_BSD
525 extern __pid_t getpgrp __P ((void));
526 #else
527 # ifdef __REDIRECT
528 extern __pid_t __REDIRECT (getpgrp, __P ((__pid_t __pid)), __getpgid);
529 # else
530 # define getpgrp __getpgid
531 # endif
532 #endif
534 /* Get the process group ID of process PID. */
535 extern __pid_t __getpgid __P ((__pid_t __pid));
536 #ifdef __USE_XOPEN_EXTENDED
537 extern __pid_t getpgid __P ((__pid_t __pid));
538 #endif
541 /* Set the process group ID of the process matching PID to PGID.
542 If PID is zero, the current process's process group ID is set.
543 If PGID is zero, the process ID of the process is used. */
544 extern int __setpgid __P ((__pid_t __pid, __pid_t __pgid));
545 extern int setpgid __P ((__pid_t __pid, __pid_t __pgid));
547 #if defined __USE_SVID || defined __USE_BSD || defined __USE_XOPEN_EXTENDED
548 /* Both System V and BSD have `setpgrp' functions, but with different
549 calling conventions. The BSD function is the same as POSIX.1 `setpgid'
550 (above). The System V function takes no arguments and puts the calling
551 process in its on group like `setpgid (0, 0)'.
553 New programs should always use `setpgid' instead.
555 The default in GNU is to provide the System V function. The BSD
556 function is available under -D_BSD_SOURCE. */
558 # ifndef __FAVOR_BSD
560 /* Set the process group ID of the calling process to its own PID.
561 This is exactly the same as `setpgid (0, 0)'. */
562 extern int setpgrp __P ((void));
564 # else
566 /* Another name for `setpgid' (above). */
567 # ifdef __REDIRECT
568 extern int __REDIRECT (setpgrp, __P ((__pid_t __pid, __pid_t __pgrp)),
569 setpgid);
570 # else
571 # define setpgrp setpgid
572 # endif
574 # endif /* Favor BSD. */
575 #endif /* Use SVID or BSD. */
577 /* Create a new session with the calling process as its leader.
578 The process group IDs of the session and the calling process
579 are set to the process ID of the calling process, which is returned. */
580 extern __pid_t setsid __P ((void));
582 #ifdef __USE_XOPEN_EXTENDED
583 /* Return the session ID of the given process. */
584 extern __pid_t getsid __P ((__pid_t __pid));
585 #endif
587 /* Get the real user ID of the calling process. */
588 extern __uid_t getuid __P ((void));
590 /* Get the effective user ID of the calling process. */
591 extern __uid_t geteuid __P ((void));
593 /* Get the real group ID of the calling process. */
594 extern __gid_t getgid __P ((void));
596 /* Get the effective group ID of the calling process. */
597 extern __gid_t getegid __P ((void));
599 /* If SIZE is zero, return the number of supplementary groups
600 the calling process is in. Otherwise, fill in the group IDs
601 of its supplementary groups in LIST and return the number written. */
602 extern int getgroups __P ((int __size, __gid_t __list[]));
604 #ifdef __USE_GNU
605 /* Return nonzero iff the calling process is in group GID. */
606 extern int group_member __P ((__gid_t __gid));
607 #endif
609 /* Set the user ID of the calling process to UID.
610 If the calling process is the super-user, set the real
611 and effective user IDs, and the saved set-user-ID to UID;
612 if not, the effective user ID is set to UID. */
613 extern int setuid __P ((__uid_t __uid));
615 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
616 /* Set the real user ID of the calling process to RUID,
617 and the effective user ID of the calling process to EUID. */
618 extern int setreuid __P ((__uid_t __ruid, __uid_t __euid));
619 #endif
621 #ifdef __USE_BSD
622 /* Set the effective user ID of the calling process to UID. */
623 extern int seteuid __P ((__uid_t __uid));
624 #endif /* Use BSD. */
626 /* Set the group ID of the calling process to GID.
627 If the calling process is the super-user, set the real
628 and effective group IDs, and the saved set-group-ID to GID;
629 if not, the effective group ID is set to GID. */
630 extern int setgid __P ((__gid_t __gid));
632 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
633 /* Set the real group ID of the calling process to RGID,
634 and the effective group ID of the calling process to EGID. */
635 extern int setregid __P ((__gid_t __rgid, __gid_t __egid));
636 #endif
638 #ifdef __USE_BSD
639 /* Set the effective group ID of the calling process to GID. */
640 extern int setegid __P ((__gid_t __gid));
641 #endif /* Use BSD. */
644 /* Clone the calling process, creating an exact copy.
645 Return -1 for errors, 0 to the new process,
646 and the process ID of the new process to the old process. */
647 extern __pid_t __fork __P ((void));
648 extern __pid_t fork __P ((void));
650 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
651 /* Clone the calling process, but without copying the whole address space.
652 The calling process is suspended until the new process exits or is
653 replaced by a call to `execve'. Return -1 for errors, 0 to the new process,
654 and the process ID of the new process to the old process. */
655 extern __pid_t vfork __P ((void));
656 #endif /* Use BSD. */
659 /* Return the pathname of the terminal FD is open on, or NULL on errors.
660 The returned storage is good only until the next call to this function. */
661 extern char *ttyname __P ((int __fd));
663 /* Store at most BUFLEN characters of the pathname of the terminal FD is
664 open on in BUF. Return 0 on success, otherwise an error number. */
665 extern int ttyname_r __P ((int __fd, char *__buf, size_t __buflen));
667 /* Return 1 if FD is a valid descriptor associated
668 with a terminal, zero if not. */
669 extern int isatty __P ((int __fd));
671 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
672 /* Return the index into the active-logins file (utmp) for
673 the controlling terminal. */
674 extern int ttyslot __P ((void));
675 #endif
678 /* Make a link to FROM named TO. */
679 extern int link __P ((__const char *__from, __const char *__to));
681 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
682 /* Make a symbolic link to FROM named TO. */
683 extern int symlink __P ((__const char *__from, __const char *__to));
685 /* Read the contents of the symbolic link PATH into no more than
686 LEN bytes of BUF. The contents are not null-terminated.
687 Returns the number of characters read, or -1 for errors. */
688 extern int readlink __P ((__const char *__path, char *__buf, size_t __len));
689 #endif /* Use BSD. */
691 /* Remove the link NAME. */
692 extern int unlink __P ((__const char *__name));
694 /* Remove the directory PATH. */
695 extern int rmdir __P ((__const char *__path));
698 /* Return the foreground process group ID of FD. */
699 extern __pid_t tcgetpgrp __P ((int __fd));
701 /* Set the foreground process group ID of FD set PGRP_ID. */
702 extern int tcsetpgrp __P ((int __fd, __pid_t __pgrp_id));
705 /* Return the login name of the user. */
706 extern char *getlogin __P ((void));
707 #ifdef __USE_REENTRANT
708 /* Return at most NAME_LEN characters of the login name of the user in NAME.
709 If it cannot be determined or some other error occurred, return the error
710 code. Otherwise return 0. */
711 extern int getlogin_r __P ((char *__name, size_t __name_len));
712 #endif
714 #ifdef __USE_BSD
715 /* Set the login name returned by `getlogin'. */
716 extern int setlogin __P ((__const char *__name));
717 #endif
720 #ifdef __USE_POSIX2
721 /* Get definitions and prototypes for functions to process the
722 arguments in ARGV (ARGC of them, minus the program name) for
723 options given in OPTS. */
724 # define __need_getopt
725 # include <getopt.h>
726 #endif
729 #if defined __USE_BSD || defined __USE_XOPEN
731 /* Put the name of the current host in no more than LEN bytes of NAME.
732 The result is null-terminated if LEN is large enough for the full
733 name and the terminator. */
734 extern int gethostname __P ((char *__name, size_t __len));
736 /* Set the name of the current host to NAME, which is LEN bytes long.
737 This call is restricted to the super-user. */
738 extern int sethostname __P ((__const char *__name, size_t __len));
740 /* Set the current machine's Internet number to ID.
741 This call is restricted to the super-user. */
742 extern int sethostid __P ((long int __id));
745 /* Get and set the NIS (aka YP) domain name, if any.
746 Called just like `gethostname' and `sethostname'.
747 The NIS domain name is usually the empty string when not using NIS. */
748 extern int getdomainname __P ((char *__name, size_t __len));
749 extern int setdomainname __P ((__const char *__name, size_t __len));
752 /* Make all changes done to FD actually appear on disk. */
753 extern int fsync __P ((int __fd));
756 /* Revoke access permissions to all processes currently communicating
757 with the control terminal, and then send a SIGHUP signal to the process
758 group of the control terminal. */
759 extern int vhangup __P ((void));
761 /* Revoke the access of all descriptors currently open on FILE. */
762 extern int revoke __P ((__const char *__file));
765 /* Enable statistical profiling, writing samples of the PC into at most
766 SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
767 is enabled, the system examines the user PC and increments
768 SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536]. If SCALE is zero,
769 disable profiling. Returns zero on success, -1 on error. */
770 extern int profil __P ((unsigned short int *__sample_buffer, size_t __size,
771 size_t __offset, unsigned int __scale));
774 /* Turn accounting on if NAME is an existing file. The system will then write
775 a record for each process as it terminates, to this file. If NAME is NULL,
776 turn accounting off. This call is restricted to the super-user. */
777 extern int acct __P ((__const char *__name));
779 /* Make PATH be the root directory (the starting point for absolute paths).
780 This call is restricted to the super-user. */
781 extern int chroot __P ((__const char *__path));
784 /* Successive calls return the shells listed in `/etc/shells'. */
785 extern char *getusershell __P ((void));
786 extern void endusershell __P ((void)); /* Discard cached info. */
787 extern void setusershell __P ((void)); /* Rewind and re-read the file. */
790 /* Prompt with PROMPT and read a string from the terminal without echoing.
791 Uses /dev/tty if possible; otherwise stderr and stdin. */
792 extern char *getpass __P ((__const char *__prompt));
794 /* Put the program in the background, and dissociate from the controlling
795 terminal. If NOCHDIR is zero, do `chdir ("/")'. If NOCLOSE is zero,
796 redirects stdin, stdout, and stderr to /dev/null. */
797 extern int daemon __P ((int __nochdir, int __noclose));
799 #endif /* Use BSD || X/Open. */
802 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
804 /* Return the current machine's Internet number. */
805 extern long int gethostid __P ((void));
807 /* Make all changes done to all files actually appear on disk. */
808 extern int sync __P ((void));
811 /* Return the number of bytes in a page. This is the system's page size,
812 which is not necessarily the same as the hardware page size. */
813 extern int __getpagesize __P ((void));
814 extern int getpagesize __P ((void));
817 /* Truncate FILE to LENGTH bytes. */
818 #ifndef __USE_FILE_OFFSET64
819 extern int truncate __P ((__const char *__file, __off_t __length));
820 #else
821 # ifdef __REDIRECT
822 extern int __REDIRECT (truncate,
823 __P ((__const char *__file, __off64_t __length)),
824 truncate64);
825 # else
826 # define truncate truncate64
827 # endif
828 #endif
829 #ifdef __USE_LARGEFILE64
830 extern int truncate64 __P ((__const char *__file, __off64_t __length));
831 #endif
833 /* Truncate the file FD is open on to LENGTH bytes. */
834 extern int __ftruncate __P ((int __fd, __off_t __length));
835 #ifndef __USE_FILE_OFFSET64
836 extern int ftruncate __P ((int __fd, __off_t __length));
837 #else
838 # ifdef __REDIRECT
839 extern int __REDIRECT (ftruncate, __P ((int __fd, __off64_t __length)),
840 ftruncate64);
841 # else
842 # define ftruncate ftruncate64
843 # endif
844 #endif
845 #ifdef __USE_LARGEFILE64
846 extern int ftruncate64 __P ((int __fd, __off64_t __length));
847 #endif
850 /* Return the maximum number of file descriptors
851 the current process could possibly have. */
852 extern int getdtablesize __P ((void));
854 #endif /* Use BSD || X/Open Unix. */
857 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
859 /* Set the end of accessible data space (aka "the break") to ADDR.
860 Returns zero on success and -1 for errors (with errno set). */
861 extern int brk __P ((__ptr_t __addr));
863 # define __need_ptrdiff_t
864 # include <stddef.h>
866 /* Increase or decrease the end of accessible data space by DELTA bytes.
867 If successful, returns the address the previous end of data space
868 (i.e. the beginning of the new space, if DELTA > 0);
869 returns (void *) -1 for errors (with errno set). */
870 extern __ptr_t __sbrk __P ((ptrdiff_t __delta));
871 extern __ptr_t sbrk __P ((ptrdiff_t __delta));
872 #endif
875 #ifdef __USE_MISC
876 /* Invoke `system call' number SYSNO, passing it the remaining arguments.
877 This is completely system-dependent, and not often useful.
879 In Unix, `syscall' sets `errno' for all errors and most calls return -1
880 for errors; in many systems you cannot pass arguments or get return
881 values for all system calls (`pipe', `fork', and `getppid' typically
882 among them).
884 In Mach, all system calls take normal arguments and always return an
885 error code (zero for success). */
886 extern long int syscall __P ((long int __sysno, ...));
888 #endif /* Use misc. */
891 #if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK
892 /* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both
893 files consistent. Some systems have them there and some here, and some
894 software depends on the macros being defined without including both. */
896 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
897 LEN is always relative to the current file position.
898 The CMD argument is one of the following. */
900 # define F_ULOCK 0 /* Unlock a previously locked region. */
901 # define F_LOCK 1 /* Lock a region for exclusive use. */
902 # define F_TLOCK 2 /* Test and lock a region for exclusive use. */
903 # define F_TEST 3 /* Test a region for other processes locks. */
905 # ifndef __USE_FILE_OFFSET64
906 extern int lockf __P ((int __fd, int __cmd, __off_t __len));
907 # else
908 # ifdef __REDIRECT
909 extern int __REDIRECT (lockf, __P ((int __fd, int __cmd, __off64_t __len)),
910 lockf64);
911 # else
912 # define lockf lockf64
913 # endif
914 # endif
915 # ifdef __USE_LARGEFILE64
916 extern int lockf64 __P ((int __fd, int __cmd, __off64_t __len));
917 # endif
918 #endif /* Use misc and F_LOCK not already defined. */
921 #ifdef __USE_GNU
923 /* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno'
924 set to EINTR. */
926 # define TEMP_FAILURE_RETRY(expression) \
927 (__extension__ \
928 ({ long int __result; \
929 do __result = (long int) (expression); \
930 while (__result == -1L && errno == EINTR); \
931 __result; })) \
934 /* This variable is set nonzero at startup if the process's effective
935 IDs differ from its real IDs, or it is otherwise indicated that
936 extra security should be used. When this is set the dynamic linker
937 and some functions contained in the C library ignore various
938 environment variables that normally affect them. */
939 extern int __libc_enable_secure;
941 #endif
943 #if defined __USE_POSIX199309 || defined __USE_UNIX98
944 /* Synchronize at least the data part of a file with the underlying
945 media. */
946 extern int fdatasync __P ((int __fildes));
947 #endif /* Use POSIX199309 */
950 /* XPG4.2 specifies that prototypes for the encryption functions must
951 be defined here. */
952 #ifdef __USE_XOPEN
953 /* Encrypt at most 8 characters from KEY using salt to perturb DES. */
954 extern char *crypt __P ((__const char *__key, __const char *__salt));
956 /* Setup DES tables according KEY. */
957 extern void setkey __P ((__const char *__key));
959 /* Encrypt data in BLOCK in place if EDFLAG is zero; otherwise decrypt
960 block in place. */
961 extern void encrypt __P ((char *__block, int __edflag));
964 /* Swab pairs bytes in the first N bytes of the area pointed to by
965 FROM and copy the result to TO. The value of TO must not be in the
966 range [FROM - N + 1, FROM - 1]. If N is odd the first byte in FROM
967 is without partner. */
968 extern void swab __P ((__const __ptr_t __from, __ptr_t __to, ssize_t __n));
969 #endif
972 /* The Single Unix specification, version 2, demands these prototypes
973 to be here. They are also found in <stdio.h>. */
974 #ifdef __USE_XOPEN
975 /* Return the name of the controlling terminal. */
976 extern char *ctermid __P ((char *__s));
978 /* Return the name of the current user. This function should not be
979 used and might go away some time. */
980 extern char *cuserid __P ((char *__s));
982 /* Rename file OLD to NEW. */
983 extern int rename __P ((__const char *__old, __const char *__new));
984 #endif
987 #ifdef __USE_POSIX199309
988 /* This function is only available if the system has POSIX threads. */
990 /* Install handlers to be called when a new process is created with FORK.
991 The PREPARE handler is called in the parent process just before performing
992 FORK. The PARENT handler is called in the parent process just after FORK.
993 The CHILD handler is called in the child process. Each of the three
994 handlers can be NULL, meaning that no handler needs to be called at that
995 point.
996 PTHREAD_ATFORK can be called several times, in which case the PREPARE
997 handlers are called in LIFO order (last added with PTHREAD_ATFORK,
998 first called before FORK), and the PARENT and CHILD handlers are called
999 in FIFO (first added, first called). */
1000 extern int pthread_atfork __P ((void (*__prepare) (void),
1001 void (*__parent) (void),
1002 void (*__child) (void)));
1003 #endif
1005 __END_DECLS
1007 #endif /* unistd.h */