1/* Copyright (C) 1991-2022 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 __fortified_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 __fortified_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 __fortified_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 __fortified_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 
533#ifdef __USE_GNU 
534/* Return a malloc'd string containing the current directory name. 
535 If the environment variable `PWD' is set, and its value is correct, 
536 that value is used. */ 
537extern char *get_current_dir_name (void) __THROW; 
538#endif 
539 
540#if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \ 
541 || defined __USE_MISC 
542/* Put the absolute pathname of the current working directory in BUF. 
543 If successful, return BUF. If not, put an error message in 
544 BUF and return NULL. BUF should be at least PATH_MAX bytes long. */ 
545extern char *getwd (char *__buf) 
546 __THROW __nonnull ((1)) __attribute_deprecated__ __wur 
547 __attr_access ((__write_only__, 1)); 
548#endif 
549 
550 
551/* Duplicate FD, returning a new file descriptor on the same file. */ 
552extern int dup (int __fd) __THROW __wur; 
553 
554/* Duplicate FD to FD2, closing FD2 and making it open on the same file. */ 
555extern int dup2 (int __fd, int __fd2) __THROW; 
556 
557#ifdef __USE_GNU 
558/* Duplicate FD to FD2, closing FD2 and making it open on the same 
559 file while setting flags according to FLAGS. */ 
560extern int dup3 (int __fd, int __fd2, int __flags) __THROW; 
561#endif 
562 
563/* NULL-terminated array of "NAME=VALUE" environment variables. */ 
564extern char **__environ; 
565#ifdef __USE_GNU 
566extern char **environ; 
567#endif 
568 
569 
570/* Replace the current process, executing PATH with arguments ARGV and 
571 environment ENVP. ARGV and ENVP are terminated by NULL pointers. */ 
572extern int execve (const char *__path, char *const __argv[], 
573 char *const __envp[]) __THROW __nonnull ((1, 2)); 
574 
575#ifdef __USE_XOPEN2K8 
576/* Execute the file FD refers to, overlaying the running program image. 
577 ARGV and ENVP are passed to the new program, as for `execve'. */ 
578extern int fexecve (int __fd, char *const __argv[], char *const __envp[]) 
579 __THROW __nonnull ((2)); 
580#endif 
581 
582 
583/* Execute PATH with arguments ARGV and environment from `environ'. */ 
584extern int execv (const char *__path, char *const __argv[]) 
585 __THROW __nonnull ((1, 2)); 
586 
587/* Execute PATH with all arguments after PATH until a NULL pointer, 
588 and the argument after that for environment. */ 
589extern int execle (const char *__path, const char *__arg, ...) 
590 __THROW __nonnull ((1, 2)); 
591 
592/* Execute PATH with all arguments after PATH until 
593 a NULL pointer and environment from `environ'. */ 
594extern int execl (const char *__path, const char *__arg, ...) 
595 __THROW __nonnull ((1, 2)); 
596 
597/* Execute FILE, searching in the `PATH' environment variable if it contains 
598 no slashes, with arguments ARGV and environment from `environ'. */ 
599extern int execvp (const char *__file, char *const __argv[]) 
600 __THROW __nonnull ((1, 2)); 
601 
602/* Execute FILE, searching in the `PATH' environment variable if 
603 it contains no slashes, with all arguments after FILE until a 
604 NULL pointer and environment from `environ'. */ 
605extern int execlp (const char *__file, const char *__arg, ...) 
606 __THROW __nonnull ((1, 2)); 
607 
608#ifdef __USE_GNU 
609/* Execute FILE, searching in the `PATH' environment variable if it contains 
610 no slashes, with arguments ARGV and environment from `environ'. */ 
611extern int execvpe (const char *__file, char *const __argv[], 
612 char *const __envp[]) 
613 __THROW __nonnull ((1, 2)); 
614#endif 
615 
616 
617#if defined __USE_MISC || defined __USE_XOPEN 
618/* Add INC to priority of the current process. */ 
619extern int nice (int __inc) __THROW __wur; 
620#endif 
621 
622 
623/* Terminate program execution with the low-order 8 bits of STATUS. */ 
624extern void _exit (int __status) __attribute__ ((__noreturn__)); 
625 
626 
627/* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf'; 
628 the `_SC_*' symbols for the NAME argument to `sysconf'; 
629 and the `_CS_*' symbols for the NAME argument to `confstr'. */ 
630#include <bits/confname.h> 
631 
632/* Get file-specific configuration information about PATH. */ 
633extern long int pathconf (const char *__path, int __name) 
634 __THROW __nonnull ((1)); 
635 
636/* Get file-specific configuration about descriptor FD. */ 
637extern long int fpathconf (int __fd, int __name) __THROW; 
638 
639/* Get the value of the system variable NAME. */ 
640extern long int sysconf (int __name) __THROW; 
641 
642#ifdef __USE_POSIX2 
643/* Get the value of the string-valued system variable NAME. */ 
644extern size_t confstr (int __name, char *__buf, size_t __len) __THROW 
645 __fortified_attr_access (__write_only__, 2, 3); 
646#endif 
647 
648 
649/* Get the process ID of the calling process. */ 
650extern __pid_t getpid (void) __THROW; 
651 
652/* Get the process ID of the calling process's parent. */ 
653extern __pid_t getppid (void) __THROW; 
654 
655/* Get the process group ID of the calling process. */ 
656extern __pid_t getpgrp (void) __THROW; 
657 
658/* Get the process group ID of process PID. */ 
659extern __pid_t __getpgid (__pid_t __pid) __THROW; 
660#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8 
661extern __pid_t getpgid (__pid_t __pid) __THROW; 
662#endif 
663 
664 
665/* Set the process group ID of the process matching PID to PGID. 
666 If PID is zero, the current process's process group ID is set. 
667 If PGID is zero, the process ID of the process is used. */ 
668extern int setpgid (__pid_t __pid, __pid_t __pgid) __THROW; 
669 
670#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED 
671/* Both System V and BSD have `setpgrp' functions, but with different 
672 calling conventions. The BSD function is the same as POSIX.1 `setpgid' 
673 (above). The System V function takes no arguments and puts the calling 
674 process in its on group like `setpgid (0, 0)'. 
675 
676 New programs should always use `setpgid' instead. 
677 
678 GNU provides the POSIX.1 function. */ 
679 
680/* Set the process group ID of the calling process to its own PID. 
681 This is exactly the same as `setpgid (0, 0)'. */ 
682extern int setpgrp (void) __THROW; 
683 
684#endif /* Use misc or X/Open. */ 
685 
686/* Create a new session with the calling process as its leader. 
687 The process group IDs of the session and the calling process 
688 are set to the process ID of the calling process, which is returned. */ 
689extern __pid_t setsid (void) __THROW; 
690 
691#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8 
692/* Return the session ID of the given process. */ 
693extern __pid_t getsid (__pid_t __pid) __THROW; 
694#endif 
695 
696/* Get the real user ID of the calling process. */ 
697extern __uid_t getuid (void) __THROW; 
698 
699/* Get the effective user ID of the calling process. */ 
700extern __uid_t geteuid (void) __THROW; 
701 
702/* Get the real group ID of the calling process. */ 
703extern __gid_t getgid (void) __THROW; 
704 
705/* Get the effective group ID of the calling process. */ 
706extern __gid_t getegid (void) __THROW; 
707 
708/* If SIZE is zero, return the number of supplementary groups 
709 the calling process is in. Otherwise, fill in the group IDs 
710 of its supplementary groups in LIST and return the number written. */ 
711extern int getgroups (int __size, __gid_t __list[]) __THROW __wur 
712 __fortified_attr_access (__write_only__, 2, 1); 
713#ifdef __USE_GNU 
714/* Return nonzero iff the calling process is in group GID. */ 
715extern int group_member (__gid_t __gid) __THROW; 
716#endif 
717 
718/* Set the user ID of the calling process to UID. 
719 If the calling process is the super-user, set the real 
720 and effective user IDs, and the saved set-user-ID to UID; 
721 if not, the effective user ID is set to UID. */ 
722extern int setuid (__uid_t __uid) __THROW __wur; 
723 
724#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED 
725/* Set the real user ID of the calling process to RUID, 
726 and the effective user ID of the calling process to EUID. */ 
727extern int setreuid (__uid_t __ruid, __uid_t __euid) __THROW __wur; 
728#endif 
729 
730#ifdef __USE_XOPEN2K 
731/* Set the effective user ID of the calling process to UID. */ 
732extern int seteuid (__uid_t __uid) __THROW __wur; 
733#endif /* Use POSIX.1-2001. */ 
734 
735/* Set the group ID of the calling process to GID. 
736 If the calling process is the super-user, set the real 
737 and effective group IDs, and the saved set-group-ID to GID; 
738 if not, the effective group ID is set to GID. */ 
739extern int setgid (__gid_t __gid) __THROW __wur; 
740 
741#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED 
742/* Set the real group ID of the calling process to RGID, 
743 and the effective group ID of the calling process to EGID. */ 
744extern int setregid (__gid_t __rgid, __gid_t __egid) __THROW __wur; 
745#endif 
746 
747#ifdef __USE_XOPEN2K 
748/* Set the effective group ID of the calling process to GID. */ 
749extern int setegid (__gid_t __gid) __THROW __wur; 
750#endif /* Use POSIX.1-2001. */ 
751 
752#ifdef __USE_GNU 
753/* Fetch the real user ID, effective user ID, and saved-set user ID, 
754 of the calling process. */ 
755extern int getresuid (__uid_t *__ruid, __uid_t *__euid, __uid_t *__suid) 
756 __THROW; 
757 
758/* Fetch the real group ID, effective group ID, and saved-set group ID, 
759 of the calling process. */ 
760extern int getresgid (__gid_t *__rgid, __gid_t *__egid, __gid_t *__sgid) 
761 __THROW; 
762 
763/* Set the real user ID, effective user ID, and saved-set user ID, 
764 of the calling process to RUID, EUID, and SUID, respectively. */ 
765extern int setresuid (__uid_t __ruid, __uid_t __euid, __uid_t __suid) 
766 __THROW __wur; 
767 
768/* Set the real group ID, effective group ID, and saved-set group ID, 
769 of the calling process to RGID, EGID, and SGID, respectively. */ 
770extern int setresgid (__gid_t __rgid, __gid_t __egid, __gid_t __sgid) 
771 __THROW __wur; 
772#endif 
773 
774 
775/* Clone the calling process, creating an exact copy. 
776 Return -1 for errors, 0 to the new process, 
777 and the process ID of the new process to the old process. */ 
778extern __pid_t fork (void) __THROWNL; 
779 
780#if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \ 
781 || defined __USE_MISC 
782/* Clone the calling process, but without copying the whole address space. 
783 The calling process is suspended until the new process exits or is 
784 replaced by a call to `execve'. Return -1 for errors, 0 to the new process, 
785 and the process ID of the new process to the old process. */ 
786extern __pid_t vfork (void) __THROW; 
787#endif /* Use misc or XPG < 7. */ 
788 
789#ifdef __USE_GNU 
790/* This is similar to fork, however it does not run the atfork handlers 
791 neither reinitialize any internal locks in multithread case. 
792 Different than fork, _Fork is async-signal-safe. */ 
793extern __pid_t _Fork (void) __THROW; 
794#endif 
795 
796 
797/* Return the pathname of the terminal FD is open on, or NULL on errors. 
798 The returned storage is good only until the next call to this function. */ 
799extern char *ttyname (int __fd) __THROW; 
800 
801/* Store at most BUFLEN characters of the pathname of the terminal FD is 
802 open on in BUF. Return 0 on success, otherwise an error number. */ 
803extern int ttyname_r (int __fd, char *__buf, size_t __buflen) 
804 __THROW __nonnull ((2)) __wur 
805 __fortified_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 
841 __fortified_attr_access (__write_only__, 2, 3); 
842 
843#endif /* Use POSIX.1-2001. */ 
844 
845#ifdef __USE_ATFILE 
846/* Like symlink but a relative path in TO is interpreted relative to TOFD. */ 
847extern int symlinkat (const char *__from, int __tofd, 
848 const char *__to) __THROW __nonnull ((1, 3)) __wur; 
849 
850/* Like readlink but a relative PATH is interpreted relative to FD. */ 
851extern ssize_t readlinkat (int __fd, const char *__restrict __path, 
852 char *__restrict __buf, size_t __len) 
853 __THROW __nonnull ((2, 3)) __wur 
854 __fortified_attr_access (__write_only__, 3, 4); 
855#endif 
856 
857/* Remove the link NAME. */ 
858extern int unlink (const char *__name) __THROW __nonnull ((1)); 
859 
860#ifdef __USE_ATFILE 
861/* Remove the link NAME relative to FD. */ 
862extern int unlinkat (int __fd, const char *__name, int __flag) 
863 __THROW __nonnull ((2)); 
864#endif 
865 
866/* Remove the directory PATH. */ 
867extern int rmdir (const char *__path) __THROW __nonnull ((1)); 
868 
869 
870/* Return the foreground process group ID of FD. */ 
871extern __pid_t tcgetpgrp (int __fd) __THROW; 
872 
873/* Set the foreground process group ID of FD set PGRP_ID. */ 
874extern int tcsetpgrp (int __fd, __pid_t __pgrp_id) __THROW; 
875 
876 
877/* Return the login name of the user. 
878 
879 This function is a possible cancellation point and therefore not 
880 marked with __THROW. */ 
881extern char *getlogin (void); 
882#ifdef __USE_POSIX199506 
883/* Return at most NAME_LEN characters of the login name of the user in NAME. 
884 If it cannot be determined or some other error occurred, return the error 
885 code. Otherwise return 0. 
886 
887 This function is a possible cancellation point and therefore not 
888 marked with __THROW. */ 
889extern int getlogin_r (char *__name, size_t __name_len) __nonnull ((1)) 
890 __fortified_attr_access (__write_only__, 1, 2); 
891#endif 
892 
893#ifdef __USE_MISC 
894/* Set the login name returned by `getlogin'. */ 
895extern int setlogin (const char *__name) __THROW __nonnull ((1)); 
896#endif 
897 
898 
899#ifdef __USE_POSIX2 
900/* Get definitions and prototypes for functions to process the 
901 arguments in ARGV (ARGC of them, minus the program name) for 
902 options given in OPTS. */ 
903# include <bits/getopt_posix.h> 
904#endif 
905 
906 
907#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K 
908/* Put the name of the current host in no more than LEN bytes of NAME. 
909 The result is null-terminated if LEN is large enough for the full 
910 name and the terminator. */ 
911extern int gethostname (char *__name, size_t __len) __THROW __nonnull ((1)) 
912 __fortified_attr_access (__write_only__, 1, 2); 
913#endif 
914 
915 
916#if defined __USE_MISC 
917/* Set the name of the current host to NAME, which is LEN bytes long. 
918 This call is restricted to the super-user. */ 
919extern int sethostname (const char *__name, size_t __len) 
920 __THROW __nonnull ((1)) __wur __attr_access ((__read_only__, 1, 2)); 
921 
922/* Set the current machine's Internet number to ID. 
923 This call is restricted to the super-user. */ 
924extern int sethostid (long int __id) __THROW __wur; 
925 
926 
927/* Get and set the NIS (aka YP) domain name, if any. 
928 Called just like `gethostname' and `sethostname'. 
929 The NIS domain name is usually the empty string when not using NIS. */ 
930extern int getdomainname (char *__name, size_t __len) 
931 __THROW __nonnull ((1)) __wur 
932 __fortified_attr_access (__write_only__, 1, 2); 
933extern int setdomainname (const char *__name, size_t __len) 
934 __THROW __nonnull ((1)) __wur __attr_access ((__read_only__, 1, 2)); 
935 
936/* Revoke access permissions to all processes currently communicating 
937 with the control terminal, and then send a SIGHUP signal to the process 
938 group of the control terminal. */ 
939extern int vhangup (void) __THROW; 
940 
941/* Revoke the access of all descriptors currently open on FILE. */ 
942extern int revoke (const char *__file) __THROW __nonnull ((1)) __wur; 
943 
944 
945/* Enable statistical profiling, writing samples of the PC into at most 
946 SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling 
947 is enabled, the system examines the user PC and increments 
948 SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536]. If SCALE is zero, 
949 disable profiling. Returns zero on success, -1 on error. */ 
950extern int profil (unsigned short int *__sample_buffer, size_t __size, 
951 size_t __offset, unsigned int __scale) 
952 __THROW __nonnull ((1)); 
953 
954 
955/* Turn accounting on if NAME is an existing file. The system will then write 
956 a record for each process as it terminates, to this file. If NAME is NULL, 
957 turn accounting off. This call is restricted to the super-user. */ 
958extern int acct (const char *__name) __THROW; 
959 
960 
961/* Successive calls return the shells listed in `/etc/shells'. */ 
962extern char *getusershell (void) __THROW; 
963extern void endusershell (void) __THROW; /* Discard cached info. */ 
964extern void setusershell (void) __THROW; /* Rewind and re-read the file. */ 
965 
966 
967/* Put the program in the background, and dissociate from the controlling 
968 terminal. If NOCHDIR is zero, do `chdir ("/")'. If NOCLOSE is zero, 
969 redirects stdin, stdout, and stderr to /dev/null. */ 
970extern int daemon (int __nochdir, int __noclose) __THROW __wur; 
971#endif /* Use misc. */ 
972 
973 
974#if defined __USE_MISC || (defined __USE_XOPEN && !defined __USE_XOPEN2K) 
975/* Make PATH be the root directory (the starting point for absolute paths). 
976 This call is restricted to the super-user. */ 
977extern int chroot (const char *__path) __THROW __nonnull ((1)) __wur; 
978 
979/* Prompt with PROMPT and read a string from the terminal without echoing. 
980 Uses /dev/tty if possible; otherwise stderr and stdin. */ 
981extern char *getpass (const char *__prompt) __nonnull ((1)); 
982#endif /* Use misc || X/Open. */ 
983 
984 
985/* Make all changes done to FD actually appear on disk. 
986 
987 This function is a cancellation point and therefore not marked with 
988 __THROW. */ 
989extern int fsync (int __fd); 
990 
991 
992#ifdef __USE_GNU 
993/* Make all changes done to all files on the file system associated 
994 with FD actually appear on disk. */ 
995extern int syncfs (int __fd) __THROW; 
996#endif 
997 
998 
999#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED 
1000 
1001/* Return identifier for the current host. */ 
1002extern long int gethostid (void); 
1003 
1004/* Make all changes done to all files actually appear on disk. */ 
1005extern void sync (void) __THROW; 
1006 
1007 
1008# if defined __USE_MISC || !defined __USE_XOPEN2K 
1009/* Return the number of bytes in a page. This is the system's page size, 
1010 which is not necessarily the same as the hardware page size. */ 
1011extern int getpagesize (void) __THROW __attribute__ ((__const__)); 
1012 
1013 
1014/* Return the maximum number of file descriptors 
1015 the current process could possibly have. */ 
1016extern int getdtablesize (void) __THROW; 
1017# endif 
1018 
1019#endif /* Use misc || X/Open Unix. */ 
1020 
1021 
1022#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8 
1023 
1024/* Truncate FILE to LENGTH bytes. */ 
1025# ifndef __USE_FILE_OFFSET64 
1026extern int truncate (const char *__file, __off_t __length) 
1027 __THROW __nonnull ((1)) __wur; 
1028# else 
1029# ifdef __REDIRECT_NTH 
1030extern int __REDIRECT_NTH (truncate, 
1031 (const char *__file, __off64_t __length), 
1032 truncate64) __nonnull ((1)) __wur; 
1033# else 
1034# define truncate truncate64 
1035# endif 
1036# endif 
1037# ifdef __USE_LARGEFILE64 
1038extern int truncate64 (const char *__file, __off64_t __length) 
1039 __THROW __nonnull ((1)) __wur; 
1040# endif 
1041 
1042#endif /* Use X/Open Unix || POSIX 2008. */ 
1043 
1044#if defined __USE_POSIX199309 \ 
1045 || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K 
1046 
1047/* Truncate the file FD is open on to LENGTH bytes. */ 
1048# ifndef __USE_FILE_OFFSET64 
1049extern int ftruncate (int __fd, __off_t __length) __THROW __wur; 
1050# else 
1051# ifdef __REDIRECT_NTH 
1052extern int __REDIRECT_NTH (ftruncate, (int __fd, __off64_t __length), 
1053 ftruncate64) __wur; 
1054# else 
1055# define ftruncate ftruncate64 
1056# endif 
1057# endif 
1058# ifdef __USE_LARGEFILE64 
1059extern int ftruncate64 (int __fd, __off64_t __length) __THROW __wur; 
1060# endif 
1061 
1062#endif /* Use POSIX.1b || X/Open Unix || XPG6. */ 
1063 
1064 
1065#if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K) \ 
1066 || defined __USE_MISC 
1067 
1068/* Set the end of accessible data space (aka "the break") to ADDR. 
1069 Returns zero on success and -1 for errors (with errno set). */ 
1070extern int brk (void *__addr) __THROW __wur; 
1071 
1072/* Increase or decrease the end of accessible data space by DELTA bytes. 
1073 If successful, returns the address the previous end of data space 
1074 (i.e. the beginning of the new space, if DELTA > 0); 
1075 returns (void *) -1 for errors (with errno set). */ 
1076extern void *sbrk (intptr_t __delta) __THROW; 
1077#endif 
1078 
1079 
1080#ifdef __USE_MISC 
1081/* Invoke `system call' number SYSNO, passing it the remaining arguments. 
1082 This is completely system-dependent, and not often useful. 
1083 
1084 In Unix, `syscall' sets `errno' for all errors and most calls return -1 
1085 for errors; in many systems you cannot pass arguments or get return 
1086 values for all system calls (`pipe', `fork', and `getppid' typically 
1087 among them). 
1088 
1089 In Mach, all system calls take normal arguments and always return an 
1090 error code (zero for success). */ 
1091extern long int syscall (long int __sysno, ...) __THROW; 
1092 
1093#endif /* Use misc. */ 
1094 
1095 
1096#if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK 
1097/* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both 
1098 files consistent. Some systems have them there and some here, and some 
1099 software depends on the macros being defined without including both. */ 
1100 
1101/* `lockf' is a simpler interface to the locking facilities of `fcntl'. 
1102 LEN is always relative to the current file position. 
1103 The CMD argument is one of the following. 
1104 
1105 This function is a cancellation point and therefore not marked with 
1106 __THROW. */ 
1107 
1108# define F_ULOCK 0 /* Unlock a previously locked region. */ 
1109# define F_LOCK 1 /* Lock a region for exclusive use. */ 
1110# define F_TLOCK 2 /* Test and lock a region for exclusive use. */ 
1111# define F_TEST 3 /* Test a region for other processes locks. */ 
1112 
1113# ifndef __USE_FILE_OFFSET64 
1114extern int lockf (int __fd, int __cmd, __off_t __len) __wur; 
1115# else 
1116# ifdef __REDIRECT 
1117extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len), 
1118 lockf64) __wur; 
1119# else 
1120# define lockf lockf64 
1121# endif 
1122# endif 
1123# ifdef __USE_LARGEFILE64 
1124extern int lockf64 (int __fd, int __cmd, __off64_t __len) __wur; 
1125# endif 
1126#endif /* Use misc and F_LOCK not already defined. */ 
1127 
1128 
1129#ifdef __USE_GNU 
1130 
1131/* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno' 
1132 set to EINTR. */ 
1133 
1134# define TEMP_FAILURE_RETRY(expression) \ 
1135 (__extension__ \ 
1136 ({ long int __result; \ 
1137 do __result = (long int) (expression); \ 
1138 while (__result == -1L && errno == EINTR); \ 
1139 __result; })) 
1140 
1141/* Copy LENGTH bytes from INFD to OUTFD. */ 
1142ssize_t copy_file_range (int __infd, __off64_t *__pinoff, 
1143 int __outfd, __off64_t *__poutoff, 
1144 size_t __length, unsigned int __flags); 
1145#endif /* __USE_GNU */ 
1146 
1147#if defined __USE_POSIX199309 || defined __USE_UNIX98 
1148/* Synchronize at least the data part of a file with the underlying 
1149 media. */ 
1150extern int fdatasync (int __fildes); 
1151#endif /* Use POSIX199309 */ 
1152 
1153#ifdef __USE_MISC 
1154/* One-way hash PHRASE, returning a string suitable for storage in the 
1155 user database. SALT selects the one-way function to use, and 
1156 ensures that no two users' hashes are the same, even if they use 
1157 the same passphrase. The return value points to static storage 
1158 which will be overwritten by the next call to crypt. */ 
1159extern char *crypt (const char *__key, const char *__salt) 
1160 __THROW __nonnull ((1, 2)); 
1161#endif 
1162 
1163#ifdef __USE_XOPEN 
1164/* Swab pairs bytes in the first N bytes of the area pointed to by 
1165 FROM and copy the result to TO. The value of TO must not be in the 
1166 range [FROM - N + 1, FROM - 1]. If N is odd the first byte in FROM 
1167 is without partner. */ 
1168extern void swab (const void *__restrict __from, void *__restrict __to, 
1169 ssize_t __n) __THROW __nonnull ((1, 2)) 
1170 __attr_access ((__read_only__, 1, 3)) 
1171 __attr_access ((__write_only__, 2, 3)); 
1172#endif 
1173 
1174 
1175/* Prior to Issue 6, the Single Unix Specification required these 
1176 prototypes to appear in this header. They are also found in 
1177 <stdio.h>. */ 
1178#if defined __USE_XOPEN && !defined __USE_XOPEN2K 
1179/* Return the name of the controlling terminal. */ 
1180extern char *ctermid (char *__s) __THROW; 
1181 
1182/* Return the name of the current user. */ 
1183extern char *cuserid (char *__s); 
1184#endif 
1185 
1186 
1187/* Unix98 requires this function to be declared here. In other 
1188 standards it is in <pthread.h>. */ 
1189#if defined __USE_UNIX98 && !defined __USE_XOPEN2K 
1190extern int pthread_atfork (void (*__prepare) (void), 
1191 void (*__parent) (void), 
1192 void (*__child) (void)) __THROW; 
1193#endif 
1194 
1195#ifdef __USE_MISC 
1196/* Write LENGTH bytes of randomness starting at BUFFER. Return 0 on 
1197 success or -1 on error. */ 
1198int getentropy (void *__buffer, size_t __length) __wur 
1199 __attr_access ((__write_only__, 1, 2)); 
1200#endif 
1201 
1202#ifdef __USE_GNU 
1203/* Close all file descriptors in the range FD up to MAX_FD. The flag FLAGS 
1204 are define by the CLOSE_RANGE prefix. This function behaves like close 
1205 on the range and gaps where the file descriptor is invalid or errors 
1206 encountered while closing file descriptors are ignored. Returns 0 on 
1207 successor or -1 for failure (and sets errno accordingly). */ 
1208extern int close_range (unsigned int __fd, unsigned int __max_fd, 
1209 int __flags) __THROW; 
1210#endif 
1211 
1212/* Define some macros helping to catch buffer overflows. */ 
1213#if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function 
1214# include <bits/unistd.h> 
1215#endif 
1216 
1217/* System-specific extensions. */ 
1218#include <bits/unistd_ext.h> 
1219 
1220__END_DECLS 
1221 
1222#endif /* unistd.h */ 
1223