1/* Copyright (C) 1991-2021 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
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.
8
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.
13
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 <https://www.gnu.org/licenses/>. */
17
18/*
19 * POSIX Standard: 2.10 Symbolic Constants <unistd.h>
20 */
21
22#ifndef _UNISTD_H
23#define _UNISTD_H 1
24
25#include <features.h>
26
27__BEGIN_DECLS
28
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'. */
31
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
48
49/* These are not #ifdef __USE_POSIX2 because they are
50 in the theoretically application-owned namespace. */
51
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
65
66/* The utilities on GNU systems also correspond to this version. */
67#define _POSIX2_VERSION __POSIX2_THIS_VERSION
68
69/* This symbol was required until the 2001 edition of POSIX. */
70#define _POSIX2_C_VERSION __POSIX2_THIS_VERSION
71
72/* If defined, the implementation supports the
73 C Language Bindings Option. */
74#define _POSIX2_C_BIND __POSIX2_THIS_VERSION
75
76/* If defined, the implementation supports the
77 C Language Development Utilities Option. */
78#define _POSIX2_C_DEV __POSIX2_THIS_VERSION
79
80/* If defined, the implementation supports the
81 Software Development Utilities Option. */
82#define _POSIX2_SW_DEV __POSIX2_THIS_VERSION
83
84/* If defined, the implementation supports the
85 creation of locales with the localedef utility. */
86#define _POSIX2_LOCALEDEF __POSIX2_THIS_VERSION
87
88/* X/Open version number to which the library conforms. It is selectable. */
89#ifdef __USE_XOPEN2K8
90# define _XOPEN_VERSION 700
91#elif defined __USE_XOPEN2K
92# define _XOPEN_VERSION 600
93#elif defined __USE_UNIX98
94# define _XOPEN_VERSION 500
95#else
96# define _XOPEN_VERSION 4
97#endif
98
99/* Commands and utilities from XPG4 are available. */
100#define _XOPEN_XCU_VERSION 4
101
102/* We are compatible with the old published standards as well. */
103#define _XOPEN_XPG2 1
104#define _XOPEN_XPG3 1
105#define _XOPEN_XPG4 1
106
107/* The X/Open Unix extensions are available. */
108#define _XOPEN_UNIX 1
109
110/* The enhanced internationalization capabilities according to XPG4.2
111 are present. */
112#define _XOPEN_ENH_I18N 1
113
114/* The legacy interfaces are also available. */
115#define _XOPEN_LEGACY 1
116
117
118/* Get values of POSIX options:
119
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'.
123
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'.
161
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.
165
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.
176
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'.
181
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.
195
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.
200 */
201
202#include <bits/posix_opt.h>
203
204/* Get the environment definitions from Unix98. */
205#if defined __USE_UNIX98 || defined __USE_XOPEN2K
206# include <bits/environments.h>
207#endif
208
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. */
213
214
215/* All functions that are not declared anywhere else. */
216
217#include <bits/types.h>
218
219#ifndef __ssize_t_defined
220typedef __ssize_t ssize_t;
221# define __ssize_t_defined
222#endif
223
224#define __need_size_t
225#define __need_NULL
226#include <stddef.h>
227
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
232typedef __gid_t gid_t;
233# define __gid_t_defined
234# endif
235
236# ifndef __uid_t_defined
237typedef __uid_t uid_t;
238# define __uid_t_defined
239# endif
240
241# ifndef __off_t_defined
242# ifndef __USE_FILE_OFFSET64
243typedef __off_t off_t;
244# else
245typedef __off64_t off_t;
246# endif
247# define __off_t_defined
248# endif
249# if defined __USE_LARGEFILE64 && !defined __off64_t_defined
250typedef __off64_t off64_t;
251# define __off64_t_defined
252# endif
253
254# ifndef __useconds_t_defined
255typedef __useconds_t useconds_t;
256# define __useconds_t_defined
257# endif
258
259# ifndef __pid_t_defined
260typedef __pid_t pid_t;
261# define __pid_t_defined
262# endif
263#endif /* X/Open */
264
265#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
266# ifndef __intptr_t_defined
267typedef __intptr_t intptr_t;
268# define __intptr_t_defined
269# endif
270#endif
271
272#if defined __USE_MISC || defined __USE_XOPEN
273# ifndef __socklen_t_defined
274typedef __socklen_t socklen_t;
275# define __socklen_t_defined
276# endif
277#endif
278
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. */
285
286/* Test for access to NAME using the real UID and real GID. */
287extern int access (const char *__name, int __type) __THROW __nonnull ((1));
288
289#ifdef __USE_GNU
290/* Test for access to NAME using the effective UID and GID
291 (as normal file operations use). */
292extern int euidaccess (const char *__name, int __type)
293 __THROW __nonnull ((1));
294
295/* An alias for `euidaccess', used by some other systems. */
296extern int eaccess (const char *__name, int __type)
297 __THROW __nonnull ((1));
298
299/* Execute program relative to a directory file descriptor. */
300extern int execveat (int __fd, const char *__path, char *const __argv[],
301 char *const __envp[], int __flags)
302 __THROW __nonnull ((2, 3));
303#endif
304
305#ifdef __USE_ATFILE
306/* Test for access to FILE relative to the directory FD is open on.
307 If AT_EACCESS is set in FLAG, then use effective IDs like `eaccess',
308 otherwise use real IDs like `access'. */
309extern int faccessat (int __fd, const char *__file, int __type, int __flag)
310 __THROW __nonnull ((2)) __wur;
311#endif /* Use GNU. */
312
313
314/* Values for the WHENCE argument to lseek. */
315#ifndef _STDIO_H /* <stdio.h> has the same definitions. */
316# define SEEK_SET 0 /* Seek from beginning of file. */
317# define SEEK_CUR 1 /* Seek from current position. */
318# define SEEK_END 2 /* Seek from end of file. */
319# ifdef __USE_GNU
320# define SEEK_DATA 3 /* Seek to next data. */
321# define SEEK_HOLE 4 /* Seek to next hole. */
322# endif
323#endif
324
325#if defined __USE_MISC && !defined L_SET
326/* Old BSD names for the same constants; just for compatibility. */
327# define L_SET SEEK_SET
328# define L_INCR SEEK_CUR
329# define L_XTND SEEK_END
330#endif
331
332
333/* Move FD's file position to OFFSET bytes from the
334 beginning of the file (if WHENCE is SEEK_SET),
335 the current position (if WHENCE is SEEK_CUR),
336 or the end of the file (if WHENCE is SEEK_END).
337 Return the new file position. */
338#ifndef __USE_FILE_OFFSET64
339extern __off_t lseek (int __fd, __off_t __offset, int __whence) __THROW;
340#else
341# ifdef __REDIRECT_NTH
342extern __off64_t __REDIRECT_NTH (lseek,
343 (int __fd, __off64_t __offset, int __whence),
344 lseek64);
345# else
346# define lseek lseek64
347# endif
348#endif
349#ifdef __USE_LARGEFILE64
350extern __off64_t lseek64 (int __fd, __off64_t __offset, int __whence)
351 __THROW;
352#endif
353
354/* Close the file descriptor FD.
355
356 This function is a cancellation point and therefore not marked with
357 __THROW. */
358extern int close (int __fd);
359
360#ifdef __USE_MISC
361/* Close all open file descriptors greater than or equal to LOWFD.
362 Negative LOWFD is clamped to 0. */
363extern void closefrom (int __lowfd) __THROW;
364#endif
365
366/* Read NBYTES into BUF from FD. Return the
367 number read, -1 for errors or 0 for EOF.
368
369 This function is a cancellation point and therefore not marked with
370 __THROW. */
371extern ssize_t read (int __fd, void *__buf, size_t __nbytes) __wur
372 __attr_access ((__write_only__, 2, 3));
373
374/* Write N bytes of BUF to FD. Return the number written, or -1.
375
376 This function is a cancellation point and therefore not marked with
377 __THROW. */
378extern ssize_t write (int __fd, const void *__buf, size_t __n) __wur
379 __attr_access ((__read_only__, 2, 3));
380
381#if defined __USE_UNIX98 || defined __USE_XOPEN2K8
382# ifndef __USE_FILE_OFFSET64
383/* Read NBYTES into BUF from FD at the given position OFFSET without
384 changing the file pointer. Return the number read, -1 for errors
385 or 0 for EOF.
386
387 This function is a cancellation point and therefore not marked with
388 __THROW. */
389extern ssize_t pread (int __fd, void *__buf, size_t __nbytes,
390 __off_t __offset) __wur
391 __attr_access ((__write_only__, 2, 3));
392
393/* Write N bytes of BUF to FD at the given position OFFSET without
394 changing the file pointer. Return the number written, or -1.
395
396 This function is a cancellation point and therefore not marked with
397 __THROW. */
398extern ssize_t pwrite (int __fd, const void *__buf, size_t __n,
399 __off_t __offset) __wur
400 __attr_access ((__read_only__, 2, 3));
401
402# else
403# ifdef __REDIRECT
404extern ssize_t __REDIRECT (pread, (int __fd, void *__buf, size_t __nbytes,
405 __off64_t __offset),
406 pread64) __wur
407 __attr_access ((__write_only__, 2, 3));
408extern ssize_t __REDIRECT (pwrite, (int __fd, const void *__buf,
409 size_t __nbytes, __off64_t __offset),
410 pwrite64) __wur
411 __attr_access ((__read_only__, 2, 3));
412# else
413# define pread pread64
414# define pwrite pwrite64
415# endif
416# endif
417
418# ifdef __USE_LARGEFILE64
419/* Read NBYTES into BUF from FD at the given position OFFSET without
420 changing the file pointer. Return the number read, -1 for errors
421 or 0 for EOF. */
422extern ssize_t pread64 (int __fd, void *__buf, size_t __nbytes,
423 __off64_t __offset) __wur
424 __attr_access ((__write_only__, 2, 3));
425/* Write N bytes of BUF to FD at the given position OFFSET without
426 changing the file pointer. Return the number written, or -1. */
427extern ssize_t pwrite64 (int __fd, const void *__buf, size_t __n,
428 __off64_t __offset) __wur
429 __attr_access ((__read_only__, 2, 3));
430# endif
431#endif
432
433/* Create a one-way communication channel (pipe).
434 If successful, two file descriptors are stored in PIPEDES;
435 bytes written on PIPEDES[1] can be read from PIPEDES[0].
436 Returns 0 if successful, -1 if not. */
437extern int pipe (int __pipedes[2]) __THROW __wur;
438
439#ifdef __USE_GNU
440/* Same as pipe but apply flags passed in FLAGS to the new file
441 descriptors. */
442extern int pipe2 (int __pipedes[2], int __flags) __THROW __wur;
443#endif
444
445/* Schedule an alarm. In SECONDS seconds, the process will get a SIGALRM.
446 If SECONDS is zero, any currently scheduled alarm will be cancelled.
447 The function returns the number of seconds remaining until the last
448 alarm scheduled would have signaled, or zero if there wasn't one.
449 There is no return value to indicate an error, but you can set `errno'
450 to 0 and check its value after calling `alarm', and this might tell you.
451 The signal may come late due to processor scheduling. */
452extern unsigned int alarm (unsigned int __seconds) __THROW;
453
454/* Make the process sleep for SECONDS seconds, or until a signal arrives
455 and is not ignored. The function returns the number of seconds less
456 than SECONDS which it actually slept (thus zero if it slept the full time).
457 If a signal handler does a `longjmp' or modifies the handling of the
458 SIGALRM signal while inside `sleep' call, the handling of the SIGALRM
459 signal afterwards is undefined. There is no return value to indicate
460 error, but if `sleep' returns SECONDS, it probably didn't work.
461
462 This function is a cancellation point and therefore not marked with
463 __THROW. */
464extern unsigned int sleep (unsigned int __seconds);
465
466#if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \
467 || defined __USE_MISC
468/* Set an alarm to go off (generating a SIGALRM signal) in VALUE
469 microseconds. If INTERVAL is nonzero, when the alarm goes off, the
470 timer is reset to go off every INTERVAL microseconds thereafter.
471 Returns the number of microseconds remaining before the alarm. */
472extern __useconds_t ualarm (__useconds_t __value, __useconds_t __interval)
473 __THROW;
474
475/* Sleep USECONDS microseconds, or until a signal arrives that is not blocked
476 or ignored.
477
478 This function is a cancellation point and therefore not marked with
479 __THROW. */
480extern int usleep (__useconds_t __useconds);
481#endif
482
483
484/* Suspend the process until a signal arrives.
485 This always returns -1 and sets `errno' to EINTR.
486
487 This function is a cancellation point and therefore not marked with
488 __THROW. */
489extern int pause (void);
490
491
492/* Change the owner and group of FILE. */
493extern int chown (const char *__file, __uid_t __owner, __gid_t __group)
494 __THROW __nonnull ((1)) __wur;
495
496#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
497/* Change the owner and group of the file that FD is open on. */
498extern int fchown (int __fd, __uid_t __owner, __gid_t __group) __THROW __wur;
499
500
501/* Change owner and group of FILE, if it is a symbolic
502 link the ownership of the symbolic link is changed. */
503extern int lchown (const char *__file, __uid_t __owner, __gid_t __group)
504 __THROW __nonnull ((1)) __wur;
505
506#endif /* Use X/Open Unix. */
507
508#ifdef __USE_ATFILE
509/* Change the owner and group of FILE relative to the directory FD is open
510 on. */
511extern int fchownat (int __fd, const char *__file, __uid_t __owner,
512 __gid_t __group, int __flag)
513 __THROW __nonnull ((2)) __wur;
514#endif /* Use GNU. */
515
516/* Change the process's working directory to PATH. */
517extern int chdir (const char *__path) __THROW __nonnull ((1)) __wur;
518
519#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
520/* Change the process's working directory to the one FD is open on. */
521extern int fchdir (int __fd) __THROW __wur;
522#endif
523
524/* Get the pathname of the current working directory,
525 and put it in SIZE bytes of BUF. Returns NULL if the
526 directory couldn't be determined or SIZE was too small.
527 If successful, returns BUF. In GNU, if BUF is NULL,
528 an array is allocated with `malloc'; the array is SIZE
529 bytes long, unless SIZE == 0, in which case it is as
530 big as necessary. */
531extern char *getcwd (char *__buf, size_t __size) __THROW __wur
532 __attr_access ((__write_only__, 1, 2));
533
534#ifdef __USE_GNU
535/* Return a malloc'd string containing the current directory name.
536 If the environment variable `PWD' is set, and its value is correct,
537 that value is used. */
538extern char *get_current_dir_name (void) __THROW;
539#endif
540
541#if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \
542 || defined __USE_MISC
543/* Put the absolute pathname of the current working directory in BUF.
544 If successful, return BUF. If not, put an error message in
545 BUF and return NULL. BUF should be at least PATH_MAX bytes long. */
546extern char *getwd (char *__buf)
547 __THROW __nonnull ((1)) __attribute_deprecated__ __wur
548 __attr_access ((__write_only__, 1));
549#endif
550
551
552/* Duplicate FD, returning a new file descriptor on the same file. */
553extern int dup (int __fd) __THROW __wur;
554
555/* Duplicate FD to FD2, closing FD2 and making it open on the same file. */
556extern int dup2 (int __fd, int __fd2) __THROW;
557
558#ifdef __USE_GNU
559/* Duplicate FD to FD2, closing FD2 and making it open on the same
560 file while setting flags according to FLAGS. */
561extern int dup3 (int __fd, int __fd2, int __flags) __THROW;
562#endif
563
564/* NULL-terminated array of "NAME=VALUE" environment variables. */
565extern char **__environ;
566#ifdef __USE_GNU
567extern char **environ;
568#endif
569
570
571/* Replace the current process, executing PATH with arguments ARGV and
572 environment ENVP. ARGV and ENVP are terminated by NULL pointers. */
573extern int execve (const char *__path, char *const __argv[],
574 char *const __envp[]) __THROW __nonnull ((1, 2));
575
576#ifdef __USE_XOPEN2K8
577/* Execute the file FD refers to, overlaying the running program image.
578 ARGV and ENVP are passed to the new program, as for `execve'. */
579extern int fexecve (int __fd, char *const __argv[], char *const __envp[])
580 __THROW __nonnull ((2));
581#endif
582
583
584/* Execute PATH with arguments ARGV and environment from `environ'. */
585extern int execv (const char *__path, char *const __argv[])
586 __THROW __nonnull ((1, 2));
587
588/* Execute PATH with all arguments after PATH until a NULL pointer,
589 and the argument after that for environment. */
590extern int execle (const char *__path, const char *__arg, ...)
591 __THROW __nonnull ((1, 2));
592
593/* Execute PATH with all arguments after PATH until
594 a NULL pointer and environment from `environ'. */
595extern int execl (const char *__path, const char *__arg, ...)
596 __THROW __nonnull ((1, 2));
597
598/* Execute FILE, searching in the `PATH' environment variable if it contains
599 no slashes, with arguments ARGV and environment from `environ'. */
600extern int execvp (const char *__file, char *const __argv[])
601 __THROW __nonnull ((1, 2));
602
603/* Execute FILE, searching in the `PATH' environment variable if
604 it contains no slashes, with all arguments after FILE until a
605 NULL pointer and environment from `environ'. */
606extern int execlp (const char *__file, const char *__arg, ...)
607 __THROW __nonnull ((1, 2));
608
609#ifdef __USE_GNU
610/* Execute FILE, searching in the `PATH' environment variable if it contains
611 no slashes, with arguments ARGV and environment from `environ'. */
612extern int execvpe (const char *__file, char *const __argv[],
613 char *const __envp[])
614 __THROW __nonnull ((1, 2));
615#endif
616
617
618#if defined __USE_MISC || defined __USE_XOPEN
619/* Add INC to priority of the current process. */
620extern int nice (int __inc) __THROW __wur;
621#endif
622
623
624/* Terminate program execution with the low-order 8 bits of STATUS. */
625extern void _exit (int __status) __attribute__ ((__noreturn__));
626
627
628/* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf';
629 the `_SC_*' symbols for the NAME argument to `sysconf';
630 and the `_CS_*' symbols for the NAME argument to `confstr'. */
631#include <bits/confname.h>
632
633/* Get file-specific configuration information about PATH. */
634extern long int pathconf (const char *__path, int __name)
635 __THROW __nonnull ((1));
636
637/* Get file-specific configuration about descriptor FD. */
638extern long int fpathconf (int __fd, int __name) __THROW;
639
640/* Get the value of the system variable NAME. */
641extern long int sysconf (int __name) __THROW;
642
643#ifdef __USE_POSIX2
644/* Get the value of the string-valued system variable NAME. */
645extern size_t confstr (int __name, char *__buf, size_t __len) __THROW
646 __attr_access ((__write_only__, 2, 3));
647#endif
648
649
650/* Get the process ID of the calling process. */
651extern __pid_t getpid (void) __THROW;
652
653/* Get the process ID of the calling process's parent. */
654extern __pid_t getppid (void) __THROW;
655
656/* Get the process group ID of the calling process. */
657extern __pid_t getpgrp (void) __THROW;
658
659/* Get the process group ID of process PID. */
660extern __pid_t __getpgid (__pid_t __pid) __THROW;
661#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
662extern __pid_t getpgid (__pid_t __pid) __THROW;
663#endif
664
665
666/* Set the process group ID of the process matching PID to PGID.
667 If PID is zero, the current process's process group ID is set.
668 If PGID is zero, the process ID of the process is used. */
669extern int setpgid (__pid_t __pid, __pid_t __pgid) __THROW;
670
671#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
672/* Both System V and BSD have `setpgrp' functions, but with different
673 calling conventions. The BSD function is the same as POSIX.1 `setpgid'
674 (above). The System V function takes no arguments and puts the calling
675 process in its on group like `setpgid (0, 0)'.
676
677 New programs should always use `setpgid' instead.
678
679 GNU provides the POSIX.1 function. */
680
681/* Set the process group ID of the calling process to its own PID.
682 This is exactly the same as `setpgid (0, 0)'. */
683extern int setpgrp (void) __THROW;
684
685#endif /* Use misc or X/Open. */
686
687/* Create a new session with the calling process as its leader.
688 The process group IDs of the session and the calling process
689 are set to the process ID of the calling process, which is returned. */
690extern __pid_t setsid (void) __THROW;
691
692#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
693/* Return the session ID of the given process. */
694extern __pid_t getsid (__pid_t __pid) __THROW;
695#endif
696
697/* Get the real user ID of the calling process. */
698extern __uid_t getuid (void) __THROW;
699
700/* Get the effective user ID of the calling process. */
701extern __uid_t geteuid (void) __THROW;
702
703/* Get the real group ID of the calling process. */
704extern __gid_t getgid (void) __THROW;
705
706/* Get the effective group ID of the calling process. */
707extern __gid_t getegid (void) __THROW;
708
709/* If SIZE is zero, return the number of supplementary groups
710 the calling process is in. Otherwise, fill in the group IDs
711 of its supplementary groups in LIST and return the number written. */
712extern int getgroups (int __size, __gid_t __list[]) __THROW __wur
713 __attr_access ((__write_only__, 2, 1));
714#ifdef __USE_GNU
715/* Return nonzero iff the calling process is in group GID. */
716extern int group_member (__gid_t __gid) __THROW;
717#endif
718
719/* Set the user ID of the calling process to UID.
720 If the calling process is the super-user, set the real
721 and effective user IDs, and the saved set-user-ID to UID;
722 if not, the effective user ID is set to UID. */
723extern int setuid (__uid_t __uid) __THROW __wur;
724
725#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
726/* Set the real user ID of the calling process to RUID,
727 and the effective user ID of the calling process to EUID. */
728extern int setreuid (__uid_t __ruid, __uid_t __euid) __THROW __wur;
729#endif
730
731#ifdef __USE_XOPEN2K
732/* Set the effective user ID of the calling process to UID. */
733extern int seteuid (__uid_t __uid) __THROW __wur;
734#endif /* Use POSIX.1-2001. */
735
736/* Set the group ID of the calling process to GID.
737 If the calling process is the super-user, set the real
738 and effective group IDs, and the saved set-group-ID to GID;
739 if not, the effective group ID is set to GID. */
740extern int setgid (__gid_t __gid) __THROW __wur;
741
742#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
743/* Set the real group ID of the calling process to RGID,
744 and the effective group ID of the calling process to EGID. */
745extern int setregid (__gid_t __rgid, __gid_t __egid) __THROW __wur;
746#endif
747
748#ifdef __USE_XOPEN2K
749/* Set the effective group ID of the calling process to GID. */
750extern int setegid (__gid_t __gid) __THROW __wur;
751#endif /* Use POSIX.1-2001. */
752
753#ifdef __USE_GNU
754/* Fetch the real user ID, effective user ID, and saved-set user ID,
755 of the calling process. */
756extern int getresuid (__uid_t *__ruid, __uid_t *__euid, __uid_t *__suid)
757 __THROW;
758
759/* Fetch the real group ID, effective group ID, and saved-set group ID,
760 of the calling process. */
761extern int getresgid (__gid_t *__rgid, __gid_t *__egid, __gid_t *__sgid)
762 __THROW;
763
764/* Set the real user ID, effective user ID, and saved-set user ID,
765 of the calling process to RUID, EUID, and SUID, respectively. */
766extern int setresuid (__uid_t __ruid, __uid_t __euid, __uid_t __suid)
767 __THROW __wur;
768
769/* Set the real group ID, effective group ID, and saved-set group ID,
770 of the calling process to RGID, EGID, and SGID, respectively. */
771extern int setresgid (__gid_t __rgid, __gid_t __egid, __gid_t __sgid)
772 __THROW __wur;
773#endif
774
775
776/* Clone the calling process, creating an exact copy.
777 Return -1 for errors, 0 to the new process,
778 and the process ID of the new process to the old process. */
779extern __pid_t fork (void) __THROWNL;
780
781#if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \
782 || defined __USE_MISC
783/* Clone the calling process, but without copying the whole address space.
784 The calling process is suspended until the new process exits or is
785 replaced by a call to `execve'. Return -1 for errors, 0 to the new process,
786 and the process ID of the new process to the old process. */
787extern __pid_t vfork (void) __THROW;
788#endif /* Use misc or XPG < 7. */
789
790#ifdef __USE_GNU
791/* This is similar to fork, however it does not run the atfork handlers
792 neither reinitialize any internal locks in multithread case.
793 Different than fork, _Fork is async-signal-safe. */
794extern __pid_t _Fork (void) __THROW;
795#endif
796
797
798/* Return the pathname of the terminal FD is open on, or NULL on errors.
799 The returned storage is good only until the next call to this function. */
800extern char *ttyname (int __fd) __THROW;
801
802/* Store at most BUFLEN characters of the pathname of the terminal FD is
803 open on in BUF. Return 0 on success, otherwise an error number. */
804extern int ttyname_r (int __fd, char *__buf, size_t __buflen)
805 __THROW __nonnull ((2)) __wur __attr_access ((__write_only__, 2, 3));
806
807/* Return 1 if FD is a valid descriptor associated
808 with a terminal, zero if not. */
809extern int isatty (int __fd) __THROW;
810
811#ifdef __USE_MISC
812/* Return the index into the active-logins file (utmp) for
813 the controlling terminal. */
814extern int ttyslot (void) __THROW;
815#endif
816
817
818/* Make a link to FROM named TO. */
819extern int link (const char *__from, const char *__to)
820 __THROW __nonnull ((1, 2)) __wur;
821
822#ifdef __USE_ATFILE
823/* Like link but relative paths in TO and FROM are interpreted relative
824 to FROMFD and TOFD respectively. */
825extern int linkat (int __fromfd, const char *__from, int __tofd,
826 const char *__to, int __flags)
827 __THROW __nonnull ((2, 4)) __wur;
828#endif
829
830#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
831/* Make a symbolic link to FROM named TO. */
832extern int symlink (const char *__from, const char *__to)
833 __THROW __nonnull ((1, 2)) __wur;
834
835/* Read the contents of the symbolic link PATH into no more than
836 LEN bytes of BUF. The contents are not null-terminated.
837 Returns the number of characters read, or -1 for errors. */
838extern ssize_t readlink (const char *__restrict __path,
839 char *__restrict __buf, size_t __len)
840 __THROW __nonnull ((1, 2)) __wur __attr_access ((__write_only__, 2, 3));
841
842#endif /* Use POSIX.1-2001. */
843
844#ifdef __USE_ATFILE
845/* Like symlink but a relative path in TO is interpreted relative to TOFD. */
846extern int symlinkat (const char *__from, int __tofd,
847 const char *__to) __THROW __nonnull ((1, 3)) __wur;
848
849/* Like readlink but a relative PATH is interpreted relative to FD. */
850extern ssize_t readlinkat (int __fd, const char *__restrict __path,
851 char *__restrict __buf, size_t __len)
852 __THROW __nonnull ((2, 3)) __wur __attr_access ((__write_only__, 3, 4));
853#endif
854
855/* Remove the link NAME. */
856extern int unlink (const char *__name) __THROW __nonnull ((1));
857
858#ifdef __USE_ATFILE
859/* Remove the link NAME relative to FD. */
860extern int unlinkat (int __fd, const char *__name, int __flag)
861 __THROW __nonnull ((2));
862#endif
863
864/* Remove the directory PATH. */
865extern int rmdir (const char *__path) __THROW __nonnull ((1));
866
867
868/* Return the foreground process group ID of FD. */
869extern __pid_t tcgetpgrp (int __fd) __THROW;
870
871/* Set the foreground process group ID of FD set PGRP_ID. */
872extern int tcsetpgrp (int __fd, __pid_t __pgrp_id) __THROW;
873
874
875/* Return the login name of the user.
876
877 This function is a possible cancellation point and therefore not
878 marked with __THROW. */
879extern char *getlogin (void);
880#ifdef __USE_POSIX199506
881/* Return at most NAME_LEN characters of the login name of the user in NAME.
882 If it cannot be determined or some other error occurred, return the error
883 code. Otherwise return 0.
884
885 This function is a possible cancellation point and therefore not
886 marked with __THROW. */
887extern int getlogin_r (char *__name, size_t __name_len) __nonnull ((1))
888 __attr_access ((__write_only__, 1, 2));
889#endif
890
891#ifdef __USE_MISC
892/* Set the login name returned by `getlogin'. */
893extern int setlogin (const char *__name) __THROW __nonnull ((1));
894#endif
895
896
897#ifdef __USE_POSIX2
898/* Get definitions and prototypes for functions to process the
899 arguments in ARGV (ARGC of them, minus the program name) for
900 options given in OPTS. */
901# include <bits/getopt_posix.h>
902#endif
903
904
905#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
906/* Put the name of the current host in no more than LEN bytes of NAME.
907 The result is null-terminated if LEN is large enough for the full
908 name and the terminator. */
909extern int gethostname (char *__name, size_t __len) __THROW __nonnull ((1))
910 __attr_access ((__write_only__, 1, 2));
911#endif
912
913
914#if defined __USE_MISC
915/* Set the name of the current host to NAME, which is LEN bytes long.
916 This call is restricted to the super-user. */
917extern int sethostname (const char *__name, size_t __len)
918 __THROW __nonnull ((1)) __wur __attr_access ((__read_only__, 1, 2));
919
920/* Set the current machine's Internet number to ID.
921 This call is restricted to the super-user. */
922extern int sethostid (long int __id) __THROW __wur;
923
924
925/* Get and set the NIS (aka YP) domain name, if any.
926 Called just like `gethostname' and `sethostname'.
927 The NIS domain name is usually the empty string when not using NIS. */
928extern int getdomainname (char *__name, size_t __len)
929 __THROW __nonnull ((1)) __wur __attr_access ((__write_only__, 1, 2));
930extern int setdomainname (const char *__name, size_t __len)
931 __THROW __nonnull ((1)) __wur __attr_access ((__read_only__, 1, 2));
932
933/* Revoke access permissions to all processes currently communicating
934 with the control terminal, and then send a SIGHUP signal to the process
935 group of the control terminal. */
936extern int vhangup (void) __THROW;
937
938/* Revoke the access of all descriptors currently open on FILE. */
939extern int revoke (const char *__file) __THROW __nonnull ((1)) __wur;
940
941
942/* Enable statistical profiling, writing samples of the PC into at most
943 SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
944 is enabled, the system examines the user PC and increments
945 SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536]. If SCALE is zero,
946 disable profiling. Returns zero on success, -1 on error. */
947extern int profil (unsigned short int *__sample_buffer, size_t __size,
948 size_t __offset, unsigned int __scale)
949 __THROW __nonnull ((1));
950
951
952/* Turn accounting on if NAME is an existing file. The system will then write
953 a record for each process as it terminates, to this file. If NAME is NULL,
954 turn accounting off. This call is restricted to the super-user. */
955extern int acct (const char *__name) __THROW;
956
957
958/* Successive calls return the shells listed in `/etc/shells'. */
959extern char *getusershell (void) __THROW;
960extern void endusershell (void) __THROW; /* Discard cached info. */
961extern void setusershell (void) __THROW; /* Rewind and re-read the file. */
962
963
964/* Put the program in the background, and dissociate from the controlling
965 terminal. If NOCHDIR is zero, do `chdir ("/")'. If NOCLOSE is zero,
966 redirects stdin, stdout, and stderr to /dev/null. */
967extern int daemon (int __nochdir, int __noclose) __THROW __wur;
968#endif /* Use misc. */
969
970
971#if defined __USE_MISC || (defined __USE_XOPEN && !defined __USE_XOPEN2K)
972/* Make PATH be the root directory (the starting point for absolute paths).
973 This call is restricted to the super-user. */
974extern int chroot (const char *__path) __THROW __nonnull ((1)) __wur;
975
976/* Prompt with PROMPT and read a string from the terminal without echoing.
977 Uses /dev/tty if possible; otherwise stderr and stdin. */
978extern char *getpass (const char *__prompt) __nonnull ((1));
979#endif /* Use misc || X/Open. */
980
981
982/* Make all changes done to FD actually appear on disk.
983
984 This function is a cancellation point and therefore not marked with
985 __THROW. */
986extern int fsync (int __fd);
987
988
989#ifdef __USE_GNU
990/* Make all changes done to all files on the file system associated
991 with FD actually appear on disk. */
992extern int syncfs (int __fd) __THROW;
993#endif
994
995
996#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
997
998/* Return identifier for the current host. */
999extern long int gethostid (void);
1000
1001/* Make all changes done to all files actually appear on disk. */
1002extern void sync (void) __THROW;
1003
1004
1005# if defined __USE_MISC || !defined __USE_XOPEN2K
1006/* Return the number of bytes in a page. This is the system's page size,
1007 which is not necessarily the same as the hardware page size. */
1008extern int getpagesize (void) __THROW __attribute__ ((__const__));
1009
1010
1011/* Return the maximum number of file descriptors
1012 the current process could possibly have. */
1013extern int getdtablesize (void) __THROW;
1014# endif
1015
1016#endif /* Use misc || X/Open Unix. */
1017
1018
1019#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
1020
1021/* Truncate FILE to LENGTH bytes. */
1022# ifndef __USE_FILE_OFFSET64
1023extern int truncate (const char *__file, __off_t __length)
1024 __THROW __nonnull ((1)) __wur;
1025# else
1026# ifdef __REDIRECT_NTH
1027extern int __REDIRECT_NTH (truncate,
1028 (const char *__file, __off64_t __length),
1029 truncate64) __nonnull ((1)) __wur;
1030# else
1031# define truncate truncate64
1032# endif
1033# endif
1034# ifdef __USE_LARGEFILE64
1035extern int truncate64 (const char *__file, __off64_t __length)
1036 __THROW __nonnull ((1)) __wur;
1037# endif
1038
1039#endif /* Use X/Open Unix || POSIX 2008. */
1040
1041#if defined __USE_POSIX199309 \
1042 || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
1043
1044/* Truncate the file FD is open on to LENGTH bytes. */
1045# ifndef __USE_FILE_OFFSET64
1046extern int ftruncate (int __fd, __off_t __length) __THROW __wur;
1047# else
1048# ifdef __REDIRECT_NTH
1049extern int __REDIRECT_NTH (ftruncate, (int __fd, __off64_t __length),
1050 ftruncate64) __wur;
1051# else
1052# define ftruncate ftruncate64
1053# endif
1054# endif
1055# ifdef __USE_LARGEFILE64
1056extern int ftruncate64 (int __fd, __off64_t __length) __THROW __wur;
1057# endif
1058
1059#endif /* Use POSIX.1b || X/Open Unix || XPG6. */
1060
1061
1062#if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K) \
1063 || defined __USE_MISC
1064
1065/* Set the end of accessible data space (aka "the break") to ADDR.
1066 Returns zero on success and -1 for errors (with errno set). */
1067extern int brk (void *__addr) __THROW __wur;
1068
1069/* Increase or decrease the end of accessible data space by DELTA bytes.
1070 If successful, returns the address the previous end of data space
1071 (i.e. the beginning of the new space, if DELTA > 0);
1072 returns (void *) -1 for errors (with errno set). */
1073extern void *sbrk (intptr_t __delta) __THROW;
1074#endif
1075
1076
1077#ifdef __USE_MISC
1078/* Invoke `system call' number SYSNO, passing it the remaining arguments.
1079 This is completely system-dependent, and not often useful.
1080
1081 In Unix, `syscall' sets `errno' for all errors and most calls return -1
1082 for errors; in many systems you cannot pass arguments or get return
1083 values for all system calls (`pipe', `fork', and `getppid' typically
1084 among them).
1085
1086 In Mach, all system calls take normal arguments and always return an
1087 error code (zero for success). */
1088extern long int syscall (long int __sysno, ...) __THROW;
1089
1090#endif /* Use misc. */
1091
1092
1093#if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK
1094/* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both
1095 files consistent. Some systems have them there and some here, and some
1096 software depends on the macros being defined without including both. */
1097
1098/* `lockf' is a simpler interface to the locking facilities of `fcntl'.
1099 LEN is always relative to the current file position.
1100 The CMD argument is one of the following.
1101
1102 This function is a cancellation point and therefore not marked with
1103 __THROW. */
1104
1105# define F_ULOCK 0 /* Unlock a previously locked region. */
1106# define F_LOCK 1 /* Lock a region for exclusive use. */
1107# define F_TLOCK 2 /* Test and lock a region for exclusive use. */
1108# define F_TEST 3 /* Test a region for other processes locks. */
1109
1110# ifndef __USE_FILE_OFFSET64
1111extern int lockf (int __fd, int __cmd, __off_t __len) __wur;
1112# else
1113# ifdef __REDIRECT
1114extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len),
1115 lockf64) __wur;
1116# else
1117# define lockf lockf64
1118# endif
1119# endif
1120# ifdef __USE_LARGEFILE64
1121extern int lockf64 (int __fd, int __cmd, __off64_t __len) __wur;
1122# endif
1123#endif /* Use misc and F_LOCK not already defined. */
1124
1125
1126#ifdef __USE_GNU
1127
1128/* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno'
1129 set to EINTR. */
1130
1131# define TEMP_FAILURE_RETRY(expression) \
1132 (__extension__ \
1133 ({ long int __result; \
1134 do __result = (long int) (expression); \
1135 while (__result == -1L && errno == EINTR); \
1136 __result; }))
1137
1138/* Copy LENGTH bytes from INFD to OUTFD. */
1139ssize_t copy_file_range (int __infd, __off64_t *__pinoff,
1140 int __outfd, __off64_t *__poutoff,
1141 size_t __length, unsigned int __flags);
1142#endif /* __USE_GNU */
1143
1144#if defined __USE_POSIX199309 || defined __USE_UNIX98
1145/* Synchronize at least the data part of a file with the underlying
1146 media. */
1147extern int fdatasync (int __fildes);
1148#endif /* Use POSIX199309 */
1149
1150#ifdef __USE_MISC
1151/* One-way hash PHRASE, returning a string suitable for storage in the
1152 user database. SALT selects the one-way function to use, and
1153 ensures that no two users' hashes are the same, even if they use
1154 the same passphrase. The return value points to static storage
1155 which will be overwritten by the next call to crypt. */
1156extern char *crypt (const char *__key, const char *__salt)
1157 __THROW __nonnull ((1, 2));
1158#endif
1159
1160#ifdef __USE_XOPEN
1161/* Swab pairs bytes in the first N bytes of the area pointed to by
1162 FROM and copy the result to TO. The value of TO must not be in the
1163 range [FROM - N + 1, FROM - 1]. If N is odd the first byte in FROM
1164 is without partner. */
1165extern void swab (const void *__restrict __from, void *__restrict __to,
1166 ssize_t __n) __THROW __nonnull ((1, 2))
1167 __attr_access ((__read_only__, 1, 3))
1168 __attr_access ((__write_only__, 2, 3));
1169#endif
1170
1171
1172/* Prior to Issue 6, the Single Unix Specification required these
1173 prototypes to appear in this header. They are also found in
1174 <stdio.h>. */
1175#if defined __USE_XOPEN && !defined __USE_XOPEN2K
1176/* Return the name of the controlling terminal. */
1177extern char *ctermid (char *__s) __THROW;
1178
1179/* Return the name of the current user. */
1180extern char *cuserid (char *__s);
1181#endif
1182
1183
1184/* Unix98 requires this function to be declared here. In other
1185 standards it is in <pthread.h>. */
1186#if defined __USE_UNIX98 && !defined __USE_XOPEN2K
1187extern int pthread_atfork (void (*__prepare) (void),
1188 void (*__parent) (void),
1189 void (*__child) (void)) __THROW;
1190#endif
1191
1192#ifdef __USE_MISC
1193/* Write LENGTH bytes of randomness starting at BUFFER. Return 0 on
1194 success or -1 on error. */
1195int getentropy (void *__buffer, size_t __length) __wur
1196 __attr_access ((__write_only__, 1, 2));
1197#endif
1198
1199/* Define some macros helping to catch buffer overflows. */
1200#if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
1201# include <bits/unistd.h>
1202#endif
1203
1204/* System-specific extensions. */
1205#include <bits/unistd_ext.h>
1206
1207__END_DECLS
1208
1209#endif /* unistd.h */
1210