include/unistd.h

   1 /* Copyright (C) 1991-2021 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <https://www.gnu.org/licenses/>.  */
  17
  18 /*
  19  *      POSIX Standard: 2.10 Symbolic Constants         <unistd.h>
  20  */
  21
  22 #ifndef _UNISTD_H
  23 #define _UNISTD_H       1
  24
  25 #include <features.h>
  26
  27 __BEGIN_DECLS
  28
  29 /* These may be used to determine what facilities are present at compile time.
  30    Their values can be obtained at run time from `sysconf'.  */
  31
  32 #ifdef __USE_XOPEN2K8
  33 /* POSIX Standard approved as ISO/IEC 9945-1 as of September 2008.  */
  34 # define _POSIX_VERSION 200809L
  35 #elif defined __USE_XOPEN2K
  36 /* POSIX Standard approved as ISO/IEC 9945-1 as of December 2001.  */
  37 # define _POSIX_VERSION 200112L
  38 #elif defined __USE_POSIX199506
  39 /* POSIX Standard approved as ISO/IEC 9945-1 as of June 1995.  */
  40 # define _POSIX_VERSION 199506L
  41 #elif defined __USE_POSIX199309
  42 /* POSIX Standard approved as ISO/IEC 9945-1 as of September 1993.  */
  43 # define _POSIX_VERSION 199309L
  44 #else
  45 /* POSIX Standard approved as ISO/IEC 9945-1 as of September 1990.  */
  46 # define _POSIX_VERSION 199009L
  47 #endif
  48
  49 /* These are not #ifdef __USE_POSIX2 because they are
  50    in the theoretically application-owned namespace.  */
  51
  52 #ifdef __USE_XOPEN2K8
  53 # define __POSIX2_THIS_VERSION  200809L
  54 /* The utilities on GNU systems also correspond to this version.  */
  55 #elif defined __USE_XOPEN2K
  56 /* The utilities on GNU systems also correspond to this version.  */
  57 # define __POSIX2_THIS_VERSION  200112L
  58 #elif defined __USE_POSIX199506
  59 /* The utilities on GNU systems also correspond to this version.  */
  60 # define __POSIX2_THIS_VERSION  199506L
  61 #else
  62 /* The utilities on GNU systems also correspond to this version.  */
  63 # define __POSIX2_THIS_VERSION  199209L
  64 #endif
  65
  66 /* The utilities on GNU systems also correspond to this version.  */
  67 #define _POSIX2_VERSION __POSIX2_THIS_VERSION
  68
  69 /* This symbol was required until the 2001 edition of POSIX.  */
  70 #define _POSIX2_C_VERSION       __POSIX2_THIS_VERSION
  71
  72 /* If defined, the implementation supports the
  73    C Language Bindings Option.  */
  74 #define _POSIX2_C_BIND  __POSIX2_THIS_VERSION
  75
  76 /* If defined, the implementation supports the
  77    C Language Development Utilities Option.  */
  78 #define _POSIX2_C_DEV   __POSIX2_THIS_VERSION
  79
  80 /* If defined, the implementation supports the
  81    Software Development Utilities Option.  */
  82 #define _POSIX2_SW_DEV  __POSIX2_THIS_VERSION
  83
  84 /* If defined, the implementation supports the
  85    creation of locales with the localedef utility.  */
  86 #define _POSIX2_LOCALEDEF       __POSIX2_THIS_VERSION
  87
  88 /* X/Open version number to which the library conforms.  It is selectable.  */
  89 #ifdef __USE_XOPEN2K8
  90 # define _XOPEN_VERSION 700
  91 #elif defined __USE_XOPEN2K
  92 # define _XOPEN_VERSION 600
  93 #elif defined __USE_UNIX98
  94 # define _XOPEN_VERSION 500
  95 #else
  96 # define _XOPEN_VERSION 4
  97 #endif
  98
  99 /* Commands and utilities from XPG4 are available.  */
 100 #define _XOPEN_XCU_VERSION      4
 101
 102 /* We are compatible with the old published standards as well.  */
 103 #define _XOPEN_XPG2     1
 104 #define _XOPEN_XPG3     1
 105 #define _XOPEN_XPG4     1
 106
 107 /* The X/Open Unix extensions are available.  */
 108 #define _XOPEN_UNIX     1
 109
 110 /* The enhanced internationalization capabilities according to XPG4.2
 111    are present.  */
 112 #define _XOPEN_ENH_I18N 1
 113
 114 /* The legacy interfaces are also available.  */
 115 #define _XOPEN_LEGACY   1
 116
 117
 118 /* Get values of POSIX options:
 119
 120    If these symbols are defined, the corresponding features are
 121    always available.  If not, they may be available sometimes.
 122    The current values can be obtained with `sysconf'.
 123
 124    _POSIX_JOB_CONTROL           Job control is supported.
 125    _POSIX_SAVED_IDS             Processes have a saved set-user-ID
 126                                 and a saved set-group-ID.
 127    _POSIX_REALTIME_SIGNALS      Real-time, queued signals are supported.
 128    _POSIX_PRIORITY_SCHEDULING   Priority scheduling is supported.
 129    _POSIX_TIMERS                POSIX.4 clocks and timers are supported.
 130    _POSIX_ASYNCHRONOUS_IO       Asynchronous I/O is supported.
 131    _POSIX_PRIORITIZED_IO        Prioritized asynchronous I/O is supported.
 132    _POSIX_SYNCHRONIZED_IO       Synchronizing file data is supported.
 133    _POSIX_FSYNC                 The fsync function is present.
 134    _POSIX_MAPPED_FILES          Mapping of files to memory is supported.
 135    _POSIX_MEMLOCK               Locking of all memory is supported.
 136    _POSIX_MEMLOCK_RANGE         Locking of ranges of memory is supported.
 137    _POSIX_MEMORY_PROTECTION     Setting of memory protections is supported.
 138    _POSIX_MESSAGE_PASSING       POSIX.4 message queues are supported.
 139    _POSIX_SEMAPHORES            POSIX.4 counting semaphores are supported.
 140    _POSIX_SHARED_MEMORY_OBJECTS POSIX.4 shared memory objects are supported.
 141    _POSIX_THREADS               POSIX.1c pthreads are supported.
 142    _POSIX_THREAD_ATTR_STACKADDR Thread stack address attribute option supported.
 143    _POSIX_THREAD_ATTR_STACKSIZE Thread stack size attribute option supported.
 144    _POSIX_THREAD_SAFE_FUNCTIONS Thread-safe functions are supported.
 145    _POSIX_THREAD_PRIORITY_SCHEDULING
 146                                 POSIX.1c thread execution scheduling supported.
 147    _POSIX_THREAD_PRIO_INHERIT   Thread priority inheritance option supported.
 148    _POSIX_THREAD_PRIO_PROTECT   Thread priority protection option supported.
 149    _POSIX_THREAD_PROCESS_SHARED Process-shared synchronization supported.
 150    _POSIX_PII                   Protocol-independent interfaces are supported.
 151    _POSIX_PII_XTI               XTI protocol-indep. interfaces are supported.
 152    _POSIX_PII_SOCKET            Socket protocol-indep. interfaces are supported.
 153    _POSIX_PII_INTERNET          Internet family of protocols supported.
 154    _POSIX_PII_INTERNET_STREAM   Connection-mode Internet protocol supported.
 155    _POSIX_PII_INTERNET_DGRAM    Connectionless Internet protocol supported.
 156    _POSIX_PII_OSI               ISO/OSI family of protocols supported.
 157    _POSIX_PII_OSI_COTS          Connection-mode ISO/OSI service supported.
 158    _POSIX_PII_OSI_CLTS          Connectionless ISO/OSI service supported.
 159    _POSIX_POLL                  Implementation supports `poll' function.
 160    _POSIX_SELECT                Implementation supports `select' and `pselect'.
 161
 162    _XOPEN_REALTIME              X/Open realtime support is available.
 163    _XOPEN_REALTIME_THREADS      X/Open realtime thread support is available.
 164    _XOPEN_SHM                   Shared memory interface according to XPG4.2.
 165
 166    _XBS5_ILP32_OFF32            Implementation provides environment with 32-bit
 167                                 int, long, pointer, and off_t types.
 168    _XBS5_ILP32_OFFBIG           Implementation provides environment with 32-bit
 169                                 int, long, and pointer and off_t with at least
 170                                 64 bits.
 171    _XBS5_LP64_OFF64             Implementation provides environment with 32-bit
 172                                 int, and 64-bit long, pointer, and off_t types.
 173    _XBS5_LPBIG_OFFBIG           Implementation provides environment with at
 174                                 least 32 bits int and long, pointer, and off_t
 175                                 with at least 64 bits.
 176
 177    If any of these symbols is defined as -1, the corresponding option is not
 178    true for any file.  If any is defined as other than -1, the corresponding
 179    option is true for all files.  If a symbol is not defined at all, the value
 180    for a specific file can be obtained from `pathconf' and `fpathconf'.
 181
 182    _POSIX_CHOWN_RESTRICTED      Only the super user can use `chown' to change
 183                                 the owner of a file.  `chown' can only be used
 184                                 to change the group ID of a file to a group of
 185                                 which the calling process is a member.
 186    _POSIX_NO_TRUNC              Pathname components longer than
 187                                 NAME_MAX generate an error.
 188    _POSIX_VDISABLE              If defined, if the value of an element of the
 189                                 `c_cc' member of `struct termios' is
 190                                 _POSIX_VDISABLE, no character will have the
 191                                 effect associated with that element.
 192    _POSIX_SYNC_IO               Synchronous I/O may be performed.
 193    _POSIX_ASYNC_IO              Asynchronous I/O may be performed.
 194    _POSIX_PRIO_IO               Prioritized Asynchronous I/O may be performed.
 195
 196    Support for the Large File Support interface is not generally available.
 197    If it is available the following constants are defined to one.
 198    _LFS64_LARGEFILE             Low-level I/O supports large files.
 199    _LFS64_STDIO                 Standard I/O supports large files.
 200    */
 201
 202 #include <bits/posix_opt.h>
 203
 204 /* Get the environment definitions from Unix98.  */
 205 #if defined __USE_UNIX98 || defined __USE_XOPEN2K
 206 # include <bits/environments.h>
 207 #endif
 208
 209 /* Standard file descriptors.  */
 210 #define STDIN_FILENO    0       /* Standard input.  */
 211 #define STDOUT_FILENO   1       /* Standard output.  */
 212 #define STDERR_FILENO   2       /* Standard error output.  */
 213
 214
 215 /* All functions that are not declared anywhere else.  */
 216
 217 #include <bits/types.h>
 218
 219 #ifndef __ssize_t_defined
 220 typedef __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
 232 typedef __gid_t gid_t;
 233 #  define __gid_t_defined
 234 # endif
 235
 236 # ifndef __uid_t_defined
 237 typedef __uid_t uid_t;
 238 #  define __uid_t_defined
 239 # endif
 240
 241 # ifndef __off_t_defined
 242 #  ifndef __USE_FILE_OFFSET64
 243 typedef __off_t off_t;
 244 #  else
 245 typedef __off64_t off_t;
 246 #  endif
 247 #  define __off_t_defined
 248 # endif
 249 # if defined __USE_LARGEFILE64 && !defined __off64_t_defined
 250 typedef __off64_t off64_t;
 251 #  define __off64_t_defined
 252 # endif
 253
 254 # ifndef __useconds_t_defined
 255 typedef __useconds_t useconds_t;
 256 #  define __useconds_t_defined
 257 # endif
 258
 259 # ifndef __pid_t_defined
 260 typedef __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
 267 typedef __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
 274 typedef __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.  */
 287 extern 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).  */
 292 extern int euidaccess (const char *__name, int __type)
 293      __THROW __nonnull ((1));
 294
 295 /* An alias for `euidaccess', used by some other systems.  */
 296 extern int eaccess (const char *__name, int __type)
 297      __THROW __nonnull ((1));
 298 #endif
 299
 300 #ifdef __USE_ATFILE
 301 /* Test for access to FILE relative to the directory FD is open on.
 302    If AT_EACCESS is set in FLAG, then use effective IDs like `eaccess',
 303    otherwise use real IDs like `access'.  */
 304 extern int faccessat (int __fd, const char *__file, int __type, int __flag)
 305      __THROW __nonnull ((2)) __wur;
 306 #endif /* Use GNU.  */
 307
 308
 309 /* Values for the WHENCE argument to lseek.  */
 310 #ifndef _STDIO_H                /* <stdio.h> has the same definitions.  */
 311 # define SEEK_SET       0       /* Seek from beginning of file.  */
 312 # define SEEK_CUR       1       /* Seek from current position.  */
 313 # define SEEK_END       2       /* Seek from end of file.  */
 314 # ifdef __USE_GNU
 315 #  define SEEK_DATA     3       /* Seek to next data.  */
 316 #  define SEEK_HOLE     4       /* Seek to next hole.  */
 317 # endif
 318 #endif
 319
 320 #if defined __USE_MISC && !defined L_SET
 321 /* Old BSD names for the same constants; just for compatibility.  */
 322 # define L_SET          SEEK_SET
 323 # define L_INCR         SEEK_CUR
 324 # define L_XTND         SEEK_END
 325 #endif
 326
 327
 328 /* Move FD's file position to OFFSET bytes from the
 329    beginning of the file (if WHENCE is SEEK_SET),
 330    the current position (if WHENCE is SEEK_CUR),
 331    or the end of the file (if WHENCE is SEEK_END).
 332    Return the new file position.  */
 333 #ifndef __USE_FILE_OFFSET64
 334 extern __off_t lseek (int __fd, __off_t __offset, int __whence) __THROW;
 335 #else
 336 # ifdef __REDIRECT_NTH
 337 extern __off64_t __REDIRECT_NTH (lseek,
 338                                  (int __fd, __off64_t __offset, int __whence),
 339                                  lseek64);
 340 # else
 341 #  define lseek lseek64
 342 # endif
 343 #endif
 344 #ifdef __USE_LARGEFILE64
 345 extern __off64_t lseek64 (int __fd, __off64_t __offset, int __whence)
 346      __THROW;
 347 #endif
 348
 349 /* Close the file descriptor FD.
 350
 351    This function is a cancellation point and therefore not marked with
 352    __THROW.  */
 353 extern int close (int __fd);
 354
 355 /* Read NBYTES into BUF from FD.  Return the
 356    number read, -1 for errors or 0 for EOF.
 357
 358    This function is a cancellation point and therefore not marked with
 359    __THROW.  */
 360 extern ssize_t read (int __fd, void *__buf, size_t __nbytes) __wur
 361     __attr_access ((__write_only__, 2, 3));
 362
 363 /* Write N bytes of BUF to FD.  Return the number written, or -1.
 364
 365    This function is a cancellation point and therefore not marked with
 366    __THROW.  */
 367 extern ssize_t write (int __fd, const void *__buf, size_t __n) __wur
 368     __attr_access ((__read_only__, 2, 3));
 369
 370 #if defined __USE_UNIX98 || defined __USE_XOPEN2K8
 371 # ifndef __USE_FILE_OFFSET64
 372 /* Read NBYTES into BUF from FD at the given position OFFSET without
 373    changing the file pointer.  Return the number read, -1 for errors
 374    or 0 for EOF.
 375
 376    This function is a cancellation point and therefore not marked with
 377    __THROW.  */
 378 extern ssize_t pread (int __fd, void *__buf, size_t __nbytes,
 379                       __off_t __offset) __wur
 380     __attr_access ((__write_only__, 2, 3));
 381
 382 /* Write N bytes of BUF to FD at the given position OFFSET without
 383    changing the file pointer.  Return the number written, or -1.
 384
 385    This function is a cancellation point and therefore not marked with
 386    __THROW.  */
 387 extern ssize_t pwrite (int __fd, const void *__buf, size_t __n,
 388                        __off_t __offset) __wur
 389     __attr_access ((__read_only__, 2, 3));
 390
 391 # else
 392 #  ifdef __REDIRECT
 393 extern ssize_t __REDIRECT (pread, (int __fd, void *__buf, size_t __nbytes,
 394                                    __off64_t __offset),
 395                            pread64) __wur
 396     __attr_access ((__write_only__, 2, 3));
 397 extern ssize_t __REDIRECT (pwrite, (int __fd, const void *__buf,
 398                                     size_t __nbytes, __off64_t __offset),
 399                            pwrite64) __wur
 400     __attr_access ((__read_only__, 2, 3));
 401 #  else
 402 #   define pread pread64
 403 #   define pwrite pwrite64
 404 #  endif
 405 # endif
 406
 407 # ifdef __USE_LARGEFILE64
 408 /* Read NBYTES into BUF from FD at the given position OFFSET without
 409    changing the file pointer.  Return the number read, -1 for errors
 410    or 0 for EOF.  */
 411 extern ssize_t pread64 (int __fd, void *__buf, size_t __nbytes,
 412                         __off64_t __offset) __wur
 413     __attr_access ((__write_only__, 2, 3));
 414 /* Write N bytes of BUF to FD at the given position OFFSET without
 415    changing the file pointer.  Return the number written, or -1.  */
 416 extern ssize_t pwrite64 (int __fd, const void *__buf, size_t __n,
 417                          __off64_t __offset) __wur
 418     __attr_access ((__read_only__, 2, 3));
 419 # endif
 420 #endif
 421
 422 /* Create a one-way communication channel (pipe).
 423    If successful, two file descriptors are stored in PIPEDES;
 424    bytes written on PIPEDES[1] can be read from PIPEDES[0].
 425    Returns 0 if successful, -1 if not.  */
 426 extern int pipe (int __pipedes[2]) __THROW __wur;
 427
 428 #ifdef __USE_GNU
 429 /* Same as pipe but apply flags passed in FLAGS to the new file
 430    descriptors.  */
 431 extern int pipe2 (int __pipedes[2], int __flags) __THROW __wur;
 432 #endif
 433
 434 /* Schedule an alarm.  In SECONDS seconds, the process will get a SIGALRM.
 435    If SECONDS is zero, any currently scheduled alarm will be cancelled.
 436    The function returns the number of seconds remaining until the last
 437    alarm scheduled would have signaled, or zero if there wasn't one.
 438    There is no return value to indicate an error, but you can set `errno'
 439    to 0 and check its value after calling `alarm', and this might tell you.
 440    The signal may come late due to processor scheduling.  */
 441 extern unsigned int alarm (unsigned int __seconds) __THROW;
 442
 443 /* Make the process sleep for SECONDS seconds, or until a signal arrives
 444    and is not ignored.  The function returns the number of seconds less
 445    than SECONDS which it actually slept (thus zero if it slept the full time).
 446    If a signal handler does a `longjmp' or modifies the handling of the
 447    SIGALRM signal while inside `sleep' call, the handling of the SIGALRM
 448    signal afterwards is undefined.  There is no return value to indicate
 449    error, but if `sleep' returns SECONDS, it probably didn't work.
 450
 451    This function is a cancellation point and therefore not marked with
 452    __THROW.  */
 453 extern unsigned int sleep (unsigned int __seconds);
 454
 455 #if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \
 456     || defined __USE_MISC
 457 /* Set an alarm to go off (generating a SIGALRM signal) in VALUE
 458    microseconds.  If INTERVAL is nonzero, when the alarm goes off, the
 459    timer is reset to go off every INTERVAL microseconds thereafter.
 460    Returns the number of microseconds remaining before the alarm.  */
 461 extern __useconds_t ualarm (__useconds_t __value, __useconds_t __interval)
 462      __THROW;
 463
 464 /* Sleep USECONDS microseconds, or until a signal arrives that is not blocked
 465    or ignored.
 466
 467    This function is a cancellation point and therefore not marked with
 468    __THROW.  */
 469 extern int usleep (__useconds_t __useconds);
 470 #endif
 471
 472
 473 /* Suspend the process until a signal arrives.
 474    This always returns -1 and sets `errno' to EINTR.
 475
 476    This function is a cancellation point and therefore not marked with
 477    __THROW.  */
 478 extern int pause (void);
 479
 480
 481 /* Change the owner and group of FILE.  */
 482 extern int chown (const char *__file, __uid_t __owner, __gid_t __group)
 483      __THROW __nonnull ((1)) __wur;
 484
 485 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
 486 /* Change the owner and group of the file that FD is open on.  */
 487 extern int fchown (int __fd, __uid_t __owner, __gid_t __group) __THROW __wur;
 488
 489
 490 /* Change owner and group of FILE, if it is a symbolic
 491    link the ownership of the symbolic link is changed.  */
 492 extern int lchown (const char *__file, __uid_t __owner, __gid_t __group)
 493      __THROW __nonnull ((1)) __wur;
 494
 495 #endif /* Use X/Open Unix.  */
 496
 497 #ifdef __USE_ATFILE
 498 /* Change the owner and group of FILE relative to the directory FD is open
 499    on.  */
 500 extern int fchownat (int __fd, const char *__file, __uid_t __owner,
 501                      __gid_t __group, int __flag)
 502      __THROW __nonnull ((2)) __wur;
 503 #endif /* Use GNU.  */
 504
 505 /* Change the process's working directory to PATH.  */
 506 extern int chdir (const char *__path) __THROW __nonnull ((1)) __wur;
 507
 508 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
 509 /* Change the process's working directory to the one FD is open on.  */
 510 extern int fchdir (int __fd) __THROW __wur;
 511 #endif
 512
 513 /* Get the pathname of the current working directory,
 514    and put it in SIZE bytes of BUF.  Returns NULL if the
 515    directory couldn't be determined or SIZE was too small.
 516    If successful, returns BUF.  In GNU, if BUF is NULL,
 517    an array is allocated with `malloc'; the array is SIZE
 518    bytes long, unless SIZE == 0, in which case it is as
 519    big as necessary.  */
 520 extern char *getcwd (char *__buf, size_t __size) __THROW __wur
 521     __attr_access ((__write_only__, 1, 2));
 522
 523 #ifdef  __USE_GNU
 524 /* Return a malloc'd string containing the current directory name.
 525    If the environment variable `PWD' is set, and its value is correct,
 526    that value is used.  */
 527 extern char *get_current_dir_name (void) __THROW;
 528 #endif
 529
 530 #if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \
 531     || defined __USE_MISC
 532 /* Put the absolute pathname of the current working directory in BUF.
 533    If successful, return BUF.  If not, put an error message in
 534    BUF and return NULL.  BUF should be at least PATH_MAX bytes long.  */
 535 extern char *getwd (char *__buf)
 536      __THROW __nonnull ((1)) __attribute_deprecated__ __wur
 537     __attr_access ((__write_only__, 1));
 538 #endif
 539
 540
 541 /* Duplicate FD, returning a new file descriptor on the same file.  */
 542 extern int dup (int __fd) __THROW __wur;
 543
 544 /* Duplicate FD to FD2, closing FD2 and making it open on the same file.  */
 545 extern int dup2 (int __fd, int __fd2) __THROW;
 546
 547 #ifdef __USE_GNU
 548 /* Duplicate FD to FD2, closing FD2 and making it open on the same
 549    file while setting flags according to FLAGS.  */
 550 extern int dup3 (int __fd, int __fd2, int __flags) __THROW;
 551 #endif
 552
 553 /* NULL-terminated array of "NAME=VALUE" environment variables.  */
 554 extern char **__environ;
 555 #ifdef __USE_GNU
 556 extern char **environ;
 557 #endif
 558
 559
 560 /* Replace the current process, executing PATH with arguments ARGV and
 561    environment ENVP.  ARGV and ENVP are terminated by NULL pointers.  */
 562 extern int execve (const char *__path, char *const __argv[],
 563                    char *const __envp[]) __THROW __nonnull ((1, 2));
 564
 565 #ifdef __USE_XOPEN2K8
 566 /* Execute the file FD refers to, overlaying the running program image.
 567    ARGV and ENVP are passed to the new program, as for `execve'.  */
 568 extern int fexecve (int __fd, char *const __argv[], char *const __envp[])
 569      __THROW __nonnull ((2));
 570 #endif
 571
 572
 573 /* Execute PATH with arguments ARGV and environment from `environ'.  */
 574 extern int execv (const char *__path, char *const __argv[])
 575      __THROW __nonnull ((1, 2));
 576
 577 /* Execute PATH with all arguments after PATH until a NULL pointer,
 578    and the argument after that for environment.  */
 579 extern int execle (const char *__path, const char *__arg, ...)
 580      __THROW __nonnull ((1, 2));
 581
 582 /* Execute PATH with all arguments after PATH until
 583    a NULL pointer and environment from `environ'.  */
 584 extern int execl (const char *__path, const char *__arg, ...)
 585      __THROW __nonnull ((1, 2));
 586
 587 /* Execute FILE, searching in the `PATH' environment variable if it contains
 588    no slashes, with arguments ARGV and environment from `environ'.  */
 589 extern int execvp (const char *__file, char *const __argv[])
 590      __THROW __nonnull ((1, 2));
 591
 592 /* Execute FILE, searching in the `PATH' environment variable if
 593    it contains no slashes, with all arguments after FILE until a
 594    NULL pointer and environment from `environ'.  */
 595 extern int execlp (const char *__file, const char *__arg, ...)
 596      __THROW __nonnull ((1, 2));
 597
 598 #ifdef __USE_GNU
 599 /* Execute FILE, searching in the `PATH' environment variable if it contains
 600    no slashes, with arguments ARGV and environment from `environ'.  */
 601 extern int execvpe (const char *__file, char *const __argv[],
 602                     char *const __envp[])
 603      __THROW __nonnull ((1, 2));
 604 #endif
 605
 606
 607 #if defined __USE_MISC || defined __USE_XOPEN
 608 /* Add INC to priority of the current process.  */
 609 extern int nice (int __inc) __THROW __wur;
 610 #endif
 611
 612
 613 /* Terminate program execution with the low-order 8 bits of STATUS.  */
 614 extern void _exit (int __status) __attribute__ ((__noreturn__));
 615
 616
 617 /* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf';
 618    the `_SC_*' symbols for the NAME argument to `sysconf';
 619    and the `_CS_*' symbols for the NAME argument to `confstr'.  */
 620 #include <bits/confname.h>
 621
 622 /* Get file-specific configuration information about PATH.  */
 623 extern long int pathconf (const char *__path, int __name)
 624      __THROW __nonnull ((1));
 625
 626 /* Get file-specific configuration about descriptor FD.  */
 627 extern long int fpathconf (int __fd, int __name) __THROW;
 628
 629 /* Get the value of the system variable NAME.  */
 630 extern long int sysconf (int __name) __THROW;
 631
 632 #ifdef  __USE_POSIX2
 633 /* Get the value of the string-valued system variable NAME.  */
 634 extern size_t confstr (int __name, char *__buf, size_t __len) __THROW
 635     __attr_access ((__write_only__, 2, 3));
 636 #endif
 637
 638
 639 /* Get the process ID of the calling process.  */
 640 extern __pid_t getpid (void) __THROW;
 641
 642 /* Get the process ID of the calling process's parent.  */
 643 extern __pid_t getppid (void) __THROW;
 644
 645 /* Get the process group ID of the calling process.  */
 646 extern __pid_t getpgrp (void) __THROW;
 647
 648 /* Get the process group ID of process PID.  */
 649 extern __pid_t __getpgid (__pid_t __pid) __THROW;
 650 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
 651 extern __pid_t getpgid (__pid_t __pid) __THROW;
 652 #endif
 653
 654
 655 /* Set the process group ID of the process matching PID to PGID.
 656    If PID is zero, the current process's process group ID is set.
 657    If PGID is zero, the process ID of the process is used.  */
 658 extern int setpgid (__pid_t __pid, __pid_t __pgid) __THROW;
 659
 660 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 661 /* Both System V and BSD have `setpgrp' functions, but with different
 662    calling conventions.  The BSD function is the same as POSIX.1 `setpgid'
 663    (above).  The System V function takes no arguments and puts the calling
 664    process in its on group like `setpgid (0, 0)'.
 665
 666    New programs should always use `setpgid' instead.
 667
 668    GNU provides the POSIX.1 function.  */
 669
 670 /* Set the process group ID of the calling process to its own PID.
 671    This is exactly the same as `setpgid (0, 0)'.  */
 672 extern int setpgrp (void) __THROW;
 673
 674 #endif  /* Use misc or X/Open.  */
 675
 676 /* Create a new session with the calling process as its leader.
 677    The process group IDs of the session and the calling process
 678    are set to the process ID of the calling process, which is returned.  */
 679 extern __pid_t setsid (void) __THROW;
 680
 681 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
 682 /* Return the session ID of the given process.  */
 683 extern __pid_t getsid (__pid_t __pid) __THROW;
 684 #endif
 685
 686 /* Get the real user ID of the calling process.  */
 687 extern __uid_t getuid (void) __THROW;
 688
 689 /* Get the effective user ID of the calling process.  */
 690 extern __uid_t geteuid (void) __THROW;
 691
 692 /* Get the real group ID of the calling process.  */
 693 extern __gid_t getgid (void) __THROW;
 694
 695 /* Get the effective group ID of the calling process.  */
 696 extern __gid_t getegid (void) __THROW;
 697
 698 /* If SIZE is zero, return the number of supplementary groups
 699    the calling process is in.  Otherwise, fill in the group IDs
 700    of its supplementary groups in LIST and return the number written.  */
 701 extern int getgroups (int __size, __gid_t __list[]) __THROW __wur
 702     __attr_access ((__write_only__, 2, 1));
 703 #ifdef  __USE_GNU
 704 /* Return nonzero iff the calling process is in group GID.  */
 705 extern int group_member (__gid_t __gid) __THROW;
 706 #endif
 707
 708 /* Set the user ID of the calling process to UID.
 709    If the calling process is the super-user, set the real
 710    and effective user IDs, and the saved set-user-ID to UID;
 711    if not, the effective user ID is set to UID.  */
 712 extern int setuid (__uid_t __uid) __THROW __wur;
 713
 714 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 715 /* Set the real user ID of the calling process to RUID,
 716    and the effective user ID of the calling process to EUID.  */
 717 extern int setreuid (__uid_t __ruid, __uid_t __euid) __THROW __wur;
 718 #endif
 719
 720 #ifdef __USE_XOPEN2K
 721 /* Set the effective user ID of the calling process to UID.  */
 722 extern int seteuid (__uid_t __uid) __THROW __wur;
 723 #endif /* Use POSIX.1-2001.  */
 724
 725 /* Set the group ID of the calling process to GID.
 726    If the calling process is the super-user, set the real
 727    and effective group IDs, and the saved set-group-ID to GID;
 728    if not, the effective group ID is set to GID.  */
 729 extern int setgid (__gid_t __gid) __THROW __wur;
 730
 731 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 732 /* Set the real group ID of the calling process to RGID,
 733    and the effective group ID of the calling process to EGID.  */
 734 extern int setregid (__gid_t __rgid, __gid_t __egid) __THROW __wur;
 735 #endif
 736
 737 #ifdef __USE_XOPEN2K
 738 /* Set the effective group ID of the calling process to GID.  */
 739 extern int setegid (__gid_t __gid) __THROW __wur;
 740 #endif /* Use POSIX.1-2001.  */
 741
 742 #ifdef __USE_GNU
 743 /* Fetch the real user ID, effective user ID, and saved-set user ID,
 744    of the calling process.  */
 745 extern int getresuid (__uid_t *__ruid, __uid_t *__euid, __uid_t *__suid)
 746      __THROW;
 747
 748 /* Fetch the real group ID, effective group ID, and saved-set group ID,
 749    of the calling process.  */
 750 extern int getresgid (__gid_t *__rgid, __gid_t *__egid, __gid_t *__sgid)
 751      __THROW;
 752
 753 /* Set the real user ID, effective user ID, and saved-set user ID,
 754    of the calling process to RUID, EUID, and SUID, respectively.  */
 755 extern int setresuid (__uid_t __ruid, __uid_t __euid, __uid_t __suid)
 756      __THROW __wur;
 757
 758 /* Set the real group ID, effective group ID, and saved-set group ID,
 759    of the calling process to RGID, EGID, and SGID, respectively.  */
 760 extern int setresgid (__gid_t __rgid, __gid_t __egid, __gid_t __sgid)
 761      __THROW __wur;
 762 #endif
 763
 764
 765 /* Clone the calling process, creating an exact copy.
 766    Return -1 for errors, 0 to the new process,
 767    and the process ID of the new process to the old process.  */
 768 extern __pid_t fork (void) __THROWNL;
 769
 770 #if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \
 771     || defined __USE_MISC
 772 /* Clone the calling process, but without copying the whole address space.
 773    The calling process is suspended until the new process exits or is
 774    replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
 775    and the process ID of the new process to the old process.  */
 776 extern __pid_t vfork (void) __THROW;
 777 #endif /* Use misc or XPG < 7. */
 778
 779
 780 /* Return the pathname of the terminal FD is open on, or NULL on errors.
 781    The returned storage is good only until the next call to this function.  */
 782 extern char *ttyname (int __fd) __THROW;
 783
 784 /* Store at most BUFLEN characters of the pathname of the terminal FD is
 785    open on in BUF.  Return 0 on success, otherwise an error number.  */
 786 extern int ttyname_r (int __fd, char *__buf, size_t __buflen)
 787      __THROW __nonnull ((2)) __wur __attr_access ((__write_only__, 2, 3));
 788
 789 /* Return 1 if FD is a valid descriptor associated
 790    with a terminal, zero if not.  */
 791 extern int isatty (int __fd) __THROW;
 792
 793 #ifdef __USE_MISC
 794 /* Return the index into the active-logins file (utmp) for
 795    the controlling terminal.  */
 796 extern int ttyslot (void) __THROW;
 797 #endif
 798
 799
 800 /* Make a link to FROM named TO.  */
 801 extern int link (const char *__from, const char *__to)
 802      __THROW __nonnull ((1, 2)) __wur;
 803
 804 #ifdef __USE_ATFILE
 805 /* Like link but relative paths in TO and FROM are interpreted relative
 806    to FROMFD and TOFD respectively.  */
 807 extern int linkat (int __fromfd, const char *__from, int __tofd,
 808                    const char *__to, int __flags)
 809      __THROW __nonnull ((2, 4)) __wur;
 810 #endif
 811
 812 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
 813 /* Make a symbolic link to FROM named TO.  */
 814 extern int symlink (const char *__from, const char *__to)
 815      __THROW __nonnull ((1, 2)) __wur;
 816
 817 /* Read the contents of the symbolic link PATH into no more than
 818    LEN bytes of BUF.  The contents are not null-terminated.
 819    Returns the number of characters read, or -1 for errors.  */
 820 extern ssize_t readlink (const char *__restrict __path,
 821                          char *__restrict __buf, size_t __len)
 822      __THROW __nonnull ((1, 2)) __wur __attr_access ((__write_only__, 2, 3));
 823
 824 #endif /* Use POSIX.1-2001.  */
 825
 826 #ifdef __USE_ATFILE
 827 /* Like symlink but a relative path in TO is interpreted relative to TOFD.  */
 828 extern int symlinkat (const char *__from, int __tofd,
 829                       const char *__to) __THROW __nonnull ((1, 3)) __wur;
 830
 831 /* Like readlink but a relative PATH is interpreted relative to FD.  */
 832 extern ssize_t readlinkat (int __fd, const char *__restrict __path,
 833                            char *__restrict __buf, size_t __len)
 834      __THROW __nonnull ((2, 3)) __wur __attr_access ((__write_only__, 3, 4));
 835 #endif
 836
 837 /* Remove the link NAME.  */
 838 extern int unlink (const char *__name) __THROW __nonnull ((1));
 839
 840 #ifdef __USE_ATFILE
 841 /* Remove the link NAME relative to FD.  */
 842 extern int unlinkat (int __fd, const char *__name, int __flag)
 843      __THROW __nonnull ((2));
 844 #endif
 845
 846 /* Remove the directory PATH.  */
 847 extern int rmdir (const char *__path) __THROW __nonnull ((1));
 848
 849
 850 /* Return the foreground process group ID of FD.  */
 851 extern __pid_t tcgetpgrp (int __fd) __THROW;
 852
 853 /* Set the foreground process group ID of FD set PGRP_ID.  */
 854 extern int tcsetpgrp (int __fd, __pid_t __pgrp_id) __THROW;
 855
 856
 857 /* Return the login name of the user.
 858
 859    This function is a possible cancellation point and therefore not
 860    marked with __THROW.  */
 861 extern char *getlogin (void);
 862 #ifdef __USE_POSIX199506
 863 /* Return at most NAME_LEN characters of the login name of the user in NAME.
 864    If it cannot be determined or some other error occurred, return the error
 865    code.  Otherwise return 0.
 866
 867    This function is a possible cancellation point and therefore not
 868    marked with __THROW.  */
 869 extern int getlogin_r (char *__name, size_t __name_len) __nonnull ((1))
 870     __attr_access ((__write_only__, 1, 2));
 871 #endif
 872
 873 #ifdef  __USE_MISC
 874 /* Set the login name returned by `getlogin'.  */
 875 extern int setlogin (const char *__name) __THROW __nonnull ((1));
 876 #endif
 877
 878
 879 #ifdef  __USE_POSIX2
 880 /* Get definitions and prototypes for functions to process the
 881    arguments in ARGV (ARGC of them, minus the program name) for
 882    options given in OPTS.  */
 883 # include <bits/getopt_posix.h>
 884 #endif
 885
 886
 887 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
 888 /* Put the name of the current host in no more than LEN bytes of NAME.
 889    The result is null-terminated if LEN is large enough for the full
 890    name and the terminator.  */
 891 extern int gethostname (char *__name, size_t __len) __THROW __nonnull ((1))
 892     __attr_access ((__write_only__, 1, 2));
 893 #endif
 894
 895
 896 #if defined __USE_MISC
 897 /* Set the name of the current host to NAME, which is LEN bytes long.
 898    This call is restricted to the super-user.  */
 899 extern int sethostname (const char *__name, size_t __len)
 900      __THROW __nonnull ((1)) __wur __attr_access ((__read_only__, 1, 2));
 901
 902 /* Set the current machine's Internet number to ID.
 903    This call is restricted to the super-user.  */
 904 extern int sethostid (long int __id) __THROW __wur;
 905
 906
 907 /* Get and set the NIS (aka YP) domain name, if any.
 908    Called just like `gethostname' and `sethostname'.
 909    The NIS domain name is usually the empty string when not using NIS.  */
 910 extern int getdomainname (char *__name, size_t __len)
 911      __THROW __nonnull ((1)) __wur __attr_access ((__write_only__, 1, 2));
 912 extern int setdomainname (const char *__name, size_t __len)
 913      __THROW __nonnull ((1)) __wur __attr_access ((__read_only__, 1, 2));
 914
 915 /* Revoke access permissions to all processes currently communicating
 916    with the control terminal, and then send a SIGHUP signal to the process
 917    group of the control terminal.  */
 918 extern int vhangup (void) __THROW;
 919
 920 /* Revoke the access of all descriptors currently open on FILE.  */
 921 extern int revoke (const char *__file) __THROW __nonnull ((1)) __wur;
 922
 923
 924 /* Enable statistical profiling, writing samples of the PC into at most
 925    SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
 926    is enabled, the system examines the user PC and increments
 927    SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536].  If SCALE is zero,
 928    disable profiling.  Returns zero on success, -1 on error.  */
 929 extern int profil (unsigned short int *__sample_buffer, size_t __size,
 930                    size_t __offset, unsigned int __scale)
 931      __THROW __nonnull ((1));
 932
 933
 934 /* Turn accounting on if NAME is an existing file.  The system will then write
 935    a record for each process as it terminates, to this file.  If NAME is NULL,
 936    turn accounting off.  This call is restricted to the super-user.  */
 937 extern int acct (const char *__name) __THROW;
 938
 939
 940 /* Successive calls return the shells listed in `/etc/shells'.  */
 941 extern char *getusershell (void) __THROW;
 942 extern void endusershell (void) __THROW; /* Discard cached info.  */
 943 extern void setusershell (void) __THROW; /* Rewind and re-read the file.  */
 944
 945
 946 /* Put the program in the background, and dissociate from the controlling
 947    terminal.  If NOCHDIR is zero, do `chdir ("/")'.  If NOCLOSE is zero,
 948    redirects stdin, stdout, and stderr to /dev/null.  */
 949 extern int daemon (int __nochdir, int __noclose) __THROW __wur;
 950 #endif /* Use misc.  */
 951
 952
 953 #if defined __USE_MISC || (defined __USE_XOPEN && !defined __USE_XOPEN2K)
 954 /* Make PATH be the root directory (the starting point for absolute paths).
 955    This call is restricted to the super-user.  */
 956 extern int chroot (const char *__path) __THROW __nonnull ((1)) __wur;
 957
 958 /* Prompt with PROMPT and read a string from the terminal without echoing.
 959    Uses /dev/tty if possible; otherwise stderr and stdin.  */
 960 extern char *getpass (const char *__prompt) __nonnull ((1));
 961 #endif /* Use misc || X/Open.  */
 962
 963
 964 /* Make all changes done to FD actually appear on disk.
 965
 966    This function is a cancellation point and therefore not marked with
 967    __THROW.  */
 968 extern int fsync (int __fd);
 969
 970
 971 #ifdef __USE_GNU
 972 /* Make all changes done to all files on the file system associated
 973    with FD actually appear on disk.  */
 974 extern int syncfs (int __fd) __THROW;
 975 #endif
 976
 977
 978 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 979
 980 /* Return identifier for the current host.  */
 981 extern long int gethostid (void);
 982
 983 /* Make all changes done to all files actually appear on disk.  */
 984 extern void sync (void) __THROW;
 985
 986
 987 # if defined __USE_MISC || !defined __USE_XOPEN2K
 988 /* Return the number of bytes in a page.  This is the system's page size,
 989    which is not necessarily the same as the hardware page size.  */
 990 extern int getpagesize (void)  __THROW __attribute__ ((__const__));
 991
 992
 993 /* Return the maximum number of file descriptors
 994    the current process could possibly have.  */
 995 extern int getdtablesize (void) __THROW;
 996 # endif
 997
 998 #endif /* Use misc || X/Open Unix.  */
 999
1000
1001 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
1002
1003 /* Truncate FILE to LENGTH bytes.  */
1004 # ifndef __USE_FILE_OFFSET64
1005 extern int truncate (const char *__file, __off_t __length)
1006      __THROW __nonnull ((1)) __wur;
1007 # else
1008 #  ifdef __REDIRECT_NTH
1009 extern int __REDIRECT_NTH (truncate,
1010                            (const char *__file, __off64_t __length),
1011                            truncate64) __nonnull ((1)) __wur;
1012 #  else
1013 #   define truncate truncate64
1014 #  endif
1015 # endif
1016 # ifdef __USE_LARGEFILE64
1017 extern int truncate64 (const char *__file, __off64_t __length)
1018      __THROW __nonnull ((1)) __wur;
1019 # endif
1020
1021 #endif /* Use X/Open Unix || POSIX 2008.  */
1022
1023 #if defined __USE_POSIX199309 \
1024     || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
1025
1026 /* Truncate the file FD is open on to LENGTH bytes.  */
1027 # ifndef __USE_FILE_OFFSET64
1028 extern int ftruncate (int __fd, __off_t __length) __THROW __wur;
1029 # else
1030 #  ifdef __REDIRECT_NTH
1031 extern int __REDIRECT_NTH (ftruncate, (int __fd, __off64_t __length),
1032                            ftruncate64) __wur;
1033 #  else
1034 #   define ftruncate ftruncate64
1035 #  endif
1036 # endif
1037 # ifdef __USE_LARGEFILE64
1038 extern int ftruncate64 (int __fd, __off64_t __length) __THROW __wur;
1039 # endif
1040
1041 #endif /* Use POSIX.1b || X/Open Unix || XPG6.  */
1042
1043
1044 #if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K) \
1045     || defined __USE_MISC
1046
1047 /* Set the end of accessible data space (aka "the break") to ADDR.
1048    Returns zero on success and -1 for errors (with errno set).  */
1049 extern int brk (void *__addr) __THROW __wur;
1050
1051 /* Increase or decrease the end of accessible data space by DELTA bytes.
1052    If successful, returns the address the previous end of data space
1053    (i.e. the beginning of the new space, if DELTA > 0);
1054    returns (void *) -1 for errors (with errno set).  */
1055 extern void *sbrk (intptr_t __delta) __THROW;
1056 #endif
1057
1058
1059 #ifdef __USE_MISC
1060 /* Invoke `system call' number SYSNO, passing it the remaining arguments.
1061    This is completely system-dependent, and not often useful.
1062
1063    In Unix, `syscall' sets `errno' for all errors and most calls return -1
1064    for errors; in many systems you cannot pass arguments or get return
1065    values for all system calls (`pipe', `fork', and `getppid' typically
1066    among them).
1067
1068    In Mach, all system calls take normal arguments and always return an
1069    error code (zero for success).  */
1070 extern long int syscall (long int __sysno, ...) __THROW;
1071
1072 #endif  /* Use misc.  */
1073
1074
1075 #if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK
1076 /* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both
1077    files consistent.  Some systems have them there and some here, and some
1078    software depends on the macros being defined without including both.  */
1079
1080 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
1081    LEN is always relative to the current file position.
1082    The CMD argument is one of the following.
1083
1084    This function is a cancellation point and therefore not marked with
1085    __THROW.  */
1086
1087 # define F_ULOCK 0      /* Unlock a previously locked region.  */
1088 # define F_LOCK  1      /* Lock a region for exclusive use.  */
1089 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
1090 # define F_TEST  3      /* Test a region for other processes locks.  */
1091
1092 # ifndef __USE_FILE_OFFSET64
1093 extern int lockf (int __fd, int __cmd, __off_t __len) __wur;
1094 # else
1095 #  ifdef __REDIRECT
1096 extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len),
1097                        lockf64) __wur;
1098 #  else
1099 #   define lockf lockf64
1100 #  endif
1101 # endif
1102 # ifdef __USE_LARGEFILE64
1103 extern int lockf64 (int __fd, int __cmd, __off64_t __len) __wur;
1104 # endif
1105 #endif /* Use misc and F_LOCK not already defined.  */
1106
1107
1108 #ifdef __USE_GNU
1109
1110 /* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno'
1111    set to EINTR.  */
1112
1113 # define TEMP_FAILURE_RETRY(expression) \
1114   (__extension__                                                              \
1115     ({ long int __result;                                                     \
1116        do __result = (long int) (expression);                                 \
1117        while (__result == -1L && errno == EINTR);                             \
1118        __result; }))
1119
1120 /* Copy LENGTH bytes from INFD to OUTFD.  */
1121 ssize_t copy_file_range (int __infd, __off64_t *__pinoff,
1122                          int __outfd, __off64_t *__poutoff,
1123                          size_t __length, unsigned int __flags);
1124 #endif /* __USE_GNU */
1125
1126 #if defined __USE_POSIX199309 || defined __USE_UNIX98
1127 /* Synchronize at least the data part of a file with the underlying
1128    media.  */
1129 extern int fdatasync (int __fildes);
1130 #endif /* Use POSIX199309 */
1131
1132 #ifdef __USE_MISC
1133 /* One-way hash PHRASE, returning a string suitable for storage in the
1134    user database.  SALT selects the one-way function to use, and
1135    ensures that no two users' hashes are the same, even if they use
1136    the same passphrase.  The return value points to static storage
1137    which will be overwritten by the next call to crypt.  */
1138 extern char *crypt (const char *__key, const char *__salt)
1139      __THROW __nonnull ((1, 2));
1140 #endif
1141
1142 #ifdef  __USE_XOPEN
1143 /* Swab pairs bytes in the first N bytes of the area pointed to by
1144    FROM and copy the result to TO.  The value of TO must not be in the
1145    range [FROM - N + 1, FROM - 1].  If N is odd the first byte in FROM
1146    is without partner.  */
1147 extern void swab (const void *__restrict __from, void *__restrict __to,
1148                   ssize_t __n) __THROW __nonnull ((1, 2))
1149     __attr_access ((__read_only__, 1, 3))
1150     __attr_access ((__write_only__, 2, 3));
1151 #endif
1152
1153
1154 /* Prior to Issue 6, the Single Unix Specification required these
1155    prototypes to appear in this header.  They are also found in
1156    <stdio.h>.  */
1157 #if defined __USE_XOPEN && !defined __USE_XOPEN2K
1158 /* Return the name of the controlling terminal.  */
1159 extern char *ctermid (char *__s) __THROW;
1160
1161 /* Return the name of the current user.  */
1162 extern char *cuserid (char *__s);
1163 #endif
1164
1165
1166 /* Unix98 requires this function to be declared here.  In other
1167    standards it is in <pthread.h>.  */
1168 #if defined __USE_UNIX98 && !defined __USE_XOPEN2K
1169 extern int pthread_atfork (void (*__prepare) (void),
1170                            void (*__parent) (void),
1171                            void (*__child) (void)) __THROW;
1172 #endif
1173
1174 #ifdef __USE_MISC
1175 /* Write LENGTH bytes of randomness starting at BUFFER.  Return 0 on
1176    success or -1 on error.  */
1177 int getentropy (void *__buffer, size_t __length) __wur
1178     __attr_access ((__write_only__, 1, 2));
1179 #endif
1180
1181 /* Define some macros helping to catch buffer overflows.  */
1182 #if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
1183 # include <bits/unistd.h>
1184 #endif
1185
1186 /* System-specific extensions.  */
1187 #include <bits/unistd_ext.h>
1188
1189 __END_DECLS
1190
1191 #endif /* unistd.h  */