posix/unistd.h

   1 /* Copyright (C) 1991-2016 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    <http://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 /* Encryption is present.  */
 111 #define _XOPEN_CRYPT    1
 112
 113 /* The enhanced internationalization capabilities according to XPG4.2
 114    are present.  */
 115 #define _XOPEN_ENH_I18N 1
 116
 117 /* The legacy interfaces are also available.  */
 118 #define _XOPEN_LEGACY   1
 119
 120
 121 /* Get values of POSIX options:
 122
 123    If these symbols are defined, the corresponding features are
 124    always available.  If not, they may be available sometimes.
 125    The current values can be obtained with `sysconf'.
 126
 127    _POSIX_JOB_CONTROL           Job control is supported.
 128    _POSIX_SAVED_IDS             Processes have a saved set-user-ID
 129                                 and a saved set-group-ID.
 130    _POSIX_REALTIME_SIGNALS      Real-time, queued signals are supported.
 131    _POSIX_PRIORITY_SCHEDULING   Priority scheduling is supported.
 132    _POSIX_TIMERS                POSIX.4 clocks and timers are supported.
 133    _POSIX_ASYNCHRONOUS_IO       Asynchronous I/O is supported.
 134    _POSIX_PRIORITIZED_IO        Prioritized asynchronous I/O is supported.
 135    _POSIX_SYNCHRONIZED_IO       Synchronizing file data is supported.
 136    _POSIX_FSYNC                 The fsync function is present.
 137    _POSIX_MAPPED_FILES          Mapping of files to memory is supported.
 138    _POSIX_MEMLOCK               Locking of all memory is supported.
 139    _POSIX_MEMLOCK_RANGE         Locking of ranges of memory is supported.
 140    _POSIX_MEMORY_PROTECTION     Setting of memory protections is supported.
 141    _POSIX_MESSAGE_PASSING       POSIX.4 message queues are supported.
 142    _POSIX_SEMAPHORES            POSIX.4 counting semaphores are supported.
 143    _POSIX_SHARED_MEMORY_OBJECTS POSIX.4 shared memory objects are supported.
 144    _POSIX_THREADS               POSIX.1c pthreads are supported.
 145    _POSIX_THREAD_ATTR_STACKADDR Thread stack address attribute option supported.
 146    _POSIX_THREAD_ATTR_STACKSIZE Thread stack size attribute option supported.
 147    _POSIX_THREAD_SAFE_FUNCTIONS Thread-safe functions are supported.
 148    _POSIX_THREAD_PRIORITY_SCHEDULING
 149                                 POSIX.1c thread execution scheduling supported.
 150    _POSIX_THREAD_PRIO_INHERIT   Thread priority inheritance option supported.
 151    _POSIX_THREAD_PRIO_PROTECT   Thread priority protection option supported.
 152    _POSIX_THREAD_PROCESS_SHARED Process-shared synchronization supported.
 153    _POSIX_PII                   Protocol-independent interfaces are supported.
 154    _POSIX_PII_XTI               XTI protocol-indep. interfaces are supported.
 155    _POSIX_PII_SOCKET            Socket protocol-indep. interfaces are supported.
 156    _POSIX_PII_INTERNET          Internet family of protocols supported.
 157    _POSIX_PII_INTERNET_STREAM   Connection-mode Internet protocol supported.
 158    _POSIX_PII_INTERNET_DGRAM    Connectionless Internet protocol supported.
 159    _POSIX_PII_OSI               ISO/OSI family of protocols supported.
 160    _POSIX_PII_OSI_COTS          Connection-mode ISO/OSI service supported.
 161    _POSIX_PII_OSI_CLTS          Connectionless ISO/OSI service supported.
 162    _POSIX_POLL                  Implementation supports `poll' function.
 163    _POSIX_SELECT                Implementation supports `select' and `pselect'.
 164
 165    _XOPEN_REALTIME              X/Open realtime support is available.
 166    _XOPEN_REALTIME_THREADS      X/Open realtime thread support is available.
 167    _XOPEN_SHM                   Shared memory interface according to XPG4.2.
 168
 169    _XBS5_ILP32_OFF32            Implementation provides environment with 32-bit
 170                                 int, long, pointer, and off_t types.
 171    _XBS5_ILP32_OFFBIG           Implementation provides environment with 32-bit
 172                                 int, long, and pointer and off_t with at least
 173                                 64 bits.
 174    _XBS5_LP64_OFF64             Implementation provides environment with 32-bit
 175                                 int, and 64-bit long, pointer, and off_t types.
 176    _XBS5_LPBIG_OFFBIG           Implementation provides environment with at
 177                                 least 32 bits int and long, pointer, and off_t
 178                                 with at least 64 bits.
 179
 180    If any of these symbols is defined as -1, the corresponding option is not
 181    true for any file.  If any is defined as other than -1, the corresponding
 182    option is true for all files.  If a symbol is not defined at all, the value
 183    for a specific file can be obtained from `pathconf' and `fpathconf'.
 184
 185    _POSIX_CHOWN_RESTRICTED      Only the super user can use `chown' to change
 186                                 the owner of a file.  `chown' can only be used
 187                                 to change the group ID of a file to a group of
 188                                 which the calling process is a member.
 189    _POSIX_NO_TRUNC              Pathname components longer than
 190                                 NAME_MAX generate an error.
 191    _POSIX_VDISABLE              If defined, if the value of an element of the
 192                                 `c_cc' member of `struct termios' is
 193                                 _POSIX_VDISABLE, no character will have the
 194                                 effect associated with that element.
 195    _POSIX_SYNC_IO               Synchronous I/O may be performed.
 196    _POSIX_ASYNC_IO              Asynchronous I/O may be performed.
 197    _POSIX_PRIO_IO               Prioritized Asynchronous I/O may be performed.
 198
 199    Support for the Large File Support interface is not generally available.
 200    If it is available the following constants are defined to one.
 201    _LFS64_LARGEFILE             Low-level I/O supports large files.
 202    _LFS64_STDIO                 Standard I/O supports large files.
 203    */
 204
 205 #include <bits/posix_opt.h>
 206
 207 /* Get the environment definitions from Unix98.  */
 208 #if defined __USE_UNIX98 || defined __USE_XOPEN2K
 209 # include <bits/environments.h>
 210 #endif
 211
 212 /* Standard file descriptors.  */
 213 #define STDIN_FILENO    0       /* Standard input.  */
 214 #define STDOUT_FILENO   1       /* Standard output.  */
 215 #define STDERR_FILENO   2       /* Standard error output.  */
 216
 217
 218 /* All functions that are not declared anywhere else.  */
 219
 220 #include <bits/types.h>
 221
 222 #ifndef __ssize_t_defined
 223 typedef __ssize_t ssize_t;
 224 # define __ssize_t_defined
 225 #endif
 226
 227 #define __need_size_t
 228 #define __need_NULL
 229 #include <stddef.h>
 230
 231 #if defined __USE_XOPEN || defined __USE_XOPEN2K
 232 /* The Single Unix specification says that some more types are
 233    available here.  */
 234 # ifndef __gid_t_defined
 235 typedef __gid_t gid_t;
 236 #  define __gid_t_defined
 237 # endif
 238
 239 # ifndef __uid_t_defined
 240 typedef __uid_t uid_t;
 241 #  define __uid_t_defined
 242 # endif
 243
 244 # ifndef __off_t_defined
 245 #  ifndef __USE_FILE_OFFSET64
 246 typedef __off_t off_t;
 247 #  else
 248 typedef __off64_t off_t;
 249 #  endif
 250 #  define __off_t_defined
 251 # endif
 252 # if defined __USE_LARGEFILE64 && !defined __off64_t_defined
 253 typedef __off64_t off64_t;
 254 #  define __off64_t_defined
 255 # endif
 256
 257 # ifndef __useconds_t_defined
 258 typedef __useconds_t useconds_t;
 259 #  define __useconds_t_defined
 260 # endif
 261
 262 # ifndef __pid_t_defined
 263 typedef __pid_t pid_t;
 264 #  define __pid_t_defined
 265 # endif
 266 #endif  /* X/Open */
 267
 268 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
 269 # ifndef __intptr_t_defined
 270 typedef __intptr_t intptr_t;
 271 #  define __intptr_t_defined
 272 # endif
 273 #endif
 274
 275 #if defined __USE_MISC || defined __USE_XOPEN
 276 # ifndef __socklen_t_defined
 277 typedef __socklen_t socklen_t;
 278 #  define __socklen_t_defined
 279 # endif
 280 #endif
 281
 282 /* Values for the second argument to access.
 283    These may be OR'd together.  */
 284 #define R_OK    4               /* Test for read permission.  */
 285 #define W_OK    2               /* Test for write permission.  */
 286 #define X_OK    1               /* Test for execute permission.  */
 287 #define F_OK    0               /* Test for existence.  */
 288
 289 /* Test for access to NAME using the real UID and real GID.  */
 290 extern int access (const char *__name, int __type) __THROW __nonnull ((1));
 291
 292 #ifdef __USE_GNU
 293 /* Test for access to NAME using the effective UID and GID
 294    (as normal file operations use).  */
 295 extern int euidaccess (const char *__name, int __type)
 296      __THROW __nonnull ((1));
 297
 298 /* An alias for `euidaccess', used by some other systems.  */
 299 extern int eaccess (const char *__name, int __type)
 300      __THROW __nonnull ((1));
 301 #endif
 302
 303 #ifdef __USE_ATFILE
 304 /* Test for access to FILE relative to the directory FD is open on.
 305    If AT_EACCESS is set in FLAG, then use effective IDs like `eaccess',
 306    otherwise use real IDs like `access'.  */
 307 extern int faccessat (int __fd, const char *__file, int __type, int __flag)
 308      __THROW __nonnull ((2)) __wur;
 309 #endif /* Use GNU.  */
 310
 311
 312 /* Values for the WHENCE argument to lseek.  */
 313 #ifndef _STDIO_H                /* <stdio.h> has the same definitions.  */
 314 # define SEEK_SET       0       /* Seek from beginning of file.  */
 315 # define SEEK_CUR       1       /* Seek from current position.  */
 316 # define SEEK_END       2       /* Seek from end of file.  */
 317 # ifdef __USE_GNU
 318 #  define SEEK_DATA     3       /* Seek to next data.  */
 319 #  define SEEK_HOLE     4       /* Seek to next hole.  */
 320 # endif
 321 #endif
 322
 323 #if defined __USE_MISC && !defined L_SET
 324 /* Old BSD names for the same constants; just for compatibility.  */
 325 # define L_SET          SEEK_SET
 326 # define L_INCR         SEEK_CUR
 327 # define L_XTND         SEEK_END
 328 #endif
 329
 330
 331 /* Move FD's file position to OFFSET bytes from the
 332    beginning of the file (if WHENCE is SEEK_SET),
 333    the current position (if WHENCE is SEEK_CUR),
 334    or the end of the file (if WHENCE is SEEK_END).
 335    Return the new file position.  */
 336 #ifndef __USE_FILE_OFFSET64
 337 extern __off_t lseek (int __fd, __off_t __offset, int __whence) __THROW;
 338 #else
 339 # ifdef __REDIRECT_NTH
 340 extern __off64_t __REDIRECT_NTH (lseek,
 341                                  (int __fd, __off64_t __offset, int __whence),
 342                                  lseek64);
 343 # else
 344 #  define lseek lseek64
 345 # endif
 346 #endif
 347 #ifdef __USE_LARGEFILE64
 348 extern __off64_t lseek64 (int __fd, __off64_t __offset, int __whence)
 349      __THROW;
 350 #endif
 351
 352 /* Close the file descriptor FD.
 353
 354    This function is a cancellation point and therefore not marked with
 355    __THROW.  */
 356 extern int close (int __fd);
 357
 358 /* Read NBYTES into BUF from FD.  Return the
 359    number read, -1 for errors or 0 for EOF.
 360
 361    This function is a cancellation point and therefore not marked with
 362    __THROW.  */
 363 extern ssize_t read (int __fd, void *__buf, size_t __nbytes) __wur;
 364
 365 /* Write N bytes of BUF to FD.  Return the number written, or -1.
 366
 367    This function is a cancellation point and therefore not marked with
 368    __THROW.  */
 369 extern ssize_t write (int __fd, const void *__buf, size_t __n) __wur;
 370
 371 #if defined __USE_UNIX98 || defined __USE_XOPEN2K8
 372 # ifndef __USE_FILE_OFFSET64
 373 /* Read NBYTES into BUF from FD at the given position OFFSET without
 374    changing the file pointer.  Return the number read, -1 for errors
 375    or 0 for EOF.
 376
 377    This function is a cancellation point and therefore not marked with
 378    __THROW.  */
 379 extern ssize_t pread (int __fd, void *__buf, size_t __nbytes,
 380                       __off_t __offset) __wur;
 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 # else
 390 #  ifdef __REDIRECT
 391 extern ssize_t __REDIRECT (pread, (int __fd, void *__buf, size_t __nbytes,
 392                                    __off64_t __offset),
 393                            pread64) __wur;
 394 extern ssize_t __REDIRECT (pwrite, (int __fd, const void *__buf,
 395                                     size_t __nbytes, __off64_t __offset),
 396                            pwrite64) __wur;
 397 #  else
 398 #   define pread pread64
 399 #   define pwrite pwrite64
 400 #  endif
 401 # endif
 402
 403 # ifdef __USE_LARGEFILE64
 404 /* Read NBYTES into BUF from FD at the given position OFFSET without
 405    changing the file pointer.  Return the number read, -1 for errors
 406    or 0 for EOF.  */
 407 extern ssize_t pread64 (int __fd, void *__buf, size_t __nbytes,
 408                         __off64_t __offset) __wur;
 409 /* Write N bytes of BUF to FD at the given position OFFSET without
 410    changing the file pointer.  Return the number written, or -1.  */
 411 extern ssize_t pwrite64 (int __fd, const void *__buf, size_t __n,
 412                          __off64_t __offset) __wur;
 413 # endif
 414 #endif
 415
 416 /* Create a one-way communication channel (pipe).
 417    If successful, two file descriptors are stored in PIPEDES;
 418    bytes written on PIPEDES[1] can be read from PIPEDES[0].
 419    Returns 0 if successful, -1 if not.  */
 420 extern int pipe (int __pipedes[2]) __THROW __wur;
 421
 422 #ifdef __USE_GNU
 423 /* Same as pipe but apply flags passed in FLAGS to the new file
 424    descriptors.  */
 425 extern int pipe2 (int __pipedes[2], int __flags) __THROW __wur;
 426 #endif
 427
 428 /* Schedule an alarm.  In SECONDS seconds, the process will get a SIGALRM.
 429    If SECONDS is zero, any currently scheduled alarm will be cancelled.
 430    The function returns the number of seconds remaining until the last
 431    alarm scheduled would have signaled, or zero if there wasn't one.
 432    There is no return value to indicate an error, but you can set `errno'
 433    to 0 and check its value after calling `alarm', and this might tell you.
 434    The signal may come late due to processor scheduling.  */
 435 extern unsigned int alarm (unsigned int __seconds) __THROW;
 436
 437 /* Make the process sleep for SECONDS seconds, or until a signal arrives
 438    and is not ignored.  The function returns the number of seconds less
 439    than SECONDS which it actually slept (thus zero if it slept the full time).
 440    If a signal handler does a `longjmp' or modifies the handling of the
 441    SIGALRM signal while inside `sleep' call, the handling of the SIGALRM
 442    signal afterwards is undefined.  There is no return value to indicate
 443    error, but if `sleep' returns SECONDS, it probably didn't work.
 444
 445    This function is a cancellation point and therefore not marked with
 446    __THROW.  */
 447 extern unsigned int sleep (unsigned int __seconds);
 448
 449 #if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \
 450     || defined __USE_MISC
 451 /* Set an alarm to go off (generating a SIGALRM signal) in VALUE
 452    microseconds.  If INTERVAL is nonzero, when the alarm goes off, the
 453    timer is reset to go off every INTERVAL microseconds thereafter.
 454    Returns the number of microseconds remaining before the alarm.  */
 455 extern __useconds_t ualarm (__useconds_t __value, __useconds_t __interval)
 456      __THROW;
 457
 458 /* Sleep USECONDS microseconds, or until a signal arrives that is not blocked
 459    or ignored.
 460
 461    This function is a cancellation point and therefore not marked with
 462    __THROW.  */
 463 extern int usleep (__useconds_t __useconds);
 464 #endif
 465
 466
 467 /* Suspend the process until a signal arrives.
 468    This always returns -1 and sets `errno' to EINTR.
 469
 470    This function is a cancellation point and therefore not marked with
 471    __THROW.  */
 472 extern int pause (void);
 473
 474
 475 /* Change the owner and group of FILE.  */
 476 extern int chown (const char *__file, __uid_t __owner, __gid_t __group)
 477      __THROW __nonnull ((1)) __wur;
 478
 479 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
 480 /* Change the owner and group of the file that FD is open on.  */
 481 extern int fchown (int __fd, __uid_t __owner, __gid_t __group) __THROW __wur;
 482
 483
 484 /* Change owner and group of FILE, if it is a symbolic
 485    link the ownership of the symbolic link is changed.  */
 486 extern int lchown (const char *__file, __uid_t __owner, __gid_t __group)
 487      __THROW __nonnull ((1)) __wur;
 488
 489 #endif /* Use X/Open Unix.  */
 490
 491 #ifdef __USE_ATFILE
 492 /* Change the owner and group of FILE relative to the directory FD is open
 493    on.  */
 494 extern int fchownat (int __fd, const char *__file, __uid_t __owner,
 495                      __gid_t __group, int __flag)
 496      __THROW __nonnull ((2)) __wur;
 497 #endif /* Use GNU.  */
 498
 499 /* Change the process's working directory to PATH.  */
 500 extern int chdir (const char *__path) __THROW __nonnull ((1)) __wur;
 501
 502 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
 503 /* Change the process's working directory to the one FD is open on.  */
 504 extern int fchdir (int __fd) __THROW __wur;
 505 #endif
 506
 507 /* Get the pathname of the current working directory,
 508    and put it in SIZE bytes of BUF.  Returns NULL if the
 509    directory couldn't be determined or SIZE was too small.
 510    If successful, returns BUF.  In GNU, if BUF is NULL,
 511    an array is allocated with `malloc'; the array is SIZE
 512    bytes long, unless SIZE == 0, in which case it is as
 513    big as necessary.  */
 514 extern char *getcwd (char *__buf, size_t __size) __THROW __wur;
 515
 516 #ifdef  __USE_GNU
 517 /* Return a malloc'd string containing the current directory name.
 518    If the environment variable `PWD' is set, and its value is correct,
 519    that value is used.  */
 520 extern char *get_current_dir_name (void) __THROW;
 521 #endif
 522
 523 #if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \
 524     || defined __USE_MISC
 525 /* Put the absolute pathname of the current working directory in BUF.
 526    If successful, return BUF.  If not, put an error message in
 527    BUF and return NULL.  BUF should be at least PATH_MAX bytes long.  */
 528 extern char *getwd (char *__buf)
 529      __THROW __nonnull ((1)) __attribute_deprecated__ __wur;
 530 #endif
 531
 532
 533 /* Duplicate FD, returning a new file descriptor on the same file.  */
 534 extern int dup (int __fd) __THROW __wur;
 535
 536 /* Duplicate FD to FD2, closing FD2 and making it open on the same file.  */
 537 extern int dup2 (int __fd, int __fd2) __THROW;
 538
 539 #ifdef __USE_GNU
 540 /* Duplicate FD to FD2, closing FD2 and making it open on the same
 541    file while setting flags according to FLAGS.  */
 542 extern int dup3 (int __fd, int __fd2, int __flags) __THROW;
 543 #endif
 544
 545 /* NULL-terminated array of "NAME=VALUE" environment variables.  */
 546 extern char **__environ;
 547 #ifdef __USE_GNU
 548 extern char **environ;
 549 #endif
 550
 551
 552 /* Replace the current process, executing PATH with arguments ARGV and
 553    environment ENVP.  ARGV and ENVP are terminated by NULL pointers.  */
 554 extern int execve (const char *__path, char *const __argv[],
 555                    char *const __envp[]) __THROW __nonnull ((1, 2));
 556
 557 #ifdef __USE_XOPEN2K8
 558 /* Execute the file FD refers to, overlaying the running program image.
 559    ARGV and ENVP are passed to the new program, as for `execve'.  */
 560 extern int fexecve (int __fd, char *const __argv[], char *const __envp[])
 561      __THROW __nonnull ((2));
 562 #endif
 563
 564
 565 /* Execute PATH with arguments ARGV and environment from `environ'.  */
 566 extern int execv (const char *__path, char *const __argv[])
 567      __THROW __nonnull ((1, 2));
 568
 569 /* Execute PATH with all arguments after PATH until a NULL pointer,
 570    and the argument after that for environment.  */
 571 extern int execle (const char *__path, const char *__arg, ...)
 572      __THROW __nonnull ((1, 2));
 573
 574 /* Execute PATH with all arguments after PATH until
 575    a NULL pointer and environment from `environ'.  */
 576 extern int execl (const char *__path, const char *__arg, ...)
 577      __THROW __nonnull ((1, 2));
 578
 579 /* Execute FILE, searching in the `PATH' environment variable if it contains
 580    no slashes, with arguments ARGV and environment from `environ'.  */
 581 extern int execvp (const char *__file, char *const __argv[])
 582      __THROW __nonnull ((1, 2));
 583
 584 /* Execute FILE, searching in the `PATH' environment variable if
 585    it contains no slashes, with all arguments after FILE until a
 586    NULL pointer and environment from `environ'.  */
 587 extern int execlp (const char *__file, const char *__arg, ...)
 588      __THROW __nonnull ((1, 2));
 589
 590 #ifdef __USE_GNU
 591 /* Execute FILE, searching in the `PATH' environment variable if it contains
 592    no slashes, with arguments ARGV and environment from `environ'.  */
 593 extern int execvpe (const char *__file, char *const __argv[],
 594                     char *const __envp[])
 595      __THROW __nonnull ((1, 2));
 596 #endif
 597
 598
 599 #if defined __USE_MISC || defined __USE_XOPEN
 600 /* Add INC to priority of the current process.  */
 601 extern int nice (int __inc) __THROW __wur;
 602 #endif
 603
 604
 605 /* Terminate program execution with the low-order 8 bits of STATUS.  */
 606 extern void _exit (int __status) __attribute__ ((__noreturn__));
 607
 608
 609 /* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf';
 610    the `_SC_*' symbols for the NAME argument to `sysconf';
 611    and the `_CS_*' symbols for the NAME argument to `confstr'.  */
 612 #include <bits/confname.h>
 613
 614 /* Get file-specific configuration information about PATH.  */
 615 extern long int pathconf (const char *__path, int __name)
 616      __THROW __nonnull ((1));
 617
 618 /* Get file-specific configuration about descriptor FD.  */
 619 extern long int fpathconf (int __fd, int __name) __THROW;
 620
 621 /* Get the value of the system variable NAME.  */
 622 extern long int sysconf (int __name) __THROW;
 623
 624 #ifdef  __USE_POSIX2
 625 /* Get the value of the string-valued system variable NAME.  */
 626 extern size_t confstr (int __name, char *__buf, size_t __len) __THROW;
 627 #endif
 628
 629
 630 /* Get the process ID of the calling process.  */
 631 extern __pid_t getpid (void) __THROW;
 632
 633 /* Get the process ID of the calling process's parent.  */
 634 extern __pid_t getppid (void) __THROW;
 635
 636 /* Get the process group ID of the calling process.  */
 637 extern __pid_t getpgrp (void) __THROW;
 638
 639 /* Get the process group ID of process PID.  */
 640 extern __pid_t __getpgid (__pid_t __pid) __THROW;
 641 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
 642 extern __pid_t getpgid (__pid_t __pid) __THROW;
 643 #endif
 644
 645
 646 /* Set the process group ID of the process matching PID to PGID.
 647    If PID is zero, the current process's process group ID is set.
 648    If PGID is zero, the process ID of the process is used.  */
 649 extern int setpgid (__pid_t __pid, __pid_t __pgid) __THROW;
 650
 651 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 652 /* Both System V and BSD have `setpgrp' functions, but with different
 653    calling conventions.  The BSD function is the same as POSIX.1 `setpgid'
 654    (above).  The System V function takes no arguments and puts the calling
 655    process in its on group like `setpgid (0, 0)'.
 656
 657    New programs should always use `setpgid' instead.
 658
 659    GNU provides the POSIX.1 function.  */
 660
 661 /* Set the process group ID of the calling process to its own PID.
 662    This is exactly the same as `setpgid (0, 0)'.  */
 663 extern int setpgrp (void) __THROW;
 664
 665 #endif  /* Use misc or X/Open.  */
 666
 667 /* Create a new session with the calling process as its leader.
 668    The process group IDs of the session and the calling process
 669    are set to the process ID of the calling process, which is returned.  */
 670 extern __pid_t setsid (void) __THROW;
 671
 672 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
 673 /* Return the session ID of the given process.  */
 674 extern __pid_t getsid (__pid_t __pid) __THROW;
 675 #endif
 676
 677 /* Get the real user ID of the calling process.  */
 678 extern __uid_t getuid (void) __THROW;
 679
 680 /* Get the effective user ID of the calling process.  */
 681 extern __uid_t geteuid (void) __THROW;
 682
 683 /* Get the real group ID of the calling process.  */
 684 extern __gid_t getgid (void) __THROW;
 685
 686 /* Get the effective group ID of the calling process.  */
 687 extern __gid_t getegid (void) __THROW;
 688
 689 /* If SIZE is zero, return the number of supplementary groups
 690    the calling process is in.  Otherwise, fill in the group IDs
 691    of its supplementary groups in LIST and return the number written.  */
 692 extern int getgroups (int __size, __gid_t __list[]) __THROW __wur;
 693
 694 #ifdef  __USE_GNU
 695 /* Return nonzero iff the calling process is in group GID.  */
 696 extern int group_member (__gid_t __gid) __THROW;
 697 #endif
 698
 699 /* Set the user ID of the calling process to UID.
 700    If the calling process is the super-user, set the real
 701    and effective user IDs, and the saved set-user-ID to UID;
 702    if not, the effective user ID is set to UID.  */
 703 extern int setuid (__uid_t __uid) __THROW __wur;
 704
 705 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 706 /* Set the real user ID of the calling process to RUID,
 707    and the effective user ID of the calling process to EUID.  */
 708 extern int setreuid (__uid_t __ruid, __uid_t __euid) __THROW __wur;
 709 #endif
 710
 711 #ifdef __USE_XOPEN2K
 712 /* Set the effective user ID of the calling process to UID.  */
 713 extern int seteuid (__uid_t __uid) __THROW __wur;
 714 #endif /* Use POSIX.1-2001.  */
 715
 716 /* Set the group ID of the calling process to GID.
 717    If the calling process is the super-user, set the real
 718    and effective group IDs, and the saved set-group-ID to GID;
 719    if not, the effective group ID is set to GID.  */
 720 extern int setgid (__gid_t __gid) __THROW __wur;
 721
 722 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 723 /* Set the real group ID of the calling process to RGID,
 724    and the effective group ID of the calling process to EGID.  */
 725 extern int setregid (__gid_t __rgid, __gid_t __egid) __THROW __wur;
 726 #endif
 727
 728 #ifdef __USE_XOPEN2K
 729 /* Set the effective group ID of the calling process to GID.  */
 730 extern int setegid (__gid_t __gid) __THROW __wur;
 731 #endif /* Use POSIX.1-2001.  */
 732
 733 #ifdef __USE_GNU
 734 /* Fetch the real user ID, effective user ID, and saved-set user ID,
 735    of the calling process.  */
 736 extern int getresuid (__uid_t *__ruid, __uid_t *__euid, __uid_t *__suid)
 737      __THROW;
 738
 739 /* Fetch the real group ID, effective group ID, and saved-set group ID,
 740    of the calling process.  */
 741 extern int getresgid (__gid_t *__rgid, __gid_t *__egid, __gid_t *__sgid)
 742      __THROW;
 743
 744 /* Set the real user ID, effective user ID, and saved-set user ID,
 745    of the calling process to RUID, EUID, and SUID, respectively.  */
 746 extern int setresuid (__uid_t __ruid, __uid_t __euid, __uid_t __suid)
 747      __THROW __wur;
 748
 749 /* Set the real group ID, effective group ID, and saved-set group ID,
 750    of the calling process to RGID, EGID, and SGID, respectively.  */
 751 extern int setresgid (__gid_t __rgid, __gid_t __egid, __gid_t __sgid)
 752      __THROW __wur;
 753 #endif
 754
 755
 756 /* Clone the calling process, creating an exact copy.
 757    Return -1 for errors, 0 to the new process,
 758    and the process ID of the new process to the old process.  */
 759 extern __pid_t fork (void) __THROWNL;
 760
 761 #if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8) \
 762     || defined __USE_MISC
 763 /* Clone the calling process, but without copying the whole address space.
 764    The calling process is suspended until the new process exits or is
 765    replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
 766    and the process ID of the new process to the old process.  */
 767 extern __pid_t vfork (void) __THROW;
 768 #endif /* Use misc or XPG < 7. */
 769
 770
 771 /* Return the pathname of the terminal FD is open on, or NULL on errors.
 772    The returned storage is good only until the next call to this function.  */
 773 extern char *ttyname (int __fd) __THROW;
 774
 775 /* Store at most BUFLEN characters of the pathname of the terminal FD is
 776    open on in BUF.  Return 0 on success, otherwise an error number.  */
 777 extern int ttyname_r (int __fd, char *__buf, size_t __buflen)
 778      __THROW __nonnull ((2)) __wur;
 779
 780 /* Return 1 if FD is a valid descriptor associated
 781    with a terminal, zero if not.  */
 782 extern int isatty (int __fd) __THROW;
 783
 784 #if defined __USE_MISC \
 785     || (defined __USE_XOPEN_EXTENDED && !defined __USE_UNIX98)
 786 /* Return the index into the active-logins file (utmp) for
 787    the controlling terminal.  */
 788 extern int ttyslot (void) __THROW;
 789 #endif
 790
 791
 792 /* Make a link to FROM named TO.  */
 793 extern int link (const char *__from, const char *__to)
 794      __THROW __nonnull ((1, 2)) __wur;
 795
 796 #ifdef __USE_ATFILE
 797 /* Like link but relative paths in TO and FROM are interpreted relative
 798    to FROMFD and TOFD respectively.  */
 799 extern int linkat (int __fromfd, const char *__from, int __tofd,
 800                    const char *__to, int __flags)
 801      __THROW __nonnull ((2, 4)) __wur;
 802 #endif
 803
 804 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
 805 /* Make a symbolic link to FROM named TO.  */
 806 extern int symlink (const char *__from, const char *__to)
 807      __THROW __nonnull ((1, 2)) __wur;
 808
 809 /* Read the contents of the symbolic link PATH into no more than
 810    LEN bytes of BUF.  The contents are not null-terminated.
 811    Returns the number of characters read, or -1 for errors.  */
 812 extern ssize_t readlink (const char *__restrict __path,
 813                          char *__restrict __buf, size_t __len)
 814      __THROW __nonnull ((1, 2)) __wur;
 815 #endif /* Use POSIX.1-2001.  */
 816
 817 #ifdef __USE_ATFILE
 818 /* Like symlink but a relative path in TO is interpreted relative to TOFD.  */
 819 extern int symlinkat (const char *__from, int __tofd,
 820                       const char *__to) __THROW __nonnull ((1, 3)) __wur;
 821
 822 /* Like readlink but a relative PATH is interpreted relative to FD.  */
 823 extern ssize_t readlinkat (int __fd, const char *__restrict __path,
 824                            char *__restrict __buf, size_t __len)
 825      __THROW __nonnull ((2, 3)) __wur;
 826 #endif
 827
 828 /* Remove the link NAME.  */
 829 extern int unlink (const char *__name) __THROW __nonnull ((1));
 830
 831 #ifdef __USE_ATFILE
 832 /* Remove the link NAME relative to FD.  */
 833 extern int unlinkat (int __fd, const char *__name, int __flag)
 834      __THROW __nonnull ((2));
 835 #endif
 836
 837 /* Remove the directory PATH.  */
 838 extern int rmdir (const char *__path) __THROW __nonnull ((1));
 839
 840
 841 /* Return the foreground process group ID of FD.  */
 842 extern __pid_t tcgetpgrp (int __fd) __THROW;
 843
 844 /* Set the foreground process group ID of FD set PGRP_ID.  */
 845 extern int tcsetpgrp (int __fd, __pid_t __pgrp_id) __THROW;
 846
 847
 848 /* Return the login name of the user.
 849
 850    This function is a possible cancellation point and therefore not
 851    marked with __THROW.  */
 852 extern char *getlogin (void);
 853 #if defined __USE_REENTRANT || defined __USE_POSIX199506
 854 /* Return at most NAME_LEN characters of the login name of the user in NAME.
 855    If it cannot be determined or some other error occurred, return the error
 856    code.  Otherwise return 0.
 857
 858    This function is a possible cancellation point and therefore not
 859    marked with __THROW.  */
 860 extern int getlogin_r (char *__name, size_t __name_len) __nonnull ((1));
 861 #endif
 862
 863 #ifdef  __USE_MISC
 864 /* Set the login name returned by `getlogin'.  */
 865 extern int setlogin (const char *__name) __THROW __nonnull ((1));
 866 #endif
 867
 868
 869 #ifdef  __USE_POSIX2
 870 /* Get definitions and prototypes for functions to process the
 871    arguments in ARGV (ARGC of them, minus the program name) for
 872    options given in OPTS.  */
 873 # define __need_getopt
 874 # include <getopt.h>
 875 #endif
 876
 877
 878 #if defined __USE_UNIX98 || defined __USE_XOPEN2K
 879 /* Put the name of the current host in no more than LEN bytes of NAME.
 880    The result is null-terminated if LEN is large enough for the full
 881    name and the terminator.  */
 882 extern int gethostname (char *__name, size_t __len) __THROW __nonnull ((1));
 883 #endif
 884
 885
 886 #if defined __USE_MISC
 887 /* Set the name of the current host to NAME, which is LEN bytes long.
 888    This call is restricted to the super-user.  */
 889 extern int sethostname (const char *__name, size_t __len)
 890      __THROW __nonnull ((1)) __wur;
 891
 892 /* Set the current machine's Internet number to ID.
 893    This call is restricted to the super-user.  */
 894 extern int sethostid (long int __id) __THROW __wur;
 895
 896
 897 /* Get and set the NIS (aka YP) domain name, if any.
 898    Called just like `gethostname' and `sethostname'.
 899    The NIS domain name is usually the empty string when not using NIS.  */
 900 extern int getdomainname (char *__name, size_t __len)
 901      __THROW __nonnull ((1)) __wur;
 902 extern int setdomainname (const char *__name, size_t __len)
 903      __THROW __nonnull ((1)) __wur;
 904
 905
 906 /* Revoke access permissions to all processes currently communicating
 907    with the control terminal, and then send a SIGHUP signal to the process
 908    group of the control terminal.  */
 909 extern int vhangup (void) __THROW;
 910
 911 /* Revoke the access of all descriptors currently open on FILE.  */
 912 extern int revoke (const char *__file) __THROW __nonnull ((1)) __wur;
 913
 914
 915 /* Enable statistical profiling, writing samples of the PC into at most
 916    SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
 917    is enabled, the system examines the user PC and increments
 918    SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536].  If SCALE is zero,
 919    disable profiling.  Returns zero on success, -1 on error.  */
 920 extern int profil (unsigned short int *__sample_buffer, size_t __size,
 921                    size_t __offset, unsigned int __scale)
 922      __THROW __nonnull ((1));
 923
 924
 925 /* Turn accounting on if NAME is an existing file.  The system will then write
 926    a record for each process as it terminates, to this file.  If NAME is NULL,
 927    turn accounting off.  This call is restricted to the super-user.  */
 928 extern int acct (const char *__name) __THROW;
 929
 930
 931 /* Successive calls return the shells listed in `/etc/shells'.  */
 932 extern char *getusershell (void) __THROW;
 933 extern void endusershell (void) __THROW; /* Discard cached info.  */
 934 extern void setusershell (void) __THROW; /* Rewind and re-read the file.  */
 935
 936
 937 /* Put the program in the background, and dissociate from the controlling
 938    terminal.  If NOCHDIR is zero, do `chdir ("/")'.  If NOCLOSE is zero,
 939    redirects stdin, stdout, and stderr to /dev/null.  */
 940 extern int daemon (int __nochdir, int __noclose) __THROW __wur;
 941 #endif /* Use misc.  */
 942
 943
 944 #if defined __USE_MISC || (defined __USE_XOPEN && !defined __USE_XOPEN2K)
 945 /* Make PATH be the root directory (the starting point for absolute paths).
 946    This call is restricted to the super-user.  */
 947 extern int chroot (const char *__path) __THROW __nonnull ((1)) __wur;
 948
 949 /* Prompt with PROMPT and read a string from the terminal without echoing.
 950    Uses /dev/tty if possible; otherwise stderr and stdin.  */
 951 extern char *getpass (const char *__prompt) __nonnull ((1));
 952 #endif /* Use misc || X/Open.  */
 953
 954
 955 /* Make all changes done to FD actually appear on disk.
 956
 957    This function is a cancellation point and therefore not marked with
 958    __THROW.  */
 959 extern int fsync (int __fd);
 960
 961
 962 #ifdef __USE_GNU
 963 /* Make all changes done to all files on the file system associated
 964    with FD actually appear on disk.  */
 965 extern int syncfs (int __fd) __THROW;
 966 #endif
 967
 968
 969 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 970
 971 /* Return identifier for the current host.  */
 972 extern long int gethostid (void);
 973
 974 /* Make all changes done to all files actually appear on disk.  */
 975 extern void sync (void) __THROW;
 976
 977
 978 # if defined __USE_MISC || !defined __USE_XOPEN2K
 979 /* Return the number of bytes in a page.  This is the system's page size,
 980    which is not necessarily the same as the hardware page size.  */
 981 extern int getpagesize (void)  __THROW __attribute__ ((__const__));
 982
 983
 984 /* Return the maximum number of file descriptors
 985    the current process could possibly have.  */
 986 extern int getdtablesize (void) __THROW;
 987 # endif
 988
 989 #endif /* Use misc || X/Open Unix.  */
 990
 991
 992 #if defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K8
 993
 994 /* Truncate FILE to LENGTH bytes.  */
 995 # ifndef __USE_FILE_OFFSET64
 996 extern int truncate (const char *__file, __off_t __length)
 997      __THROW __nonnull ((1)) __wur;
 998 # else
 999 #  ifdef __REDIRECT_NTH
1000 extern int __REDIRECT_NTH (truncate,
1001                            (const char *__file, __off64_t __length),
1002                            truncate64) __nonnull ((1)) __wur;
1003 #  else
1004 #   define truncate truncate64
1005 #  endif
1006 # endif
1007 # ifdef __USE_LARGEFILE64
1008 extern int truncate64 (const char *__file, __off64_t __length)
1009      __THROW __nonnull ((1)) __wur;
1010 # endif
1011
1012 #endif /* Use X/Open Unix || POSIX 2008.  */
1013
1014 #if defined __USE_POSIX199309 \
1015     || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
1016
1017 /* Truncate the file FD is open on to LENGTH bytes.  */
1018 # ifndef __USE_FILE_OFFSET64
1019 extern int ftruncate (int __fd, __off_t __length) __THROW __wur;
1020 # else
1021 #  ifdef __REDIRECT_NTH
1022 extern int __REDIRECT_NTH (ftruncate, (int __fd, __off64_t __length),
1023                            ftruncate64) __wur;
1024 #  else
1025 #   define ftruncate ftruncate64
1026 #  endif
1027 # endif
1028 # ifdef __USE_LARGEFILE64
1029 extern int ftruncate64 (int __fd, __off64_t __length) __THROW __wur;
1030 # endif
1031
1032 #endif /* Use POSIX.1b || X/Open Unix || XPG6.  */
1033
1034
1035 #if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K) \
1036     || defined __USE_MISC
1037
1038 /* Set the end of accessible data space (aka "the break") to ADDR.
1039    Returns zero on success and -1 for errors (with errno set).  */
1040 extern int brk (void *__addr) __THROW __wur;
1041
1042 /* Increase or decrease the end of accessible data space by DELTA bytes.
1043    If successful, returns the address the previous end of data space
1044    (i.e. the beginning of the new space, if DELTA > 0);
1045    returns (void *) -1 for errors (with errno set).  */
1046 extern void *sbrk (intptr_t __delta) __THROW;
1047 #endif
1048
1049
1050 #ifdef __USE_MISC
1051 /* Invoke `system call' number SYSNO, passing it the remaining arguments.
1052    This is completely system-dependent, and not often useful.
1053
1054    In Unix, `syscall' sets `errno' for all errors and most calls return -1
1055    for errors; in many systems you cannot pass arguments or get return
1056    values for all system calls (`pipe', `fork', and `getppid' typically
1057    among them).
1058
1059    In Mach, all system calls take normal arguments and always return an
1060    error code (zero for success).  */
1061 extern long int syscall (long int __sysno, ...) __THROW;
1062
1063 #endif  /* Use misc.  */
1064
1065
1066 #if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK
1067 /* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both
1068    files consistent.  Some systems have them there and some here, and some
1069    software depends on the macros being defined without including both.  */
1070
1071 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
1072    LEN is always relative to the current file position.
1073    The CMD argument is one of the following.
1074
1075    This function is a cancellation point and therefore not marked with
1076    __THROW.  */
1077
1078 # define F_ULOCK 0      /* Unlock a previously locked region.  */
1079 # define F_LOCK  1      /* Lock a region for exclusive use.  */
1080 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
1081 # define F_TEST  3      /* Test a region for other processes locks.  */
1082
1083 # ifndef __USE_FILE_OFFSET64
1084 extern int lockf (int __fd, int __cmd, __off_t __len) __wur;
1085 # else
1086 #  ifdef __REDIRECT
1087 extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len),
1088                        lockf64) __wur;
1089 #  else
1090 #   define lockf lockf64
1091 #  endif
1092 # endif
1093 # ifdef __USE_LARGEFILE64
1094 extern int lockf64 (int __fd, int __cmd, __off64_t __len) __wur;
1095 # endif
1096 #endif /* Use misc and F_LOCK not already defined.  */
1097
1098
1099 #ifdef __USE_GNU
1100
1101 /* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno'
1102    set to EINTR.  */
1103
1104 # define TEMP_FAILURE_RETRY(expression) \
1105   (__extension__                                                              \
1106     ({ long int __result;                                                     \
1107        do __result = (long int) (expression);                                 \
1108        while (__result == -1L && errno == EINTR);                             \
1109        __result; }))
1110 #endif
1111
1112 #if defined __USE_POSIX199309 || defined __USE_UNIX98
1113 /* Synchronize at least the data part of a file with the underlying
1114    media.  */
1115 extern int fdatasync (int __fildes);
1116 #endif /* Use POSIX199309 */
1117
1118
1119 /* XPG4.2 specifies that prototypes for the encryption functions must
1120    be defined here.  */
1121 #ifdef  __USE_XOPEN
1122 /* Encrypt at most 8 characters from KEY using salt to perturb DES.  */
1123 extern char *crypt (const char *__key, const char *__salt)
1124      __THROW __nonnull ((1, 2));
1125
1126 /* Encrypt data in BLOCK in place if EDFLAG is zero; otherwise decrypt
1127    block in place.  */
1128 extern void encrypt (char *__glibc_block, int __edflag)
1129      __THROW __nonnull ((1));
1130
1131
1132 /* Swab pairs bytes in the first N bytes of the area pointed to by
1133    FROM and copy the result to TO.  The value of TO must not be in the
1134    range [FROM - N + 1, FROM - 1].  If N is odd the first byte in FROM
1135    is without partner.  */
1136 extern void swab (const void *__restrict __from, void *__restrict __to,
1137                   ssize_t __n) __THROW __nonnull ((1, 2));
1138 #endif
1139
1140
1141 /* The Single Unix specification demands this prototype to be here.
1142    It is also found in <stdio.h>.  */
1143 #if defined __USE_XOPEN && !defined __USE_XOPEN2K
1144 /* Return the name of the controlling terminal.  */
1145 extern char *ctermid (char *__s) __THROW;
1146 #endif
1147
1148
1149 /* Define some macros helping to catch buffer overflows.  */
1150 #if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
1151 # include <bits/unistd.h>
1152 #endif
1153
1154 __END_DECLS
1155
1156 #endif /* unistd.h  */