1/* Copyright (C) 1991-2020 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#endif 
299 
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'. */ 
304extern int faccessat (int __fd, const char *__file, int __type, int __flag) 
305 __THROW __nonnull ((2)) __wur; 
306#endif /* Use GNU. */ 
307 
308 
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 
319 
320#if defined __USE_MISC && !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 
326 
327 
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 
334extern __off_t lseek (int __fd, __off_t __offset, int __whence) __THROW; 
335#else 
336# ifdef __REDIRECT_NTH 
337extern __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 
345extern __off64_t lseek64 (int __fd, __off64_t __offset, int __whence) 
346 __THROW; 
347#endif 
348 
349/* Close the file descriptor FD. 
350 
351 This function is a cancellation point and therefore not marked with 
352 __THROW. */ 
353extern int close (int __fd); 
354 
355/* Read NBYTES into BUF from FD. Return the 
356 number read, -1 for errors or 0 for EOF. 
357 
358 This function is a cancellation point and therefore not marked with 
359 __THROW. */ 
360extern ssize_t read (int __fd, void *__buf, size_t __nbytes) __wur; 
361 
362/* Write N bytes of BUF to FD. Return the number written, or -1. 
363 
364 This function is a cancellation point and therefore not marked with 
365 __THROW. */ 
366extern ssize_t write (int __fd, const void *__buf, size_t __n) __wur; 
367 
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. 
373 
374 This function is a cancellation point and therefore not marked with 
375 __THROW. */ 
376extern ssize_t pread (int __fd, void *__buf, size_t __nbytes, 
377 __off_t __offset) __wur; 
378 
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. 
381 
382 This function is a cancellation point and therefore not marked with 
383 __THROW. */ 
384extern ssize_t pwrite (int __fd, const void *__buf, size_t __n, 
385 __off_t __offset) __wur; 
386# else 
387# ifdef __REDIRECT 
388extern ssize_t __REDIRECT (pread, (int __fd, void *__buf, size_t __nbytes, 
389 __off64_t __offset), 
390 pread64) __wur; 
391extern 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 
399 
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. */ 
404extern 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. */ 
408extern ssize_t pwrite64 (int __fd, const void *__buf, size_t __n, 
409 __off64_t __offset) __wur; 
410# endif 
411#endif 
412 
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. */ 
417extern int pipe (int __pipedes[2]) __THROW __wur; 
418 
419#ifdef __USE_GNU 
420/* Same as pipe but apply flags passed in FLAGS to the new file 
421 descriptors. */ 
422extern int pipe2 (int __pipedes[2], int __flags) __THROW __wur; 
423#endif 
424 
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. */ 
432extern unsigned int alarm (unsigned int __seconds) __THROW; 
433 
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. 
441 
442 This function is a cancellation point and therefore not marked with 
443 __THROW. */ 
444extern unsigned int sleep (unsigned int __seconds); 
445 
446#if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \ 
447 || defined __USE_MISC 
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. */ 
452extern __useconds_t ualarm (__useconds_t __value, __useconds_t __interval) 
453 __THROW; 
454 
455/* Sleep USECONDS microseconds, or until a signal arrives that is not blocked 
456 or ignored. 
457 
458 This function is a cancellation point and therefore not marked with 
459 __THROW. */ 
460extern int usleep (__useconds_t __useconds); 
461#endif 
462 
463 
464/* Suspend the process until a signal arrives. 
465 This always returns -1 and sets `errno' to EINTR. 
466 
467 This function is a cancellation point and therefore not marked with 
468 __THROW. */ 
469extern int pause (void); 
470 
471 
472/* Change the owner and group of FILE. */ 
473extern int chown (const char *__file, __uid_t __owner, __gid_t __group) 
474 __THROW __nonnull ((1)) __wur; 
475 
476#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8 
477/* Change the owner and group of the file that FD is open on. */ 
478extern int fchown (int __fd, __uid_t __owner, __gid_t __group) __THROW __wur; 
479 
480 
481/* Change owner and group of FILE, if it is a symbolic 
482 link the ownership of the symbolic link is changed. */ 
483extern int lchown (const char *__file, __uid_t __owner, __gid_t __group) 
484 __THROW __nonnull ((1)) __wur; 
485 
486#endif /* Use X/Open Unix. */ 
487 
488#ifdef __USE_ATFILE 
489/* Change the owner and group of FILE relative to the directory FD is open 
490 on. */ 
491extern 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. */ 
495 
496/* Change the process's working directory to PATH. */ 
497extern int chdir (const char *__path) __THROW __nonnull ((1)) __wur; 
498 
499#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8 
500/* Change the process's working directory to the one FD is open on. */ 
501extern int fchdir (int __fd) __THROW __wur; 
502#endif 
503 
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. */ 
511extern char *getcwd (char *__buf, size_t __size) __THROW __wur; 
512 
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. */ 
517extern char *get_current_dir_name (void) __THROW; 
518#endif 
519 
520#if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \ 
521 || defined __USE_MISC 
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. */ 
525extern char *getwd (char *__buf) 
526 __THROW __nonnull ((1)) __attribute_deprecated__ __wur; 
527#endif 
528 
529 
530/* Duplicate FD, returning a new file descriptor on the same file. */ 
531extern int dup (int __fd) __THROW __wur; 
532 
533/* Duplicate FD to FD2, closing FD2 and making it open on the same file. */ 
534extern int dup2 (int __fd, int __fd2) __THROW; 
535 
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. */ 
539extern int dup3 (int __fd, int __fd2, int __flags) __THROW; 
540#endif 
541 
542/* NULL-terminated array of "NAME=VALUE" environment variables. */ 
543extern char **__environ; 
544#ifdef __USE_GNU 
545extern char **environ; 
546#endif 
547 
548 
549/* Replace the current process, executing PATH with arguments ARGV and 
550 environment ENVP. ARGV and ENVP are terminated by NULL pointers. */ 
551extern int execve (const char *__path, char *const __argv[], 
552 char *const __envp[]) __THROW __nonnull ((1, 2)); 
553 
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'. */ 
557extern int fexecve (int __fd, char *const __argv[], char *const __envp[]) 
558 __THROW __nonnull ((2)); 
559#endif 
560 
561 
562/* Execute PATH with arguments ARGV and environment from `environ'. */ 
563extern int execv (const char *__path, char *const __argv[]) 
564 __THROW __nonnull ((1, 2)); 
565 
566/* Execute PATH with all arguments after PATH until a NULL pointer, 
567 and the argument after that for environment. */ 
568extern int execle (const char *__path, const char *__arg, ...) 
569 __THROW __nonnull ((1, 2)); 
570 
571/* Execute PATH with all arguments after PATH until 
572 a NULL pointer and environment from `environ'. */ 
573extern int execl (const char *__path, const char *__arg, ...) 
574 __THROW __nonnull ((1, 2)); 
575 
576/* Execute FILE, searching in the `PATH' environment variable if it contains 
577 no slashes, with arguments ARGV and environment from `environ'. */ 
578extern int execvp (const char *__file, char *const __argv[]) 
579 __THROW __nonnull ((1, 2)); 
580 
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'. */ 
584extern int execlp (const char *__file, const char *__arg, ...) 
585 __THROW __nonnull ((1, 2)); 
586 
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'. */ 
590extern int execvpe (const char *__file, char *const __argv[], 
591 char *const __envp[]) 
592 __THROW __nonnull ((1, 2)); 
593#endif 
594 
595 
596#if defined __USE_MISC || defined __USE_XOPEN 
597/* Add INC to priority of the current process. */ 
598extern int nice (int __inc) __THROW __wur; 
599#endif 
600 
601 
602/* Terminate program execution with the low-order 8 bits of STATUS. */ 
603extern void _exit (int __status) __attribute__ ((__noreturn__)); 
604 
605 
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> 
610 
611/* Get file-specific configuration information about PATH. */ 
612extern long int pathconf (const char *__path, int __name) 
613 __THROW __nonnull ((1)); 
614 
615/* Get file-specific configuration about descriptor FD. */ 
616extern long int fpathconf (int __fd, int __name) __THROW; 
617 
618/* Get the value of the system variable NAME. */ 
619extern long int sysconf (int __name) __THROW; 
620 
621#ifdef __USE_POSIX2 
622/* Get the value of the string-valued system variable NAME. */ 
623extern size_t confstr (int __name, char *__buf, size_t __len) __THROW; 
624#endif 
625 
626 
627/* Get the process ID of the calling process. */ 
628extern __pid_t getpid (void) __THROW; 
629 
630/* Get the process ID of the calling process's parent. */ 
631extern __pid_t getppid (void) __THROW; 
632 
633/* Get the process group ID of the calling process. */ 
634extern __pid_t getpgrp (void) __THROW; 
635 
636/* Get the process group ID of process PID. */ 
637extern __pid_t __getpgid (__pid_t __pid) __THROW; 
638#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8 
639extern __pid_t getpgid (__pid_t __pid) __THROW; 
640#endif 
641 
642 
643/* Set the process group ID of the process matching PID to PGID. 
644 If PID is zero, the current process's process group ID is set. 
645 If PGID is zero, the process ID of the process is used. */ 
646extern int setpgid (__pid_t __pid, __pid_t __pgid) __THROW; 
647 
648#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED 
649/* Both System V and BSD have `setpgrp' functions, but with different 
650 calling conventions. The BSD function is the same as POSIX.1 `setpgid' 
651 (above). The System V function takes no arguments and puts the calling 
652 process in its on group like `setpgid (0, 0)'. 
653 
654 New programs should always use `setpgid' instead. 
655 
656 GNU provides the POSIX.1 function. */ 
657 
658/* Set the process group ID of the calling process to its own PID. 
659 This is exactly the same as `setpgid (0, 0)'. */ 
660extern int setpgrp (void) __THROW; 
661 
662#endif /* Use misc or X/Open. */ 
663 
664/* Create a new session with the calling process as its leader. 
665 The process group IDs of the session and the calling process 
666 are set to the process ID of the calling process, which is returned. */ 
667extern __pid_t setsid (void) __THROW; 
668 
669#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8 
670/* Return the session ID of the given process. */ 
671extern __pid_t getsid (__pid_t __pid) __THROW; 
672#endif 
673 
674/* Get the real user ID of the calling process. */ 
675extern __uid_t getuid (void) __THROW; 
676 
677/* Get the effective user ID of the calling process. */ 
678extern __uid_t geteuid (void) __THROW; 
679 
680/* Get the real group ID of the calling process. */ 
681extern __gid_t getgid (void) __THROW; 
682 
683/* Get the effective group ID of the calling process. */ 
684extern __gid_t getegid (void) __THROW; 
685 
686/* If SIZE is zero, return the number of supplementary groups 
687 the calling process is in. Otherwise, fill in the group IDs 
688 of its supplementary groups in LIST and return the number written. */ 
689extern int getgroups (int __size, __gid_t __list[]) __THROW __wur; 
690 
691#ifdef __USE_GNU 
692/* Return nonzero iff the calling process is in group GID. */ 
693extern int group_member (__gid_t __gid) __THROW; 
694#endif 
695 
696/* Set the user ID of the calling process to UID. 
697 If the calling process is the super-user, set the real 
698 and effective user IDs, and the saved set-user-ID to UID; 
699 if not, the effective user ID is set to UID. */ 
700extern int setuid (__uid_t __uid) __THROW __wur; 
701 
702#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED 
703/* Set the real user ID of the calling process to RUID, 
704 and the effective user ID of the calling process to EUID. */ 
705extern int setreuid (__uid_t __ruid, __uid_t __euid) __THROW __wur; 
706#endif 
707 
708#ifdef __USE_XOPEN2K 
709/* Set the effective user ID of the calling process to UID. */ 
710extern int seteuid (__uid_t __uid) __THROW __wur; 
711#endif /* Use POSIX.1-2001. */ 
712 
713/* Set the group ID of the calling process to GID. 
714 If the calling process is the super-user, set the real 
715 and effective group IDs, and the saved set-group-ID to GID; 
716 if not, the effective group ID is set to GID. */ 
717extern int setgid (__gid_t __gid) __THROW __wur; 
718 
719#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED 
720/* Set the real group ID of the calling process to RGID, 
721 and the effective group ID of the calling process to EGID. */ 
722extern int setregid (__gid_t __rgid, __gid_t __egid) __THROW __wur; 
723#endif 
724 
725#ifdef __USE_XOPEN2K 
726/* Set the effective group ID of the calling process to GID. */ 
727extern int setegid (__gid_t __gid) __THROW __wur; 
728#endif /* Use POSIX.1-2001. */ 
729 
730#ifdef __USE_GNU 
731/* Fetch the real user ID, effective user ID, and saved-set user ID, 
732 of the calling process. */ 
733extern int getresuid (__uid_t *__ruid, __uid_t *__euid, __uid_t *__suid) 
734 __THROW; 
735 
736/* Fetch the real group ID, effective group ID, and saved-set group ID, 
737 of the calling process. */ 
738extern int getresgid (__gid_t *__rgid, __gid_t *__egid, __gid_t *__sgid) 
739 __THROW; 
740 
741/* Set the real user ID, effective user ID, and saved-set user ID, 
742 of the calling process to RUID, EUID, and SUID, respectively. */ 
743extern int setresuid (__uid_t __ruid, __uid_t __euid, __uid_t __suid) 
744 __THROW __wur; 
745 
746/* Set the real group ID, effective group ID, and saved-set group ID, 
747 of the calling process to RGID, EGID, and SGID, respectively. */ 
748extern int setresgid (__gid_t __rgid, __gid_t __egid, __gid_t __sgid) 
749 __THROW __wur; 
750#endif 
751 
752 
753/* Clone the calling process, creating an exact copy. 
754 Return -1 for errors, 0 to the new process, 
755 and the process ID of the new process to the old process. */ 
756extern __pid_t fork (void) __THROWNL; 
757 
758#if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \ 
759 || defined __USE_MISC 
760/* Clone the calling process, but without copying the whole address space. 
761 The calling process is suspended until the new process exits or is 
762 replaced by a call to `execve'. Return -1 for errors, 0 to the new process, 
763 and the process ID of the new process to the old process. */ 
764extern __pid_t vfork (void) __THROW; 
765#endif /* Use misc or XPG < 7. */ 
766 
767 
768/* Return the pathname of the terminal FD is open on, or NULL on errors. 
769 The returned storage is good only until the next call to this function. */ 
770extern char *ttyname (int __fd) __THROW; 
771 
772/* Store at most BUFLEN characters of the pathname of the terminal FD is 
773 open on in BUF. Return 0 on success, otherwise an error number. */ 
774extern int ttyname_r (int __fd, char *__buf, size_t __buflen) 
775 __THROW __nonnull ((2)) __wur; 
776 
777/* Return 1 if FD is a valid descriptor associated 
778 with a terminal, zero if not. */ 
779extern int isatty (int __fd) __THROW; 
780 
781#ifdef __USE_MISC 
782/* Return the index into the active-logins file (utmp) for 
783 the controlling terminal. */ 
784extern int ttyslot (void) __THROW; 
785#endif 
786 
787 
788/* Make a link to FROM named TO. */ 
789extern int link (const char *__from, const char *__to) 
790 __THROW __nonnull ((1, 2)) __wur; 
791 
792#ifdef __USE_ATFILE 
793/* Like link but relative paths in TO and FROM are interpreted relative 
794 to FROMFD and TOFD respectively. */ 
795extern int linkat (int __fromfd, const char *__from, int __tofd, 
796 const char *__to, int __flags) 
797 __THROW __nonnull ((2, 4)) __wur; 
798#endif 
799 
800#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K 
801/* Make a symbolic link to FROM named TO. */ 
802extern int symlink (const char *__from, const char *__to) 
803 __THROW __nonnull ((1, 2)) __wur; 
804 
805/* Read the contents of the symbolic link PATH into no more than 
806 LEN bytes of BUF. The contents are not null-terminated. 
807 Returns the number of characters read, or -1 for errors. */ 
808extern ssize_t readlink (const char *__restrict __path, 
809 char *__restrict __buf, size_t __len) 
810 __THROW __nonnull ((1, 2)) __wur; 
811#endif /* Use POSIX.1-2001. */ 
812 
813#ifdef __USE_ATFILE 
814/* Like symlink but a relative path in TO is interpreted relative to TOFD. */ 
815extern int symlinkat (const char *__from, int __tofd, 
816 const char *__to) __THROW __nonnull ((1, 3)) __wur; 
817 
818/* Like readlink but a relative PATH is interpreted relative to FD. */ 
819extern ssize_t readlinkat (int __fd, const char *__restrict __path, 
820 char *__restrict __buf, size_t __len) 
821 __THROW __nonnull ((2, 3)) __wur; 
822#endif 
823 
824/* Remove the link NAME. */ 
825extern int unlink (const char *__name) __THROW __nonnull ((1)); 
826 
827#ifdef __USE_ATFILE 
828/* Remove the link NAME relative to FD. */ 
829extern int unlinkat (int __fd, const char *__name, int __flag) 
830 __THROW __nonnull ((2)); 
831#endif 
832 
833/* Remove the directory PATH. */ 
834extern int rmdir (const char *__path) __THROW __nonnull ((1)); 
835 
836 
837/* Return the foreground process group ID of FD. */ 
838extern __pid_t tcgetpgrp (int __fd) __THROW; 
839 
840/* Set the foreground process group ID of FD set PGRP_ID. */ 
841extern int tcsetpgrp (int __fd, __pid_t __pgrp_id) __THROW; 
842 
843 
844/* Return the login name of the user. 
845 
846 This function is a possible cancellation point and therefore not 
847 marked with __THROW. */ 
848extern char *getlogin (void); 
849#ifdef __USE_POSIX199506 
850/* Return at most NAME_LEN characters of the login name of the user in NAME. 
851 If it cannot be determined or some other error occurred, return the error 
852 code. Otherwise return 0. 
853 
854 This function is a possible cancellation point and therefore not 
855 marked with __THROW. */ 
856extern int getlogin_r (char *__name, size_t __name_len) __nonnull ((1)); 
857#endif 
858 
859#ifdef __USE_MISC 
860/* Set the login name returned by `getlogin'. */ 
861extern int setlogin (const char *__name) __THROW __nonnull ((1)); 
862#endif 
863 
864 
865#ifdef __USE_POSIX2 
866/* Get definitions and prototypes for functions to process the 
867 arguments in ARGV (ARGC of them, minus the program name) for 
868 options given in OPTS. */ 
869# include <bits/getopt_posix.h> 
870#endif 
871 
872 
873#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K 
874/* Put the name of the current host in no more than LEN bytes of NAME. 
875 The result is null-terminated if LEN is large enough for the full 
876 name and the terminator. */ 
877extern int gethostname (char *__name, size_t __len) __THROW __nonnull ((1)); 
878#endif 
879 
880 
881#if defined __USE_MISC 
882/* Set the name of the current host to NAME, which is LEN bytes long. 
883 This call is restricted to the super-user. */ 
884extern int sethostname (const char *__name, size_t __len) 
885 __THROW __nonnull ((1)) __wur; 
886 
887/* Set the current machine's Internet number to ID. 
888 This call is restricted to the super-user. */ 
889extern int sethostid (long int __id) __THROW __wur; 
890 
891 
892/* Get and set the NIS (aka YP) domain name, if any. 
893 Called just like `gethostname' and `sethostname'. 
894 The NIS domain name is usually the empty string when not using NIS. */ 
895extern int getdomainname (char *__name, size_t __len) 
896 __THROW __nonnull ((1)) __wur; 
897extern int setdomainname (const char *__name, size_t __len) 
898 __THROW __nonnull ((1)) __wur; 
899 
900 
901/* Revoke access permissions to all processes currently communicating 
902 with the control terminal, and then send a SIGHUP signal to the process 
903 group of the control terminal. */ 
904extern int vhangup (void) __THROW; 
905 
906/* Revoke the access of all descriptors currently open on FILE. */ 
907extern int revoke (const char *__file) __THROW __nonnull ((1)) __wur; 
908 
909 
910/* Enable statistical profiling, writing samples of the PC into at most 
911 SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling 
912 is enabled, the system examines the user PC and increments 
913 SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536]. If SCALE is zero, 
914 disable profiling. Returns zero on success, -1 on error. */ 
915extern int profil (unsigned short int *__sample_buffer, size_t __size, 
916 size_t __offset, unsigned int __scale) 
917 __THROW __nonnull ((1)); 
918 
919 
920/* Turn accounting on if NAME is an existing file. The system will then write 
921 a record for each process as it terminates, to this file. If NAME is NULL, 
922 turn accounting off. This call is restricted to the super-user. */ 
923extern int acct (const char *__name) __THROW; 
924 
925 
926/* Successive calls return the shells listed in `/etc/shells'. */ 
927extern char *getusershell (void) __THROW; 
928extern void endusershell (void) __THROW; /* Discard cached info. */ 
929extern void setusershell (void) __THROW; /* Rewind and re-read the file. */ 
930 
931 
932/* Put the program in the background, and dissociate from the controlling 
933 terminal. If NOCHDIR is zero, do `chdir ("/")'. If NOCLOSE is zero, 
934 redirects stdin, stdout, and stderr to /dev/null. */ 
935extern int daemon (int __nochdir, int __noclose) __THROW __wur; 
936#endif /* Use misc. */ 
937 
938 
939#if defined __USE_MISC || (defined __USE_XOPEN && !defined __USE_XOPEN2K) 
940/* Make PATH be the root directory (the starting point for absolute paths). 
941 This call is restricted to the super-user. */ 
942extern int chroot (const char *__path) __THROW __nonnull ((1)) __wur; 
943 
944/* Prompt with PROMPT and read a string from the terminal without echoing. 
945 Uses /dev/tty if possible; otherwise stderr and stdin. */ 
946extern char *getpass (const char *__prompt) __nonnull ((1)); 
947#endif /* Use misc || X/Open. */ 
948 
949 
950/* Make all changes done to FD actually appear on disk. 
951 
952 This function is a cancellation point and therefore not marked with 
953 __THROW. */ 
954extern int fsync (int __fd); 
955 
956 
957#ifdef __USE_GNU 
958/* Make all changes done to all files on the file system associated 
959 with FD actually appear on disk. */ 
960extern int syncfs (int __fd) __THROW; 
961#endif 
962 
963 
964#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED 
965 
966/* Return identifier for the current host. */ 
967extern long int gethostid (void); 
968 
969/* Make all changes done to all files actually appear on disk. */ 
970extern void sync (void) __THROW; 
971 
972 
973# if defined __USE_MISC || !defined __USE_XOPEN2K 
974/* Return the number of bytes in a page. This is the system's page size, 
975 which is not necessarily the same as the hardware page size. */ 
976extern int getpagesize (void) __THROW __attribute__ ((__const__)); 
977 
978 
979/* Return the maximum number of file descriptors 
980 the current process could possibly have. */ 
981extern int getdtablesize (void) __THROW; 
982# endif 
983 
984#endif /* Use misc || X/Open Unix. */ 
985 
986 
987#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8 
988 
989/* Truncate FILE to LENGTH bytes. */ 
990# ifndef __USE_FILE_OFFSET64 
991extern int truncate (const char *__file, __off_t __length) 
992 __THROW __nonnull ((1)) __wur; 
993# else 
994# ifdef __REDIRECT_NTH 
995extern int __REDIRECT_NTH (truncate, 
996 (const char *__file, __off64_t __length), 
997 truncate64) __nonnull ((1)) __wur; 
998# else 
999# define truncate truncate64 
1000# endif 
1001# endif 
1002# ifdef __USE_LARGEFILE64 
1003extern int truncate64 (const char *__file, __off64_t __length) 
1004 __THROW __nonnull ((1)) __wur; 
1005# endif 
1006 
1007#endif /* Use X/Open Unix || POSIX 2008. */ 
1008 
1009#if defined __USE_POSIX199309 \ 
1010 || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K 
1011 
1012/* Truncate the file FD is open on to LENGTH bytes. */ 
1013# ifndef __USE_FILE_OFFSET64 
1014extern int ftruncate (int __fd, __off_t __length) __THROW __wur; 
1015# else 
1016# ifdef __REDIRECT_NTH 
1017extern int __REDIRECT_NTH (ftruncate, (int __fd, __off64_t __length), 
1018 ftruncate64) __wur; 
1019# else 
1020# define ftruncate ftruncate64 
1021# endif 
1022# endif 
1023# ifdef __USE_LARGEFILE64 
1024extern int ftruncate64 (int __fd, __off64_t __length) __THROW __wur; 
1025# endif 
1026 
1027#endif /* Use POSIX.1b || X/Open Unix || XPG6. */ 
1028 
1029 
1030#if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K) \ 
1031 || defined __USE_MISC 
1032 
1033/* Set the end of accessible data space (aka "the break") to ADDR. 
1034 Returns zero on success and -1 for errors (with errno set). */ 
1035extern int brk (void *__addr) __THROW __wur; 
1036 
1037/* Increase or decrease the end of accessible data space by DELTA bytes. 
1038 If successful, returns the address the previous end of data space 
1039 (i.e. the beginning of the new space, if DELTA > 0); 
1040 returns (void *) -1 for errors (with errno set). */ 
1041extern void *sbrk (intptr_t __delta) __THROW; 
1042#endif 
1043 
1044 
1045#ifdef __USE_MISC 
1046/* Invoke `system call' number SYSNO, passing it the remaining arguments. 
1047 This is completely system-dependent, and not often useful. 
1048 
1049 In Unix, `syscall' sets `errno' for all errors and most calls return -1 
1050 for errors; in many systems you cannot pass arguments or get return 
1051 values for all system calls (`pipe', `fork', and `getppid' typically 
1052 among them). 
1053 
1054 In Mach, all system calls take normal arguments and always return an 
1055 error code (zero for success). */ 
1056extern long int syscall (long int __sysno, ...) __THROW; 
1057 
1058#endif /* Use misc. */ 
1059 
1060 
1061#if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK 
1062/* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both 
1063 files consistent. Some systems have them there and some here, and some 
1064 software depends on the macros being defined without including both. */ 
1065 
1066/* `lockf' is a simpler interface to the locking facilities of `fcntl'. 
1067 LEN is always relative to the current file position. 
1068 The CMD argument is one of the following. 
1069 
1070 This function is a cancellation point and therefore not marked with 
1071 __THROW. */ 
1072 
1073# define F_ULOCK 0 /* Unlock a previously locked region. */ 
1074# define F_LOCK 1 /* Lock a region for exclusive use. */ 
1075# define F_TLOCK 2 /* Test and lock a region for exclusive use. */ 
1076# define F_TEST 3 /* Test a region for other processes locks. */ 
1077 
1078# ifndef __USE_FILE_OFFSET64 
1079extern int lockf (int __fd, int __cmd, __off_t __len) __wur; 
1080# else 
1081# ifdef __REDIRECT 
1082extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len), 
1083 lockf64) __wur; 
1084# else 
1085# define lockf lockf64 
1086# endif 
1087# endif 
1088# ifdef __USE_LARGEFILE64 
1089extern int lockf64 (int __fd, int __cmd, __off64_t __len) __wur; 
1090# endif 
1091#endif /* Use misc and F_LOCK not already defined. */ 
1092 
1093 
1094#ifdef __USE_GNU 
1095 
1096/* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno' 
1097 set to EINTR. */ 
1098 
1099# define TEMP_FAILURE_RETRY(expression) \ 
1100 (__extension__ \ 
1101 ({ long int __result; \ 
1102 do __result = (long int) (expression); \ 
1103 while (__result == -1L && errno == EINTR); \ 
1104 __result; })) 
1105 
1106/* Copy LENGTH bytes from INFD to OUTFD. */ 
1107ssize_t copy_file_range (int __infd, __off64_t *__pinoff, 
1108 int __outfd, __off64_t *__poutoff, 
1109 size_t __length, unsigned int __flags); 
1110#endif /* __USE_GNU */ 
1111 
1112#if defined __USE_POSIX199309 || defined __USE_UNIX98 
1113/* Synchronize at least the data part of a file with the underlying 
1114 media. */ 
1115extern int fdatasync (int __fildes); 
1116#endif /* Use POSIX199309 */ 
1117 
1118#ifdef __USE_MISC 
1119/* One-way hash PHRASE, returning a string suitable for storage in the 
1120 user database. SALT selects the one-way function to use, and 
1121 ensures that no two users' hashes are the same, even if they use 
1122 the same passphrase. The return value points to static storage 
1123 which will be overwritten by the next call to crypt. */ 
1124extern char *crypt (const char *__key, const char *__salt) 
1125 __THROW __nonnull ((1, 2)); 
1126#endif 
1127 
1128#ifdef __USE_XOPEN 
1129/* Swab pairs bytes in the first N bytes of the area pointed to by 
1130 FROM and copy the result to TO. The value of TO must not be in the 
1131 range [FROM - N + 1, FROM - 1]. If N is odd the first byte in FROM 
1132 is without partner. */ 
1133extern void swab (const void *__restrict __from, void *__restrict __to, 
1134 ssize_t __n) __THROW __nonnull ((1, 2)); 
1135#endif 
1136 
1137 
1138/* Prior to Issue 6, the Single Unix Specification required these 
1139 prototypes to appear in this header. They are also found in 
1140 <stdio.h>. */ 
1141#if defined __USE_XOPEN && !defined __USE_XOPEN2K 
1142/* Return the name of the controlling terminal. */ 
1143extern char *ctermid (char *__s) __THROW; 
1144 
1145/* Return the name of the current user. */ 
1146extern char *cuserid (char *__s); 
1147#endif 
1148 
1149 
1150/* Unix98 requires this function to be declared here. In other 
1151 standards it is in <pthread.h>. */ 
1152#if defined __USE_UNIX98 && !defined __USE_XOPEN2K 
1153extern int pthread_atfork (void (*__prepare) (void), 
1154 void (*__parent) (void), 
1155 void (*__child) (void)) __THROW; 
1156#endif 
1157 
1158#ifdef __USE_MISC 
1159/* Write LENGTH bytes of randomness starting at BUFFER. Return 0 on 
1160 success or -1 on error. */ 
1161int getentropy (void *__buffer, size_t __length) __wur; 
1162#endif 
1163 
1164/* Define some macros helping to catch buffer overflows. */ 
1165#if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function 
1166# include <bits/unistd.h> 
1167#endif 
1168 
1169/* System-specific extensions. */ 
1170#include <bits/unistd_ext.h> 
1171 
1172__END_DECLS 
1173 
1174#endif /* unistd.h */ 
1175