posix/unistd.h

   1 /* Copyright (C) 1991-2002, 2003, 2004 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_UNIX98
  60 # define _XOPEN_VERSION 500
  61 #else
  62 # define _XOPEN_VERSION 4
  63 #endif
  64
  65 /* Commands and utilities from XPG4 are available.  */
  66 #define _XOPEN_XCU_VERSION      4
  67
  68 /* We are compatible with the old published standards as well.  */
  69 #define _XOPEN_XPG2     1
  70 #define _XOPEN_XPG3     1
  71 #define _XOPEN_XPG4     1
  72
  73 /* The X/Open Unix extensions are available.  */
  74 #define _XOPEN_UNIX     1
  75
  76 /* Encryption is present.  */
  77 #define _XOPEN_CRYPT    1
  78
  79 /* The enhanced internationalization capabilities according to XPG4.2
  80    are present.  */
  81 #define _XOPEN_ENH_I18N 1
  82
  83 /* The legacy interfaces are also available.  */
  84 #define _XOPEN_LEGACY   1
  85
  86
  87 /* Get values of POSIX options:
  88
  89    If these symbols are defined, the corresponding features are
  90    always available.  If not, they may be available sometimes.
  91    The current values can be obtained with `sysconf'.
  92
  93    _POSIX_JOB_CONTROL           Job control is supported.
  94    _POSIX_SAVED_IDS             Processes have a saved set-user-ID
  95                                 and a saved set-group-ID.
  96    _POSIX_REALTIME_SIGNALS      Real-time, queued signals are supported.
  97    _POSIX_PRIORITY_SCHEDULING   Priority scheduling is supported.
  98    _POSIX_TIMERS                POSIX.4 clocks and timers are supported.
  99    _POSIX_ASYNCHRONOUS_IO       Asynchronous I/O is supported.
 100    _POSIX_PRIORITIZED_IO        Prioritized asynchronous I/O is supported.
 101    _POSIX_SYNCHRONIZED_IO       Synchronizing file data is supported.
 102    _POSIX_FSYNC                 The fsync function is present.
 103    _POSIX_MAPPED_FILES          Mapping of files to memory is supported.
 104    _POSIX_MEMLOCK               Locking of all memory is supported.
 105    _POSIX_MEMLOCK_RANGE         Locking of ranges of memory is supported.
 106    _POSIX_MEMORY_PROTECTION     Setting of memory protections is supported.
 107    _POSIX_MESSAGE_PASSING       POSIX.4 message queues are supported.
 108    _POSIX_SEMAPHORES            POSIX.4 counting semaphores are supported.
 109    _POSIX_SHARED_MEMORY_OBJECTS POSIX.4 shared memory objects are supported.
 110    _POSIX_THREADS               POSIX.1c pthreads are supported.
 111    _POSIX_THREAD_ATTR_STACKADDR Thread stack address attribute option supported.
 112    _POSIX_THREAD_ATTR_STACKSIZE Thread stack size attribute option supported.
 113    _POSIX_THREAD_SAFE_FUNCTIONS Thread-safe functions are supported.
 114    _POSIX_THREAD_PRIORITY_SCHEDULING
 115                                 POSIX.1c thread execution scheduling supported.
 116    _POSIX_THREAD_PRIO_INHERIT   Thread priority inheritance option supported.
 117    _POSIX_THREAD_PRIO_PROTECT   Thread priority protection option supported.
 118    _POSIX_THREAD_PROCESS_SHARED Process-shared synchronization supported.
 119    _POSIX_PII                   Protocol-independent interfaces are supported.
 120    _POSIX_PII_XTI               XTI protocol-indep. interfaces are supported.
 121    _POSIX_PII_SOCKET            Socket protocol-indep. interfaces are supported.
 122    _POSIX_PII_INTERNET          Internet family of protocols supported.
 123    _POSIX_PII_INTERNET_STREAM   Connection-mode Internet protocol supported.
 124    _POSIX_PII_INTERNET_DGRAM    Connectionless Internet protocol supported.
 125    _POSIX_PII_OSI               ISO/OSI family of protocols supported.
 126    _POSIX_PII_OSI_COTS          Connection-mode ISO/OSI service supported.
 127    _POSIX_PII_OSI_CLTS          Connectionless ISO/OSI service supported.
 128    _POSIX_POLL                  Implementation supports `poll' function.
 129    _POSIX_SELECT                Implementation supports `select' and `pselect'.
 130
 131    _XOPEN_REALTIME              X/Open realtime support is available.
 132    _XOPEN_REALTIME_THREADS      X/Open realtime thread support is available.
 133    _XOPEN_SHM                   Shared memory interface according to XPG4.2.
 134
 135    _XBS5_ILP32_OFF32            Implementation provides environment with 32-bit
 136                                 int, long, pointer, and off_t types.
 137    _XBS5_ILP32_OFFBIG           Implementation provides environment with 32-bit
 138                                 int, long, and pointer and off_t with at least
 139                                 64 bits.
 140    _XBS5_LP64_OFF64             Implementation provides environment with 32-bit
 141                                 int, and 64-bit long, pointer, and off_t types.
 142    _XBS5_LPBIG_OFFBIG           Implementation provides environment with at
 143                                 least 32 bits int and long, pointer, and off_t
 144                                 with at least 64 bits.
 145
 146    If any of these symbols is defined as -1, the corresponding option is not
 147    true for any file.  If any is defined as other than -1, the corresponding
 148    option is true for all files.  If a symbol is not defined at all, the value
 149    for a specific file can be obtained from `pathconf' and `fpathconf'.
 150
 151    _POSIX_CHOWN_RESTRICTED      Only the super user can use `chown' to change
 152                                 the owner of a file.  `chown' can only be used
 153                                 to change the group ID of a file to a group of
 154                                 which the calling process is a member.
 155    _POSIX_NO_TRUNC              Pathname components longer than
 156                                 NAME_MAX generate an error.
 157    _POSIX_VDISABLE              If defined, if the value of an element of the
 158                                 `c_cc' member of `struct termios' is
 159                                 _POSIX_VDISABLE, no character will have the
 160                                 effect associated with that element.
 161    _POSIX_SYNC_IO               Synchronous I/O may be performed.
 162    _POSIX_ASYNC_IO              Asynchronous I/O may be performed.
 163    _POSIX_PRIO_IO               Prioritized Asynchronous I/O may be performed.
 164
 165    Support for the Large File Support interface is not generally available.
 166    If it is available the following constants are defined to one.
 167    _LFS64_LARGEFILE             Low-level I/O supports large files.
 168    _LFS64_STDIO                 Standard I/O supports large files.
 169    */
 170
 171 #include <bits/posix_opt.h>
 172
 173 /* Get the environment definitions from Unix98.  */
 174 #ifdef __USE_UNIX98
 175 # include <bits/environments.h>
 176 #endif
 177
 178 /* Standard file descriptors.  */
 179 #define STDIN_FILENO    0       /* Standard input.  */
 180 #define STDOUT_FILENO   1       /* Standard output.  */
 181 #define STDERR_FILENO   2       /* Standard error output.  */
 182
 183
 184 /* All functions that are not declared anywhere else.  */
 185
 186 #include <bits/types.h>
 187
 188 #ifndef __ssize_t_defined
 189 typedef __ssize_t ssize_t;
 190 # define __ssize_t_defined
 191 #endif
 192
 193 #define __need_size_t
 194 #define __need_NULL
 195 #include <stddef.h>
 196
 197 #if defined __USE_XOPEN || defined __USE_XOPEN2K
 198 /* The Single Unix specification says that some more types are
 199    available here.  */
 200 # ifndef __gid_t_defined
 201 typedef __gid_t gid_t;
 202 #  define __gid_t_defined
 203 # endif
 204
 205 # ifndef __uid_t_defined
 206 typedef __uid_t uid_t;
 207 #  define __uid_t_defined
 208 # endif
 209
 210 # ifndef __off_t_defined
 211 #  ifndef __USE_FILE_OFFSET64
 212 typedef __off_t off_t;
 213 #  else
 214 typedef __off64_t off_t;
 215 #  endif
 216 #  define __off_t_defined
 217 # endif
 218 # if defined __USE_LARGEFILE64 && !defined __off64_t_defined
 219 typedef __off64_t off64_t;
 220 #  define __off64_t_defined
 221 # endif
 222
 223 # ifndef __useconds_t_defined
 224 typedef __useconds_t useconds_t;
 225 #  define __useconds_t_defined
 226 # endif
 227
 228 # ifndef __pid_t_defined
 229 typedef __pid_t pid_t;
 230 #  define __pid_t_defined
 231 # endif
 232 #endif  /* X/Open */
 233
 234 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 235 # ifndef __intptr_t_defined
 236 typedef __intptr_t intptr_t;
 237 #  define __intptr_t_defined
 238 # endif
 239 #endif
 240
 241 #if defined __USE_BSD || defined __USE_XOPEN
 242 # ifndef __socklen_t_defined
 243 typedef __socklen_t socklen_t;
 244 #  define __socklen_t_defined
 245 # endif
 246 #endif
 247
 248 /* Values for the second argument to access.
 249    These may be OR'd together.  */
 250 #define R_OK    4               /* Test for read permission.  */
 251 #define W_OK    2               /* Test for write permission.  */
 252 #define X_OK    1               /* Test for execute permission.  */
 253 #define F_OK    0               /* Test for existence.  */
 254
 255 /* Test for access to NAME using the real UID and real GID.  */
 256 extern int access (__const char *__name, int __type) __THROW;
 257
 258 #ifdef __USE_GNU
 259 /* Test for access to NAME using the effective UID and GID
 260    (as normal file operations use).  */
 261 extern int euidaccess (__const char *__name, int __type) __THROW;
 262 #endif
 263
 264
 265 /* Values for the WHENCE argument to lseek.  */
 266 #ifndef _STDIO_H                /* <stdio.h> has the same definitions.  */
 267 # define SEEK_SET       0       /* Seek from beginning of file.  */
 268 # define SEEK_CUR       1       /* Seek from current position.  */
 269 # define SEEK_END       2       /* Seek from end of file.  */
 270 #endif
 271
 272 #if defined __USE_BSD && !defined L_SET
 273 /* Old BSD names for the same constants; just for compatibility.  */
 274 # define L_SET          SEEK_SET
 275 # define L_INCR         SEEK_CUR
 276 # define L_XTND         SEEK_END
 277 #endif
 278
 279
 280 /* Move FD's file position to OFFSET bytes from the
 281    beginning of the file (if WHENCE is SEEK_SET),
 282    the current position (if WHENCE is SEEK_CUR),
 283    or the end of the file (if WHENCE is SEEK_END).
 284    Return the new file position.  */
 285 #ifndef __USE_FILE_OFFSET64
 286 extern __off_t lseek (int __fd, __off_t __offset, int __whence) __THROW;
 287 #else
 288 # ifdef __REDIRECT_NTH
 289 extern __off64_t __REDIRECT_NTH (lseek,
 290                                  (int __fd, __off64_t __offset, int __whence),
 291                                  lseek64);
 292 # else
 293 #  define lseek lseek64
 294 # endif
 295 #endif
 296 #ifdef __USE_LARGEFILE64
 297 extern __off64_t lseek64 (int __fd, __off64_t __offset, int __whence) __THROW;
 298 #endif
 299
 300 /* Close the file descriptor FD.
 301
 302    This function is a cancellation point and therefore not marked with
 303    __THROW.  */
 304 extern int close (int __fd);
 305
 306 /* Read NBYTES into BUF from FD.  Return the
 307    number read, -1 for errors or 0 for EOF.
 308
 309    This function is a cancellation point and therefore not marked with
 310    __THROW.  */
 311 extern ssize_t read (int __fd, void *__buf, size_t __nbytes);
 312
 313 /* Write N bytes of BUF to FD.  Return the number written, or -1.
 314
 315    This function is a cancellation point and therefore not marked with
 316    __THROW.  */
 317 extern ssize_t write (int __fd, __const void *__buf, size_t __n);
 318
 319 #ifdef __USE_UNIX98
 320 # ifndef __USE_FILE_OFFSET64
 321 /* Read NBYTES into BUF from FD at the given position OFFSET without
 322    changing the file pointer.  Return the number read, -1 for errors
 323    or 0 for EOF.
 324
 325    This function is a cancellation point and therefore not marked with
 326    __THROW.  */
 327 extern ssize_t pread (int __fd, void *__buf, size_t __nbytes,
 328                       __off_t __offset);
 329
 330 /* Write N bytes of BUF to FD at the given position OFFSET without
 331    changing the file pointer.  Return the number written, or -1.
 332
 333    This function is a cancellation point and therefore not marked with
 334    __THROW.  */
 335 extern ssize_t pwrite (int __fd, __const void *__buf, size_t __n,
 336                        __off_t __offset);
 337 # else
 338 #  ifdef __REDIRECT
 339 extern ssize_t __REDIRECT (pread, (int __fd, void *__buf, size_t __nbytes,
 340                                    __off64_t __offset),
 341                            pread64);
 342 extern ssize_t __REDIRECT (pwrite, (int __fd, __const void *__buf,
 343                                     size_t __nbytes, __off64_t __offset),
 344                            pwrite64);
 345 #  else
 346 #   define pread pread64
 347 #   define pwrite pwrite64
 348 #  endif
 349 # endif
 350
 351 # ifdef __USE_LARGEFILE64
 352 /* Read NBYTES into BUF from FD at the given position OFFSET without
 353    changing the file pointer.  Return the number read, -1 for errors
 354    or 0 for EOF.  */
 355 extern ssize_t pread64 (int __fd, void *__buf, size_t __nbytes,
 356                         __off64_t __offset);
 357 /* Write N bytes of BUF to FD at the given position OFFSET without
 358    changing the file pointer.  Return the number written, or -1.  */
 359 extern ssize_t pwrite64 (int __fd, __const void *__buf, size_t __n,
 360                          __off64_t __offset);
 361 # endif
 362 #endif
 363
 364 /* Create a one-way communication channel (pipe).
 365    If successful, two file descriptors are stored in PIPEDES;
 366    bytes written on PIPEDES[1] can be read from PIPEDES[0].
 367    Returns 0 if successful, -1 if not.  */
 368 extern int pipe (int __pipedes[2]) __THROW;
 369
 370 /* Schedule an alarm.  In SECONDS seconds, the process will get a SIGALRM.
 371    If SECONDS is zero, any currently scheduled alarm will be cancelled.
 372    The function returns the number of seconds remaining until the last
 373    alarm scheduled would have signaled, or zero if there wasn't one.
 374    There is no return value to indicate an error, but you can set `errno'
 375    to 0 and check its value after calling `alarm', and this might tell you.
 376    The signal may come late due to processor scheduling.  */
 377 extern unsigned int alarm (unsigned int __seconds) __THROW;
 378
 379 /* Make the process sleep for SECONDS seconds, or until a signal arrives
 380    and is not ignored.  The function returns the number of seconds less
 381    than SECONDS which it actually slept (thus zero if it slept the full time).
 382    If a signal handler does a `longjmp' or modifies the handling of the
 383    SIGALRM signal while inside `sleep' call, the handling of the SIGALRM
 384    signal afterwards is undefined.  There is no return value to indicate
 385    error, but if `sleep' returns SECONDS, it probably didn't work.
 386
 387    This function is a cancellation point and therefore not marked with
 388    __THROW.  */
 389 extern unsigned int sleep (unsigned int __seconds);
 390
 391 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 392 /* Set an alarm to go off (generating a SIGALRM signal) in VALUE
 393    microseconds.  If INTERVAL is nonzero, when the alarm goes off, the
 394    timer is reset to go off every INTERVAL microseconds thereafter.
 395    Returns the number of microseconds remaining before the alarm.  */
 396 extern __useconds_t ualarm (__useconds_t __value, __useconds_t __interval)
 397      __THROW;
 398
 399 /* Sleep USECONDS microseconds, or until a signal arrives that is not blocked
 400    or ignored.
 401
 402    This function is a cancellation point and therefore not marked with
 403    __THROW.  */
 404 extern int usleep (__useconds_t __useconds);
 405 #endif
 406
 407
 408 /* Suspend the process until a signal arrives.
 409    This always returns -1 and sets `errno' to EINTR.
 410
 411    This function is a cancellation point and therefore not marked with
 412    __THROW.  */
 413 extern int pause (void);
 414
 415
 416 /* Change the owner and group of FILE.  */
 417 extern int chown (__const char *__file, __uid_t __owner, __gid_t __group)
 418      __THROW;
 419
 420 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 421 /* Change the owner and group of the file that FD is open on.  */
 422 extern int fchown (int __fd, __uid_t __owner, __gid_t __group) __THROW;
 423
 424
 425 /* Change owner and group of FILE, if it is a symbolic
 426    link the ownership of the symbolic link is changed.  */
 427 extern int lchown (__const char *__file, __uid_t __owner, __gid_t __group)
 428      __THROW;
 429
 430 #endif /* Use BSD || X/Open Unix.  */
 431
 432 /* Change the process's working directory to PATH.  */
 433 extern int chdir (__const char *__path) __THROW;
 434
 435 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 436 /* Change the process's working directory to the one FD is open on.  */
 437 extern int fchdir (int __fd) __THROW;
 438 #endif
 439
 440 /* Get the pathname of the current working directory,
 441    and put it in SIZE bytes of BUF.  Returns NULL if the
 442    directory couldn't be determined or SIZE was too small.
 443    If successful, returns BUF.  In GNU, if BUF is NULL,
 444    an array is allocated with `malloc'; the array is SIZE
 445    bytes long, unless SIZE == 0, in which case it is as
 446    big as necessary.  */
 447 extern char *getcwd (char *__buf, size_t __size) __THROW;
 448
 449 #ifdef  __USE_GNU
 450 /* Return a malloc'd string containing the current directory name.
 451    If the environment variable `PWD' is set, and its value is correct,
 452    that value is used.  */
 453 extern char *get_current_dir_name (void) __THROW;
 454 #endif
 455
 456 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 457 /* Put the absolute pathname of the current working directory in BUF.
 458    If successful, return BUF.  If not, put an error message in
 459    BUF and return NULL.  BUF should be at least PATH_MAX bytes long.  */
 460 extern char *getwd (char *__buf) __THROW;
 461 #endif
 462
 463
 464 /* Duplicate FD, returning a new file descriptor on the same file.  */
 465 extern int dup (int __fd) __THROW;
 466
 467 /* Duplicate FD to FD2, closing FD2 and making it open on the same file.  */
 468 extern int dup2 (int __fd, int __fd2) __THROW;
 469
 470 /* NULL-terminated array of "NAME=VALUE" environment variables.  */
 471 extern char **__environ;
 472 #ifdef __USE_GNU
 473 extern char **environ;
 474 #endif
 475
 476
 477 /* Replace the current process, executing PATH with arguments ARGV and
 478    environment ENVP.  ARGV and ENVP are terminated by NULL pointers.  */
 479 extern int execve (__const char *__path, char *__const __argv[],
 480                    char *__const __envp[]) __THROW;
 481
 482 #ifdef __USE_GNU
 483 /* Execute the file FD refers to, overlaying the running program image.
 484    ARGV and ENVP are passed to the new program, as for `execve'.  */
 485 extern int fexecve (int __fd, char *__const __argv[], char *__const __envp[])
 486      __THROW;
 487 #endif
 488
 489
 490 /* Execute PATH with arguments ARGV and environment from `environ'.  */
 491 extern int execv (__const char *__path, char *__const __argv[]) __THROW;
 492
 493 /* Execute PATH with all arguments after PATH until a NULL pointer,
 494    and the argument after that for environment.  */
 495 extern int execle (__const char *__path, __const char *__arg, ...) __THROW;
 496
 497 /* Execute PATH with all arguments after PATH until
 498    a NULL pointer and environment from `environ'.  */
 499 extern int execl (__const char *__path, __const char *__arg, ...) __THROW;
 500
 501 /* Execute FILE, searching in the `PATH' environment variable if it contains
 502    no slashes, with arguments ARGV and environment from `environ'.  */
 503 extern int execvp (__const char *__file, char *__const __argv[]) __THROW;
 504
 505 /* Execute FILE, searching in the `PATH' environment variable if
 506    it contains no slashes, with all arguments after FILE until a
 507    NULL pointer and environment from `environ'.  */
 508 extern int execlp (__const char *__file, __const char *__arg, ...) __THROW;
 509
 510
 511 #if defined __USE_MISC || defined __USE_XOPEN
 512 /* Add INC to priority of the current process.  */
 513 extern int nice (int __inc) __THROW;
 514 #endif
 515
 516
 517 /* Terminate program execution with the low-order 8 bits of STATUS.  */
 518 extern void _exit (int __status) __attribute__ ((__noreturn__));
 519
 520
 521 /* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf';
 522    the `_SC_*' symbols for the NAME argument to `sysconf';
 523    and the `_CS_*' symbols for the NAME argument to `confstr'.  */
 524 #include <bits/confname.h>
 525
 526 /* Get file-specific configuration information about PATH.  */
 527 extern long int pathconf (__const char *__path, int __name) __THROW;
 528
 529 /* Get file-specific configuration about descriptor FD.  */
 530 extern long int fpathconf (int __fd, int __name) __THROW;
 531
 532 /* Get the value of the system variable NAME.  */
 533 extern long int sysconf (int __name) __THROW __attribute__ ((__const__));
 534
 535 #ifdef  __USE_POSIX2
 536 /* Get the value of the string-valued system variable NAME.  */
 537 extern size_t confstr (int __name, char *__buf, size_t __len) __THROW;
 538 #endif
 539
 540
 541 /* Get the process ID of the calling process.  */
 542 extern __pid_t getpid (void) __THROW;
 543
 544 /* Get the process ID of the calling process's parent.  */
 545 extern __pid_t getppid (void) __THROW;
 546
 547 /* Get the process group ID of the calling process.
 548    This function is different on old BSD. */
 549 #ifndef __FAVOR_BSD
 550 extern __pid_t getpgrp (void) __THROW;
 551 #else
 552 # ifdef __REDIRECT_NTH
 553 extern __pid_t __REDIRECT_NTH (getpgrp, (__pid_t __pid), __getpgid);
 554 # else
 555 #  define getpgrp __getpgid
 556 # endif
 557 #endif
 558
 559 /* Get the process group ID of process PID.  */
 560 extern __pid_t __getpgid (__pid_t __pid) __THROW;
 561 #ifdef __USE_XOPEN_EXTENDED
 562 extern __pid_t getpgid (__pid_t __pid) __THROW;
 563 #endif
 564
 565
 566 /* Set the process group ID of the process matching PID to PGID.
 567    If PID is zero, the current process's process group ID is set.
 568    If PGID is zero, the process ID of the process is used.  */
 569 extern int setpgid (__pid_t __pid, __pid_t __pgid) __THROW;
 570
 571 #if defined __USE_SVID || defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 572 /* Both System V and BSD have `setpgrp' functions, but with different
 573    calling conventions.  The BSD function is the same as POSIX.1 `setpgid'
 574    (above).  The System V function takes no arguments and puts the calling
 575    process in its on group like `setpgid (0, 0)'.
 576
 577    New programs should always use `setpgid' instead.
 578
 579    The default in GNU is to provide the System V function.  The BSD
 580    function is available under -D_BSD_SOURCE.  */
 581
 582 # ifndef __FAVOR_BSD
 583
 584 /* Set the process group ID of the calling process to its own PID.
 585    This is exactly the same as `setpgid (0, 0)'.  */
 586 extern int setpgrp (void) __THROW;
 587
 588 # else
 589
 590 /* Another name for `setpgid' (above).  */
 591 #  ifdef __REDIRECT_NTH
 592 extern int __REDIRECT_NTH (setpgrp, (__pid_t __pid, __pid_t __pgrp), setpgid);
 593 #  else
 594 #   define setpgrp setpgid
 595 #  endif
 596
 597 # endif /* Favor BSD.  */
 598 #endif  /* Use SVID or BSD.  */
 599
 600 /* Create a new session with the calling process as its leader.
 601    The process group IDs of the session and the calling process
 602    are set to the process ID of the calling process, which is returned.  */
 603 extern __pid_t setsid (void) __THROW;
 604
 605 #ifdef __USE_XOPEN_EXTENDED
 606 /* Return the session ID of the given process.  */
 607 extern __pid_t getsid (__pid_t __pid) __THROW;
 608 #endif
 609
 610 /* Get the real user ID of the calling process.  */
 611 extern __uid_t getuid (void) __THROW;
 612
 613 /* Get the effective user ID of the calling process.  */
 614 extern __uid_t geteuid (void) __THROW;
 615
 616 /* Get the real group ID of the calling process.  */
 617 extern __gid_t getgid (void) __THROW;
 618
 619 /* Get the effective group ID of the calling process.  */
 620 extern __gid_t getegid (void) __THROW;
 621
 622 /* If SIZE is zero, return the number of supplementary groups
 623    the calling process is in.  Otherwise, fill in the group IDs
 624    of its supplementary groups in LIST and return the number written.  */
 625 extern int getgroups (int __size, __gid_t __list[]) __THROW;
 626
 627 #ifdef  __USE_GNU
 628 /* Return nonzero iff the calling process is in group GID.  */
 629 extern int group_member (__gid_t __gid) __THROW;
 630 #endif
 631
 632 /* Set the user ID of the calling process to UID.
 633    If the calling process is the super-user, set the real
 634    and effective user IDs, and the saved set-user-ID to UID;
 635    if not, the effective user ID is set to UID.  */
 636 extern int setuid (__uid_t __uid) __THROW;
 637
 638 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 639 /* Set the real user ID of the calling process to RUID,
 640    and the effective user ID of the calling process to EUID.  */
 641 extern int setreuid (__uid_t __ruid, __uid_t __euid) __THROW;
 642 #endif
 643
 644 #if defined __USE_BSD || defined __USE_XOPEN2K
 645 /* Set the effective user ID of the calling process to UID.  */
 646 extern int seteuid (__uid_t __uid) __THROW;
 647 #endif /* Use BSD.  */
 648
 649 /* Set the group ID of the calling process to GID.
 650    If the calling process is the super-user, set the real
 651    and effective group IDs, and the saved set-group-ID to GID;
 652    if not, the effective group ID is set to GID.  */
 653 extern int setgid (__gid_t __gid) __THROW;
 654
 655 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 656 /* Set the real group ID of the calling process to RGID,
 657    and the effective group ID of the calling process to EGID.  */
 658 extern int setregid (__gid_t __rgid, __gid_t __egid) __THROW;
 659 #endif
 660
 661 #if defined __USE_BSD || defined __USE_XOPEN2K
 662 /* Set the effective group ID of the calling process to GID.  */
 663 extern int setegid (__gid_t __gid) __THROW;
 664 #endif /* Use BSD.  */
 665
 666 #ifdef __USE_GNU
 667 /* Fetch the effective user ID, real user ID, and saved-set user ID,
 668    of the calling process.  */
 669 extern int getresuid (__uid_t *__euid, __uid_t *__ruid, __uid_t *__suid);
 670
 671 /* Fetch the effective group ID, real group ID, and saved-set group ID,
 672    of the calling process.  */
 673 extern int getresgid (__gid_t *__egid, __gid_t *__rgid, __gid_t *__sgid);
 674
 675 /* Set the effective user ID, real user ID, and saved-set user ID,
 676    of the calling process to EUID, RUID, and SUID, respectively.  */
 677 extern int setresuid (__uid_t __euid, __uid_t __ruid, __uid_t __suid);
 678
 679 /* Set the effective group ID, real group ID, and saved-set group ID,
 680    of the calling process to EGID, RGID, and SGID, respectively.  */
 681 extern int setresgid (__gid_t __egid, __gid_t __rgid, __gid_t __sgid);
 682 #endif
 683
 684
 685 /* Clone the calling process, creating an exact copy.
 686    Return -1 for errors, 0 to the new process,
 687    and the process ID of the new process to the old process.  */
 688 extern __pid_t fork (void) __THROW;
 689
 690 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 691 /* Clone the calling process, but without copying the whole address space.
 692    The calling process is suspended until the new process exits or is
 693    replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
 694    and the process ID of the new process to the old process.  */
 695 extern __pid_t vfork (void) __THROW;
 696 #endif /* Use BSD. */
 697
 698
 699 /* Return the pathname of the terminal FD is open on, or NULL on errors.
 700    The returned storage is good only until the next call to this function.  */
 701 extern char *ttyname (int __fd) __THROW;
 702
 703 /* Store at most BUFLEN characters of the pathname of the terminal FD is
 704    open on in BUF.  Return 0 on success, otherwise an error number.  */
 705 extern int ttyname_r (int __fd, char *__buf, size_t __buflen) __THROW;
 706
 707 /* Return 1 if FD is a valid descriptor associated
 708    with a terminal, zero if not.  */
 709 extern int isatty (int __fd) __THROW;
 710
 711 #if defined __USE_BSD \
 712     || (defined __USE_XOPEN_EXTENDED && !defined __USE_UNIX98)
 713 /* Return the index into the active-logins file (utmp) for
 714    the controlling terminal.  */
 715 extern int ttyslot (void) __THROW;
 716 #endif
 717
 718
 719 /* Make a link to FROM named TO.  */
 720 extern int link (__const char *__from, __const char *__to) __THROW;
 721
 722 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 723 /* Make a symbolic link to FROM named TO.  */
 724 extern int symlink (__const char *__from, __const char *__to) __THROW;
 725
 726 /* Read the contents of the symbolic link PATH into no more than
 727    LEN bytes of BUF.  The contents are not null-terminated.
 728    Returns the number of characters read, or -1 for errors.  */
 729 extern int readlink (__const char *__restrict __path, char *__restrict __buf,
 730                      size_t __len) __THROW;
 731 #endif /* Use BSD.  */
 732
 733 /* Remove the link NAME.  */
 734 extern int unlink (__const char *__name) __THROW;
 735
 736 /* Remove the directory PATH.  */
 737 extern int rmdir (__const char *__path) __THROW;
 738
 739
 740 /* Return the foreground process group ID of FD.  */
 741 extern __pid_t tcgetpgrp (int __fd) __THROW;
 742
 743 /* Set the foreground process group ID of FD set PGRP_ID.  */
 744 extern int tcsetpgrp (int __fd, __pid_t __pgrp_id) __THROW;
 745
 746
 747 /* Return the login name of the user.
 748
 749    This function is a possible cancellation points and therefore not
 750    marked with __THROW.  */
 751 extern char *getlogin (void);
 752 #if defined __USE_REENTRANT || defined __USE_UNIX98
 753 /* Return at most NAME_LEN characters of the login name of the user in NAME.
 754    If it cannot be determined or some other error occurred, return the error
 755    code.  Otherwise return 0.
 756
 757    This function is a possible cancellation points and therefore not
 758    marked with __THROW.  */
 759 extern int getlogin_r (char *__name, size_t __name_len);
 760 #endif
 761
 762 #ifdef  __USE_BSD
 763 /* Set the login name returned by `getlogin'.  */
 764 extern int setlogin (__const char *__name) __THROW;
 765 #endif
 766
 767
 768 #ifdef  __USE_POSIX2
 769 /* Get definitions and prototypes for functions to process the
 770    arguments in ARGV (ARGC of them, minus the program name) for
 771    options given in OPTS.  */
 772 # define __need_getopt
 773 # include <getopt.h>
 774 #endif
 775
 776
 777 #if defined __USE_BSD || defined __USE_UNIX98
 778 /* Put the name of the current host in no more than LEN bytes of NAME.
 779    The result is null-terminated if LEN is large enough for the full
 780    name and the terminator.  */
 781 extern int gethostname (char *__name, size_t __len) __THROW;
 782 #endif
 783
 784
 785 #if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_UNIX98)
 786 /* Set the name of the current host to NAME, which is LEN bytes long.
 787    This call is restricted to the super-user.  */
 788 extern int sethostname (__const char *__name, size_t __len) __THROW;
 789
 790 /* Set the current machine's Internet number to ID.
 791    This call is restricted to the super-user.  */
 792 extern int sethostid (long int __id) __THROW;
 793
 794
 795 /* Get and set the NIS (aka YP) domain name, if any.
 796    Called just like `gethostname' and `sethostname'.
 797    The NIS domain name is usually the empty string when not using NIS.  */
 798 extern int getdomainname (char *__name, size_t __len) __THROW;
 799 extern int setdomainname (__const char *__name, size_t __len) __THROW;
 800
 801
 802 /* Revoke access permissions to all processes currently communicating
 803    with the control terminal, and then send a SIGHUP signal to the process
 804    group of the control terminal.  */
 805 extern int vhangup (void) __THROW;
 806
 807 /* Revoke the access of all descriptors currently open on FILE.  */
 808 extern int revoke (__const char *__file) __THROW;
 809
 810
 811 /* Enable statistical profiling, writing samples of the PC into at most
 812    SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
 813    is enabled, the system examines the user PC and increments
 814    SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536].  If SCALE is zero,
 815    disable profiling.  Returns zero on success, -1 on error.  */
 816 extern int profil (unsigned short int *__sample_buffer, size_t __size,
 817                    size_t __offset, unsigned int __scale) __THROW;
 818
 819
 820 /* Turn accounting on if NAME is an existing file.  The system will then write
 821    a record for each process as it terminates, to this file.  If NAME is NULL,
 822    turn accounting off.  This call is restricted to the super-user.  */
 823 extern int acct (__const char *__name) __THROW;
 824
 825
 826 /* Successive calls return the shells listed in `/etc/shells'.  */
 827 extern char *getusershell (void) __THROW;
 828 extern void endusershell (void) __THROW; /* Discard cached info.  */
 829 extern void setusershell (void) __THROW; /* Rewind and re-read the file.  */
 830
 831
 832 /* Put the program in the background, and dissociate from the controlling
 833    terminal.  If NOCHDIR is zero, do `chdir ("/")'.  If NOCLOSE is zero,
 834    redirects stdin, stdout, and stderr to /dev/null.  */
 835 extern int daemon (int __nochdir, int __noclose) __THROW;
 836 #endif /* Use BSD || X/Open.  */
 837
 838
 839 #if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_XOPEN2K)
 840 /* Make PATH be the root directory (the starting point for absolute paths).
 841    This call is restricted to the super-user.  */
 842 extern int chroot (__const char *__path) __THROW;
 843
 844 /* Prompt with PROMPT and read a string from the terminal without echoing.
 845    Uses /dev/tty if possible; otherwise stderr and stdin.  */
 846 extern char *getpass (__const char *__prompt);
 847 #endif /* Use BSD || X/Open.  */
 848
 849
 850 #if defined __USE_BSD || defined __USE_XOPEN
 851 /* Make all changes done to FD actually appear on disk.
 852
 853    This function is a cancellation point and therefore not marked with
 854    __THROW.  */
 855 extern int fsync (int __fd);
 856 #endif /* Use BSD || X/Open.  */
 857
 858
 859 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 860
 861 /* Return identifier for the current host.  */
 862 extern long int gethostid (void);
 863
 864 /* Make all changes done to all files actually appear on disk.  */
 865 extern void sync (void) __THROW;
 866
 867
 868 /* Return the number of bytes in a page.  This is the system's page size,
 869    which is not necessarily the same as the hardware page size.  */
 870 extern int getpagesize (void)  __THROW __attribute__ ((__const__));
 871
 872
 873 /* Truncate FILE to LENGTH bytes.  */
 874 # ifndef __USE_FILE_OFFSET64
 875 extern int truncate (__const char *__file, __off_t __length) __THROW;
 876 # else
 877 #  ifdef __REDIRECT_NTH
 878 extern int __REDIRECT_NTH (truncate,
 879                            (__const char *__file, __off64_t __length),
 880                            truncate64);
 881 #  else
 882 #   define truncate truncate64
 883 #  endif
 884 # endif
 885 # ifdef __USE_LARGEFILE64
 886 extern int truncate64 (__const char *__file, __off64_t __length) __THROW;
 887 # endif
 888
 889 /* Truncate the file FD is open on to LENGTH bytes.  */
 890 # ifndef __USE_FILE_OFFSET64
 891 extern int ftruncate (int __fd, __off_t __length) __THROW;
 892 # else
 893 #  ifdef __REDIRECT_NTH
 894 extern int __REDIRECT_NTH (ftruncate, (int __fd, __off64_t __length),
 895                            ftruncate64);
 896 #  else
 897 #   define ftruncate ftruncate64
 898 #  endif
 899 # endif
 900 # ifdef __USE_LARGEFILE64
 901 extern int ftruncate64 (int __fd, __off64_t __length) __THROW;
 902 # endif
 903
 904
 905 /* Return the maximum number of file descriptors
 906    the current process could possibly have.  */
 907 extern int getdtablesize (void) __THROW;
 908
 909 #endif /* Use BSD || X/Open Unix.  */
 910
 911
 912 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 913
 914 /* Set the end of accessible data space (aka "the break") to ADDR.
 915    Returns zero on success and -1 for errors (with errno set).  */
 916 extern int brk (void *__addr) __THROW;
 917
 918 /* Increase or decrease the end of accessible data space by DELTA bytes.
 919    If successful, returns the address the previous end of data space
 920    (i.e. the beginning of the new space, if DELTA > 0);
 921    returns (void *) -1 for errors (with errno set).  */
 922 extern void *sbrk (intptr_t __delta) __THROW;
 923 #endif
 924
 925
 926 #ifdef __USE_MISC
 927 /* Invoke `system call' number SYSNO, passing it the remaining arguments.
 928    This is completely system-dependent, and not often useful.
 929
 930    In Unix, `syscall' sets `errno' for all errors and most calls return -1
 931    for errors; in many systems you cannot pass arguments or get return
 932    values for all system calls (`pipe', `fork', and `getppid' typically
 933    among them).
 934
 935    In Mach, all system calls take normal arguments and always return an
 936    error code (zero for success).  */
 937 extern long int syscall (long int __sysno, ...) __THROW;
 938
 939 #endif  /* Use misc.  */
 940
 941
 942 #if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK
 943 /* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both
 944    files consistent.  Some systems have them there and some here, and some
 945    software depends on the macros being defined without including both.  */
 946
 947 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
 948    LEN is always relative to the current file position.
 949    The CMD argument is one of the following.
 950
 951    This function is a cancellation point and therefore not marked with
 952    __THROW.  */
 953
 954 # define F_ULOCK 0      /* Unlock a previously locked region.  */
 955 # define F_LOCK  1      /* Lock a region for exclusive use.  */
 956 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
 957 # define F_TEST  3      /* Test a region for other processes locks.  */
 958
 959 # ifndef __USE_FILE_OFFSET64
 960 extern int lockf (int __fd, int __cmd, __off_t __len);
 961 # else
 962 #  ifdef __REDIRECT
 963 extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len),
 964                        lockf64);
 965 #  else
 966 #   define lockf lockf64
 967 #  endif
 968 # endif
 969 # ifdef __USE_LARGEFILE64
 970 extern int lockf64 (int __fd, int __cmd, __off64_t __len);
 971 # endif
 972 #endif /* Use misc and F_LOCK not already defined.  */
 973
 974
 975 #ifdef __USE_GNU
 976
 977 /* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno'
 978    set to EINTR.  */
 979
 980 # define TEMP_FAILURE_RETRY(expression) \
 981   (__extension__                                                              \
 982     ({ long int __result;                                                     \
 983        do __result = (long int) (expression);                                 \
 984        while (__result == -1L && errno == EINTR);                             \
 985        __result; }))
 986 #endif
 987
 988 #if defined __USE_POSIX199309 || defined __USE_UNIX98
 989 /* Synchronize at least the data part of a file with the underlying
 990    media.  */
 991 extern int fdatasync (int __fildes) __THROW;
 992 #endif /* Use POSIX199309 */
 993
 994
 995 /* XPG4.2 specifies that prototypes for the encryption functions must
 996    be defined here.  */
 997 #ifdef  __USE_XOPEN
 998 /* Encrypt at most 8 characters from KEY using salt to perturb DES.  */
 999 extern char *crypt (__const char *__key, __const char *__salt) __THROW;
1000
1001 /* Encrypt data in BLOCK in place if EDFLAG is zero; otherwise decrypt
1002    block in place.  */
1003 extern void encrypt (char *__block, int __edflag) __THROW;
1004
1005
1006 /* Swab pairs bytes in the first N bytes of the area pointed to by
1007    FROM and copy the result to TO.  The value of TO must not be in the
1008    range [FROM - N + 1, FROM - 1].  If N is odd the first byte in FROM
1009    is without partner.  */
1010 extern void swab (__const void *__restrict __from, void *__restrict __to,
1011                   ssize_t __n) __THROW;
1012 #endif
1013
1014
1015 /* The Single Unix specification demands this prototype to be here.
1016    It is also found in <stdio.h>.  */
1017 #ifdef __USE_XOPEN
1018 /* Return the name of the controlling terminal.  */
1019 extern char *ctermid (char *__s) __THROW;
1020 #endif
1021
1022 __END_DECLS
1023
1024 #endif /* unistd.h  */