posix/unistd.h

   1 /* Copyright (C) 1991-1999, 2000, 2001 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 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 #ifndef __USE_FILE_OFFSET64
 290 extern __off_t lseek (int __fd, __off_t __offset, int __whence) __THROW;
 291 #else
 292 # ifdef __REDIRECT
 293 extern __off64_t __REDIRECT (lseek,
 294                              (int __fd, __off64_t __offset, int __whence)
 295                              __THROW,
 296                              lseek64);
 297 # else
 298 #  define lseek lseek64
 299 # endif
 300 #endif
 301 #ifdef __USE_LARGEFILE64
 302 extern __off64_t lseek64 (int __fd, __off64_t __offset, int __whence) __THROW;
 303 #endif
 304
 305 /* Close the file descriptor FD.  */
 306 extern int close (int __fd) __THROW;
 307
 308 /* Read NBYTES into BUF from FD.  Return the
 309    number read, -1 for errors or 0 for EOF.  */
 310 extern ssize_t read (int __fd, void *__buf, size_t __nbytes) __THROW;
 311
 312 /* Write N bytes of BUF to FD.  Return the number written, or -1.  */
 313 extern ssize_t write (int __fd, __const void *__buf, size_t __n) __THROW;
 314
 315 #ifdef __USE_UNIX98
 316 # ifndef __USE_FILE_OFFSET64
 317 extern ssize_t pread (int __fd, void *__buf, size_t __nbytes, __off_t __offset)
 318      __THROW;
 319 extern ssize_t pwrite (int __fd, __const void *__buf, size_t __n,
 320                        __off_t __offset) __THROW;
 321 # else
 322 #  ifdef __REDIRECT
 323 extern ssize_t __REDIRECT (pread, (int __fd, void *__buf, size_t __nbytes,
 324                                    __off64_t __offset) __THROW,
 325                            pread64);
 326 extern ssize_t __REDIRECT (pwrite, (int __fd, __const void *__buf,
 327                                     size_t __nbytes, __off64_t __offset)
 328                            __THROW,
 329                         pwrite64);
 330 #  else
 331 #   define pread pread64
 332 #   define pwrite pwrite64
 333 #  endif
 334 # endif
 335
 336 # ifdef __USE_LARGEFILE64
 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 extern ssize_t pread64 (int __fd, void *__buf, size_t __nbytes,
 341                         __off64_t __offset) __THROW;
 342 /* Write N bytes of BUF to FD at the given position OFFSET without
 343    changing the file pointer.  Return the number written, or -1.  */
 344 extern ssize_t pwrite64 (int __fd, __const void *__buf, size_t __n,
 345                          __off64_t __offset) __THROW;
 346 # endif
 347 #endif
 348
 349 /* Create a one-way communication channel (pipe).
 350    If successful, two file descriptors are stored in PIPEDES;
 351    bytes written on PIPEDES[1] can be read from PIPEDES[0].
 352    Returns 0 if successful, -1 if not.  */
 353 extern int pipe (int __pipedes[2]) __THROW;
 354
 355 /* Schedule an alarm.  In SECONDS seconds, the process will get a SIGALRM.
 356    If SECONDS is zero, any currently scheduled alarm will be cancelled.
 357    The function returns the number of seconds remaining until the last
 358    alarm scheduled would have signaled, or zero if there wasn't one.
 359    There is no return value to indicate an error, but you can set `errno'
 360    to 0 and check its value after calling `alarm', and this might tell you.
 361    The signal may come late due to processor scheduling.  */
 362 extern unsigned int alarm (unsigned int __seconds) __THROW;
 363
 364 /* Make the process sleep for SECONDS seconds, or until a signal arrives
 365    and is not ignored.  The function returns the number of seconds less
 366    than SECONDS which it actually slept (thus zero if it slept the full time).
 367    If a signal handler does a `longjmp' or modifies the handling of the
 368    SIGALRM signal while inside `sleep' call, the handling of the SIGALRM
 369    signal afterwards is undefined.  There is no return value to indicate
 370    error, but if `sleep' returns SECONDS, it probably didn't work.  */
 371 extern unsigned int sleep (unsigned int __seconds) __THROW;
 372
 373 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 374 /* Set an alarm to go off (generating a SIGALRM signal) in VALUE
 375    microseconds.  If INTERVAL is nonzero, when the alarm goes off, the
 376    timer is reset to go off every INTERVAL microseconds thereafter.
 377    Returns the number of microseconds remaining before the alarm.  */
 378 extern __useconds_t ualarm (__useconds_t __value, __useconds_t __interval)
 379      __THROW;
 380
 381 /* Sleep USECONDS microseconds, or until a signal arrives that is not blocked
 382    or ignored.  */
 383 extern int usleep (__useconds_t __useconds) __THROW;
 384 #endif
 385
 386
 387 /* Suspend the process until a signal arrives.
 388    This always returns -1 and sets `errno' to EINTR.  */
 389 extern int pause (void) __THROW;
 390
 391
 392 /* Change the owner and group of FILE.  */
 393 extern int chown (__const char *__file, __uid_t __owner, __gid_t __group)
 394      __THROW;
 395
 396 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 397 /* Change the owner and group of the file that FD is open on.  */
 398 extern int fchown (int __fd, __uid_t __owner, __gid_t __group) __THROW;
 399
 400
 401 /* Change owner and group of FILE, if it is a symbolic
 402    link the ownership of the symbolic link is changed.  */
 403 extern int lchown (__const char *__file, __uid_t __owner, __gid_t __group)
 404      __THROW;
 405
 406 #endif /* Use BSD || X/Open Unix.  */
 407
 408 /* Change the process's working directory to PATH.  */
 409 extern int chdir (__const char *__path) __THROW;
 410
 411 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 412 /* Change the process's working directory to the one FD is open on.  */
 413 extern int fchdir (int __fd) __THROW;
 414 #endif
 415
 416 /* Get the pathname of the current working directory,
 417    and put it in SIZE bytes of BUF.  Returns NULL if the
 418    directory couldn't be determined or SIZE was too small.
 419    If successful, returns BUF.  In GNU, if BUF is NULL,
 420    an array is allocated with `malloc'; the array is SIZE
 421    bytes long, unless SIZE == 0, in which case it is as
 422    big as necessary.  */
 423 extern char *getcwd (char *__buf, size_t __size) __THROW;
 424
 425 #ifdef  __USE_GNU
 426 /* Return a malloc'd string containing the current directory name.
 427    If the environment variable `PWD' is set, and its value is correct,
 428    that value is used.  */
 429 extern char *get_current_dir_name (void) __THROW;
 430 #endif
 431
 432 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 433 /* Put the absolute pathname of the current working directory in BUF.
 434    If successful, return BUF.  If not, put an error message in
 435    BUF and return NULL.  BUF should be at least PATH_MAX bytes long.  */
 436 extern char *getwd (char *__buf) __THROW;
 437 #endif
 438
 439
 440 /* Duplicate FD, returning a new file descriptor on the same file.  */
 441 extern int dup (int __fd) __THROW;
 442
 443 /* Duplicate FD to FD2, closing FD2 and making it open on the same file.  */
 444 extern int dup2 (int __fd, int __fd2) __THROW;
 445
 446 /* NULL-terminated array of "NAME=VALUE" environment variables.  */
 447 extern char **__environ;
 448 #ifdef __USE_GNU
 449 extern char **environ;
 450 #endif
 451
 452
 453 /* Replace the current process, executing PATH with arguments ARGV and
 454    environment ENVP.  ARGV and ENVP are terminated by NULL pointers.  */
 455 extern int execve (__const char *__path, char *__const __argv[],
 456                    char *__const __envp[]) __THROW;
 457
 458 #ifdef __USE_GNU
 459 /* Execute the file FD refers to, overlaying the running program image.
 460    ARGV and ENVP are passed to the new program, as for `execve'.  */
 461 extern int fexecve (int __fd, char *__const __argv[], char *__const __envp[])
 462      __THROW;
 463 #endif
 464
 465
 466 /* Execute PATH with arguments ARGV and environment from `environ'.  */
 467 extern int execv (__const char *__path, char *__const __argv[]) __THROW;
 468
 469 /* Execute PATH with all arguments after PATH until a NULL pointer,
 470    and the argument after that for environment.  */
 471 extern int execle (__const char *__path, __const char *__arg, ...) __THROW;
 472
 473 /* Execute PATH with all arguments after PATH until
 474    a NULL pointer and environment from `environ'.  */
 475 extern int execl (__const char *__path, __const char *__arg, ...) __THROW;
 476
 477 /* Execute FILE, searching in the `PATH' environment variable if it contains
 478    no slashes, with arguments ARGV and environment from `environ'.  */
 479 extern int execvp (__const char *__file, char *__const __argv[]) __THROW;
 480
 481 /* Execute FILE, searching in the `PATH' environment variable if
 482    it contains no slashes, with all arguments after FILE until a
 483    NULL pointer and environment from `environ'.  */
 484 extern int execlp (__const char *__file, __const char *__arg, ...) __THROW;
 485
 486
 487 #if defined __USE_MISC || defined __USE_XOPEN
 488 /* Add INC to priority of the current process.  */
 489 extern int nice (int __inc) __THROW;
 490 #endif
 491
 492
 493 /* Terminate program execution with the low-order 8 bits of STATUS.  */
 494 extern void _exit (int __status) __attribute__ ((__noreturn__));
 495
 496
 497 /* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf';
 498    the `_SC_*' symbols for the NAME argument to `sysconf';
 499    and the `_CS_*' symbols for the NAME argument to `confstr'.  */
 500 #include <bits/confname.h>
 501
 502 /* Get file-specific configuration information about PATH.  */
 503 extern long int pathconf (__const char *__path, int __name) __THROW;
 504
 505 /* Get file-specific configuration about descriptor FD.  */
 506 extern long int fpathconf (int __fd, int __name) __THROW;
 507
 508 /* Get the value of the system variable NAME.  */
 509 extern long int sysconf (int __name) __THROW __attribute__ ((__const__));
 510
 511 #ifdef  __USE_POSIX2
 512 /* Get the value of the string-valued system variable NAME.  */
 513 extern size_t confstr (int __name, char *__buf, size_t __len) __THROW;
 514 #endif
 515
 516
 517 /* Get the process ID of the calling process.  */
 518 extern __pid_t getpid (void) __THROW;
 519
 520 /* Get the process ID of the calling process's parent.  */
 521 extern __pid_t getppid (void) __THROW;
 522
 523 /* Get the process group ID of the calling process.
 524    This function is different on old BSD. */
 525 #ifndef __FAVOR_BSD
 526 extern __pid_t getpgrp (void) __THROW;
 527 #else
 528 # ifdef __REDIRECT
 529 extern __pid_t __REDIRECT (getpgrp, (__pid_t __pid) __THROW, __getpgid);
 530 # else
 531 #  define getpgrp __getpgid
 532 # endif
 533 #endif
 534
 535 /* Get the process group ID of process PID.  */
 536 extern __pid_t __getpgid (__pid_t __pid) __THROW;
 537 #ifdef __USE_XOPEN_EXTENDED
 538 extern __pid_t getpgid (__pid_t __pid) __THROW;
 539 #endif
 540
 541
 542 /* Set the process group ID of the process matching PID to PGID.
 543    If PID is zero, the current process's process group ID is set.
 544    If PGID is zero, the process ID of the process is used.  */
 545 extern int setpgid (__pid_t __pid, __pid_t __pgid) __THROW;
 546
 547 #if defined __USE_SVID || defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 548 /* Both System V and BSD have `setpgrp' functions, but with different
 549    calling conventions.  The BSD function is the same as POSIX.1 `setpgid'
 550    (above).  The System V function takes no arguments and puts the calling
 551    process in its on group like `setpgid (0, 0)'.
 552
 553    New programs should always use `setpgid' instead.
 554
 555    The default in GNU is to provide the System V function.  The BSD
 556    function is available under -D_BSD_SOURCE.  */
 557
 558 # ifndef __FAVOR_BSD
 559
 560 /* Set the process group ID of the calling process to its own PID.
 561    This is exactly the same as `setpgid (0, 0)'.  */
 562 extern int setpgrp (void) __THROW;
 563
 564 # else
 565
 566 /* Another name for `setpgid' (above).  */
 567 #  ifdef __REDIRECT
 568 extern int __REDIRECT (setpgrp, (__pid_t __pid, __pid_t __pgrp) __THROW,
 569                        setpgid);
 570 #  else
 571 #   define setpgrp setpgid
 572 #  endif
 573
 574 # endif /* Favor BSD.  */
 575 #endif  /* Use SVID or BSD.  */
 576
 577 /* Create a new session with the calling process as its leader.
 578    The process group IDs of the session and the calling process
 579    are set to the process ID of the calling process, which is returned.  */
 580 extern __pid_t setsid (void) __THROW;
 581
 582 #ifdef __USE_XOPEN_EXTENDED
 583 /* Return the session ID of the given process.  */
 584 extern __pid_t getsid (__pid_t __pid) __THROW;
 585 #endif
 586
 587 /* Get the real user ID of the calling process.  */
 588 extern __uid_t getuid (void) __THROW;
 589
 590 /* Get the effective user ID of the calling process.  */
 591 extern __uid_t geteuid (void) __THROW;
 592
 593 /* Get the real group ID of the calling process.  */
 594 extern __gid_t getgid (void) __THROW;
 595
 596 /* Get the effective group ID of the calling process.  */
 597 extern __gid_t getegid (void) __THROW;
 598
 599 /* If SIZE is zero, return the number of supplementary groups
 600    the calling process is in.  Otherwise, fill in the group IDs
 601    of its supplementary groups in LIST and return the number written.  */
 602 extern int getgroups (int __size, __gid_t __list[]) __THROW;
 603
 604 #ifdef  __USE_GNU
 605 /* Return nonzero iff the calling process is in group GID.  */
 606 extern int group_member (__gid_t __gid) __THROW;
 607 #endif
 608
 609 /* Set the user ID of the calling process to UID.
 610    If the calling process is the super-user, set the real
 611    and effective user IDs, and the saved set-user-ID to UID;
 612    if not, the effective user ID is set to UID.  */
 613 extern int setuid (__uid_t __uid) __THROW;
 614
 615 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 616 /* Set the real user ID of the calling process to RUID,
 617    and the effective user ID of the calling process to EUID.  */
 618 extern int setreuid (__uid_t __ruid, __uid_t __euid) __THROW;
 619 #endif
 620
 621 #if defined __USE_BSD || defined __USE_XOPEN2K
 622 /* Set the effective user ID of the calling process to UID.  */
 623 extern int seteuid (__uid_t __uid) __THROW;
 624 #endif /* Use BSD.  */
 625
 626 /* Set the group ID of the calling process to GID.
 627    If the calling process is the super-user, set the real
 628    and effective group IDs, and the saved set-group-ID to GID;
 629    if not, the effective group ID is set to GID.  */
 630 extern int setgid (__gid_t __gid) __THROW;
 631
 632 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 633 /* Set the real group ID of the calling process to RGID,
 634    and the effective group ID of the calling process to EGID.  */
 635 extern int setregid (__gid_t __rgid, __gid_t __egid) __THROW;
 636 #endif
 637
 638 #if defined __USE_BSD || defined __USE_XOPEN2K
 639 /* Set the effective group ID of the calling process to GID.  */
 640 extern int setegid (__gid_t __gid) __THROW;
 641 #endif /* Use BSD.  */
 642
 643
 644 /* Clone the calling process, creating an exact copy.
 645    Return -1 for errors, 0 to the new process,
 646    and the process ID of the new process to the old process.  */
 647 extern __pid_t fork (void) __THROW;
 648
 649 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 650 /* Clone the calling process, but without copying the whole address space.
 651    The calling process is suspended until the new process exits or is
 652    replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
 653    and the process ID of the new process to the old process.  */
 654 extern __pid_t vfork (void) __THROW;
 655 #endif /* Use BSD. */
 656
 657
 658 /* Return the pathname of the terminal FD is open on, or NULL on errors.
 659    The returned storage is good only until the next call to this function.  */
 660 extern char *ttyname (int __fd) __THROW;
 661
 662 /* Store at most BUFLEN characters of the pathname of the terminal FD is
 663    open on in BUF.  Return 0 on success, otherwise an error number.  */
 664 extern int ttyname_r (int __fd, char *__buf, size_t __buflen) __THROW;
 665
 666 /* Return 1 if FD is a valid descriptor associated
 667    with a terminal, zero if not.  */
 668 extern int isatty (int __fd) __THROW;
 669
 670 #if defined __USE_BSD \
 671     || (defined __USE_XOPEN_EXTENDED && !defined __USE_UNIX98)
 672 /* Return the index into the active-logins file (utmp) for
 673    the controlling terminal.  */
 674 extern int ttyslot (void) __THROW;
 675 #endif
 676
 677
 678 /* Make a link to FROM named TO.  */
 679 extern int link (__const char *__from, __const char *__to) __THROW;
 680
 681 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 682 /* Make a symbolic link to FROM named TO.  */
 683 extern int symlink (__const char *__from, __const char *__to) __THROW;
 684
 685 /* Read the contents of the symbolic link PATH into no more than
 686    LEN bytes of BUF.  The contents are not null-terminated.
 687    Returns the number of characters read, or -1 for errors.  */
 688 extern int readlink (__const char *__restrict __path, char *__restrict __buf,
 689                      size_t __len) __THROW;
 690 #endif /* Use BSD.  */
 691
 692 /* Remove the link NAME.  */
 693 extern int unlink (__const char *__name) __THROW;
 694
 695 /* Remove the directory PATH.  */
 696 extern int rmdir (__const char *__path) __THROW;
 697
 698
 699 /* Return the foreground process group ID of FD.  */
 700 extern __pid_t tcgetpgrp (int __fd) __THROW;
 701
 702 /* Set the foreground process group ID of FD set PGRP_ID.  */
 703 extern int tcsetpgrp (int __fd, __pid_t __pgrp_id) __THROW;
 704
 705
 706 /* Return the login name of the user.  */
 707 extern char *getlogin (void) __THROW;
 708 #if defined __USE_REENTRANT || defined __USE_UNIX98
 709 /* Return at most NAME_LEN characters of the login name of the user in NAME.
 710    If it cannot be determined or some other error occurred, return the error
 711    code.  Otherwise return 0.  */
 712 extern int getlogin_r (char *__name, size_t __name_len) __THROW;
 713 #endif
 714
 715 #ifdef  __USE_BSD
 716 /* Set the login name returned by `getlogin'.  */
 717 extern int setlogin (__const char *__name) __THROW;
 718 #endif
 719
 720
 721 #ifdef  __USE_POSIX2
 722 /* Get definitions and prototypes for functions to process the
 723    arguments in ARGV (ARGC of them, minus the program name) for
 724    options given in OPTS.  */
 725 # define __need_getopt
 726 # include <getopt.h>
 727 #endif
 728
 729
 730 #if defined __USE_BSD || defined __USE_XOPEN2K
 731 /* Put the name of the current host in no more than LEN bytes of NAME.
 732    The result is null-terminated if LEN is large enough for the full
 733    name and the terminator.  */
 734 extern int gethostname (char *__name, size_t __len) __THROW;
 735 #endif
 736
 737
 738 #if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_UNIX98)
 739 /* Set the name of the current host to NAME, which is LEN bytes long.
 740    This call is restricted to the super-user.  */
 741 extern int sethostname (__const char *__name, size_t __len) __THROW;
 742
 743 /* Set the current machine's Internet number to ID.
 744    This call is restricted to the super-user.  */
 745 extern int sethostid (long int __id) __THROW;
 746
 747
 748 /* Get and set the NIS (aka YP) domain name, if any.
 749    Called just like `gethostname' and `sethostname'.
 750    The NIS domain name is usually the empty string when not using NIS.  */
 751 extern int getdomainname (char *__name, size_t __len) __THROW;
 752 extern int setdomainname (__const char *__name, size_t __len) __THROW;
 753
 754
 755 /* Revoke access permissions to all processes currently communicating
 756    with the control terminal, and then send a SIGHUP signal to the process
 757    group of the control terminal.  */
 758 extern int vhangup (void) __THROW;
 759
 760 /* Revoke the access of all descriptors currently open on FILE.  */
 761 extern int revoke (__const char *__file) __THROW;
 762
 763
 764 /* Enable statistical profiling, writing samples of the PC into at most
 765    SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
 766    is enabled, the system examines the user PC and increments
 767    SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536].  If SCALE is zero,
 768    disable profiling.  Returns zero on success, -1 on error.  */
 769 extern int profil (unsigned short int *__sample_buffer, size_t __size,
 770                    size_t __offset, unsigned int __scale) __THROW;
 771
 772
 773 /* Turn accounting on if NAME is an existing file.  The system will then write
 774    a record for each process as it terminates, to this file.  If NAME is NULL,
 775    turn accounting off.  This call is restricted to the super-user.  */
 776 extern int acct (__const char *__name) __THROW;
 777
 778
 779 /* Successive calls return the shells listed in `/etc/shells'.  */
 780 extern char *getusershell (void) __THROW;
 781 extern void endusershell (void) __THROW; /* Discard cached info.  */
 782 extern void setusershell (void) __THROW; /* Rewind and re-read the file.  */
 783
 784
 785 /* Put the program in the background, and dissociate from the controlling
 786    terminal.  If NOCHDIR is zero, do `chdir ("/")'.  If NOCLOSE is zero,
 787    redirects stdin, stdout, and stderr to /dev/null.  */
 788 extern int daemon (int __nochdir, int __noclose) __THROW;
 789 #endif /* Use BSD || X/Open.  */
 790
 791
 792 #if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_XOPEN2K)
 793 /* Make PATH be the root directory (the starting point for absolute paths).
 794    This call is restricted to the super-user.  */
 795 extern int chroot (__const char *__path) __THROW;
 796
 797 /* Prompt with PROMPT and read a string from the terminal without echoing.
 798    Uses /dev/tty if possible; otherwise stderr and stdin.  */
 799 extern char *getpass (__const char *__prompt) __THROW;
 800 #endif /* Use BSD || X/Open.  */
 801
 802
 803 #if defined __USE_BSD || defined __USE_XOPEN
 804 /* Make all changes done to FD actually appear on disk.  */
 805 extern int fsync (int __fd) __THROW;
 806 #endif /* Use BSD || X/Open.  */
 807
 808
 809 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 810
 811 /* Return the current machine's Internet number.  */
 812 extern long int gethostid (void) __THROW;
 813
 814 /* Make all changes done to all files actually appear on disk.  */
 815 extern void sync (void) __THROW;
 816
 817
 818 /* Return the number of bytes in a page.  This is the system's page size,
 819    which is not necessarily the same as the hardware page size.  */
 820 extern int getpagesize (void)  __THROW __attribute__ ((__const__));
 821
 822
 823 /* Truncate FILE to LENGTH bytes.  */
 824 # ifndef __USE_FILE_OFFSET64
 825 extern int truncate (__const char *__file, __off_t __length) __THROW;
 826 # else
 827 #  ifdef __REDIRECT
 828 extern int __REDIRECT (truncate,
 829                        (__const char *__file, __off64_t __length) __THROW,
 830                        truncate64);
 831 #  else
 832 #   define truncate truncate64
 833 #  endif
 834 # endif
 835 # ifdef __USE_LARGEFILE64
 836 extern int truncate64 (__const char *__file, __off64_t __length) __THROW;
 837 # endif
 838
 839 /* Truncate the file FD is open on to LENGTH bytes.  */
 840 # ifndef __USE_FILE_OFFSET64
 841 extern int ftruncate (int __fd, __off_t __length) __THROW;
 842 # else
 843 #  ifdef __REDIRECT
 844 extern int __REDIRECT (ftruncate, (int __fd, __off64_t __length) __THROW,
 845                        ftruncate64);
 846 #  else
 847 #   define ftruncate ftruncate64
 848 #  endif
 849 # endif
 850 # ifdef __USE_LARGEFILE64
 851 extern int ftruncate64 (int __fd, __off64_t __length) __THROW;
 852 # endif
 853
 854
 855 /* Return the maximum number of file descriptors
 856    the current process could possibly have.  */
 857 extern int getdtablesize (void) __THROW;
 858
 859 #endif /* Use BSD || X/Open Unix.  */
 860
 861
 862 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 863
 864 /* Set the end of accessible data space (aka "the break") to ADDR.
 865    Returns zero on success and -1 for errors (with errno set).  */
 866 extern int brk (void *__addr) __THROW;
 867
 868 /* Increase or decrease the end of accessible data space by DELTA bytes.
 869    If successful, returns the address the previous end of data space
 870    (i.e. the beginning of the new space, if DELTA > 0);
 871    returns (void *) -1 for errors (with errno set).  */
 872 extern void *sbrk (intptr_t __delta) __THROW;
 873 #endif
 874
 875
 876 #ifdef __USE_MISC
 877 /* Invoke `system call' number SYSNO, passing it the remaining arguments.
 878    This is completely system-dependent, and not often useful.
 879
 880    In Unix, `syscall' sets `errno' for all errors and most calls return -1
 881    for errors; in many systems you cannot pass arguments or get return
 882    values for all system calls (`pipe', `fork', and `getppid' typically
 883    among them).
 884
 885    In Mach, all system calls take normal arguments and always return an
 886    error code (zero for success).  */
 887 extern long int syscall (long int __sysno, ...) __THROW;
 888
 889 #endif  /* Use misc.  */
 890
 891
 892 #if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK
 893 /* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both
 894    files consistent.  Some systems have them there and some here, and some
 895    software depends on the macros being defined without including both.  */
 896
 897 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
 898    LEN is always relative to the current file position.
 899    The CMD argument is one of the following.  */
 900
 901 # define F_ULOCK 0      /* Unlock a previously locked region.  */
 902 # define F_LOCK  1      /* Lock a region for exclusive use.  */
 903 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
 904 # define F_TEST  3      /* Test a region for other processes locks.  */
 905
 906 # ifndef __USE_FILE_OFFSET64
 907 extern int lockf (int __fd, int __cmd, __off_t __len) __THROW;
 908 # else
 909 #  ifdef __REDIRECT
 910 extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len) __THROW,
 911                        lockf64);
 912 #  else
 913 #   define lockf lockf64
 914 #  endif
 915 # endif
 916 # ifdef __USE_LARGEFILE64
 917 extern int lockf64 (int __fd, int __cmd, __off64_t __len) __THROW;
 918 # endif
 919 #endif /* Use misc and F_LOCK not already defined.  */
 920
 921
 922 #ifdef __USE_GNU
 923
 924 /* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno'
 925    set to EINTR.  */
 926
 927 # define TEMP_FAILURE_RETRY(expression) \
 928   (__extension__                                                              \
 929     ({ long int __result;                                                     \
 930        do __result = (long int) (expression);                                 \
 931        while (__result == -1L && errno == EINTR);                             \
 932        __result; }))
 933 #endif
 934
 935 #if defined __USE_POSIX199309 || defined __USE_UNIX98
 936 /* Synchronize at least the data part of a file with the underlying
 937    media.  */
 938 extern int fdatasync (int __fildes) __THROW;
 939 #endif /* Use POSIX199309 */
 940
 941
 942 /* XPG4.2 specifies that prototypes for the encryption functions must
 943    be defined here.  */
 944 #ifdef  __USE_XOPEN
 945 /* Encrypt at most 8 characters from KEY using salt to perturb DES.  */
 946 extern char *crypt (__const char *__key, __const char *__salt) __THROW;
 947
 948 /* Encrypt data in BLOCK in place if EDFLAG is zero; otherwise decrypt
 949    block in place.  */
 950 extern void encrypt (char *__block, int __edflag) __THROW;
 951
 952
 953 /* Swab pairs bytes in the first N bytes of the area pointed to by
 954    FROM and copy the result to TO.  The value of TO must not be in the
 955    range [FROM - N + 1, FROM - 1].  If N is odd the first byte in FROM
 956    is without partner.  */
 957 extern void swab (__const void *__restrict __from, void *__restrict __to,
 958                   ssize_t __n) __THROW;
 959 #endif
 960
 961
 962 /* The Single Unix specification demands this prototype to be here.
 963    It is also found in <stdio.h>.  */
 964 #ifdef __USE_XOPEN
 965 /* Return the name of the controlling terminal.  */
 966 extern char *ctermid (char *__s) __THROW;
 967 #endif
 968
 969
 970 #ifdef __USE_POSIX199309
 971 /* This function is only available if the system has POSIX threads.  */
 972
 973 /* Install handlers to be called when a new process is created with FORK.
 974    The PREPARE handler is called in the parent process just before performing
 975    FORK. The PARENT handler is called in the parent process just after FORK.
 976    The CHILD handler is called in the child process.  Each of the three
 977    handlers can be NULL, meaning that no handler needs to be called at that
 978    point.
 979    PTHREAD_ATFORK can be called several times, in which case the PREPARE
 980    handlers are called in LIFO order (last added with PTHREAD_ATFORK,
 981    first called before FORK), and the PARENT and CHILD handlers are called
 982    in FIFO (first added, first called). */
 983 extern int pthread_atfork (void (*__prepare) (void),
 984                            void (*__parent) (void),
 985                            void (*__child) (void)) __THROW;
 986 #endif
 987
 988 __END_DECLS
 989
 990 #endif /* unistd.h  */