posix/unistd.h

   1 /* Copyright (C) 1991-2006, 2007 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 /*
  20  *      POSIX Standard: 2.10 Symbolic Constants         <unistd.h>
  21  */
  22
  23 #ifndef _UNISTD_H
  24 #define _UNISTD_H       1
  25
  26 #include <features.h>
  27
  28 __BEGIN_DECLS
  29
  30 /* These may be used to determine what facilities are present at compile time.
  31    Their values can be obtained at run time from `sysconf'.  */
  32
  33 /* POSIX Standard approved as ISO/IEC 9945-1 as of December 2001.  */
  34 #define _POSIX_VERSION  200112L
  35
  36 /* These are not #ifdef __USE_POSIX2 because they are
  37    in the theoretically application-owned namespace.  */
  38
  39 /* The utilities on GNU systems also correspond to this version.  */
  40 #define _POSIX2_VERSION 200112L
  41
  42 /* If defined, the implementation supports the
  43    C Language Bindings Option.  */
  44 #define _POSIX2_C_BIND  200112L
  45
  46 /* If defined, the implementation supports the
  47    C Language Development Utilities Option.  */
  48 #define _POSIX2_C_DEV   200112L
  49
  50 /* If defined, the implementation supports the
  51    Software Development Utilities Option.  */
  52 #define _POSIX2_SW_DEV  200112L
  53
  54 /* If defined, the implementation supports the
  55    creation of locales with the localedef utility.  */
  56 #define _POSIX2_LOCALEDEF       200112L
  57
  58 /* X/Open version number to which the library conforms.  It is selectable.  */
  59 #ifdef __USE_XOPEN2K
  60 # define _XOPEN_VERSION 600
  61 #elif defined __USE_UNIX98
  62 # define _XOPEN_VERSION 500
  63 #else
  64 # define _XOPEN_VERSION 4
  65 #endif
  66
  67 /* Commands and utilities from XPG4 are available.  */
  68 #define _XOPEN_XCU_VERSION      4
  69
  70 /* We are compatible with the old published standards as well.  */
  71 #define _XOPEN_XPG2     1
  72 #define _XOPEN_XPG3     1
  73 #define _XOPEN_XPG4     1
  74
  75 /* The X/Open Unix extensions are available.  */
  76 #define _XOPEN_UNIX     1
  77
  78 /* Encryption is present.  */
  79 #define _XOPEN_CRYPT    1
  80
  81 /* The enhanced internationalization capabilities according to XPG4.2
  82    are present.  */
  83 #define _XOPEN_ENH_I18N 1
  84
  85 /* The legacy interfaces are also available.  */
  86 #define _XOPEN_LEGACY   1
  87
  88
  89 /* Get values of POSIX options:
  90
  91    If these symbols are defined, the corresponding features are
  92    always available.  If not, they may be available sometimes.
  93    The current values can be obtained with `sysconf'.
  94
  95    _POSIX_JOB_CONTROL           Job control is supported.
  96    _POSIX_SAVED_IDS             Processes have a saved set-user-ID
  97                                 and a saved set-group-ID.
  98    _POSIX_REALTIME_SIGNALS      Real-time, queued signals are supported.
  99    _POSIX_PRIORITY_SCHEDULING   Priority scheduling is supported.
 100    _POSIX_TIMERS                POSIX.4 clocks and timers are supported.
 101    _POSIX_ASYNCHRONOUS_IO       Asynchronous I/O is supported.
 102    _POSIX_PRIORITIZED_IO        Prioritized asynchronous I/O is supported.
 103    _POSIX_SYNCHRONIZED_IO       Synchronizing file data is supported.
 104    _POSIX_FSYNC                 The fsync function is present.
 105    _POSIX_MAPPED_FILES          Mapping of files to memory is supported.
 106    _POSIX_MEMLOCK               Locking of all memory is supported.
 107    _POSIX_MEMLOCK_RANGE         Locking of ranges of memory is supported.
 108    _POSIX_MEMORY_PROTECTION     Setting of memory protections is supported.
 109    _POSIX_MESSAGE_PASSING       POSIX.4 message queues are supported.
 110    _POSIX_SEMAPHORES            POSIX.4 counting semaphores are supported.
 111    _POSIX_SHARED_MEMORY_OBJECTS POSIX.4 shared memory objects are supported.
 112    _POSIX_THREADS               POSIX.1c pthreads are supported.
 113    _POSIX_THREAD_ATTR_STACKADDR Thread stack address attribute option supported.
 114    _POSIX_THREAD_ATTR_STACKSIZE Thread stack size attribute option supported.
 115    _POSIX_THREAD_SAFE_FUNCTIONS Thread-safe functions are supported.
 116    _POSIX_THREAD_PRIORITY_SCHEDULING
 117                                 POSIX.1c thread execution scheduling supported.
 118    _POSIX_THREAD_PRIO_INHERIT   Thread priority inheritance option supported.
 119    _POSIX_THREAD_PRIO_PROTECT   Thread priority protection option supported.
 120    _POSIX_THREAD_PROCESS_SHARED Process-shared synchronization supported.
 121    _POSIX_PII                   Protocol-independent interfaces are supported.
 122    _POSIX_PII_XTI               XTI protocol-indep. interfaces are supported.
 123    _POSIX_PII_SOCKET            Socket protocol-indep. interfaces are supported.
 124    _POSIX_PII_INTERNET          Internet family of protocols supported.
 125    _POSIX_PII_INTERNET_STREAM   Connection-mode Internet protocol supported.
 126    _POSIX_PII_INTERNET_DGRAM    Connectionless Internet protocol supported.
 127    _POSIX_PII_OSI               ISO/OSI family of protocols supported.
 128    _POSIX_PII_OSI_COTS          Connection-mode ISO/OSI service supported.
 129    _POSIX_PII_OSI_CLTS          Connectionless ISO/OSI service supported.
 130    _POSIX_POLL                  Implementation supports `poll' function.
 131    _POSIX_SELECT                Implementation supports `select' and `pselect'.
 132
 133    _XOPEN_REALTIME              X/Open realtime support is available.
 134    _XOPEN_REALTIME_THREADS      X/Open realtime thread support is available.
 135    _XOPEN_SHM                   Shared memory interface according to XPG4.2.
 136
 137    _XBS5_ILP32_OFF32            Implementation provides environment with 32-bit
 138                                 int, long, pointer, and off_t types.
 139    _XBS5_ILP32_OFFBIG           Implementation provides environment with 32-bit
 140                                 int, long, and pointer and off_t with at least
 141                                 64 bits.
 142    _XBS5_LP64_OFF64             Implementation provides environment with 32-bit
 143                                 int, and 64-bit long, pointer, and off_t types.
 144    _XBS5_LPBIG_OFFBIG           Implementation provides environment with at
 145                                 least 32 bits int and long, pointer, and off_t
 146                                 with at least 64 bits.
 147
 148    If any of these symbols is defined as -1, the corresponding option is not
 149    true for any file.  If any is defined as other than -1, the corresponding
 150    option is true for all files.  If a symbol is not defined at all, the value
 151    for a specific file can be obtained from `pathconf' and `fpathconf'.
 152
 153    _POSIX_CHOWN_RESTRICTED      Only the super user can use `chown' to change
 154                                 the owner of a file.  `chown' can only be used
 155                                 to change the group ID of a file to a group of
 156                                 which the calling process is a member.
 157    _POSIX_NO_TRUNC              Pathname components longer than
 158                                 NAME_MAX generate an error.
 159    _POSIX_VDISABLE              If defined, if the value of an element of the
 160                                 `c_cc' member of `struct termios' is
 161                                 _POSIX_VDISABLE, no character will have the
 162                                 effect associated with that element.
 163    _POSIX_SYNC_IO               Synchronous I/O may be performed.
 164    _POSIX_ASYNC_IO              Asynchronous I/O may be performed.
 165    _POSIX_PRIO_IO               Prioritized Asynchronous I/O may be performed.
 166
 167    Support for the Large File Support interface is not generally available.
 168    If it is available the following constants are defined to one.
 169    _LFS64_LARGEFILE             Low-level I/O supports large files.
 170    _LFS64_STDIO                 Standard I/O supports large files.
 171    */
 172
 173 #include <bits/posix_opt.h>
 174
 175 /* Get the environment definitions from Unix98.  */
 176 #ifdef __USE_UNIX98
 177 # include <bits/environments.h>
 178 #endif
 179
 180 /* Standard file descriptors.  */
 181 #define STDIN_FILENO    0       /* Standard input.  */
 182 #define STDOUT_FILENO   1       /* Standard output.  */
 183 #define STDERR_FILENO   2       /* Standard error output.  */
 184
 185
 186 /* All functions that are not declared anywhere else.  */
 187
 188 #include <bits/types.h>
 189
 190 #ifndef __ssize_t_defined
 191 typedef __ssize_t ssize_t;
 192 # define __ssize_t_defined
 193 #endif
 194
 195 #define __need_size_t
 196 #define __need_NULL
 197 #include <stddef.h>
 198
 199 #if defined __USE_XOPEN || defined __USE_XOPEN2K
 200 /* The Single Unix specification says that some more types are
 201    available here.  */
 202 # ifndef __gid_t_defined
 203 typedef __gid_t gid_t;
 204 #  define __gid_t_defined
 205 # endif
 206
 207 # ifndef __uid_t_defined
 208 typedef __uid_t uid_t;
 209 #  define __uid_t_defined
 210 # endif
 211
 212 # ifndef __off_t_defined
 213 #  ifndef __USE_FILE_OFFSET64
 214 typedef __off_t off_t;
 215 #  else
 216 typedef __off64_t off_t;
 217 #  endif
 218 #  define __off_t_defined
 219 # endif
 220 # if defined __USE_LARGEFILE64 && !defined __off64_t_defined
 221 typedef __off64_t off64_t;
 222 #  define __off64_t_defined
 223 # endif
 224
 225 # ifndef __useconds_t_defined
 226 typedef __useconds_t useconds_t;
 227 #  define __useconds_t_defined
 228 # endif
 229
 230 # ifndef __pid_t_defined
 231 typedef __pid_t pid_t;
 232 #  define __pid_t_defined
 233 # endif
 234 #endif  /* X/Open */
 235
 236 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 237 # ifndef __intptr_t_defined
 238 typedef __intptr_t intptr_t;
 239 #  define __intptr_t_defined
 240 # endif
 241 #endif
 242
 243 #if defined __USE_BSD || defined __USE_XOPEN
 244 # ifndef __socklen_t_defined
 245 typedef __socklen_t socklen_t;
 246 #  define __socklen_t_defined
 247 # endif
 248 #endif
 249
 250 /* Values for the second argument to access.
 251    These may be OR'd together.  */
 252 #define R_OK    4               /* Test for read permission.  */
 253 #define W_OK    2               /* Test for write permission.  */
 254 #define X_OK    1               /* Test for execute permission.  */
 255 #define F_OK    0               /* Test for existence.  */
 256
 257 /* Test for access to NAME using the real UID and real GID.  */
 258 extern int access (__const char *__name, int __type) __THROW __nonnull ((1));
 259
 260 #ifdef __USE_GNU
 261 /* Test for access to NAME using the effective UID and GID
 262    (as normal file operations use).  */
 263 extern int euidaccess (__const char *__name, int __type)
 264      __THROW __nonnull ((1));
 265
 266 /* An alias for `euidaccess', used by some other systems.  */
 267 extern int eaccess (__const char *__name, int __type)
 268      __THROW __nonnull ((1));
 269 #endif
 270
 271 #ifdef __USE_ATFILE
 272 /* Test for access to FILE relative to the directory FD is open on.
 273    If AT_EACCESS is set in FLAG, then use effective IDs like `eaccess',
 274    otherwise use real IDs like `access'.  */
 275 extern int faccessat (int __fd, __const char *__file, int __type, int __flag)
 276      __THROW __nonnull ((2)) __wur;
 277 #endif /* Use GNU.  */
 278
 279
 280 /* Values for the WHENCE argument to lseek.  */
 281 #ifndef _STDIO_H                /* <stdio.h> has the same definitions.  */
 282 # define SEEK_SET       0       /* Seek from beginning of file.  */
 283 # define SEEK_CUR       1       /* Seek from current position.  */
 284 # define SEEK_END       2       /* Seek from end of file.  */
 285 #endif
 286
 287 #if defined __USE_BSD && !defined L_SET
 288 /* Old BSD names for the same constants; just for compatibility.  */
 289 # define L_SET          SEEK_SET
 290 # define L_INCR         SEEK_CUR
 291 # define L_XTND         SEEK_END
 292 #endif
 293
 294
 295 /* Move FD's file position to OFFSET bytes from the
 296    beginning of the file (if WHENCE is SEEK_SET),
 297    the current position (if WHENCE is SEEK_CUR),
 298    or the end of the file (if WHENCE is SEEK_END).
 299    Return the new file position.  */
 300 #ifndef __USE_FILE_OFFSET64
 301 extern __off_t lseek (int __fd, __off_t __offset, int __whence) __THROW;
 302 #else
 303 # ifdef __REDIRECT_NTH
 304 extern __off64_t __REDIRECT_NTH (lseek,
 305                                  (int __fd, __off64_t __offset, int __whence),
 306                                  lseek64);
 307 # else
 308 #  define lseek lseek64
 309 # endif
 310 #endif
 311 #ifdef __USE_LARGEFILE64
 312 extern __off64_t lseek64 (int __fd, __off64_t __offset, int __whence)
 313      __THROW;
 314 #endif
 315
 316 /* Close the file descriptor FD.
 317
 318    This function is a cancellation point and therefore not marked with
 319    __THROW.  */
 320 extern int close (int __fd);
 321
 322 /* Read NBYTES into BUF from FD.  Return the
 323    number read, -1 for errors or 0 for EOF.
 324
 325    This function is a cancellation point and therefore not marked with
 326    __THROW.  */
 327 extern ssize_t read (int __fd, void *__buf, size_t __nbytes) __wur;
 328
 329 /* Write N bytes of BUF to FD.  Return the number written, or -1.
 330
 331    This function is a cancellation point and therefore not marked with
 332    __THROW.  */
 333 extern ssize_t write (int __fd, __const void *__buf, size_t __n) __wur;
 334
 335 #ifdef __USE_UNIX98
 336 # ifndef __USE_FILE_OFFSET64
 337 /* Read NBYTES into BUF from FD at the given position OFFSET without
 338    changing the file pointer.  Return the number read, -1 for errors
 339    or 0 for EOF.
 340
 341    This function is a cancellation point and therefore not marked with
 342    __THROW.  */
 343 extern ssize_t pread (int __fd, void *__buf, size_t __nbytes,
 344                       __off_t __offset) __wur;
 345
 346 /* Write N bytes of BUF to FD at the given position OFFSET without
 347    changing the file pointer.  Return the number written, or -1.
 348
 349    This function is a cancellation point and therefore not marked with
 350    __THROW.  */
 351 extern ssize_t pwrite (int __fd, __const void *__buf, size_t __n,
 352                        __off_t __offset) __wur;
 353 # else
 354 #  ifdef __REDIRECT
 355 extern ssize_t __REDIRECT (pread, (int __fd, void *__buf, size_t __nbytes,
 356                                    __off64_t __offset),
 357                            pread64) __wur;
 358 extern ssize_t __REDIRECT (pwrite, (int __fd, __const void *__buf,
 359                                     size_t __nbytes, __off64_t __offset),
 360                            pwrite64) __wur;
 361 #  else
 362 #   define pread pread64
 363 #   define pwrite pwrite64
 364 #  endif
 365 # endif
 366
 367 # ifdef __USE_LARGEFILE64
 368 /* Read NBYTES into BUF from FD at the given position OFFSET without
 369    changing the file pointer.  Return the number read, -1 for errors
 370    or 0 for EOF.  */
 371 extern ssize_t pread64 (int __fd, void *__buf, size_t __nbytes,
 372                         __off64_t __offset) __wur;
 373 /* Write N bytes of BUF to FD at the given position OFFSET without
 374    changing the file pointer.  Return the number written, or -1.  */
 375 extern ssize_t pwrite64 (int __fd, __const void *__buf, size_t __n,
 376                          __off64_t __offset) __wur;
 377 # endif
 378 #endif
 379
 380 /* Create a one-way communication channel (pipe).
 381    If successful, two file descriptors are stored in PIPEDES;
 382    bytes written on PIPEDES[1] can be read from PIPEDES[0].
 383    Returns 0 if successful, -1 if not.  */
 384 extern int pipe (int __pipedes[2]) __THROW __wur;
 385
 386 /* Schedule an alarm.  In SECONDS seconds, the process will get a SIGALRM.
 387    If SECONDS is zero, any currently scheduled alarm will be cancelled.
 388    The function returns the number of seconds remaining until the last
 389    alarm scheduled would have signaled, or zero if there wasn't one.
 390    There is no return value to indicate an error, but you can set `errno'
 391    to 0 and check its value after calling `alarm', and this might tell you.
 392    The signal may come late due to processor scheduling.  */
 393 extern unsigned int alarm (unsigned int __seconds) __THROW;
 394
 395 /* Make the process sleep for SECONDS seconds, or until a signal arrives
 396    and is not ignored.  The function returns the number of seconds less
 397    than SECONDS which it actually slept (thus zero if it slept the full time).
 398    If a signal handler does a `longjmp' or modifies the handling of the
 399    SIGALRM signal while inside `sleep' call, the handling of the SIGALRM
 400    signal afterwards is undefined.  There is no return value to indicate
 401    error, but if `sleep' returns SECONDS, it probably didn't work.
 402
 403    This function is a cancellation point and therefore not marked with
 404    __THROW.  */
 405 extern unsigned int sleep (unsigned int __seconds);
 406
 407 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 408 /* Set an alarm to go off (generating a SIGALRM signal) in VALUE
 409    microseconds.  If INTERVAL is nonzero, when the alarm goes off, the
 410    timer is reset to go off every INTERVAL microseconds thereafter.
 411    Returns the number of microseconds remaining before the alarm.  */
 412 extern __useconds_t ualarm (__useconds_t __value, __useconds_t __interval)
 413      __THROW;
 414
 415 /* Sleep USECONDS microseconds, or until a signal arrives that is not blocked
 416    or ignored.
 417
 418    This function is a cancellation point and therefore not marked with
 419    __THROW.  */
 420 extern int usleep (__useconds_t __useconds);
 421 #endif
 422
 423
 424 /* Suspend the process until a signal arrives.
 425    This always returns -1 and sets `errno' to EINTR.
 426
 427    This function is a cancellation point and therefore not marked with
 428    __THROW.  */
 429 extern int pause (void);
 430
 431
 432 /* Change the owner and group of FILE.  */
 433 extern int chown (__const char *__file, __uid_t __owner, __gid_t __group)
 434      __THROW __nonnull ((1)) __wur;
 435
 436 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 437 /* Change the owner and group of the file that FD is open on.  */
 438 extern int fchown (int __fd, __uid_t __owner, __gid_t __group) __THROW __wur;
 439
 440
 441 /* Change owner and group of FILE, if it is a symbolic
 442    link the ownership of the symbolic link is changed.  */
 443 extern int lchown (__const char *__file, __uid_t __owner, __gid_t __group)
 444      __THROW __nonnull ((1)) __wur;
 445
 446 #endif /* Use BSD || X/Open Unix.  */
 447
 448 #ifdef __USE_ATFILE
 449 /* Change the owner and group of FILE relative to the directory FD is open
 450    on.  */
 451 extern int fchownat (int __fd, __const char *__file, __uid_t __owner,
 452                      __gid_t __group, int __flag)
 453      __THROW __nonnull ((2)) __wur;
 454 #endif /* Use GNU.  */
 455
 456 /* Change the process's working directory to PATH.  */
 457 extern int chdir (__const char *__path) __THROW __nonnull ((1)) __wur;
 458
 459 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 460 /* Change the process's working directory to the one FD is open on.  */
 461 extern int fchdir (int __fd) __THROW __wur;
 462 #endif
 463
 464 /* Get the pathname of the current working directory,
 465    and put it in SIZE bytes of BUF.  Returns NULL if the
 466    directory couldn't be determined or SIZE was too small.
 467    If successful, returns BUF.  In GNU, if BUF is NULL,
 468    an array is allocated with `malloc'; the array is SIZE
 469    bytes long, unless SIZE == 0, in which case it is as
 470    big as necessary.  */
 471 extern char *getcwd (char *__buf, size_t __size) __THROW __wur;
 472
 473 #ifdef  __USE_GNU
 474 /* Return a malloc'd string containing the current directory name.
 475    If the environment variable `PWD' is set, and its value is correct,
 476    that value is used.  */
 477 extern char *get_current_dir_name (void) __THROW;
 478 #endif
 479
 480 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 481 /* Put the absolute pathname of the current working directory in BUF.
 482    If successful, return BUF.  If not, put an error message in
 483    BUF and return NULL.  BUF should be at least PATH_MAX bytes long.  */
 484 extern char *getwd (char *__buf)
 485      __THROW __nonnull ((1)) __attribute_deprecated__ __wur;
 486 #endif
 487
 488
 489 /* Duplicate FD, returning a new file descriptor on the same file.  */
 490 extern int dup (int __fd) __THROW __wur;
 491
 492 /* Duplicate FD to FD2, closing FD2 and making it open on the same file.  */
 493 extern int dup2 (int __fd, int __fd2) __THROW;
 494
 495 /* NULL-terminated array of "NAME=VALUE" environment variables.  */
 496 extern char **__environ;
 497 #ifdef __USE_GNU
 498 extern char **environ;
 499 #endif
 500
 501
 502 /* Replace the current process, executing PATH with arguments ARGV and
 503    environment ENVP.  ARGV and ENVP are terminated by NULL pointers.  */
 504 extern int execve (__const char *__path, char *__const __argv[],
 505                    char *__const __envp[]) __THROW __nonnull ((1));
 506
 507 #ifdef __USE_GNU
 508 /* Execute the file FD refers to, overlaying the running program image.
 509    ARGV and ENVP are passed to the new program, as for `execve'.  */
 510 extern int fexecve (int __fd, char *__const __argv[], char *__const __envp[])
 511      __THROW;
 512 #endif
 513
 514
 515 /* Execute PATH with arguments ARGV and environment from `environ'.  */
 516 extern int execv (__const char *__path, char *__const __argv[])
 517      __THROW __nonnull ((1));
 518
 519 /* Execute PATH with all arguments after PATH until a NULL pointer,
 520    and the argument after that for environment.  */
 521 extern int execle (__const char *__path, __const char *__arg, ...)
 522      __THROW __nonnull ((1));
 523
 524 /* Execute PATH with all arguments after PATH until
 525    a NULL pointer and environment from `environ'.  */
 526 extern int execl (__const char *__path, __const char *__arg, ...)
 527      __THROW __nonnull ((1));
 528
 529 /* Execute FILE, searching in the `PATH' environment variable if it contains
 530    no slashes, with arguments ARGV and environment from `environ'.  */
 531 extern int execvp (__const char *__file, char *__const __argv[])
 532      __THROW __nonnull ((1));
 533
 534 /* Execute FILE, searching in the `PATH' environment variable if
 535    it contains no slashes, with all arguments after FILE until a
 536    NULL pointer and environment from `environ'.  */
 537 extern int execlp (__const char *__file, __const char *__arg, ...)
 538      __THROW __nonnull ((1));
 539
 540
 541 #if defined __USE_MISC || defined __USE_XOPEN
 542 /* Add INC to priority of the current process.  */
 543 extern int nice (int __inc) __THROW __wur;
 544 #endif
 545
 546
 547 /* Terminate program execution with the low-order 8 bits of STATUS.  */
 548 extern void _exit (int __status) __attribute__ ((__noreturn__));
 549
 550
 551 /* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf';
 552    the `_SC_*' symbols for the NAME argument to `sysconf';
 553    and the `_CS_*' symbols for the NAME argument to `confstr'.  */
 554 #include <bits/confname.h>
 555
 556 /* Get file-specific configuration information about PATH.  */
 557 extern long int pathconf (__const char *__path, int __name)
 558      __THROW __nonnull ((1));
 559
 560 /* Get file-specific configuration about descriptor FD.  */
 561 extern long int fpathconf (int __fd, int __name) __THROW;
 562
 563 /* Get the value of the system variable NAME.  */
 564 extern long int sysconf (int __name) __THROW;
 565
 566 #ifdef  __USE_POSIX2
 567 /* Get the value of the string-valued system variable NAME.  */
 568 extern size_t confstr (int __name, char *__buf, size_t __len) __THROW;
 569 #endif
 570
 571
 572 /* Get the process ID of the calling process.  */
 573 extern __pid_t getpid (void) __THROW;
 574
 575 /* Get the process ID of the calling process's parent.  */
 576 extern __pid_t getppid (void) __THROW;
 577
 578 /* Get the process group ID of the calling process.
 579    This function is different on old BSD. */
 580 #ifndef __FAVOR_BSD
 581 extern __pid_t getpgrp (void) __THROW;
 582 #else
 583 # ifdef __REDIRECT_NTH
 584 extern __pid_t __REDIRECT_NTH (getpgrp, (__pid_t __pid), __getpgid);
 585 # else
 586 #  define getpgrp __getpgid
 587 # endif
 588 #endif
 589
 590 /* Get the process group ID of process PID.  */
 591 extern __pid_t __getpgid (__pid_t __pid) __THROW;
 592 #ifdef __USE_XOPEN_EXTENDED
 593 extern __pid_t getpgid (__pid_t __pid) __THROW;
 594 #endif
 595
 596
 597 /* Set the process group ID of the process matching PID to PGID.
 598    If PID is zero, the current process's process group ID is set.
 599    If PGID is zero, the process ID of the process is used.  */
 600 extern int setpgid (__pid_t __pid, __pid_t __pgid) __THROW;
 601
 602 #if defined __USE_SVID || defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 603 /* Both System V and BSD have `setpgrp' functions, but with different
 604    calling conventions.  The BSD function is the same as POSIX.1 `setpgid'
 605    (above).  The System V function takes no arguments and puts the calling
 606    process in its on group like `setpgid (0, 0)'.
 607
 608    New programs should always use `setpgid' instead.
 609
 610    The default in GNU is to provide the System V function.  The BSD
 611    function is available under -D_BSD_SOURCE.  */
 612
 613 # ifndef __FAVOR_BSD
 614
 615 /* Set the process group ID of the calling process to its own PID.
 616    This is exactly the same as `setpgid (0, 0)'.  */
 617 extern int setpgrp (void) __THROW;
 618
 619 # else
 620
 621 /* Another name for `setpgid' (above).  */
 622 #  ifdef __REDIRECT_NTH
 623 extern int __REDIRECT_NTH (setpgrp, (__pid_t __pid, __pid_t __pgrp), setpgid);
 624 #  else
 625 #   define setpgrp setpgid
 626 #  endif
 627
 628 # endif /* Favor BSD.  */
 629 #endif  /* Use SVID or BSD.  */
 630
 631 /* Create a new session with the calling process as its leader.
 632    The process group IDs of the session and the calling process
 633    are set to the process ID of the calling process, which is returned.  */
 634 extern __pid_t setsid (void) __THROW;
 635
 636 #ifdef __USE_XOPEN_EXTENDED
 637 /* Return the session ID of the given process.  */
 638 extern __pid_t getsid (__pid_t __pid) __THROW;
 639 #endif
 640
 641 /* Get the real user ID of the calling process.  */
 642 extern __uid_t getuid (void) __THROW;
 643
 644 /* Get the effective user ID of the calling process.  */
 645 extern __uid_t geteuid (void) __THROW;
 646
 647 /* Get the real group ID of the calling process.  */
 648 extern __gid_t getgid (void) __THROW;
 649
 650 /* Get the effective group ID of the calling process.  */
 651 extern __gid_t getegid (void) __THROW;
 652
 653 /* If SIZE is zero, return the number of supplementary groups
 654    the calling process is in.  Otherwise, fill in the group IDs
 655    of its supplementary groups in LIST and return the number written.  */
 656 extern int getgroups (int __size, __gid_t __list[]) __THROW __wur;
 657
 658 #ifdef  __USE_GNU
 659 /* Return nonzero iff the calling process is in group GID.  */
 660 extern int group_member (__gid_t __gid) __THROW;
 661 #endif
 662
 663 /* Set the user ID of the calling process to UID.
 664    If the calling process is the super-user, set the real
 665    and effective user IDs, and the saved set-user-ID to UID;
 666    if not, the effective user ID is set to UID.  */
 667 extern int setuid (__uid_t __uid) __THROW;
 668
 669 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 670 /* Set the real user ID of the calling process to RUID,
 671    and the effective user ID of the calling process to EUID.  */
 672 extern int setreuid (__uid_t __ruid, __uid_t __euid) __THROW;
 673 #endif
 674
 675 #if defined __USE_BSD || defined __USE_XOPEN2K
 676 /* Set the effective user ID of the calling process to UID.  */
 677 extern int seteuid (__uid_t __uid) __THROW;
 678 #endif /* Use BSD.  */
 679
 680 /* Set the group ID of the calling process to GID.
 681    If the calling process is the super-user, set the real
 682    and effective group IDs, and the saved set-group-ID to GID;
 683    if not, the effective group ID is set to GID.  */
 684 extern int setgid (__gid_t __gid) __THROW;
 685
 686 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 687 /* Set the real group ID of the calling process to RGID,
 688    and the effective group ID of the calling process to EGID.  */
 689 extern int setregid (__gid_t __rgid, __gid_t __egid) __THROW;
 690 #endif
 691
 692 #if defined __USE_BSD || defined __USE_XOPEN2K
 693 /* Set the effective group ID of the calling process to GID.  */
 694 extern int setegid (__gid_t __gid) __THROW;
 695 #endif /* Use BSD.  */
 696
 697 #ifdef __USE_GNU
 698 /* Fetch the real user ID, effective user ID, and saved-set user ID,
 699    of the calling process.  */
 700 extern int getresuid (__uid_t *__ruid, __uid_t *__euid, __uid_t *__suid)
 701      __THROW;
 702
 703 /* Fetch the real group ID, effective group ID, and saved-set group ID,
 704    of the calling process.  */
 705 extern int getresgid (__gid_t *__rgid, __gid_t *__egid, __gid_t *__sgid)
 706      __THROW;
 707
 708 /* Set the real user ID, effective user ID, and saved-set user ID,
 709    of the calling process to RUID, EUID, and SUID, respectively.  */
 710 extern int setresuid (__uid_t __ruid, __uid_t __euid, __uid_t __suid)
 711      __THROW;
 712
 713 /* Set the real group ID, effective group ID, and saved-set group ID,
 714    of the calling process to RGID, EGID, and SGID, respectively.  */
 715 extern int setresgid (__gid_t __rgid, __gid_t __egid, __gid_t __sgid)
 716      __THROW;
 717 #endif
 718
 719
 720 /* Clone the calling process, creating an exact copy.
 721    Return -1 for errors, 0 to the new process,
 722    and the process ID of the new process to the old process.  */
 723 extern __pid_t fork (void) __THROW;
 724
 725 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 726 /* Clone the calling process, but without copying the whole address space.
 727    The calling process is suspended until the new process exits or is
 728    replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
 729    and the process ID of the new process to the old process.  */
 730 extern __pid_t vfork (void) __THROW;
 731 #endif /* Use BSD. */
 732
 733
 734 /* Return the pathname of the terminal FD is open on, or NULL on errors.
 735    The returned storage is good only until the next call to this function.  */
 736 extern char *ttyname (int __fd) __THROW;
 737
 738 /* Store at most BUFLEN characters of the pathname of the terminal FD is
 739    open on in BUF.  Return 0 on success, otherwise an error number.  */
 740 extern int ttyname_r (int __fd, char *__buf, size_t __buflen)
 741      __THROW __nonnull ((2)) __wur;
 742
 743 /* Return 1 if FD is a valid descriptor associated
 744    with a terminal, zero if not.  */
 745 extern int isatty (int __fd) __THROW;
 746
 747 #if defined __USE_BSD \
 748     || (defined __USE_XOPEN_EXTENDED && !defined __USE_UNIX98)
 749 /* Return the index into the active-logins file (utmp) for
 750    the controlling terminal.  */
 751 extern int ttyslot (void) __THROW;
 752 #endif
 753
 754
 755 /* Make a link to FROM named TO.  */
 756 extern int link (__const char *__from, __const char *__to)
 757      __THROW __nonnull ((1, 2)) __wur;
 758
 759 #ifdef __USE_ATFILE
 760 /* Like link but relative paths in TO and FROM are interpreted relative
 761    to FROMFD and TOFD respectively.  */
 762 extern int linkat (int __fromfd, __const char *__from, int __tofd,
 763                    __const char *__to, int __flags)
 764      __THROW __nonnull ((2, 4)) __wur;
 765 #endif
 766
 767 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
 768 /* Make a symbolic link to FROM named TO.  */
 769 extern int symlink (__const char *__from, __const char *__to)
 770      __THROW __nonnull ((1, 2)) __wur;
 771
 772 /* Read the contents of the symbolic link PATH into no more than
 773    LEN bytes of BUF.  The contents are not null-terminated.
 774    Returns the number of characters read, or -1 for errors.  */
 775 extern ssize_t readlink (__const char *__restrict __path,
 776                          char *__restrict __buf, size_t __len)
 777      __THROW __nonnull ((1, 2)) __wur;
 778 #endif /* Use BSD.  */
 779
 780 #ifdef __USE_ATFILE
 781 /* Like symlink but a relative path in TO is interpreted relative to TOFD.  */
 782 extern int symlinkat (__const char *__from, int __tofd,
 783                       __const char *__to) __THROW __nonnull ((1, 3)) __wur;
 784
 785 /* Like readlink but a relative PATH is interpreted relative to FD.  */
 786 extern ssize_t readlinkat (int __fd, __const char *__restrict __path,
 787                            char *__restrict __buf, size_t __len)
 788      __THROW __nonnull ((2, 3)) __wur;
 789 #endif
 790
 791 /* Remove the link NAME.  */
 792 extern int unlink (__const char *__name) __THROW __nonnull ((1));
 793
 794 #ifdef __USE_ATFILE
 795 /* Remove the link NAME relative to FD.  */
 796 extern int unlinkat (int __fd, __const char *__name, int __flag)
 797      __THROW __nonnull ((2));
 798 #endif
 799
 800 /* Remove the directory PATH.  */
 801 extern int rmdir (__const char *__path) __THROW __nonnull ((1));
 802
 803
 804 /* Return the foreground process group ID of FD.  */
 805 extern __pid_t tcgetpgrp (int __fd) __THROW;
 806
 807 /* Set the foreground process group ID of FD set PGRP_ID.  */
 808 extern int tcsetpgrp (int __fd, __pid_t __pgrp_id) __THROW;
 809
 810
 811 /* Return the login name of the user.
 812
 813    This function is a possible cancellation points and therefore not
 814    marked with __THROW.  */
 815 extern char *getlogin (void);
 816 #if defined __USE_REENTRANT || defined __USE_POSIX199506
 817 /* Return at most NAME_LEN characters of the login name of the user in NAME.
 818    If it cannot be determined or some other error occurred, return the error
 819    code.  Otherwise return 0.
 820
 821    This function is a possible cancellation points and therefore not
 822    marked with __THROW.  */
 823 extern int getlogin_r (char *__name, size_t __name_len) __nonnull ((1));
 824 #endif
 825
 826 #ifdef  __USE_BSD
 827 /* Set the login name returned by `getlogin'.  */
 828 extern int setlogin (__const char *__name) __THROW __nonnull ((1));
 829 #endif
 830
 831
 832 #ifdef  __USE_POSIX2
 833 /* Get definitions and prototypes for functions to process the
 834    arguments in ARGV (ARGC of them, minus the program name) for
 835    options given in OPTS.  */
 836 # define __need_getopt
 837 # include <getopt.h>
 838 #endif
 839
 840
 841 #if defined __USE_BSD || defined __USE_UNIX98
 842 /* Put the name of the current host in no more than LEN bytes of NAME.
 843    The result is null-terminated if LEN is large enough for the full
 844    name and the terminator.  */
 845 extern int gethostname (char *__name, size_t __len) __THROW __nonnull ((1));
 846 #endif
 847
 848
 849 #if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_UNIX98)
 850 /* Set the name of the current host to NAME, which is LEN bytes long.
 851    This call is restricted to the super-user.  */
 852 extern int sethostname (__const char *__name, size_t __len)
 853      __THROW __nonnull ((1)) __wur;
 854
 855 /* Set the current machine's Internet number to ID.
 856    This call is restricted to the super-user.  */
 857 extern int sethostid (long int __id) __THROW __wur;
 858
 859
 860 /* Get and set the NIS (aka YP) domain name, if any.
 861    Called just like `gethostname' and `sethostname'.
 862    The NIS domain name is usually the empty string when not using NIS.  */
 863 extern int getdomainname (char *__name, size_t __len)
 864      __THROW __nonnull ((1)) __wur;
 865 extern int setdomainname (__const char *__name, size_t __len)
 866      __THROW __nonnull ((1)) __wur;
 867
 868
 869 /* Revoke access permissions to all processes currently communicating
 870    with the control terminal, and then send a SIGHUP signal to the process
 871    group of the control terminal.  */
 872 extern int vhangup (void) __THROW;
 873
 874 /* Revoke the access of all descriptors currently open on FILE.  */
 875 extern int revoke (__const char *__file) __THROW __nonnull ((1)) __wur;
 876
 877
 878 /* Enable statistical profiling, writing samples of the PC into at most
 879    SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
 880    is enabled, the system examines the user PC and increments
 881    SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536].  If SCALE is zero,
 882    disable profiling.  Returns zero on success, -1 on error.  */
 883 extern int profil (unsigned short int *__sample_buffer, size_t __size,
 884                    size_t __offset, unsigned int __scale)
 885      __THROW __nonnull ((1));
 886
 887
 888 /* Turn accounting on if NAME is an existing file.  The system will then write
 889    a record for each process as it terminates, to this file.  If NAME is NULL,
 890    turn accounting off.  This call is restricted to the super-user.  */
 891 extern int acct (__const char *__name) __THROW;
 892
 893
 894 /* Successive calls return the shells listed in `/etc/shells'.  */
 895 extern char *getusershell (void) __THROW;
 896 extern void endusershell (void) __THROW; /* Discard cached info.  */
 897 extern void setusershell (void) __THROW; /* Rewind and re-read the file.  */
 898
 899
 900 /* Put the program in the background, and dissociate from the controlling
 901    terminal.  If NOCHDIR is zero, do `chdir ("/")'.  If NOCLOSE is zero,
 902    redirects stdin, stdout, and stderr to /dev/null.  */
 903 extern int daemon (int __nochdir, int __noclose) __THROW __wur;
 904 #endif /* Use BSD || X/Open.  */
 905
 906
 907 #if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_XOPEN2K)
 908 /* Make PATH be the root directory (the starting point for absolute paths).
 909    This call is restricted to the super-user.  */
 910 extern int chroot (__const char *__path) __THROW __nonnull ((1)) __wur;
 911
 912 /* Prompt with PROMPT and read a string from the terminal without echoing.
 913    Uses /dev/tty if possible; otherwise stderr and stdin.  */
 914 extern char *getpass (__const char *__prompt) __nonnull ((1));
 915 #endif /* Use BSD || X/Open.  */
 916
 917
 918 #if defined __USE_BSD || defined __USE_XOPEN
 919 /* Make all changes done to FD actually appear on disk.
 920
 921    This function is a cancellation point and therefore not marked with
 922    __THROW.  */
 923 extern int fsync (int __fd);
 924 #endif /* Use BSD || X/Open.  */
 925
 926
 927 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 928
 929 /* Return identifier for the current host.  */
 930 extern long int gethostid (void);
 931
 932 /* Make all changes done to all files actually appear on disk.  */
 933 extern void sync (void) __THROW;
 934
 935
 936 /* Return the number of bytes in a page.  This is the system's page size,
 937    which is not necessarily the same as the hardware page size.  */
 938 extern int getpagesize (void)  __THROW __attribute__ ((__const__));
 939
 940
 941 /* Return the maximum number of file descriptors
 942    the current process could possibly have.  */
 943 extern int getdtablesize (void) __THROW;
 944
 945
 946 /* Truncate FILE to LENGTH bytes.  */
 947 # ifndef __USE_FILE_OFFSET64
 948 extern int truncate (__const char *__file, __off_t __length)
 949      __THROW __nonnull ((1)) __wur;
 950 # else
 951 #  ifdef __REDIRECT_NTH
 952 extern int __REDIRECT_NTH (truncate,
 953                            (__const char *__file, __off64_t __length),
 954                            truncate64) __nonnull ((1)) __wur;
 955 #  else
 956 #   define truncate truncate64
 957 #  endif
 958 # endif
 959 # ifdef __USE_LARGEFILE64
 960 extern int truncate64 (__const char *__file, __off64_t __length)
 961      __THROW __nonnull ((1)) __wur;
 962 # endif
 963
 964 #endif /* Use BSD || X/Open Unix.  */
 965
 966 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
 967
 968 /* Truncate the file FD is open on to LENGTH bytes.  */
 969 # ifndef __USE_FILE_OFFSET64
 970 extern int ftruncate (int __fd, __off_t __length) __THROW __wur;
 971 # else
 972 #  ifdef __REDIRECT_NTH
 973 extern int __REDIRECT_NTH (ftruncate, (int __fd, __off64_t __length),
 974                            ftruncate64) __wur;
 975 #  else
 976 #   define ftruncate ftruncate64
 977 #  endif
 978 # endif
 979 # ifdef __USE_LARGEFILE64
 980 extern int ftruncate64 (int __fd, __off64_t __length) __THROW __wur;
 981 # endif
 982
 983 #endif /* Use BSD || X/Open Unix || POSIX 2003.  */
 984
 985
 986 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 987
 988 /* Set the end of accessible data space (aka "the break") to ADDR.
 989    Returns zero on success and -1 for errors (with errno set).  */
 990 extern int brk (void *__addr) __THROW __wur;
 991
 992 /* Increase or decrease the end of accessible data space by DELTA bytes.
 993    If successful, returns the address the previous end of data space
 994    (i.e. the beginning of the new space, if DELTA > 0);
 995    returns (void *) -1 for errors (with errno set).  */
 996 extern void *sbrk (intptr_t __delta) __THROW;
 997 #endif
 998
 999
1000 #ifdef __USE_MISC
1001 /* Invoke `system call' number SYSNO, passing it the remaining arguments.
1002    This is completely system-dependent, and not often useful.
1003
1004    In Unix, `syscall' sets `errno' for all errors and most calls return -1
1005    for errors; in many systems you cannot pass arguments or get return
1006    values for all system calls (`pipe', `fork', and `getppid' typically
1007    among them).
1008
1009    In Mach, all system calls take normal arguments and always return an
1010    error code (zero for success).  */
1011 extern long int syscall (long int __sysno, ...) __THROW;
1012
1013 #endif  /* Use misc.  */
1014
1015
1016 #if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK
1017 /* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both
1018    files consistent.  Some systems have them there and some here, and some
1019    software depends on the macros being defined without including both.  */
1020
1021 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
1022    LEN is always relative to the current file position.
1023    The CMD argument is one of the following.
1024
1025    This function is a cancellation point and therefore not marked with
1026    __THROW.  */
1027
1028 # define F_ULOCK 0      /* Unlock a previously locked region.  */
1029 # define F_LOCK  1      /* Lock a region for exclusive use.  */
1030 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
1031 # define F_TEST  3      /* Test a region for other processes locks.  */
1032
1033 # ifndef __USE_FILE_OFFSET64
1034 extern int lockf (int __fd, int __cmd, __off_t __len) __wur;
1035 # else
1036 #  ifdef __REDIRECT
1037 extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len),
1038                        lockf64) __wur;
1039 #  else
1040 #   define lockf lockf64
1041 #  endif
1042 # endif
1043 # ifdef __USE_LARGEFILE64
1044 extern int lockf64 (int __fd, int __cmd, __off64_t __len) __wur;
1045 # endif
1046 #endif /* Use misc and F_LOCK not already defined.  */
1047
1048
1049 #ifdef __USE_GNU
1050
1051 /* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno'
1052    set to EINTR.  */
1053
1054 # define TEMP_FAILURE_RETRY(expression) \
1055   (__extension__                                                              \
1056     ({ long int __result;                                                     \
1057        do __result = (long int) (expression);                                 \
1058        while (__result == -1L && errno == EINTR);                             \
1059        __result; }))
1060 #endif
1061
1062 #if defined __USE_POSIX199309 || defined __USE_UNIX98
1063 /* Synchronize at least the data part of a file with the underlying
1064    media.  */
1065 extern int fdatasync (int __fildes);
1066 #endif /* Use POSIX199309 */
1067
1068
1069 /* XPG4.2 specifies that prototypes for the encryption functions must
1070    be defined here.  */
1071 #ifdef  __USE_XOPEN
1072 /* Encrypt at most 8 characters from KEY using salt to perturb DES.  */
1073 extern char *crypt (__const char *__key, __const char *__salt)
1074      __THROW __nonnull ((1, 2));
1075
1076 /* Encrypt data in BLOCK in place if EDFLAG is zero; otherwise decrypt
1077    block in place.  */
1078 extern void encrypt (char *__block, int __edflag) __THROW __nonnull ((1));
1079
1080
1081 /* Swab pairs bytes in the first N bytes of the area pointed to by
1082    FROM and copy the result to TO.  The value of TO must not be in the
1083    range [FROM - N + 1, FROM - 1].  If N is odd the first byte in FROM
1084    is without partner.  */
1085 extern void swab (__const void *__restrict __from, void *__restrict __to,
1086                   ssize_t __n) __THROW __nonnull ((1, 2));
1087 #endif
1088
1089
1090 /* The Single Unix specification demands this prototype to be here.
1091    It is also found in <stdio.h>.  */
1092 #ifdef __USE_XOPEN
1093 /* Return the name of the controlling terminal.  */
1094 extern char *ctermid (char *__s) __THROW;
1095 #endif
1096
1097
1098 /* Define some macros helping to catch buffer overflows.  */
1099 #if __USE_FORTIFY_LEVEL > 0 && defined __extern_always_inline
1100 # include <bits/unistd.h>
1101 #endif
1102
1103 __END_DECLS
1104
1105 #endif /* unistd.h  */