1    	/* Copyright (C) 1991-2009, 2010 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, write to the Free
16   	   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
17   	   02111-1307 USA.  */
18   	
19   	/*
20   	 *	POSIX Standard: 2.10 Symbolic Constants		<unistd.h>
21   	 */
22   	
23   	#ifndef	_UNISTD_H
24   	#define	_UNISTD_H	1
25   	
26   	#include <features.h>
27   	
28   	__BEGIN_DECLS
29   	
30   	/* These may be used to determine what facilities are present at compile time.
31   	   Their values can be obtained at run time from `sysconf'.  */
32   	
33   	#ifdef __USE_XOPEN2K8
34   	/* POSIX Standard approved as ISO/IEC 9945-1 as of September 2008.  */
35   	# define _POSIX_VERSION	200809L
36   	#elif defined __USE_XOPEN2K
37   	/* POSIX Standard approved as ISO/IEC 9945-1 as of December 2001.  */
38   	# define _POSIX_VERSION	200112L
39   	#elif defined __USE_POSIX199506
40   	/* POSIX Standard approved as ISO/IEC 9945-1 as of June 1995.  */
41   	# define _POSIX_VERSION	199506L
42   	#elif defined __USE_POSIX199309
43   	/* POSIX Standard approved as ISO/IEC 9945-1 as of September 1993.  */
44   	# define _POSIX_VERSION	199309L
45   	#else
46   	/* POSIX Standard approved as ISO/IEC 9945-1 as of September 1990.  */
47   	# define _POSIX_VERSION	199009L
48   	#endif
49   	
50   	/* These are not #ifdef __USE_POSIX2 because they are
51   	   in the theoretically application-owned namespace.  */
52   	
53   	#ifdef __USE_XOPEN2K8
54   	# define __POSIX2_THIS_VERSION	200809L
55   	/* The utilities on GNU systems also correspond to this version.  */
56   	#elif defined __USE_XOPEN2K
57   	/* The utilities on GNU systems also correspond to this version.  */
58   	# define __POSIX2_THIS_VERSION	200112L
59   	#elif defined __USE_POSIX199506
60   	/* The utilities on GNU systems also correspond to this version.  */
61   	# define __POSIX2_THIS_VERSION	199506L
62   	#else
63   	/* The utilities on GNU systems also correspond to this version.  */
64   	# define __POSIX2_THIS_VERSION	199209L
65   	#endif
66   	
67   	/* The utilities on GNU systems also correspond to this version.  */
68   	#define _POSIX2_VERSION	__POSIX2_THIS_VERSION
69   	
70   	/* If defined, the implementation supports the
71   	   C Language Bindings Option.  */
72   	#define	_POSIX2_C_BIND	__POSIX2_THIS_VERSION
73   	
74   	/* If defined, the implementation supports the
75   	   C Language Development Utilities Option.  */
76   	#define	_POSIX2_C_DEV	__POSIX2_THIS_VERSION
77   	
78   	/* If defined, the implementation supports the
79   	   Software Development Utilities Option.  */
80   	#define	_POSIX2_SW_DEV	__POSIX2_THIS_VERSION
81   	
82   	/* If defined, the implementation supports the
83   	   creation of locales with the localedef utility.  */
84   	#define _POSIX2_LOCALEDEF       __POSIX2_THIS_VERSION
85   	
86   	/* X/Open version number to which the library conforms.  It is selectable.  */
87   	#ifdef __USE_XOPEN2K8
88   	# define _XOPEN_VERSION	700
89   	#elif defined __USE_XOPEN2K
90   	# define _XOPEN_VERSION	600
91   	#elif defined __USE_UNIX98
92   	# define _XOPEN_VERSION	500
93   	#else
94   	# define _XOPEN_VERSION	4
95   	#endif
96   	
97   	/* Commands and utilities from XPG4 are available.  */
98   	#define _XOPEN_XCU_VERSION	4
99   	
100  	/* We are compatible with the old published standards as well.  */
101  	#define _XOPEN_XPG2	1
102  	#define _XOPEN_XPG3	1
103  	#define _XOPEN_XPG4	1
104  	
105  	/* The X/Open Unix extensions are available.  */
106  	#define _XOPEN_UNIX	1
107  	
108  	/* Encryption is present.  */
109  	#define	_XOPEN_CRYPT	1
110  	
111  	/* The enhanced internationalization capabilities according to XPG4.2
112  	   are present.  */
113  	#define	_XOPEN_ENH_I18N	1
114  	
115  	/* The legacy interfaces are also available.  */
116  	#define _XOPEN_LEGACY	1
117  	
118  	
119  	/* Get values of POSIX options:
120  	
121  	   If these symbols are defined, the corresponding features are
122  	   always available.  If not, they may be available sometimes.
123  	   The current values can be obtained with `sysconf'.
124  	
125  	   _POSIX_JOB_CONTROL		Job control is supported.
126  	   _POSIX_SAVED_IDS		Processes have a saved set-user-ID
127  					and a saved set-group-ID.
128  	   _POSIX_REALTIME_SIGNALS	Real-time, queued signals are supported.
129  	   _POSIX_PRIORITY_SCHEDULING	Priority scheduling is supported.
130  	   _POSIX_TIMERS		POSIX.4 clocks and timers are supported.
131  	   _POSIX_ASYNCHRONOUS_IO	Asynchronous I/O is supported.
132  	   _POSIX_PRIORITIZED_IO	Prioritized asynchronous I/O is supported.
133  	   _POSIX_SYNCHRONIZED_IO	Synchronizing file data is supported.
134  	   _POSIX_FSYNC			The fsync function is present.
135  	   _POSIX_MAPPED_FILES		Mapping of files to memory is supported.
136  	   _POSIX_MEMLOCK		Locking of all memory is supported.
137  	   _POSIX_MEMLOCK_RANGE		Locking of ranges of memory is supported.
138  	   _POSIX_MEMORY_PROTECTION	Setting of memory protections is supported.
139  	   _POSIX_MESSAGE_PASSING	POSIX.4 message queues are supported.
140  	   _POSIX_SEMAPHORES		POSIX.4 counting semaphores are supported.
141  	   _POSIX_SHARED_MEMORY_OBJECTS	POSIX.4 shared memory objects are supported.
142  	   _POSIX_THREADS		POSIX.1c pthreads are supported.
143  	   _POSIX_THREAD_ATTR_STACKADDR	Thread stack address attribute option supported.
144  	   _POSIX_THREAD_ATTR_STACKSIZE	Thread stack size attribute option supported.
145  	   _POSIX_THREAD_SAFE_FUNCTIONS	Thread-safe functions are supported.
146  	   _POSIX_THREAD_PRIORITY_SCHEDULING
147  					POSIX.1c thread execution scheduling supported.
148  	   _POSIX_THREAD_PRIO_INHERIT	Thread priority inheritance option supported.
149  	   _POSIX_THREAD_PRIO_PROTECT	Thread priority protection option supported.
150  	   _POSIX_THREAD_PROCESS_SHARED	Process-shared synchronization supported.
151  	   _POSIX_PII			Protocol-independent interfaces are supported.
152  	   _POSIX_PII_XTI		XTI protocol-indep. interfaces are supported.
153  	   _POSIX_PII_SOCKET		Socket protocol-indep. interfaces are supported.
154  	   _POSIX_PII_INTERNET		Internet family of protocols supported.
155  	   _POSIX_PII_INTERNET_STREAM	Connection-mode Internet protocol supported.
156  	   _POSIX_PII_INTERNET_DGRAM	Connectionless Internet protocol supported.
157  	   _POSIX_PII_OSI		ISO/OSI family of protocols supported.
158  	   _POSIX_PII_OSI_COTS		Connection-mode ISO/OSI service supported.
159  	   _POSIX_PII_OSI_CLTS		Connectionless ISO/OSI service supported.
160  	   _POSIX_POLL			Implementation supports `poll' function.
161  	   _POSIX_SELECT		Implementation supports `select' and `pselect'.
162  	
163  	   _XOPEN_REALTIME		X/Open realtime support is available.
164  	   _XOPEN_REALTIME_THREADS	X/Open realtime thread support is available.
165  	   _XOPEN_SHM			Shared memory interface according to XPG4.2.
166  	
167  	   _XBS5_ILP32_OFF32		Implementation provides environment with 32-bit
168  					int, long, pointer, and off_t types.
169  	   _XBS5_ILP32_OFFBIG		Implementation provides environment with 32-bit
170  					int, long, and pointer and off_t with at least
171  					64 bits.
172  	   _XBS5_LP64_OFF64		Implementation provides environment with 32-bit
173  					int, and 64-bit long, pointer, and off_t types.
174  	   _XBS5_LPBIG_OFFBIG		Implementation provides environment with at
175  					least 32 bits int and long, pointer, and off_t
176  					with at least 64 bits.
177  	
178  	   If any of these symbols is defined as -1, the corresponding option is not
179  	   true for any file.  If any is defined as other than -1, the corresponding
180  	   option is true for all files.  If a symbol is not defined at all, the value
181  	   for a specific file can be obtained from `pathconf' and `fpathconf'.
182  	
183  	   _POSIX_CHOWN_RESTRICTED	Only the super user can use `chown' to change
184  					the owner of a file.  `chown' can only be used
185  					to change the group ID of a file to a group of
186  					which the calling process is a member.
187  	   _POSIX_NO_TRUNC		Pathname components longer than
188  					NAME_MAX generate an error.
189  	   _POSIX_VDISABLE		If defined, if the value of an element of the
190  					`c_cc' member of `struct termios' is
191  					_POSIX_VDISABLE, no character will have the
192  					effect associated with that element.
193  	   _POSIX_SYNC_IO		Synchronous I/O may be performed.
194  	   _POSIX_ASYNC_IO		Asynchronous I/O may be performed.
195  	   _POSIX_PRIO_IO		Prioritized Asynchronous I/O may be performed.
196  	
197  	   Support for the Large File Support interface is not generally available.
198  	   If it is available the following constants are defined to one.
199  	   _LFS64_LARGEFILE		Low-level I/O supports large files.
200  	   _LFS64_STDIO			Standard I/O supports large files.
201  	   */
202  	
203  	#include <bits/posix_opt.h>
204  	
205  	/* Get the environment definitions from Unix98.  */
206  	#if defined __USE_UNIX98 || defined __USE_XOPEN2K
207  	# include <bits/environments.h>
208  	#endif
209  	
210  	/* Standard file descriptors.  */
211  	#define	STDIN_FILENO	0	/* Standard input.  */
212  	#define	STDOUT_FILENO	1	/* Standard output.  */
213  	#define	STDERR_FILENO	2	/* Standard error output.  */
214  	
215  	
216  	/* All functions that are not declared anywhere else.  */
217  	
218  	#include <bits/types.h>
219  	
220  	#ifndef	__ssize_t_defined
221  	typedef __ssize_t ssize_t;
222  	# define __ssize_t_defined
223  	#endif
224  	
225  	#define	__need_size_t
226  	#define __need_NULL
227  	#include <stddef.h>
228  	
229  	#if defined __USE_XOPEN || defined __USE_XOPEN2K
230  	/* The Single Unix specification says that some more types are
231  	   available here.  */
232  	# ifndef __gid_t_defined
233  	typedef __gid_t gid_t;
234  	#  define __gid_t_defined
235  	# endif
236  	
237  	# ifndef __uid_t_defined
238  	typedef __uid_t uid_t;
239  	#  define __uid_t_defined
240  	# endif
241  	
242  	# ifndef __off_t_defined
243  	#  ifndef __USE_FILE_OFFSET64
244  	typedef __off_t off_t;
245  	#  else
246  	typedef __off64_t off_t;
247  	#  endif
248  	#  define __off_t_defined
249  	# endif
250  	# if defined __USE_LARGEFILE64 && !defined __off64_t_defined
251  	typedef __off64_t off64_t;
252  	#  define __off64_t_defined
253  	# endif
254  	
255  	# ifndef __useconds_t_defined
256  	typedef __useconds_t useconds_t;
257  	#  define __useconds_t_defined
258  	# endif
259  	
260  	# ifndef __pid_t_defined
261  	typedef __pid_t pid_t;
262  	#  define __pid_t_defined
263  	# endif
264  	#endif	/* X/Open */
265  	
266  	#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
267  	# ifndef __intptr_t_defined
268  	typedef __intptr_t intptr_t;
269  	#  define __intptr_t_defined
270  	# endif
271  	#endif
272  	
273  	#if defined __USE_BSD || defined __USE_XOPEN
274  	# ifndef __socklen_t_defined
275  	typedef __socklen_t socklen_t;
276  	#  define __socklen_t_defined
277  	# endif
278  	#endif
279  	
280  	/* Values for the second argument to access.
281  	   These may be OR'd together.  */
282  	#define	R_OK	4		/* Test for read permission.  */
283  	#define	W_OK	2		/* Test for write permission.  */
284  	#define	X_OK	1		/* Test for execute permission.  */
285  	#define	F_OK	0		/* Test for existence.  */
286  	
287  	/* Test for access to NAME using the real UID and real GID.  */
288  	extern int access (__const char *__name, int __type) __THROW __nonnull ((1));
289  	
290  	#ifdef __USE_GNU
291  	/* Test for access to NAME using the effective UID and GID
292  	   (as normal file operations use).  */
293  	extern int euidaccess (__const char *__name, int __type)
294  	     __THROW __nonnull ((1));
295  	
296  	/* An alias for `euidaccess', used by some other systems.  */
297  	extern int eaccess (__const char *__name, int __type)
298  	     __THROW __nonnull ((1));
299  	#endif
300  	
301  	#ifdef __USE_ATFILE
302  	/* Test for access to FILE relative to the directory FD is open on.
303  	   If AT_EACCESS is set in FLAG, then use effective IDs like `eaccess',
304  	   otherwise use real IDs like `access'.  */
305  	extern int faccessat (int __fd, __const char *__file, int __type, int __flag)
306  	     __THROW __nonnull ((2)) __wur;
307  	#endif /* Use GNU.  */
308  	
309  	
310  	/* Values for the WHENCE argument to lseek.  */
311  	#ifndef	_STDIO_H		/* <stdio.h> has the same definitions.  */
312  	# define SEEK_SET	0	/* Seek from beginning of file.  */
313  	# define SEEK_CUR	1	/* Seek from current position.  */
314  	# define SEEK_END	2	/* Seek from end of file.  */
315  	#endif
316  	
317  	#if defined __USE_BSD && !defined L_SET
318  	/* Old BSD names for the same constants; just for compatibility.  */
319  	# define L_SET		SEEK_SET
320  	# define L_INCR		SEEK_CUR
321  	# define L_XTND		SEEK_END
322  	#endif
323  	
324  	
325  	/* Move FD's file position to OFFSET bytes from the
326  	   beginning of the file (if WHENCE is SEEK_SET),
327  	   the current position (if WHENCE is SEEK_CUR),
328  	   or the end of the file (if WHENCE is SEEK_END).
329  	   Return the new file position.  */
330  	#ifndef __USE_FILE_OFFSET64
331  	extern __off_t lseek (int __fd, __off_t __offset, int __whence) __THROW;
332  	#else
333  	# ifdef __REDIRECT_NTH
334  	extern __off64_t __REDIRECT_NTH (lseek,
335  					 (int __fd, __off64_t __offset, int __whence),
336  					 lseek64);
337  	# else
338  	#  define lseek lseek64
339  	# endif
340  	#endif
341  	#ifdef __USE_LARGEFILE64
342  	extern __off64_t lseek64 (int __fd, __off64_t __offset, int __whence)
343  	     __THROW;
344  	#endif
345  	
346  	/* Close the file descriptor FD.
347  	
348  	   This function is a cancellation point and therefore not marked with
349  	   __THROW.  */
350  	extern int close (int __fd);
351  	
352  	/* Read NBYTES into BUF from FD.  Return the
353  	   number read, -1 for errors or 0 for EOF.
354  	
355  	   This function is a cancellation point and therefore not marked with
356  	   __THROW.  */
357  	extern ssize_t read (int __fd, void *__buf, size_t __nbytes) __wur;
358  	
359  	/* Write N bytes of BUF to FD.  Return the number written, or -1.
360  	
361  	   This function is a cancellation point and therefore not marked with
362  	   __THROW.  */
363  	extern ssize_t write (int __fd, __const void *__buf, size_t __n) __wur;
364  	
365  	#if defined __USE_UNIX98 || defined __USE_XOPEN2K8
366  	# ifndef __USE_FILE_OFFSET64
367  	/* Read NBYTES into BUF from FD at the given position OFFSET without
368  	   changing the file pointer.  Return the number read, -1 for errors
369  	   or 0 for EOF.
370  	
371  	   This function is a cancellation point and therefore not marked with
372  	   __THROW.  */
373  	extern ssize_t pread (int __fd, void *__buf, size_t __nbytes,
374  			      __off_t __offset) __wur;
375  	
376  	/* Write N bytes of BUF to FD at the given position OFFSET without
377  	   changing the file pointer.  Return the number written, or -1.
378  	
379  	   This function is a cancellation point and therefore not marked with
380  	   __THROW.  */
381  	extern ssize_t pwrite (int __fd, __const void *__buf, size_t __n,
382  			       __off_t __offset) __wur;
383  	# else
384  	#  ifdef __REDIRECT
385  	extern ssize_t __REDIRECT (pread, (int __fd, void *__buf, size_t __nbytes,
386  					   __off64_t __offset),
387  				   pread64) __wur;
388  	extern ssize_t __REDIRECT (pwrite, (int __fd, __const void *__buf,
389  					    size_t __nbytes, __off64_t __offset),
390  				   pwrite64) __wur;
391  	#  else
392  	#   define pread pread64
393  	#   define pwrite pwrite64
394  	#  endif
395  	# endif
396  	
397  	# ifdef __USE_LARGEFILE64
398  	/* Read NBYTES into BUF from FD at the given position OFFSET without
399  	   changing the file pointer.  Return the number read, -1 for errors
400  	   or 0 for EOF.  */
401  	extern ssize_t pread64 (int __fd, void *__buf, size_t __nbytes,
402  				__off64_t __offset) __wur;
403  	/* Write N bytes of BUF to FD at the given position OFFSET without
404  	   changing the file pointer.  Return the number written, or -1.  */
405  	extern ssize_t pwrite64 (int __fd, __const void *__buf, size_t __n,
406  				 __off64_t __offset) __wur;
407  	# endif
408  	#endif
409  	
410  	/* Create a one-way communication channel (pipe).
411  	   If successful, two file descriptors are stored in PIPEDES;
412  	   bytes written on PIPEDES[1] can be read from PIPEDES[0].
413  	   Returns 0 if successful, -1 if not.  */
414  	extern int pipe (int __pipedes[2]) __THROW __wur;
415  	
416  	#ifdef __USE_GNU
417  	/* Same as pipe but apply flags passed in FLAGS to the new file
418  	   descriptors.  */
419  	extern int pipe2 (int __pipedes[2], int __flags) __THROW __wur;
420  	#endif
421  	
422  	/* Schedule an alarm.  In SECONDS seconds, the process will get a SIGALRM.
423  	   If SECONDS is zero, any currently scheduled alarm will be cancelled.
424  	   The function returns the number of seconds remaining until the last
425  	   alarm scheduled would have signaled, or zero if there wasn't one.
426  	   There is no return value to indicate an error, but you can set `errno'
427  	   to 0 and check its value after calling `alarm', and this might tell you.
428  	   The signal may come late due to processor scheduling.  */
429  	extern unsigned int alarm (unsigned int __seconds) __THROW;
430  	
431  	/* Make the process sleep for SECONDS seconds, or until a signal arrives
432  	   and is not ignored.  The function returns the number of seconds less
433  	   than SECONDS which it actually slept (thus zero if it slept the full time).
434  	   If a signal handler does a `longjmp' or modifies the handling of the
435  	   SIGALRM signal while inside `sleep' call, the handling of the SIGALRM
436  	   signal afterwards is undefined.  There is no return value to indicate
437  	   error, but if `sleep' returns SECONDS, it probably didn't work.
438  	
439  	   This function is a cancellation point and therefore not marked with
440  	   __THROW.  */
441  	extern unsigned int sleep (unsigned int __seconds);
442  	
443  	#if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \
444  	    || defined __USE_BSD
445  	/* Set an alarm to go off (generating a SIGALRM signal) in VALUE
446  	   microseconds.  If INTERVAL is nonzero, when the alarm goes off, the
447  	   timer is reset to go off every INTERVAL microseconds thereafter.
448  	   Returns the number of microseconds remaining before the alarm.  */
449  	extern __useconds_t ualarm (__useconds_t __value, __useconds_t __interval)
450  	     __THROW;
451  	
452  	/* Sleep USECONDS microseconds, or until a signal arrives that is not blocked
453  	   or ignored.
454  	
455  	   This function is a cancellation point and therefore not marked with
456  	   __THROW.  */
457  	extern int usleep (__useconds_t __useconds);
458  	#endif
459  	
460  	
461  	/* Suspend the process until a signal arrives.
462  	   This always returns -1 and sets `errno' to EINTR.
463  	
464  	   This function is a cancellation point and therefore not marked with
465  	   __THROW.  */
466  	extern int pause (void);
467  	
468  	
469  	/* Change the owner and group of FILE.  */
470  	extern int chown (__const char *__file, __uid_t __owner, __gid_t __group)
471  	     __THROW __nonnull ((1)) __wur;
472  	
473  	#if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
474  	/* Change the owner and group of the file that FD is open on.  */
475  	extern int fchown (int __fd, __uid_t __owner, __gid_t __group) __THROW __wur;
476  	
477  	
478  	/* Change owner and group of FILE, if it is a symbolic
479  	   link the ownership of the symbolic link is changed.  */
480  	extern int lchown (__const char *__file, __uid_t __owner, __gid_t __group)
481  	     __THROW __nonnull ((1)) __wur;
482  	
483  	#endif /* Use BSD || X/Open Unix.  */
484  	
485  	#ifdef __USE_ATFILE
486  	/* Change the owner and group of FILE relative to the directory FD is open
487  	   on.  */
488  	extern int fchownat (int __fd, __const char *__file, __uid_t __owner,
489  			     __gid_t __group, int __flag)
490  	     __THROW __nonnull ((2)) __wur;
491  	#endif /* Use GNU.  */
492  	
493  	/* Change the process's working directory to PATH.  */
494  	extern int chdir (__const char *__path) __THROW __nonnull ((1)) __wur;
495  	
496  	#if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
497  	/* Change the process's working directory to the one FD is open on.  */
498  	extern int fchdir (int __fd) __THROW __wur;
499  	#endif
500  	
501  	/* Get the pathname of the current working directory,
502  	   and put it in SIZE bytes of BUF.  Returns NULL if the
503  	   directory couldn't be determined or SIZE was too small.
504  	   If successful, returns BUF.  In GNU, if BUF is NULL,
505  	   an array is allocated with `malloc'; the array is SIZE
506  	   bytes long, unless SIZE == 0, in which case it is as
507  	   big as necessary.  */
508  	extern char *getcwd (char *__buf, size_t __size) __THROW __wur;
509  	
510  	#ifdef	__USE_GNU
511  	/* Return a malloc'd string containing the current directory name.
512  	   If the environment variable `PWD' is set, and its value is correct,
513  	   that value is used.  */
514  	extern char *get_current_dir_name (void) __THROW;
515  	#endif
516  	
517  	#if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \
518  	    || defined __USE_BSD
519  	/* Put the absolute pathname of the current working directory in BUF.
520  	   If successful, return BUF.  If not, put an error message in
521  	   BUF and return NULL.  BUF should be at least PATH_MAX bytes long.  */
522  	extern char *getwd (char *__buf)
523  	     __THROW __nonnull ((1)) __attribute_deprecated__ __wur;
524  	#endif
525  	
526  	
527  	/* Duplicate FD, returning a new file descriptor on the same file.  */
528  	extern int dup (int __fd) __THROW __wur;
529  	
530  	/* Duplicate FD to FD2, closing FD2 and making it open on the same file.  */
531  	extern int dup2 (int __fd, int __fd2) __THROW;
532  	
533  	#ifdef __USE_GNU
534  	/* Duplicate FD to FD2, closing FD2 and making it open on the same
535  	   file while setting flags according to FLAGS.  */
536  	extern int dup3 (int __fd, int __fd2, int __flags) __THROW;
537  	#endif
538  	
539  	/* NULL-terminated array of "NAME=VALUE" environment variables.  */
540  	extern char **__environ;
541  	#ifdef __USE_GNU
542  	extern char **environ;
543  	#endif
544  	
545  	
546  	/* Replace the current process, executing PATH with arguments ARGV and
547  	   environment ENVP.  ARGV and ENVP are terminated by NULL pointers.  */
548  	extern int execve (__const char *__path, char *__const __argv[],
549  			   char *__const __envp[]) __THROW __nonnull ((1, 2));
550  	
551  	#ifdef __USE_XOPEN2K8
552  	/* Execute the file FD refers to, overlaying the running program image.
553  	   ARGV and ENVP are passed to the new program, as for `execve'.  */
554  	extern int fexecve (int __fd, char *__const __argv[], char *__const __envp[])
555  	     __THROW __nonnull ((2));
556  	#endif
557  	
558  	
559  	/* Execute PATH with arguments ARGV and environment from `environ'.  */
560  	extern int execv (__const char *__path, char *__const __argv[])
561  	     __THROW __nonnull ((1, 2));
562  	
563  	/* Execute PATH with all arguments after PATH until a NULL pointer,
564  	   and the argument after that for environment.  */
565  	extern int execle (__const char *__path, __const char *__arg, ...)
566  	     __THROW __nonnull ((1, 2));
567  	
568  	/* Execute PATH with all arguments after PATH until
569  	   a NULL pointer and environment from `environ'.  */
570  	extern int execl (__const char *__path, __const char *__arg, ...)
571  	     __THROW __nonnull ((1, 2));
572  	
573  	/* Execute FILE, searching in the `PATH' environment variable if it contains
574  	   no slashes, with arguments ARGV and environment from `environ'.  */
575  	extern int execvp (__const char *__file, char *__const __argv[])
576  	     __THROW __nonnull ((1, 2));
577  	
578  	/* Execute FILE, searching in the `PATH' environment variable if
579  	   it contains no slashes, with all arguments after FILE until a
580  	   NULL pointer and environment from `environ'.  */
581  	extern int execlp (__const char *__file, __const char *__arg, ...)
582  	     __THROW __nonnull ((1, 2));
583  	
584  	#ifdef __USE_GNU
585  	/* Execute FILE, searching in the `PATH' environment variable if it contains
586  	   no slashes, with arguments ARGV and environment from `environ'.  */
587  	extern int execvpe (__const char *__file, char *__const __argv[],
588  			    char *__const __envp[])
589  	     __THROW __nonnull ((1, 2));
590  	#endif
591  	
592  	
593  	#if defined __USE_MISC || defined __USE_XOPEN
594  	/* Add INC to priority of the current process.  */
595  	extern int nice (int __inc) __THROW __wur;
596  	#endif
597  	
598  	
599  	/* Terminate program execution with the low-order 8 bits of STATUS.  */
600  	extern void _exit (int __status) __attribute__ ((__noreturn__));
601  	
602  	
603  	/* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf';
604  	   the `_SC_*' symbols for the NAME argument to `sysconf';
605  	   and the `_CS_*' symbols for the NAME argument to `confstr'.  */
606  	#include <bits/confname.h>
607  	
608  	/* Get file-specific configuration information about PATH.  */
609  	extern long int pathconf (__const char *__path, int __name)
610  	     __THROW __nonnull ((1));
611  	
612  	/* Get file-specific configuration about descriptor FD.  */
613  	extern long int fpathconf (int __fd, int __name) __THROW;
614  	
615  	/* Get the value of the system variable NAME.  */
616  	extern long int sysconf (int __name) __THROW;
617  	
618  	#ifdef	__USE_POSIX2
619  	/* Get the value of the string-valued system variable NAME.  */
620  	extern size_t confstr (int __name, char *__buf, size_t __len) __THROW;
621  	#endif
622  	
623  	
624  	/* Get the process ID of the calling process.  */
625  	extern __pid_t getpid (void) __THROW;
626  	
627  	/* Get the process ID of the calling process's parent.  */
628  	extern __pid_t getppid (void) __THROW;
629  	
630  	/* Get the process group ID of the calling process.
631  	   This function is different on old BSD. */
632  	#ifndef __FAVOR_BSD
633  	extern __pid_t getpgrp (void) __THROW;
634  	#else
635  	# ifdef __REDIRECT_NTH
636  	extern __pid_t __REDIRECT_NTH (getpgrp, (__pid_t __pid), __getpgid);
637  	# else
638  	#  define getpgrp __getpgid
639  	# endif
640  	#endif
641  	
642  	/* Get the process group ID of process PID.  */
643  	extern __pid_t __getpgid (__pid_t __pid) __THROW;
644  	#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
645  	extern __pid_t getpgid (__pid_t __pid) __THROW;
646  	#endif
647  	
648  	
649  	/* Set the process group ID of the process matching PID to PGID.
650  	   If PID is zero, the current process's process group ID is set.
651  	   If PGID is zero, the process ID of the process is used.  */
652  	extern int setpgid (__pid_t __pid, __pid_t __pgid) __THROW;
653  	
654  	#if defined __USE_SVID || defined __USE_BSD || defined __USE_XOPEN_EXTENDED
655  	/* Both System V and BSD have `setpgrp' functions, but with different
656  	   calling conventions.  The BSD function is the same as POSIX.1 `setpgid'
657  	   (above).  The System V function takes no arguments and puts the calling
658  	   process in its on group like `setpgid (0, 0)'.
659  	
660  	   New programs should always use `setpgid' instead.
661  	
662  	   The default in GNU is to provide the System V function.  The BSD
663  	   function is available under -D_BSD_SOURCE.  */
664  	
665  	# ifndef __FAVOR_BSD
666  	
667  	/* Set the process group ID of the calling process to its own PID.
668  	   This is exactly the same as `setpgid (0, 0)'.  */
669  	extern int setpgrp (void) __THROW;
670  	
671  	# else
672  	
673  	/* Another name for `setpgid' (above).  */
674  	#  ifdef __REDIRECT_NTH
675  	extern int __REDIRECT_NTH (setpgrp, (__pid_t __pid, __pid_t __pgrp), setpgid);
676  	#  else
677  	#   define setpgrp setpgid
678  	#  endif
679  	
680  	# endif	/* Favor BSD.  */
681  	#endif	/* Use SVID or BSD.  */
682  	
683  	/* Create a new session with the calling process as its leader.
684  	   The process group IDs of the session and the calling process
685  	   are set to the process ID of the calling process, which is returned.  */
686  	extern __pid_t setsid (void) __THROW;
687  	
688  	#if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
689  	/* Return the session ID of the given process.  */
690  	extern __pid_t getsid (__pid_t __pid) __THROW;
691  	#endif
692  	
693  	/* Get the real user ID of the calling process.  */
694  	extern __uid_t getuid (void) __THROW;
695  	
696  	/* Get the effective user ID of the calling process.  */
697  	extern __uid_t geteuid (void) __THROW;
698  	
699  	/* Get the real group ID of the calling process.  */
700  	extern __gid_t getgid (void) __THROW;
701  	
702  	/* Get the effective group ID of the calling process.  */
703  	extern __gid_t getegid (void) __THROW;
704  	
705  	/* If SIZE is zero, return the number of supplementary groups
706  	   the calling process is in.  Otherwise, fill in the group IDs
707  	   of its supplementary groups in LIST and return the number written.  */
708  	extern int getgroups (int __size, __gid_t __list[]) __THROW __wur;
709  	
710  	#ifdef	__USE_GNU
711  	/* Return nonzero iff the calling process is in group GID.  */
712  	extern int group_member (__gid_t __gid) __THROW;
713  	#endif
714  	
715  	/* Set the user ID of the calling process to UID.
716  	   If the calling process is the super-user, set the real
717  	   and effective user IDs, and the saved set-user-ID to UID;
718  	   if not, the effective user ID is set to UID.  */
719  	extern int setuid (__uid_t __uid) __THROW;
720  	
721  	#if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
722  	/* Set the real user ID of the calling process to RUID,
723  	   and the effective user ID of the calling process to EUID.  */
724  	extern int setreuid (__uid_t __ruid, __uid_t __euid) __THROW;
725  	#endif
726  	
727  	#if defined __USE_BSD || defined __USE_XOPEN2K
728  	/* Set the effective user ID of the calling process to UID.  */
729  	extern int seteuid (__uid_t __uid) __THROW;
730  	#endif /* Use BSD.  */
731  	
732  	/* Set the group ID of the calling process to GID.
733  	   If the calling process is the super-user, set the real
734  	   and effective group IDs, and the saved set-group-ID to GID;
735  	   if not, the effective group ID is set to GID.  */
736  	extern int setgid (__gid_t __gid) __THROW;
737  	
738  	#if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
739  	/* Set the real group ID of the calling process to RGID,
740  	   and the effective group ID of the calling process to EGID.  */
741  	extern int setregid (__gid_t __rgid, __gid_t __egid) __THROW;
742  	#endif
743  	
744  	#if defined __USE_BSD || defined __USE_XOPEN2K
745  	/* Set the effective group ID of the calling process to GID.  */
746  	extern int setegid (__gid_t __gid) __THROW;
747  	#endif /* Use BSD.  */
748  	
749  	#ifdef __USE_GNU
750  	/* Fetch the real user ID, effective user ID, and saved-set user ID,
751  	   of the calling process.  */
752  	extern int getresuid (__uid_t *__ruid, __uid_t *__euid, __uid_t *__suid)
753  	     __THROW;
754  	
755  	/* Fetch the real group ID, effective group ID, and saved-set group ID,
756  	   of the calling process.  */
757  	extern int getresgid (__gid_t *__rgid, __gid_t *__egid, __gid_t *__sgid)
758  	     __THROW;
759  	
760  	/* Set the real user ID, effective user ID, and saved-set user ID,
761  	   of the calling process to RUID, EUID, and SUID, respectively.  */
762  	extern int setresuid (__uid_t __ruid, __uid_t __euid, __uid_t __suid)
763  	     __THROW;
764  	
765  	/* Set the real group ID, effective group ID, and saved-set group ID,
766  	   of the calling process to RGID, EGID, and SGID, respectively.  */
767  	extern int setresgid (__gid_t __rgid, __gid_t __egid, __gid_t __sgid)
768  	     __THROW;
769  	#endif
770  	
771  	
772  	/* Clone the calling process, creating an exact copy.
773  	   Return -1 for errors, 0 to the new process,
774  	   and the process ID of the new process to the old process.  */
775  	extern __pid_t fork (void) __THROW;
776  	
777  	#if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \
778  	    || defined __USE_BSD
779  	/* Clone the calling process, but without copying the whole address space.
780  	   The calling process is suspended until the new process exits or is
781  	   replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
782  	   and the process ID of the new process to the old process.  */
783  	extern __pid_t vfork (void) __THROW;
784  	#endif /* Use BSD or XPG < 7. */
785  	
786  	
787  	/* Return the pathname of the terminal FD is open on, or NULL on errors.
788  	   The returned storage is good only until the next call to this function.  */
789  	extern char *ttyname (int __fd) __THROW;
790  	
791  	/* Store at most BUFLEN characters of the pathname of the terminal FD is
792  	   open on in BUF.  Return 0 on success, otherwise an error number.  */
793  	extern int ttyname_r (int __fd, char *__buf, size_t __buflen)
794  	     __THROW __nonnull ((2)) __wur;
795  	
796  	/* Return 1 if FD is a valid descriptor associated
797  	   with a terminal, zero if not.  */
798  	extern int isatty (int __fd) __THROW;
799  	
800  	#if defined __USE_BSD \
801  	    || (defined __USE_XOPEN_EXTENDED && !defined __USE_UNIX98)
802  	/* Return the index into the active-logins file (utmp) for
803  	   the controlling terminal.  */
804  	extern int ttyslot (void) __THROW;
805  	#endif
806  	
807  	
808  	/* Make a link to FROM named TO.  */
809  	extern int link (__const char *__from, __const char *__to)
810  	     __THROW __nonnull ((1, 2)) __wur;
811  	
812  	#ifdef __USE_ATFILE
813  	/* Like link but relative paths in TO and FROM are interpreted relative
814  	   to FROMFD and TOFD respectively.  */
815  	extern int linkat (int __fromfd, __const char *__from, int __tofd,
816  			   __const char *__to, int __flags)
817  	     __THROW __nonnull ((2, 4)) __wur;
818  	#endif
819  	
820  	#if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
821  	/* Make a symbolic link to FROM named TO.  */
822  	extern int symlink (__const char *__from, __const char *__to)
823  	     __THROW __nonnull ((1, 2)) __wur;
824  	
825  	/* Read the contents of the symbolic link PATH into no more than
826  	   LEN bytes of BUF.  The contents are not null-terminated.
827  	   Returns the number of characters read, or -1 for errors.  */
828  	extern ssize_t readlink (__const char *__restrict __path,
829  				 char *__restrict __buf, size_t __len)
830  	     __THROW __nonnull ((1, 2)) __wur;
831  	#endif /* Use BSD.  */
832  	
833  	#ifdef __USE_ATFILE
834  	/* Like symlink but a relative path in TO is interpreted relative to TOFD.  */
835  	extern int symlinkat (__const char *__from, int __tofd,
836  			      __const char *__to) __THROW __nonnull ((1, 3)) __wur;
837  	
838  	/* Like readlink but a relative PATH is interpreted relative to FD.  */
839  	extern ssize_t readlinkat (int __fd, __const char *__restrict __path,
840  				   char *__restrict __buf, size_t __len)
841  	     __THROW __nonnull ((2, 3)) __wur;
842  	#endif
843  	
844  	/* Remove the link NAME.  */
845  	extern int unlink (__const char *__name) __THROW __nonnull ((1));
846  	
847  	#ifdef __USE_ATFILE
848  	/* Remove the link NAME relative to FD.  */
849  	extern int unlinkat (int __fd, __const char *__name, int __flag)
850  	     __THROW __nonnull ((2));
851  	#endif
852  	
853  	/* Remove the directory PATH.  */
854  	extern int rmdir (__const char *__path) __THROW __nonnull ((1));
855  	
856  	
857  	/* Return the foreground process group ID of FD.  */
858  	extern __pid_t tcgetpgrp (int __fd) __THROW;
859  	
860  	/* Set the foreground process group ID of FD set PGRP_ID.  */
861  	extern int tcsetpgrp (int __fd, __pid_t __pgrp_id) __THROW;
862  	
863  	
864  	/* Return the login name of the user.
865  	
866  	   This function is a possible cancellation points and therefore not
867  	   marked with __THROW.  */
868  	extern char *getlogin (void);
869  	#if defined __USE_REENTRANT || defined __USE_POSIX199506
870  	/* Return at most NAME_LEN characters of the login name of the user in NAME.
871  	   If it cannot be determined or some other error occurred, return the error
872  	   code.  Otherwise return 0.
873  	
874  	   This function is a possible cancellation points and therefore not
875  	   marked with __THROW.  */
876  	extern int getlogin_r (char *__name, size_t __name_len) __nonnull ((1));
877  	#endif
878  	
879  	#ifdef	__USE_BSD
880  	/* Set the login name returned by `getlogin'.  */
881  	extern int setlogin (__const char *__name) __THROW __nonnull ((1));
882  	#endif
883  	
884  	
885  	#ifdef	__USE_POSIX2
886  	/* Get definitions and prototypes for functions to process the
887  	   arguments in ARGV (ARGC of them, minus the program name) for
888  	   options given in OPTS.  */
889  	# define __need_getopt
890  	# include <getopt.h>
891  	#endif
892  	
893  	
894  	#if defined __USE_BSD || defined __USE_UNIX98 || defined __USE_XOPEN2K
895  	/* Put the name of the current host in no more than LEN bytes of NAME.
896  	   The result is null-terminated if LEN is large enough for the full
897  	   name and the terminator.  */
898  	extern int gethostname (char *__name, size_t __len) __THROW __nonnull ((1));
899  	#endif
900  	
901  	
902  	#if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_UNIX98)
903  	/* Set the name of the current host to NAME, which is LEN bytes long.
904  	   This call is restricted to the super-user.  */
905  	extern int sethostname (__const char *__name, size_t __len)
906  	     __THROW __nonnull ((1)) __wur;
907  	
908  	/* Set the current machine's Internet number to ID.
909  	   This call is restricted to the super-user.  */
910  	extern int sethostid (long int __id) __THROW __wur;
911  	
912  	
913  	/* Get and set the NIS (aka YP) domain name, if any.
914  	   Called just like `gethostname' and `sethostname'.
915  	   The NIS domain name is usually the empty string when not using NIS.  */
916  	extern int getdomainname (char *__name, size_t __len)
917  	     __THROW __nonnull ((1)) __wur;
918  	extern int setdomainname (__const char *__name, size_t __len)
919  	     __THROW __nonnull ((1)) __wur;
920  	
921  	
922  	/* Revoke access permissions to all processes currently communicating
923  	   with the control terminal, and then send a SIGHUP signal to the process
924  	   group of the control terminal.  */
925  	extern int vhangup (void) __THROW;
926  	
927  	/* Revoke the access of all descriptors currently open on FILE.  */
928  	extern int revoke (__const char *__file) __THROW __nonnull ((1)) __wur;
929  	
930  	
931  	/* Enable statistical profiling, writing samples of the PC into at most
932  	   SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
933  	   is enabled, the system examines the user PC and increments
934  	   SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536].  If SCALE is zero,
935  	   disable profiling.  Returns zero on success, -1 on error.  */
936  	extern int profil (unsigned short int *__sample_buffer, size_t __size,
937  			   size_t __offset, unsigned int __scale)
938  	     __THROW __nonnull ((1));
939  	
940  	
941  	/* Turn accounting on if NAME is an existing file.  The system will then write
942  	   a record for each process as it terminates, to this file.  If NAME is NULL,
943  	   turn accounting off.  This call is restricted to the super-user.  */
944  	extern int acct (__const char *__name) __THROW;
945  	
946  	
947  	/* Successive calls return the shells listed in `/etc/shells'.  */
948  	extern char *getusershell (void) __THROW;
949  	extern void endusershell (void) __THROW; /* Discard cached info.  */
950  	extern void setusershell (void) __THROW; /* Rewind and re-read the file.  */
951  	
952  	
953  	/* Put the program in the background, and dissociate from the controlling
954  	   terminal.  If NOCHDIR is zero, do `chdir ("/")'.  If NOCLOSE is zero,
955  	   redirects stdin, stdout, and stderr to /dev/null.  */
956  	extern int daemon (int __nochdir, int __noclose) __THROW __wur;
957  	#endif /* Use BSD || X/Open.  */
958  	
959  	
960  	#if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_XOPEN2K)
961  	/* Make PATH be the root directory (the starting point for absolute paths).
962  	   This call is restricted to the super-user.  */
963  	extern int chroot (__const char *__path) __THROW __nonnull ((1)) __wur;
964  	
965  	/* Prompt with PROMPT and read a string from the terminal without echoing.
966  	   Uses /dev/tty if possible; otherwise stderr and stdin.  */
967  	extern char *getpass (__const char *__prompt) __nonnull ((1));
968  	#endif /* Use BSD || X/Open.  */
969  	
970  	
971  	#if defined __USE_BSD || defined __USE_XOPEN || defined __USE_XOPEN2K
972  	/* Make all changes done to FD actually appear on disk.
973  	
974  	   This function is a cancellation point and therefore not marked with
975  	   __THROW.  */
976  	extern int fsync (int __fd);
977  	#endif /* Use BSD || X/Open || Unix98.  */
978  	
979  	
980  	#if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
981  	
982  	/* Return identifier for the current host.  */
983  	extern long int gethostid (void);
984  	
985  	/* Make all changes done to all files actually appear on disk.  */
986  	extern void sync (void) __THROW;
987  	
988  	
989  	# if defined __USE_BSD || !defined __USE_XOPEN2K
990  	/* Return the number of bytes in a page.  This is the system's page size,
991  	   which is not necessarily the same as the hardware page size.  */
992  	extern int getpagesize (void)  __THROW __attribute__ ((__const__));
993  	
994  	
995  	/* Return the maximum number of file descriptors
996  	   the current process could possibly have.  */
997  	extern int getdtablesize (void) __THROW;
998  	# endif
999  	
1000 	#endif /* Use BSD || X/Open Unix.  */
1001 	
1002 	
1003 	#if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
1004 	
1005 	/* Truncate FILE to LENGTH bytes.  */
1006 	# ifndef __USE_FILE_OFFSET64
1007 	extern int truncate (__const char *__file, __off_t __length)
1008 	     __THROW __nonnull ((1)) __wur;
1009 	# else
1010 	#  ifdef __REDIRECT_NTH
1011 	extern int __REDIRECT_NTH (truncate,
1012 				   (__const char *__file, __off64_t __length),
1013 				   truncate64) __nonnull ((1)) __wur;
1014 	#  else
1015 	#   define truncate truncate64
1016 	#  endif
1017 	# endif
1018 	# ifdef __USE_LARGEFILE64
1019 	extern int truncate64 (__const char *__file, __off64_t __length)
1020 	     __THROW __nonnull ((1)) __wur;
1021 	# endif
1022 	
1023 	
1024 	/* Truncate the file FD is open on to LENGTH bytes.  */
1025 	# ifndef __USE_FILE_OFFSET64
1026 	extern int ftruncate (int __fd, __off_t __length) __THROW __wur;
1027 	# else
1028 	#  ifdef __REDIRECT_NTH
1029 	extern int __REDIRECT_NTH (ftruncate, (int __fd, __off64_t __length),
1030 				   ftruncate64) __wur;
1031 	#  else
1032 	#   define ftruncate ftruncate64
1033 	#  endif
1034 	# endif
1035 	# ifdef __USE_LARGEFILE64
1036 	extern int ftruncate64 (int __fd, __off64_t __length) __THROW __wur;
1037 	# endif
1038 	
1039 	#endif /* Use BSD || X/Open Unix || POSIX 2003.  */
1040 	
1041 	
1042 	#if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K) \
1043 	    || defined __USE_MISC
1044 	
1045 	/* Set the end of accessible data space (aka "the break") to ADDR.
1046 	   Returns zero on success and -1 for errors (with errno set).  */
1047 	extern int brk (void *__addr) __THROW __wur;
1048 	
1049 	/* Increase or decrease the end of accessible data space by DELTA bytes.
1050 	   If successful, returns the address the previous end of data space
1051 	   (i.e. the beginning of the new space, if DELTA > 0);
1052 	   returns (void *) -1 for errors (with errno set).  */
1053 	extern void *sbrk (intptr_t __delta) __THROW;
1054 	#endif
1055 	
1056 	
1057 	#ifdef __USE_MISC
1058 	/* Invoke `system call' number SYSNO, passing it the remaining arguments.
1059 	   This is completely system-dependent, and not often useful.
1060 	
1061 	   In Unix, `syscall' sets `errno' for all errors and most calls return -1
1062 	   for errors; in many systems you cannot pass arguments or get return
1063 	   values for all system calls (`pipe', `fork', and `getppid' typically
1064 	   among them).
1065 	
1066 	   In Mach, all system calls take normal arguments and always return an
1067 	   error code (zero for success).  */
1068 	extern long int syscall (long int __sysno, ...) __THROW;
1069 	
1070 	#endif	/* Use misc.  */
1071 	
1072 	
1073 	#if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK
1074 	/* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both
1075 	   files consistent.  Some systems have them there and some here, and some
1076 	   software depends on the macros being defined without including both.  */
1077 	
1078 	/* `lockf' is a simpler interface to the locking facilities of `fcntl'.
1079 	   LEN is always relative to the current file position.
1080 	   The CMD argument is one of the following.
1081 	
1082 	   This function is a cancellation point and therefore not marked with
1083 	   __THROW.  */
1084 	
1085 	# define F_ULOCK 0	/* Unlock a previously locked region.  */
1086 	# define F_LOCK  1	/* Lock a region for exclusive use.  */
1087 	# define F_TLOCK 2	/* Test and lock a region for exclusive use.  */
1088 	# define F_TEST  3	/* Test a region for other processes locks.  */
1089 	
1090 	# ifndef __USE_FILE_OFFSET64
1091 	extern int lockf (int __fd, int __cmd, __off_t __len) __wur;
1092 	# else
1093 	#  ifdef __REDIRECT
1094 	extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len),
1095 			       lockf64) __wur;
1096 	#  else
1097 	#   define lockf lockf64
1098 	#  endif
1099 	# endif
1100 	# ifdef __USE_LARGEFILE64
1101 	extern int lockf64 (int __fd, int __cmd, __off64_t __len) __wur;
1102 	# endif
1103 	#endif /* Use misc and F_LOCK not already defined.  */
1104 	
1105 	
1106 	#ifdef __USE_GNU
1107 	
1108 	/* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno'
1109 	   set to EINTR.  */
1110 	
1111 	# define TEMP_FAILURE_RETRY(expression) \
1112 	  (__extension__							      \
1113 	    ({ long int __result;						      \
1114 	       do __result = (long int) (expression);				      \
1115 	       while (__result == -1L && errno == EINTR);			      \
1116 	       __result; }))
1117 	#endif
1118 	
1119 	#if defined __USE_POSIX199309 || defined __USE_UNIX98
1120 	/* Synchronize at least the data part of a file with the underlying
1121 	   media.  */
1122 	extern int fdatasync (int __fildes);
1123 	#endif /* Use POSIX199309 */
1124 	
1125 	
1126 	/* XPG4.2 specifies that prototypes for the encryption functions must
1127 	   be defined here.  */
1128 	#ifdef	__USE_XOPEN
1129 	/* Encrypt at most 8 characters from KEY using salt to perturb DES.  */
1130 	extern char *crypt (__const char *__key, __const char *__salt)
1131 	     __THROW __nonnull ((1, 2));
1132 	
1133 	/* Encrypt data in BLOCK in place if EDFLAG is zero; otherwise decrypt
1134 	   block in place.  */
1135 	extern void encrypt (char *__block, int __edflag) __THROW __nonnull ((1));
1136 	
1137 	
1138 	/* Swab pairs bytes in the first N bytes of the area pointed to by
1139 	   FROM and copy the result to TO.  The value of TO must not be in the
1140 	   range [FROM - N + 1, FROM - 1].  If N is odd the first byte in FROM
1141 	   is without partner.  */
1142 	extern void swab (__const void *__restrict __from, void *__restrict __to,
1143 			  ssize_t __n) __THROW __nonnull ((1, 2));
1144 	#endif
1145 	
1146 	
1147 	/* The Single Unix specification demands this prototype to be here.
1148 	   It is also found in <stdio.h>.  */
1149 	#if defined __USE_XOPEN || defined __USE_XOPEN2K8
1150 	/* Return the name of the controlling terminal.  */
1151 	extern char *ctermid (char *__s) __THROW;
1152 	#endif
1153 	
1154 	
1155 	/* Define some macros helping to catch buffer overflows.  */
1156 	#if __USE_FORTIFY_LEVEL > 0 && defined __extern_always_inline
1157 	# include <bits/unistd.h>
1158 	#endif
1159 	
1160 	__END_DECLS
1161 	
1162 	#endif /* unistd.h  */
1163