posix/unistd.h

   1 /* Copyright (C) 1991-1999, 2000 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 Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    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    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 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 August, 1988 and
  34    extended by POSIX-1b (aka POSIX-4) and POSIX-1c (aka POSIX threads).  */
  35 #define _POSIX_VERSION  199506L
  36
  37 /* These are not #ifdef __USE_POSIX2 because they are
  38    in the theoretically application-owned namespace.  */
  39
  40 /* POSIX Standard approved as ISO/IEC 9945-2 as of December, 1993.  */
  41 #define _POSIX2_C_VERSION       199209L
  42
  43 /* The utilities on GNU systems also correspond to this version.  */
  44 #define _POSIX2_VERSION 199209L
  45
  46 /* If defined, the implementation supports the
  47    C Language Bindings Option.  */
  48 #define _POSIX2_C_BIND  1
  49
  50 /* If defined, the implementation supports the
  51    C Language Development Utilities Option.  */
  52 #define _POSIX2_C_DEV   1
  53
  54 /* If defined, the implementation supports the
  55    Software Development Utilities Option.  */
  56 #define _POSIX2_SW_DEV  1
  57
  58 /* If defined, the implementation supports the
  59    creation of locales with the localedef utility.  */
  60 #define _POSIX2_LOCALEDEF       1
  61
  62 /* X/Open version number to which the library conforms.  It is selectable.  */
  63 #ifdef __USE_UNIX98
  64 # define _XOPEN_VERSION 500
  65 #else
  66 # define _XOPEN_VERSION 4
  67 #endif
  68
  69 /* Commands and utilities from XPG4 are available.  */
  70 #define _XOPEN_XCU_VERSION      4
  71
  72 /* We are compatible with the old published standards as well.  */
  73 #define _XOPEN_XPG2     1
  74 #define _XOPEN_XPG3     1
  75 #define _XOPEN_XPG4     1
  76
  77 /* The X/Open Unix extensions are available.  */
  78 #define _XOPEN_UNIX     1
  79
  80 /* Encryption is present.  */
  81 #define _XOPEN_CRYPT    1
  82
  83 /* The enhanced internationalization capabilities according to XPG4.2
  84    are present.  */
  85 #define _XOPEN_ENH_I18N 1
  86
  87 /* The legacy interfaces are also available.  */
  88 #define _XOPEN_LEGACY   1
  89
  90
  91 /* Get values of POSIX options:
  92
  93    If these symbols are defined, the corresponding features are
  94    always available.  If not, they may be available sometimes.
  95    The current values can be obtained with `sysconf'.
  96
  97    _POSIX_JOB_CONTROL           Job control is supported.
  98    _POSIX_SAVED_IDS             Processes have a saved set-user-ID
  99                                 and a saved set-group-ID.
 100    _POSIX_REALTIME_SIGNALS      Real-time, queued signals are supported.
 101    _POSIX_PRIORITY_SCHEDULING   Priority scheduling is supported.
 102    _POSIX_TIMERS                POSIX.4 clocks and timers are supported.
 103    _POSIX_ASYNCHRONOUS_IO       Asynchronous I/O is supported.
 104    _POSIX_PRIORITIZED_IO        Prioritized asynchronous I/O is supported.
 105    _POSIX_SYNCHRONIZED_IO       Synchronizing file data is supported.
 106    _POSIX_FSYNC                 The fsync function is present.
 107    _POSIX_MAPPED_FILES          Mapping of files to memory is supported.
 108    _POSIX_MEMLOCK               Locking of all memory is supported.
 109    _POSIX_MEMLOCK_RANGE         Locking of ranges of memory is supported.
 110    _POSIX_MEMORY_PROTECTION     Setting of memory protections is supported.
 111    _POSIX_MESSAGE_PASSING       POSIX.4 message queues are supported.
 112    _POSIX_SEMAPHORES            POSIX.4 counting semaphores are supported.
 113    _POSIX_SHARED_MEMORY_OBJECTS POSIX.4 shared memory objects are supported.
 114    _POSIX_THREADS               POSIX.1c pthreads are supported.
 115    _POSIX_THREAD_ATTR_STACKADDR Thread stack address attribute option supported.
 116    _POSIX_THREAD_ATTR_STACKSIZE Thread stack size attribute option supported.
 117    _POSIX_THREAD_SAFE_FUNCTIONS Thread-safe functions are supported.
 118    _POSIX_THREAD_PRIORITY_SCHEDULING
 119                                 POSIX.1c thread execution scheduling supported.
 120    _POSIX_THREAD_PRIO_INHERIT   Thread priority inheritance option supported.
 121    _POSIX_THREAD_PRIO_PROTECT   Thread priority protection option supported.
 122    _POSIX_THREAD_PROCESS_SHARED Process-shared synchronization supported.
 123    _POSIX_PII                   Protocol-independent interfaces are supported.
 124    _POSIX_PII_XTI               XTI protocol-indep. interfaces are supported.
 125    _POSIX_PII_SOCKET            Socket protocol-indep. interfaces are supported.
 126    _POSIX_PII_INTERNET          Internet family of protocols supported.
 127    _POSIX_PII_INTERNET_STREAM   Connection-mode Internet protocol supported.
 128    _POSIX_PII_INTERNET_DGRAM    Connectionless Internet protocol supported.
 129    _POSIX_PII_OSI               ISO/OSI family of protocols supported.
 130    _POSIX_PII_OSI_COTS          Connection-mode ISO/OSI service supported.
 131    _POSIX_PII_OSI_CLTS          Connectionless ISO/OSI service supported.
 132    _POSIX_POLL                  Implementation supports `poll' function.
 133    _POSIX_SELECT                Implementation supports `select' and `pselect'.
 134
 135    _XOPEN_REALTIME              X/Open realtime support is available.
 136    _XOPEN_REALTIME_THREADS      X/Open realtime thread support is available.
 137    _XOPEN_SHM                   Shared memory interface according to XPG4.2.
 138
 139    _XBS5_ILP32_OFF32            Implementation provides environment with 32-bit
 140                                 int, long, pointer, and off_t types.
 141    _XBS5_ILP32_OFFBIG           Implementation provides environment with 32-bit
 142                                 int, long, and pointer and off_t with at least
 143                                 64 bits.
 144    _XBS5_LP64_OFF64             Implementation provides environment with 32-bit
 145                                 int, and 64-bit long, pointer, and off_t types.
 146    _XBS5_LPBIG_OFFBIG           Implementation provides environment with at
 147                                 least 32 bits int and long, pointer, and off_t
 148                                 with at least 64 bits.
 149
 150    If any of these symbols is defined as -1, the corresponding option is not
 151    true for any file.  If any is defined as other than -1, the corresponding
 152    option is true for all files.  If a symbol is not defined at all, the value
 153    for a specific file can be obtained from `pathconf' and `fpathconf'.
 154
 155    _POSIX_CHOWN_RESTRICTED      Only the super user can use `chown' to change
 156                                 the owner of a file.  `chown' can only be used
 157                                 to change the group ID of a file to a group of
 158                                 which the calling process is a member.
 159    _POSIX_NO_TRUNC              Pathname components longer than
 160                                 NAME_MAX generate an error.
 161    _POSIX_VDISABLE              If defined, if the value of an element of the
 162                                 `c_cc' member of `struct termios' is
 163                                 _POSIX_VDISABLE, no character will have the
 164                                 effect associated with that element.
 165    _POSIX_SYNC_IO               Synchronous I/O may be performed.
 166    _POSIX_ASYNC_IO              Asynchronous I/O may be performed.
 167    _POSIX_PRIO_IO               Prioritized Asynchronous I/O may be performed.
 168
 169    Support for the Large File Support interface is not generally available.
 170    If it is available the following constants are defined to one.
 171    _LFS64_LARGEFILE             Low-level I/O supports large files.
 172    _LFS64_STDIO                 Standard I/O supports large files.
 173    */
 174
 175 #include <bits/posix_opt.h>
 176
 177 /* Get the environment definitions from Unix98.  */
 178 #ifdef __USE_UNIX98
 179 # include <bits/environments.h>
 180 #endif
 181
 182 /* Standard file descriptors.  */
 183 #define STDIN_FILENO    0       /* Standard input.  */
 184 #define STDOUT_FILENO   1       /* Standard output.  */
 185 #define STDERR_FILENO   2       /* Standard error output.  */
 186
 187
 188 /* All functions that are not declared anywhere else.  */
 189
 190 #include <bits/types.h>
 191
 192 #ifndef __ssize_t_defined
 193 typedef __ssize_t ssize_t;
 194 # define __ssize_t_defined
 195 #endif
 196
 197 #define __need_size_t
 198 #define __need_NULL
 199 #include <stddef.h>
 200
 201 #ifdef __USE_XOPEN
 202 /* The Single Unix specification says that some more types are
 203    available here.  */
 204 # ifndef __gid_t_defined
 205 typedef __gid_t gid_t;
 206 #  define __gid_t_defined
 207 # endif
 208
 209 # ifndef __uid_t_defined
 210 typedef __uid_t uid_t;
 211 #  define __uid_t_defined
 212 # endif
 213
 214 # ifndef __off_t_defined
 215 #  ifndef __USE_FILE_OFFSET64
 216 typedef __off_t off_t;
 217 #  else
 218 typedef __off64_t off_t;
 219 #  endif
 220 #  define __off_t_defined
 221 # endif
 222 # if defined __USE_LARGEFILE64 && !defined __off64_t_defined
 223 typedef __off64_t off64_t;
 224 #  define __off64_t_defined
 225 # endif
 226
 227 # ifndef __useconds_t_defined
 228 typedef __useconds_t useconds_t;
 229 #  define __useconds_t_defined
 230 # endif
 231
 232 # ifndef __pid_t_defined
 233 typedef __pid_t pid_t;
 234 #  define __pid_t_defined
 235 # endif
 236 #endif  /* X/Open */
 237
 238 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 239 # ifndef __intptr_t_defined
 240 typedef __intptr_t intptr_t;
 241 #  define __intptr_t_defined
 242 # endif
 243 #endif
 244
 245 #if defined __USE_BSD || defined __USE_XOPEN
 246 # ifndef __socklen_t_defined
 247 typedef __socklen_t socklen_t;
 248 #  define __socklen_t_defined
 249 # endif
 250 #endif
 251
 252 /* Values for the second argument to access.
 253    These may be OR'd together.  */
 254 #define R_OK    4               /* Test for read permission.  */
 255 #define W_OK    2               /* Test for write permission.  */
 256 #define X_OK    1               /* Test for execute permission.  */
 257 #define F_OK    0               /* Test for existence.  */
 258
 259 /* Test for access to NAME using the real UID and real GID.  */
 260 extern int access (__const char *__name, int __type) __THROW;
 261
 262 #ifdef __USE_GNU
 263 /* Test for access to NAME using the effective UID and GID
 264    (as normal file operations use).  */
 265 extern int euidaccess (__const char *__name, int __type) __THROW;
 266 #endif
 267
 268
 269 /* Values for the WHENCE argument to lseek.  */
 270 #ifndef _STDIO_H                /* <stdio.h> has the same definitions.  */
 271 # define SEEK_SET       0       /* Seek from beginning of file.  */
 272 # define SEEK_CUR       1       /* Seek from current position.  */
 273 # define SEEK_END       2       /* Seek from end of file.  */
 274 #endif
 275
 276 #if defined __USE_BSD && !defined L_SET
 277 /* Old BSD names for the same constants; just for compatibility.  */
 278 # define L_SET          SEEK_SET
 279 # define L_INCR         SEEK_CUR
 280 # define L_XTND         SEEK_END
 281 #endif
 282
 283
 284 /* Move FD's file position to OFFSET bytes from the
 285    beginning of the file (if WHENCE is SEEK_SET),
 286    the current position (if WHENCE is SEEK_CUR),
 287    or the end of the file (if WHENCE is SEEK_END).
 288    Return the new file position.  */
 289 extern __off_t __lseek (int __fd, __off_t __offset, int __whence) __THROW;
 290 #ifndef __USE_FILE_OFFSET64
 291 extern __off_t lseek (int __fd, __off_t __offset, int __whence) __THROW;
 292 #else
 293 # ifdef __REDIRECT
 294 extern __off64_t __REDIRECT (lseek,
 295                              (int __fd, __off64_t __offset, int __whence)
 296                              __THROW,
 297                              lseek64);
 298 # else
 299 #  define lseek lseek64
 300 # endif
 301 #endif
 302 #ifdef __USE_LARGEFILE64
 303 extern __off64_t lseek64 (int __fd, __off64_t __offset, int __whence) __THROW;
 304 #endif
 305
 306 /* Close the file descriptor FD.  */
 307 extern int __close (int __fd) __THROW;
 308 extern int close (int __fd) __THROW;
 309
 310 /* Read NBYTES into BUF from FD.  Return the
 311    number read, -1 for errors or 0 for EOF.  */
 312 extern ssize_t __read (int __fd, void *__buf, size_t __nbytes) __THROW;
 313 extern ssize_t read (int __fd, void *__buf, size_t __nbytes) __THROW;
 314
 315 /* Write N bytes of BUF to FD.  Return the number written, or -1.  */
 316 extern ssize_t __write (int __fd, __const void *__buf, size_t __n) __THROW;
 317 extern ssize_t write (int __fd, __const void *__buf, size_t __n) __THROW;
 318
 319 #ifdef __USE_UNIX98
 320 /* Read NBYTES into BUF from FD at the given position OFFSET without
 321    changing the file pointer.  Return the number read, -1 for errors
 322    or 0 for EOF.  */
 323 extern ssize_t __pread64 (int __fd, void *__buf, size_t __nbytes,
 324                           __off64_t __offset) __THROW;
 325 /* Write N bytes of BUF to FD at the given position OFFSET without
 326    changing the file pointer.  Return the number written, or -1.  */
 327 extern ssize_t __pwrite64 (int __fd, __const void *__buf, size_t __n,
 328                            __off64_t __offset) __THROW;
 329
 330 # ifndef __USE_FILE_OFFSET64
 331 extern ssize_t pread (int __fd, void *__buf, size_t __nbytes, __off_t __offset)
 332      __THROW;
 333 extern ssize_t pwrite (int __fd, __const void *__buf, size_t __n,
 334                        __off_t __offset) __THROW;
 335 # else
 336 #  ifdef __REDIRECT
 337 extern ssize_t __REDIRECT (pread, (int __fd, void *__buf, size_t __nbytes,
 338                                    __off64_t __offset) __THROW,
 339                            pread64);
 340 extern ssize_t __REDIRECT (pwrite, (int __fd, __const void *__buf,
 341                                     size_t __nbytes, __off64_t __offset)
 342                            __THROW,
 343                         pwrite64);
 344 #  else
 345 #   define pread pread64
 346 #   define pwrite pwrite64
 347 #  endif
 348 # endif
 349
 350 # ifdef __USE_LARGEFILE64
 351 extern ssize_t pread64 (int __fd, void *__buf, size_t __nbytes,
 352                         __off64_t __offset) __THROW;
 353 extern ssize_t pwrite64 (int __fd, __const void *__buf, size_t __n,
 354                          __off64_t __offset) __THROW;
 355 # endif
 356 #endif
 357
 358 /* Create a one-way communication channel (pipe).
 359    If successful, two file descriptors are stored in PIPEDES;
 360    bytes written on PIPEDES[1] can be read from PIPEDES[0].
 361    Returns 0 if successful, -1 if not.  */
 362 extern int pipe (int __pipedes[2]) __THROW;
 363
 364 /* Schedule an alarm.  In SECONDS seconds, the process will get a SIGALRM.
 365    If SECONDS is zero, any currently scheduled alarm will be cancelled.
 366    The function returns the number of seconds remaining until the last
 367    alarm scheduled would have signaled, or zero if there wasn't one.
 368    There is no return value to indicate an error, but you can set `errno'
 369    to 0 and check its value after calling `alarm', and this might tell you.
 370    The signal may come late due to processor scheduling.  */
 371 extern unsigned int alarm (unsigned int __seconds) __THROW;
 372
 373 /* Make the process sleep for SECONDS seconds, or until a signal arrives
 374    and is not ignored.  The function returns the number of seconds less
 375    than SECONDS which it actually slept (thus zero if it slept the full time).
 376    If a signal handler does a `longjmp' or modifies the handling of the
 377    SIGALRM signal while inside `sleep' call, the handling of the SIGALRM
 378    signal afterwards is undefined.  There is no return value to indicate
 379    error, but if `sleep' returns SECONDS, it probably didn't work.  */
 380 extern unsigned int sleep (unsigned int __seconds) __THROW;
 381
 382 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 383 /* Set an alarm to go off (generating a SIGALRM signal) in VALUE
 384    microseconds.  If INTERVAL is nonzero, when the alarm goes off, the
 385    timer is reset to go off every INTERVAL microseconds thereafter.
 386    Returns the number of microseconds remaining before the alarm.  */
 387 extern __useconds_t ualarm (__useconds_t __value, __useconds_t __interval)
 388      __THROW;
 389
 390 /* Sleep USECONDS microseconds, or until a signal arrives that is not blocked
 391    or ignored.  */
 392 extern void usleep (__useconds_t __useconds) __THROW;
 393 #endif
 394
 395
 396 /* Suspend the process until a signal arrives.
 397    This always returns -1 and sets `errno' to EINTR.  */
 398 extern int pause (void) __THROW;
 399
 400
 401 /* Change the owner and group of FILE.  */
 402 extern int chown (__const char *__file, __uid_t __owner, __gid_t __group)
 403      __THROW;
 404
 405 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 406 /* Change the owner and group of the file that FD is open on.  */
 407 extern int fchown (int __fd, __uid_t __owner, __gid_t __group) __THROW;
 408
 409
 410 /* Change owner and group of FILE, if it is a symbolic
 411    link the ownership of the symbolic link is changed.  */
 412 extern int lchown (__const char *__file, __uid_t __owner, __gid_t __group)
 413      __THROW;
 414
 415 #endif /* Use BSD || X/Open Unix.  */
 416
 417 /* Change the process's working directory to PATH.  */
 418 extern int chdir (__const char *__path) __THROW;
 419
 420 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 421 /* Change the process's working directory to the one FD is open on.  */
 422 extern int fchdir (int __fd) __THROW;
 423 #endif
 424
 425 /* Get the pathname of the current working directory,
 426    and put it in SIZE bytes of BUF.  Returns NULL if the
 427    directory couldn't be determined or SIZE was too small.
 428    If successful, returns BUF.  In GNU, if BUF is NULL,
 429    an array is allocated with `malloc'; the array is SIZE
 430    bytes long, unless SIZE == 0, in which case it is as
 431    big as necessary.  */
 432 extern char *getcwd (char *__buf, size_t __size) __THROW;
 433
 434 #ifdef  __USE_GNU
 435 /* Return a malloc'd string containing the current directory name.
 436    If the environment variable `PWD' is set, and its value is correct,
 437    that value is used.  */
 438 extern char *get_current_dir_name (void) __THROW;
 439 #endif
 440
 441 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 442 /* Put the absolute pathname of the current working directory in BUF.
 443    If successful, return BUF.  If not, put an error message in
 444    BUF and return NULL.  BUF should be at least PATH_MAX bytes long.  */
 445 extern char *getwd (char *__buf) __THROW;
 446 #endif
 447
 448
 449 /* Duplicate FD, returning a new file descriptor on the same file.  */
 450 extern int dup (int __fd) __THROW;
 451
 452 /* Duplicate FD to FD2, closing FD2 and making it open on the same file.  */
 453 extern int dup2 (int __fd, int __fd2) __THROW;
 454
 455 /* NULL-terminated array of "NAME=VALUE" environment variables.  */
 456 extern char **__environ;
 457 #ifdef __USE_GNU
 458 extern char **environ;
 459 #endif
 460
 461
 462 /* Replace the current process, executing PATH with arguments ARGV and
 463    environment ENVP.  ARGV and ENVP are terminated by NULL pointers.  */
 464 extern int execve (__const char *__path, char *__const __argv[],
 465                    char *__const __envp[]) __THROW;
 466
 467 #ifdef __USE_GNU
 468 /* Execute the file FD refers to, overlaying the running program image.
 469    ARGV and ENVP are passed to the new program, as for `execve'.  */
 470 extern int fexecve (int __fd, char *__const __argv[], char *__const __envp[])
 471      __THROW;
 472 #endif
 473
 474
 475 /* Execute PATH with arguments ARGV and environment from `environ'.  */
 476 extern int execv (__const char *__path, char *__const __argv[]) __THROW;
 477
 478 /* Execute PATH with all arguments after PATH until a NULL pointer,
 479    and the argument after that for environment.  */
 480 extern int execle (__const char *__path, __const char *__arg, ...) __THROW;
 481
 482 /* Execute PATH with all arguments after PATH until
 483    a NULL pointer and environment from `environ'.  */
 484 extern int execl (__const char *__path, __const char *__arg, ...) __THROW;
 485
 486 /* Execute FILE, searching in the `PATH' environment variable if it contains
 487    no slashes, with arguments ARGV and environment from `environ'.  */
 488 extern int execvp (__const char *__file, char *__const __argv[]) __THROW;
 489
 490 /* Execute FILE, searching in the `PATH' environment variable if
 491    it contains no slashes, with all arguments after FILE until a
 492    NULL pointer and environment from `environ'.  */
 493 extern int execlp (__const char *__file, __const char *__arg, ...) __THROW;
 494
 495
 496 #if defined __USE_MISC || defined __USE_XOPEN
 497 /* Add INC to priority of the current process.  */
 498 extern int nice (int __inc) __THROW;
 499 #endif
 500
 501
 502 /* Terminate program execution with the low-order 8 bits of STATUS.  */
 503 extern void _exit (int __status) __attribute__ ((__noreturn__));
 504
 505
 506 /* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf';
 507    the `_SC_*' symbols for the NAME argument to `sysconf';
 508    and the `_CS_*' symbols for the NAME argument to `confstr'.  */
 509 #include <bits/confname.h>
 510
 511 /* Get file-specific configuration information about PATH.  */
 512 extern long int pathconf (__const char *__path, int __name) __THROW;
 513
 514 /* Get file-specific configuration about descriptor FD.  */
 515 extern long int fpathconf (int __fd, int __name) __THROW;
 516
 517 /* Get the value of the system variable NAME.  */
 518 extern long int sysconf (int __name) __THROW;
 519
 520 #ifdef  __USE_POSIX2
 521 /* Get the value of the string-valued system variable NAME.  */
 522 extern size_t confstr (int __name, char *__buf, size_t __len) __THROW;
 523 #endif
 524
 525
 526 /* Get the process ID of the calling process.  */
 527 extern __pid_t __getpid (void) __THROW;
 528 extern __pid_t getpid (void) __THROW;
 529
 530 /* Get the process ID of the calling process's parent.  */
 531 extern __pid_t getppid (void) __THROW;
 532
 533 /* Get the process group ID of the calling process.
 534    This function is different on old BSD. */
 535 #ifndef __FAVOR_BSD
 536 extern __pid_t getpgrp (void) __THROW;
 537 #else
 538 # ifdef __REDIRECT
 539 extern __pid_t __REDIRECT (getpgrp, (__pid_t __pid) __THROW, __getpgid);
 540 # else
 541 #  define getpgrp __getpgid
 542 # endif
 543 #endif
 544
 545 /* Get the process group ID of process PID.  */
 546 extern __pid_t __getpgid (__pid_t __pid) __THROW;
 547 #ifdef __USE_XOPEN_EXTENDED
 548 extern __pid_t getpgid (__pid_t __pid) __THROW;
 549 #endif
 550
 551
 552 /* Set the process group ID of the process matching PID to PGID.
 553    If PID is zero, the current process's process group ID is set.
 554    If PGID is zero, the process ID of the process is used.  */
 555 extern int __setpgid (__pid_t __pid, __pid_t __pgid) __THROW;
 556 extern int setpgid (__pid_t __pid, __pid_t __pgid) __THROW;
 557
 558 #if defined __USE_SVID || defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 559 /* Both System V and BSD have `setpgrp' functions, but with different
 560    calling conventions.  The BSD function is the same as POSIX.1 `setpgid'
 561    (above).  The System V function takes no arguments and puts the calling
 562    process in its on group like `setpgid (0, 0)'.
 563
 564    New programs should always use `setpgid' instead.
 565
 566    The default in GNU is to provide the System V function.  The BSD
 567    function is available under -D_BSD_SOURCE.  */
 568
 569 # ifndef __FAVOR_BSD
 570
 571 /* Set the process group ID of the calling process to its own PID.
 572    This is exactly the same as `setpgid (0, 0)'.  */
 573 extern int setpgrp (void) __THROW;
 574
 575 # else
 576
 577 /* Another name for `setpgid' (above).  */
 578 #  ifdef __REDIRECT
 579 extern int __REDIRECT (setpgrp, (__pid_t __pid, __pid_t __pgrp) __THROW,
 580                        setpgid);
 581 #  else
 582 #   define setpgrp setpgid
 583 #  endif
 584
 585 # endif /* Favor BSD.  */
 586 #endif  /* Use SVID or BSD.  */
 587
 588 /* Create a new session with the calling process as its leader.
 589    The process group IDs of the session and the calling process
 590    are set to the process ID of the calling process, which is returned.  */
 591 extern __pid_t setsid (void) __THROW;
 592
 593 #ifdef __USE_XOPEN_EXTENDED
 594 /* Return the session ID of the given process.  */
 595 extern __pid_t getsid (__pid_t __pid) __THROW;
 596 #endif
 597
 598 /* Get the real user ID of the calling process.  */
 599 extern __uid_t getuid (void) __THROW;
 600
 601 /* Get the effective user ID of the calling process.  */
 602 extern __uid_t geteuid (void) __THROW;
 603
 604 /* Get the real group ID of the calling process.  */
 605 extern __gid_t getgid (void) __THROW;
 606
 607 /* Get the effective group ID of the calling process.  */
 608 extern __gid_t getegid (void) __THROW;
 609
 610 /* If SIZE is zero, return the number of supplementary groups
 611    the calling process is in.  Otherwise, fill in the group IDs
 612    of its supplementary groups in LIST and return the number written.  */
 613 extern int getgroups (int __size, __gid_t __list[]) __THROW;
 614
 615 #ifdef  __USE_GNU
 616 /* Return nonzero iff the calling process is in group GID.  */
 617 extern int group_member (__gid_t __gid) __THROW;
 618 #endif
 619
 620 /* Set the user ID of the calling process to UID.
 621    If the calling process is the super-user, set the real
 622    and effective user IDs, and the saved set-user-ID to UID;
 623    if not, the effective user ID is set to UID.  */
 624 extern int setuid (__uid_t __uid) __THROW;
 625
 626 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 627 /* Set the real user ID of the calling process to RUID,
 628    and the effective user ID of the calling process to EUID.  */
 629 extern int setreuid (__uid_t __ruid, __uid_t __euid) __THROW;
 630 #endif
 631
 632 #ifdef  __USE_BSD
 633 /* Set the effective user ID of the calling process to UID.  */
 634 extern int seteuid (__uid_t __uid) __THROW;
 635 #endif /* Use BSD.  */
 636
 637 /* Set the group ID of the calling process to GID.
 638    If the calling process is the super-user, set the real
 639    and effective group IDs, and the saved set-group-ID to GID;
 640    if not, the effective group ID is set to GID.  */
 641 extern int setgid (__gid_t __gid) __THROW;
 642
 643 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 644 /* Set the real group ID of the calling process to RGID,
 645    and the effective group ID of the calling process to EGID.  */
 646 extern int setregid (__gid_t __rgid, __gid_t __egid) __THROW;
 647 #endif
 648
 649 #ifdef __USE_BSD
 650 /* Set the effective group ID of the calling process to GID.  */
 651 extern int setegid (__gid_t __gid) __THROW;
 652 #endif /* Use BSD.  */
 653
 654
 655 /* Clone the calling process, creating an exact copy.
 656    Return -1 for errors, 0 to the new process,
 657    and the process ID of the new process to the old process.  */
 658 extern __pid_t __fork (void) __THROW;
 659 extern __pid_t fork (void) __THROW;
 660
 661 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 662 /* Clone the calling process, but without copying the whole address space.
 663    The calling process is suspended until the new process exits or is
 664    replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
 665    and the process ID of the new process to the old process.  */
 666 extern __pid_t vfork (void) __THROW;
 667 #endif /* Use BSD. */
 668
 669
 670 /* Return the pathname of the terminal FD is open on, or NULL on errors.
 671    The returned storage is good only until the next call to this function.  */
 672 extern char *ttyname (int __fd) __THROW;
 673
 674 /* Store at most BUFLEN characters of the pathname of the terminal FD is
 675    open on in BUF.  Return 0 on success, otherwise an error number.  */
 676 extern int ttyname_r (int __fd, char *__buf, size_t __buflen) __THROW;
 677
 678 /* Return 1 if FD is a valid descriptor associated
 679    with a terminal, zero if not.  */
 680 extern int isatty (int __fd) __THROW;
 681
 682 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 683 /* Return the index into the active-logins file (utmp) for
 684    the controlling terminal.  */
 685 extern int ttyslot (void) __THROW;
 686 #endif
 687
 688
 689 /* Make a link to FROM named TO.  */
 690 extern int link (__const char *__from, __const char *__to) __THROW;
 691
 692 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 693 /* Make a symbolic link to FROM named TO.  */
 694 extern int symlink (__const char *__from, __const char *__to) __THROW;
 695
 696 /* Read the contents of the symbolic link PATH into no more than
 697    LEN bytes of BUF.  The contents are not null-terminated.
 698    Returns the number of characters read, or -1 for errors.  */
 699 extern int readlink (__const char *__path, char *__buf, size_t __len) __THROW;
 700 #endif /* Use BSD.  */
 701
 702 /* Remove the link NAME.  */
 703 extern int unlink (__const char *__name) __THROW;
 704
 705 /* Remove the directory PATH.  */
 706 extern int rmdir (__const char *__path) __THROW;
 707
 708
 709 /* Return the foreground process group ID of FD.  */
 710 extern __pid_t tcgetpgrp (int __fd) __THROW;
 711
 712 /* Set the foreground process group ID of FD set PGRP_ID.  */
 713 extern int tcsetpgrp (int __fd, __pid_t __pgrp_id) __THROW;
 714
 715
 716 /* Return the login name of the user.  */
 717 extern char *getlogin (void) __THROW;
 718 #ifdef __USE_REENTRANT
 719 /* Return at most NAME_LEN characters of the login name of the user in NAME.
 720    If it cannot be determined or some other error occurred, return the error
 721    code.  Otherwise return 0.  */
 722 extern int getlogin_r (char *__name, size_t __name_len) __THROW;
 723 #endif
 724
 725 #ifdef  __USE_BSD
 726 /* Set the login name returned by `getlogin'.  */
 727 extern int setlogin (__const char *__name) __THROW;
 728 #endif
 729
 730
 731 #ifdef  __USE_POSIX2
 732 /* Get definitions and prototypes for functions to process the
 733    arguments in ARGV (ARGC of them, minus the program name) for
 734    options given in OPTS.  */
 735 # define __need_getopt
 736 # include <getopt.h>
 737 #endif
 738
 739
 740 #if defined __USE_BSD || defined __USE_XOPEN
 741
 742 /* Put the name of the current host in no more than LEN bytes of NAME.
 743    The result is null-terminated if LEN is large enough for the full
 744    name and the terminator.  */
 745 extern int gethostname (char *__name, socklen_t __len) __THROW;
 746
 747 /* Set the name of the current host to NAME, which is LEN bytes long.
 748    This call is restricted to the super-user.  */
 749 extern int sethostname (__const char *__name, size_t __len) __THROW;
 750
 751 /* Set the current machine's Internet number to ID.
 752    This call is restricted to the super-user.  */
 753 extern int sethostid (long int __id) __THROW;
 754
 755
 756 /* Get and set the NIS (aka YP) domain name, if any.
 757    Called just like `gethostname' and `sethostname'.
 758    The NIS domain name is usually the empty string when not using NIS.  */
 759 extern int getdomainname (char *__name, size_t __len) __THROW;
 760 extern int setdomainname (__const char *__name, size_t __len) __THROW;
 761
 762
 763 /* Make all changes done to FD actually appear on disk.  */
 764 extern int fsync (int __fd) __THROW;
 765
 766
 767 /* Revoke access permissions to all processes currently communicating
 768    with the control terminal, and then send a SIGHUP signal to the process
 769    group of the control terminal.  */
 770 extern int vhangup (void) __THROW;
 771
 772 /* Revoke the access of all descriptors currently open on FILE.  */
 773 extern int revoke (__const char *__file) __THROW;
 774
 775
 776 /* Enable statistical profiling, writing samples of the PC into at most
 777    SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
 778    is enabled, the system examines the user PC and increments
 779    SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536].  If SCALE is zero,
 780    disable profiling.  Returns zero on success, -1 on error.  */
 781 extern int profil (unsigned short int *__sample_buffer, size_t __size,
 782                    size_t __offset, unsigned int __scale) __THROW;
 783
 784
 785 /* Turn accounting on if NAME is an existing file.  The system will then write
 786    a record for each process as it terminates, to this file.  If NAME is NULL,
 787    turn accounting off.  This call is restricted to the super-user.  */
 788 extern int acct (__const char *__name) __THROW;
 789
 790 /* Make PATH be the root directory (the starting point for absolute paths).
 791    This call is restricted to the super-user.  */
 792 extern int chroot (__const char *__path) __THROW;
 793
 794
 795 /* Successive calls return the shells listed in `/etc/shells'.  */
 796 extern char *getusershell (void) __THROW;
 797 extern void endusershell (void) __THROW; /* Discard cached info.  */
 798 extern void setusershell (void) __THROW; /* Rewind and re-read the file.  */
 799
 800
 801 /* Prompt with PROMPT and read a string from the terminal without echoing.
 802    Uses /dev/tty if possible; otherwise stderr and stdin.  */
 803 extern char *getpass (__const char *__prompt) __THROW;
 804
 805 /* Put the program in the background, and dissociate from the controlling
 806    terminal.  If NOCHDIR is zero, do `chdir ("/")'.  If NOCLOSE is zero,
 807    redirects stdin, stdout, and stderr to /dev/null.  */
 808 extern int daemon (int __nochdir, int __noclose) __THROW;
 809
 810 #endif /* Use BSD || X/Open.  */
 811
 812
 813 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 814
 815 /* Return the current machine's Internet number.  */
 816 extern long int gethostid (void) __THROW;
 817
 818 /* Make all changes done to all files actually appear on disk.  */
 819 extern int sync (void) __THROW;
 820
 821
 822 /* Return the number of bytes in a page.  This is the system's page size,
 823    which is not necessarily the same as the hardware page size.  */
 824 extern int __getpagesize (void)  __THROW __attribute__ ((__const__));
 825 extern int getpagesize (void)  __THROW __attribute__ ((__const__));
 826
 827
 828 /* Truncate FILE to LENGTH bytes.  */
 829 #ifndef __USE_FILE_OFFSET64
 830 extern int truncate (__const char *__file, __off_t __length) __THROW;
 831 #else
 832 # ifdef __REDIRECT
 833 extern int __REDIRECT (truncate,
 834                        (__const char *__file, __off64_t __length) __THROW,
 835                        truncate64);
 836 # else
 837 #  define truncate truncate64
 838 # endif
 839 #endif
 840 #ifdef __USE_LARGEFILE64
 841 extern int truncate64 (__const char *__file, __off64_t __length) __THROW;
 842 #endif
 843
 844 /* Truncate the file FD is open on to LENGTH bytes.  */
 845 extern int __ftruncate (int __fd, __off_t __length) __THROW;
 846 #ifndef __USE_FILE_OFFSET64
 847 extern int ftruncate (int __fd, __off_t __length) __THROW;
 848 #else
 849 # ifdef __REDIRECT
 850 extern int __REDIRECT (ftruncate, (int __fd, __off64_t __length) __THROW,
 851                        ftruncate64);
 852 # else
 853 #  define ftruncate ftruncate64
 854 # endif
 855 #endif
 856 #ifdef __USE_LARGEFILE64
 857 extern int ftruncate64 (int __fd, __off64_t __length) __THROW;
 858 #endif
 859
 860
 861 /* Return the maximum number of file descriptors
 862    the current process could possibly have.  */
 863 extern int getdtablesize (void) __THROW;
 864
 865 #endif /* Use BSD || X/Open Unix.  */
 866
 867
 868 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 869
 870 /* Set the end of accessible data space (aka "the break") to ADDR.
 871    Returns zero on success and -1 for errors (with errno set).  */
 872 extern int brk (void *__addr) __THROW;
 873
 874 /* Increase or decrease the end of accessible data space by DELTA bytes.
 875    If successful, returns the address the previous end of data space
 876    (i.e. the beginning of the new space, if DELTA > 0);
 877    returns (void *) -1 for errors (with errno set).  */
 878 extern void *__sbrk (intptr_t __delta) __THROW;
 879 extern void *sbrk (intptr_t __delta) __THROW;
 880 #endif
 881
 882
 883 #ifdef __USE_MISC
 884 /* Invoke `system call' number SYSNO, passing it the remaining arguments.
 885    This is completely system-dependent, and not often useful.
 886
 887    In Unix, `syscall' sets `errno' for all errors and most calls return -1
 888    for errors; in many systems you cannot pass arguments or get return
 889    values for all system calls (`pipe', `fork', and `getppid' typically
 890    among them).
 891
 892    In Mach, all system calls take normal arguments and always return an
 893    error code (zero for success).  */
 894 extern long int syscall (long int __sysno, ...) __THROW;
 895
 896 #endif  /* Use misc.  */
 897
 898
 899 #if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK
 900 /* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both
 901    files consistent.  Some systems have them there and some here, and some
 902    software depends on the macros being defined without including both.  */
 903
 904 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
 905    LEN is always relative to the current file position.
 906    The CMD argument is one of the following.  */
 907
 908 # define F_ULOCK 0      /* Unlock a previously locked region.  */
 909 # define F_LOCK  1      /* Lock a region for exclusive use.  */
 910 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
 911 # define F_TEST  3      /* Test a region for other processes locks.  */
 912
 913 # ifndef __USE_FILE_OFFSET64
 914 extern int lockf (int __fd, int __cmd, __off_t __len) __THROW;
 915 # else
 916 #  ifdef __REDIRECT
 917 extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len) __THROW,
 918                        lockf64);
 919 #  else
 920 #   define lockf lockf64
 921 #  endif
 922 # endif
 923 # ifdef __USE_LARGEFILE64
 924 extern int lockf64 (int __fd, int __cmd, __off64_t __len) __THROW;
 925 # endif
 926 #endif /* Use misc and F_LOCK not already defined.  */
 927
 928
 929 #ifdef __USE_GNU
 930
 931 /* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno'
 932    set to EINTR.  */
 933
 934 # define TEMP_FAILURE_RETRY(expression) \
 935   (__extension__                                                              \
 936     ({ long int __result;                                                     \
 937        do __result = (long int) (expression);                                 \
 938        while (__result == -1L && errno == EINTR);                             \
 939        __result; }))
 940 #endif
 941
 942 #if defined __USE_POSIX199309 || defined __USE_UNIX98
 943 /* Synchronize at least the data part of a file with the underlying
 944    media.  */
 945 extern int fdatasync (int __fildes) __THROW;
 946 #endif /* Use POSIX199309 */
 947
 948
 949 /* XPG4.2 specifies that prototypes for the encryption functions must
 950    be defined here.  */
 951 #ifdef  __USE_XOPEN
 952 /* Encrypt at most 8 characters from KEY using salt to perturb DES.  */
 953 extern char *crypt (__const char *__key, __const char *__salt) __THROW;
 954
 955 /* Setup DES tables according KEY.  */
 956 extern void setkey (__const char *__key) __THROW;
 957
 958 /* Encrypt data in BLOCK in place if EDFLAG is zero; otherwise decrypt
 959    block in place.  */
 960 extern void encrypt (char *__block, int __edflag) __THROW;
 961
 962
 963 /* Swab pairs bytes in the first N bytes of the area pointed to by
 964    FROM and copy the result to TO.  The value of TO must not be in the
 965    range [FROM - N + 1, FROM - 1].  If N is odd the first byte in FROM
 966    is without partner.  */
 967 extern void swab (__const void *__from, void *__to, ssize_t __n) __THROW;
 968 #endif
 969
 970
 971 /* The Single Unix specification, version 2, demands these prototypes
 972    to be here.  They are also found in <stdio.h>.  */
 973 #ifdef __USE_XOPEN
 974 /* Return the name of the controlling terminal.  */
 975 extern char *ctermid (char *__s) __THROW;
 976
 977 /* Return the name of the current user.  This function should not be
 978    used and might go away some time.  */
 979 extern char *cuserid (char *__s) __THROW;
 980
 981 /* Rename file OLD to NEW.  */
 982 extern int rename (__const char *__old, __const char *__new) __THROW;
 983 #endif
 984
 985
 986 #ifdef __USE_POSIX199309
 987 /* This function is only available if the system has POSIX threads.  */
 988
 989 /* Install handlers to be called when a new process is created with FORK.
 990    The PREPARE handler is called in the parent process just before performing
 991    FORK. The PARENT handler is called in the parent process just after FORK.
 992    The CHILD handler is called in the child process.  Each of the three
 993    handlers can be NULL, meaning that no handler needs to be called at that
 994    point.
 995    PTHREAD_ATFORK can be called several times, in which case the PREPARE
 996    handlers are called in LIFO order (last added with PTHREAD_ATFORK,
 997    first called before FORK), and the PARENT and CHILD handlers are called
 998    in FIFO (first added, first called). */
 999 extern int pthread_atfork (void (*__prepare) (void),
1000                            void (*__parent) (void),
1001                            void (*__child) (void)) __THROW;
1002 #endif
1003
1004 __END_DECLS
1005
1006 #endif /* unistd.h  */