posix/unistd.h

   1 /* Copyright (C) 1991-2003, 2004, 2005 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 __nonnull ((1));
 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)
 262      __THROW __nonnull ((1));
 263 #endif
 264
 265
 266 /* Values for the WHENCE argument to lseek.  */
 267 #ifndef _STDIO_H                /* <stdio.h> has the same definitions.  */
 268 # define SEEK_SET       0       /* Seek from beginning of file.  */
 269 # define SEEK_CUR       1       /* Seek from current position.  */
 270 # define SEEK_END       2       /* Seek from end of file.  */
 271 #endif
 272
 273 #if defined __USE_BSD && !defined L_SET
 274 /* Old BSD names for the same constants; just for compatibility.  */
 275 # define L_SET          SEEK_SET
 276 # define L_INCR         SEEK_CUR
 277 # define L_XTND         SEEK_END
 278 #endif
 279
 280
 281 /* Move FD's file position to OFFSET bytes from the
 282    beginning of the file (if WHENCE is SEEK_SET),
 283    the current position (if WHENCE is SEEK_CUR),
 284    or the end of the file (if WHENCE is SEEK_END).
 285    Return the new file position.  */
 286 #ifndef __USE_FILE_OFFSET64
 287 extern __off_t lseek (int __fd, __off_t __offset, int __whence) __THROW;
 288 #else
 289 # ifdef __REDIRECT_NTH
 290 extern __off64_t __REDIRECT_NTH (lseek,
 291                                  (int __fd, __off64_t __offset, int __whence),
 292                                  lseek64);
 293 # else
 294 #  define lseek lseek64
 295 # endif
 296 #endif
 297 #ifdef __USE_LARGEFILE64
 298 extern __off64_t lseek64 (int __fd, __off64_t __offset, int __whence)
 299      __THROW;
 300 #endif
 301
 302 /* Close the file descriptor FD.
 303
 304    This function is a cancellation point and therefore not marked with
 305    __THROW.  */
 306 extern int close (int __fd);
 307
 308 /* Read NBYTES into BUF from FD.  Return the
 309    number read, -1 for errors or 0 for EOF.
 310
 311    This function is a cancellation point and therefore not marked with
 312    __THROW.  */
 313 extern ssize_t read (int __fd, void *__buf, size_t __nbytes) __wur;
 314
 315 /* Write N bytes of BUF to FD.  Return the number written, or -1.
 316
 317    This function is a cancellation point and therefore not marked with
 318    __THROW.  */
 319 extern ssize_t write (int __fd, __const void *__buf, size_t __n) __wur;
 320
 321 #ifdef __USE_UNIX98
 322 # ifndef __USE_FILE_OFFSET64
 323 /* Read NBYTES into BUF from FD at the given position OFFSET without
 324    changing the file pointer.  Return the number read, -1 for errors
 325    or 0 for EOF.
 326
 327    This function is a cancellation point and therefore not marked with
 328    __THROW.  */
 329 extern ssize_t pread (int __fd, void *__buf, size_t __nbytes,
 330                       __off_t __offset) __wur;
 331
 332 /* Write N bytes of BUF to FD at the given position OFFSET without
 333    changing the file pointer.  Return the number written, or -1.
 334
 335    This function is a cancellation point and therefore not marked with
 336    __THROW.  */
 337 extern ssize_t pwrite (int __fd, __const void *__buf, size_t __n,
 338                        __off_t __offset) __wur;
 339 # else
 340 #  ifdef __REDIRECT
 341 extern ssize_t __REDIRECT (pread, (int __fd, void *__buf, size_t __nbytes,
 342                                    __off64_t __offset),
 343                            pread64) __wur;
 344 extern ssize_t __REDIRECT (pwrite, (int __fd, __const void *__buf,
 345                                     size_t __nbytes, __off64_t __offset),
 346                            pwrite64) __wur;
 347 #  else
 348 #   define pread pread64
 349 #   define pwrite pwrite64
 350 #  endif
 351 # endif
 352
 353 # ifdef __USE_LARGEFILE64
 354 /* Read NBYTES into BUF from FD at the given position OFFSET without
 355    changing the file pointer.  Return the number read, -1 for errors
 356    or 0 for EOF.  */
 357 extern ssize_t pread64 (int __fd, void *__buf, size_t __nbytes,
 358                         __off64_t __offset) __wur;
 359 /* Write N bytes of BUF to FD at the given position OFFSET without
 360    changing the file pointer.  Return the number written, or -1.  */
 361 extern ssize_t pwrite64 (int __fd, __const void *__buf, size_t __n,
 362                          __off64_t __offset) __wur;
 363 # endif
 364 #endif
 365
 366 /* Create a one-way communication channel (pipe).
 367    If successful, two file descriptors are stored in PIPEDES;
 368    bytes written on PIPEDES[1] can be read from PIPEDES[0].
 369    Returns 0 if successful, -1 if not.  */
 370 extern int pipe (int __pipedes[2]) __THROW __wur;
 371
 372 /* Schedule an alarm.  In SECONDS seconds, the process will get a SIGALRM.
 373    If SECONDS is zero, any currently scheduled alarm will be cancelled.
 374    The function returns the number of seconds remaining until the last
 375    alarm scheduled would have signaled, or zero if there wasn't one.
 376    There is no return value to indicate an error, but you can set `errno'
 377    to 0 and check its value after calling `alarm', and this might tell you.
 378    The signal may come late due to processor scheduling.  */
 379 extern unsigned int alarm (unsigned int __seconds) __THROW;
 380
 381 /* Make the process sleep for SECONDS seconds, or until a signal arrives
 382    and is not ignored.  The function returns the number of seconds less
 383    than SECONDS which it actually slept (thus zero if it slept the full time).
 384    If a signal handler does a `longjmp' or modifies the handling of the
 385    SIGALRM signal while inside `sleep' call, the handling of the SIGALRM
 386    signal afterwards is undefined.  There is no return value to indicate
 387    error, but if `sleep' returns SECONDS, it probably didn't work.
 388
 389    This function is a cancellation point and therefore not marked with
 390    __THROW.  */
 391 extern unsigned int sleep (unsigned int __seconds);
 392
 393 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 394 /* Set an alarm to go off (generating a SIGALRM signal) in VALUE
 395    microseconds.  If INTERVAL is nonzero, when the alarm goes off, the
 396    timer is reset to go off every INTERVAL microseconds thereafter.
 397    Returns the number of microseconds remaining before the alarm.  */
 398 extern __useconds_t ualarm (__useconds_t __value, __useconds_t __interval)
 399      __THROW;
 400
 401 /* Sleep USECONDS microseconds, or until a signal arrives that is not blocked
 402    or ignored.
 403
 404    This function is a cancellation point and therefore not marked with
 405    __THROW.  */
 406 extern int usleep (__useconds_t __useconds);
 407 #endif
 408
 409
 410 /* Suspend the process until a signal arrives.
 411    This always returns -1 and sets `errno' to EINTR.
 412
 413    This function is a cancellation point and therefore not marked with
 414    __THROW.  */
 415 extern int pause (void);
 416
 417
 418 /* Change the owner and group of FILE.  */
 419 extern int chown (__const char *__file, __uid_t __owner, __gid_t __group)
 420      __THROW __nonnull ((1)) __wur;
 421
 422 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 423 /* Change the owner and group of the file that FD is open on.  */
 424 extern int fchown (int __fd, __uid_t __owner, __gid_t __group) __THROW __wur;
 425
 426
 427 /* Change owner and group of FILE, if it is a symbolic
 428    link the ownership of the symbolic link is changed.  */
 429 extern int lchown (__const char *__file, __uid_t __owner, __gid_t __group)
 430      __THROW __nonnull ((1)) __wur;
 431
 432 #endif /* Use BSD || X/Open Unix.  */
 433
 434 /* Change the process's working directory to PATH.  */
 435 extern int chdir (__const char *__path) __THROW __nonnull ((1)) __wur;
 436
 437 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 438 /* Change the process's working directory to the one FD is open on.  */
 439 extern int fchdir (int __fd) __THROW __wur;
 440 #endif
 441
 442 /* Get the pathname of the current working directory,
 443    and put it in SIZE bytes of BUF.  Returns NULL if the
 444    directory couldn't be determined or SIZE was too small.
 445    If successful, returns BUF.  In GNU, if BUF is NULL,
 446    an array is allocated with `malloc'; the array is SIZE
 447    bytes long, unless SIZE == 0, in which case it is as
 448    big as necessary.  */
 449 extern char *getcwd (char *__buf, size_t __size) __THROW __wur;
 450
 451 #ifdef  __USE_GNU
 452 /* Return a malloc'd string containing the current directory name.
 453    If the environment variable `PWD' is set, and its value is correct,
 454    that value is used.  */
 455 extern char *get_current_dir_name (void) __THROW;
 456 #endif
 457
 458 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 459 /* Put the absolute pathname of the current working directory in BUF.
 460    If successful, return BUF.  If not, put an error message in
 461    BUF and return NULL.  BUF should be at least PATH_MAX bytes long.  */
 462 extern char *getwd (char *__buf)
 463      __THROW __nonnull ((1)) __attribute_deprecated__ __wur;
 464 #endif
 465
 466
 467 /* Duplicate FD, returning a new file descriptor on the same file.  */
 468 extern int dup (int __fd) __THROW __wur;
 469
 470 /* Duplicate FD to FD2, closing FD2 and making it open on the same file.  */
 471 extern int dup2 (int __fd, int __fd2) __THROW __wur;
 472
 473 /* NULL-terminated array of "NAME=VALUE" environment variables.  */
 474 extern char **__environ;
 475 #ifdef __USE_GNU
 476 extern char **environ;
 477 #endif
 478
 479
 480 /* Replace the current process, executing PATH with arguments ARGV and
 481    environment ENVP.  ARGV and ENVP are terminated by NULL pointers.  */
 482 extern int execve (__const char *__path, char *__const __argv[],
 483                    char *__const __envp[]) __THROW __nonnull ((1));
 484
 485 #ifdef __USE_GNU
 486 /* Execute the file FD refers to, overlaying the running program image.
 487    ARGV and ENVP are passed to the new program, as for `execve'.  */
 488 extern int fexecve (int __fd, char *__const __argv[], char *__const __envp[])
 489      __THROW;
 490 #endif
 491
 492
 493 /* Execute PATH with arguments ARGV and environment from `environ'.  */
 494 extern int execv (__const char *__path, char *__const __argv[])
 495      __THROW __nonnull ((1));
 496
 497 /* Execute PATH with all arguments after PATH until a NULL pointer,
 498    and the argument after that for environment.  */
 499 extern int execle (__const char *__path, __const char *__arg, ...)
 500      __THROW __nonnull ((1));
 501
 502 /* Execute PATH with all arguments after PATH until
 503    a NULL pointer and environment from `environ'.  */
 504 extern int execl (__const char *__path, __const char *__arg, ...)
 505      __THROW __nonnull ((1));
 506
 507 /* Execute FILE, searching in the `PATH' environment variable if it contains
 508    no slashes, with arguments ARGV and environment from `environ'.  */
 509 extern int execvp (__const char *__file, char *__const __argv[])
 510      __THROW __nonnull ((1));
 511
 512 /* Execute FILE, searching in the `PATH' environment variable if
 513    it contains no slashes, with all arguments after FILE until a
 514    NULL pointer and environment from `environ'.  */
 515 extern int execlp (__const char *__file, __const char *__arg, ...)
 516      __THROW __nonnull ((1));
 517
 518
 519 #if defined __USE_MISC || defined __USE_XOPEN
 520 /* Add INC to priority of the current process.  */
 521 extern int nice (int __inc) __THROW __wur;
 522 #endif
 523
 524
 525 /* Terminate program execution with the low-order 8 bits of STATUS.  */
 526 extern void _exit (int __status) __attribute__ ((__noreturn__));
 527
 528
 529 /* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf';
 530    the `_SC_*' symbols for the NAME argument to `sysconf';
 531    and the `_CS_*' symbols for the NAME argument to `confstr'.  */
 532 #include <bits/confname.h>
 533
 534 /* Get file-specific configuration information about PATH.  */
 535 extern long int pathconf (__const char *__path, int __name)
 536      __THROW __nonnull ((1));
 537
 538 /* Get file-specific configuration about descriptor FD.  */
 539 extern long int fpathconf (int __fd, int __name) __THROW;
 540
 541 /* Get the value of the system variable NAME.  */
 542 extern long int sysconf (int __name) __THROW __attribute__ ((__const__));
 543
 544 #ifdef  __USE_POSIX2
 545 /* Get the value of the string-valued system variable NAME.  */
 546 extern size_t confstr (int __name, char *__buf, size_t __len) __THROW;
 547 #endif
 548
 549
 550 /* Get the process ID of the calling process.  */
 551 extern __pid_t getpid (void) __THROW;
 552
 553 /* Get the process ID of the calling process's parent.  */
 554 extern __pid_t getppid (void) __THROW;
 555
 556 /* Get the process group ID of the calling process.
 557    This function is different on old BSD. */
 558 #ifndef __FAVOR_BSD
 559 extern __pid_t getpgrp (void) __THROW;
 560 #else
 561 # ifdef __REDIRECT_NTH
 562 extern __pid_t __REDIRECT_NTH (getpgrp, (__pid_t __pid), __getpgid);
 563 # else
 564 #  define getpgrp __getpgid
 565 # endif
 566 #endif
 567
 568 /* Get the process group ID of process PID.  */
 569 extern __pid_t __getpgid (__pid_t __pid) __THROW;
 570 #ifdef __USE_XOPEN_EXTENDED
 571 extern __pid_t getpgid (__pid_t __pid) __THROW;
 572 #endif
 573
 574
 575 /* Set the process group ID of the process matching PID to PGID.
 576    If PID is zero, the current process's process group ID is set.
 577    If PGID is zero, the process ID of the process is used.  */
 578 extern int setpgid (__pid_t __pid, __pid_t __pgid) __THROW;
 579
 580 #if defined __USE_SVID || defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 581 /* Both System V and BSD have `setpgrp' functions, but with different
 582    calling conventions.  The BSD function is the same as POSIX.1 `setpgid'
 583    (above).  The System V function takes no arguments and puts the calling
 584    process in its on group like `setpgid (0, 0)'.
 585
 586    New programs should always use `setpgid' instead.
 587
 588    The default in GNU is to provide the System V function.  The BSD
 589    function is available under -D_BSD_SOURCE.  */
 590
 591 # ifndef __FAVOR_BSD
 592
 593 /* Set the process group ID of the calling process to its own PID.
 594    This is exactly the same as `setpgid (0, 0)'.  */
 595 extern int setpgrp (void) __THROW;
 596
 597 # else
 598
 599 /* Another name for `setpgid' (above).  */
 600 #  ifdef __REDIRECT_NTH
 601 extern int __REDIRECT_NTH (setpgrp, (__pid_t __pid, __pid_t __pgrp), setpgid);
 602 #  else
 603 #   define setpgrp setpgid
 604 #  endif
 605
 606 # endif /* Favor BSD.  */
 607 #endif  /* Use SVID or BSD.  */
 608
 609 /* Create a new session with the calling process as its leader.
 610    The process group IDs of the session and the calling process
 611    are set to the process ID of the calling process, which is returned.  */
 612 extern __pid_t setsid (void) __THROW;
 613
 614 #ifdef __USE_XOPEN_EXTENDED
 615 /* Return the session ID of the given process.  */
 616 extern __pid_t getsid (__pid_t __pid) __THROW;
 617 #endif
 618
 619 /* Get the real user ID of the calling process.  */
 620 extern __uid_t getuid (void) __THROW;
 621
 622 /* Get the effective user ID of the calling process.  */
 623 extern __uid_t geteuid (void) __THROW;
 624
 625 /* Get the real group ID of the calling process.  */
 626 extern __gid_t getgid (void) __THROW;
 627
 628 /* Get the effective group ID of the calling process.  */
 629 extern __gid_t getegid (void) __THROW;
 630
 631 /* If SIZE is zero, return the number of supplementary groups
 632    the calling process is in.  Otherwise, fill in the group IDs
 633    of its supplementary groups in LIST and return the number written.  */
 634 extern int getgroups (int __size, __gid_t __list[]) __THROW __wur;
 635
 636 #ifdef  __USE_GNU
 637 /* Return nonzero iff the calling process is in group GID.  */
 638 extern int group_member (__gid_t __gid) __THROW;
 639 #endif
 640
 641 /* Set the user ID of the calling process to UID.
 642    If the calling process is the super-user, set the real
 643    and effective user IDs, and the saved set-user-ID to UID;
 644    if not, the effective user ID is set to UID.  */
 645 extern int setuid (__uid_t __uid) __THROW;
 646
 647 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 648 /* Set the real user ID of the calling process to RUID,
 649    and the effective user ID of the calling process to EUID.  */
 650 extern int setreuid (__uid_t __ruid, __uid_t __euid) __THROW;
 651 #endif
 652
 653 #if defined __USE_BSD || defined __USE_XOPEN2K
 654 /* Set the effective user ID of the calling process to UID.  */
 655 extern int seteuid (__uid_t __uid) __THROW;
 656 #endif /* Use BSD.  */
 657
 658 /* Set the group ID of the calling process to GID.
 659    If the calling process is the super-user, set the real
 660    and effective group IDs, and the saved set-group-ID to GID;
 661    if not, the effective group ID is set to GID.  */
 662 extern int setgid (__gid_t __gid) __THROW;
 663
 664 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 665 /* Set the real group ID of the calling process to RGID,
 666    and the effective group ID of the calling process to EGID.  */
 667 extern int setregid (__gid_t __rgid, __gid_t __egid) __THROW;
 668 #endif
 669
 670 #if defined __USE_BSD || defined __USE_XOPEN2K
 671 /* Set the effective group ID of the calling process to GID.  */
 672 extern int setegid (__gid_t __gid) __THROW;
 673 #endif /* Use BSD.  */
 674
 675 #ifdef __USE_GNU
 676 /* Fetch the effective user ID, real user ID, and saved-set user ID,
 677    of the calling process.  */
 678 extern int getresuid (__uid_t *__euid, __uid_t *__ruid, __uid_t *__suid)
 679      __THROW;
 680
 681 /* Fetch the effective group ID, real group ID, and saved-set group ID,
 682    of the calling process.  */
 683 extern int getresgid (__gid_t *__egid, __gid_t *__rgid, __gid_t *__sgid)
 684      __THROW;
 685
 686 /* Set the effective user ID, real user ID, and saved-set user ID,
 687    of the calling process to EUID, RUID, and SUID, respectively.  */
 688 extern int setresuid (__uid_t __euid, __uid_t __ruid, __uid_t __suid)
 689      __THROW;
 690
 691 /* Set the effective group ID, real group ID, and saved-set group ID,
 692    of the calling process to EGID, RGID, and SGID, respectively.  */
 693 extern int setresgid (__gid_t __egid, __gid_t __rgid, __gid_t __sgid)
 694      __THROW;
 695 #endif
 696
 697
 698 /* Clone the calling process, creating an exact copy.
 699    Return -1 for errors, 0 to the new process,
 700    and the process ID of the new process to the old process.  */
 701 extern __pid_t fork (void) __THROW;
 702
 703 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 704 /* Clone the calling process, but without copying the whole address space.
 705    The calling process is suspended until the new process exits or is
 706    replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
 707    and the process ID of the new process to the old process.  */
 708 extern __pid_t vfork (void) __THROW;
 709 #endif /* Use BSD. */
 710
 711
 712 /* Return the pathname of the terminal FD is open on, or NULL on errors.
 713    The returned storage is good only until the next call to this function.  */
 714 extern char *ttyname (int __fd) __THROW;
 715
 716 /* Store at most BUFLEN characters of the pathname of the terminal FD is
 717    open on in BUF.  Return 0 on success, otherwise an error number.  */
 718 extern int ttyname_r (int __fd, char *__buf, size_t __buflen)
 719      __THROW __nonnull ((2)) __wur;
 720
 721 /* Return 1 if FD is a valid descriptor associated
 722    with a terminal, zero if not.  */
 723 extern int isatty (int __fd) __THROW;
 724
 725 #if defined __USE_BSD \
 726     || (defined __USE_XOPEN_EXTENDED && !defined __USE_UNIX98)
 727 /* Return the index into the active-logins file (utmp) for
 728    the controlling terminal.  */
 729 extern int ttyslot (void) __THROW;
 730 #endif
 731
 732
 733 /* Make a link to FROM named TO.  */
 734 extern int link (__const char *__from, __const char *__to)
 735      __THROW __nonnull ((1, 2)) __wur;
 736
 737 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 738 /* Make a symbolic link to FROM named TO.  */
 739 extern int symlink (__const char *__from, __const char *__to)
 740      __THROW __nonnull ((1, 2)) __wur;
 741
 742 /* Read the contents of the symbolic link PATH into no more than
 743    LEN bytes of BUF.  The contents are not null-terminated.
 744    Returns the number of characters read, or -1 for errors.  */
 745 extern int readlink (__const char *__restrict __path, char *__restrict __buf,
 746                      size_t __len) __THROW __nonnull ((1, 2)) __wur;
 747 #endif /* Use BSD.  */
 748
 749 /* Remove the link NAME.  */
 750 extern int unlink (__const char *__name) __THROW __nonnull ((1));
 751
 752 /* Remove the directory PATH.  */
 753 extern int rmdir (__const char *__path) __THROW __nonnull ((1));
 754
 755
 756 /* Return the foreground process group ID of FD.  */
 757 extern __pid_t tcgetpgrp (int __fd) __THROW;
 758
 759 /* Set the foreground process group ID of FD set PGRP_ID.  */
 760 extern int tcsetpgrp (int __fd, __pid_t __pgrp_id) __THROW;
 761
 762
 763 /* Return the login name of the user.
 764
 765    This function is a possible cancellation points and therefore not
 766    marked with __THROW.  */
 767 extern char *getlogin (void);
 768 #if defined __USE_REENTRANT || defined __USE_UNIX98
 769 /* Return at most NAME_LEN characters of the login name of the user in NAME.
 770    If it cannot be determined or some other error occurred, return the error
 771    code.  Otherwise return 0.
 772
 773    This function is a possible cancellation points and therefore not
 774    marked with __THROW.  */
 775 extern int getlogin_r (char *__name, size_t __name_len) __nonnull ((1));
 776 #endif
 777
 778 #ifdef  __USE_BSD
 779 /* Set the login name returned by `getlogin'.  */
 780 extern int setlogin (__const char *__name) __THROW __nonnull ((1));
 781 #endif
 782
 783
 784 #ifdef  __USE_POSIX2
 785 /* Get definitions and prototypes for functions to process the
 786    arguments in ARGV (ARGC of them, minus the program name) for
 787    options given in OPTS.  */
 788 # define __need_getopt
 789 # include <getopt.h>
 790 #endif
 791
 792
 793 #if defined __USE_BSD || defined __USE_UNIX98
 794 /* Put the name of the current host in no more than LEN bytes of NAME.
 795    The result is null-terminated if LEN is large enough for the full
 796    name and the terminator.  */
 797 extern int gethostname (char *__name, size_t __len) __THROW __nonnull ((1));
 798 #endif
 799
 800
 801 #if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_UNIX98)
 802 /* Set the name of the current host to NAME, which is LEN bytes long.
 803    This call is restricted to the super-user.  */
 804 extern int sethostname (__const char *__name, size_t __len)
 805      __THROW __nonnull ((1)) __wur;
 806
 807 /* Set the current machine's Internet number to ID.
 808    This call is restricted to the super-user.  */
 809 extern int sethostid (long int __id) __THROW __wur;
 810
 811
 812 /* Get and set the NIS (aka YP) domain name, if any.
 813    Called just like `gethostname' and `sethostname'.
 814    The NIS domain name is usually the empty string when not using NIS.  */
 815 extern int getdomainname (char *__name, size_t __len)
 816      __THROW __nonnull ((1)) __wur;
 817 extern int setdomainname (__const char *__name, size_t __len)
 818      __THROW __nonnull ((1)) __wur;
 819
 820
 821 /* Revoke access permissions to all processes currently communicating
 822    with the control terminal, and then send a SIGHUP signal to the process
 823    group of the control terminal.  */
 824 extern int vhangup (void) __THROW;
 825
 826 /* Revoke the access of all descriptors currently open on FILE.  */
 827 extern int revoke (__const char *__file) __THROW __nonnull ((1)) __wur;
 828
 829
 830 /* Enable statistical profiling, writing samples of the PC into at most
 831    SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
 832    is enabled, the system examines the user PC and increments
 833    SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536].  If SCALE is zero,
 834    disable profiling.  Returns zero on success, -1 on error.  */
 835 extern int profil (unsigned short int *__sample_buffer, size_t __size,
 836                    size_t __offset, unsigned int __scale)
 837      __THROW __nonnull ((1));
 838
 839
 840 /* Turn accounting on if NAME is an existing file.  The system will then write
 841    a record for each process as it terminates, to this file.  If NAME is NULL,
 842    turn accounting off.  This call is restricted to the super-user.  */
 843 extern int acct (__const char *__name) __THROW __nonnull ((1));
 844
 845
 846 /* Successive calls return the shells listed in `/etc/shells'.  */
 847 extern char *getusershell (void) __THROW;
 848 extern void endusershell (void) __THROW; /* Discard cached info.  */
 849 extern void setusershell (void) __THROW; /* Rewind and re-read the file.  */
 850
 851
 852 /* Put the program in the background, and dissociate from the controlling
 853    terminal.  If NOCHDIR is zero, do `chdir ("/")'.  If NOCLOSE is zero,
 854    redirects stdin, stdout, and stderr to /dev/null.  */
 855 extern int daemon (int __nochdir, int __noclose) __THROW __wur;
 856 #endif /* Use BSD || X/Open.  */
 857
 858
 859 #if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_XOPEN2K)
 860 /* Make PATH be the root directory (the starting point for absolute paths).
 861    This call is restricted to the super-user.  */
 862 extern int chroot (__const char *__path) __THROW __nonnull ((1)) __wur;
 863
 864 /* Prompt with PROMPT and read a string from the terminal without echoing.
 865    Uses /dev/tty if possible; otherwise stderr and stdin.  */
 866 extern char *getpass (__const char *__prompt) __nonnull ((1));
 867 #endif /* Use BSD || X/Open.  */
 868
 869
 870 #if defined __USE_BSD || defined __USE_XOPEN
 871 /* Make all changes done to FD actually appear on disk.
 872
 873    This function is a cancellation point and therefore not marked with
 874    __THROW.  */
 875 extern int fsync (int __fd);
 876 #endif /* Use BSD || X/Open.  */
 877
 878
 879 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 880
 881 /* Return identifier for the current host.  */
 882 extern long int gethostid (void);
 883
 884 /* Make all changes done to all files actually appear on disk.  */
 885 extern void sync (void) __THROW;
 886
 887
 888 /* Return the number of bytes in a page.  This is the system's page size,
 889    which is not necessarily the same as the hardware page size.  */
 890 extern int getpagesize (void)  __THROW __attribute__ ((__const__));
 891
 892
 893 /* Return the maximum number of file descriptors
 894    the current process could possibly have.  */
 895 extern int getdtablesize (void) __THROW;
 896
 897
 898 /* Truncate FILE to LENGTH bytes.  */
 899 # ifndef __USE_FILE_OFFSET64
 900 extern int truncate (__const char *__file, __off_t __length)
 901      __THROW __nonnull ((1)) __wur;
 902 # else
 903 #  ifdef __REDIRECT_NTH
 904 extern int __REDIRECT_NTH (truncate,
 905                            (__const char *__file, __off64_t __length),
 906                            truncate64) __nonnull ((1)) __wur;
 907 #  else
 908 #   define truncate truncate64
 909 #  endif
 910 # endif
 911 # ifdef __USE_LARGEFILE64
 912 extern int truncate64 (__const char *__file, __off64_t __length)
 913      __THROW __nonnull ((1)) __wur;
 914 # endif
 915
 916 #endif /* Use BSD || X/Open Unix.  */
 917
 918 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
 919
 920 /* Truncate the file FD is open on to LENGTH bytes.  */
 921 # ifndef __USE_FILE_OFFSET64
 922 extern int ftruncate (int __fd, __off_t __length) __THROW __wur;
 923 # else
 924 #  ifdef __REDIRECT_NTH
 925 extern int __REDIRECT_NTH (ftruncate, (int __fd, __off64_t __length),
 926                            ftruncate64) __wur;
 927 #  else
 928 #   define ftruncate ftruncate64
 929 #  endif
 930 # endif
 931 # ifdef __USE_LARGEFILE64
 932 extern int ftruncate64 (int __fd, __off64_t __length) __THROW __wur;
 933 # endif
 934
 935 #endif /* Use BSD || X/Open Unix || POSIX 2003.  */
 936
 937
 938 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 939
 940 /* Set the end of accessible data space (aka "the break") to ADDR.
 941    Returns zero on success and -1 for errors (with errno set).  */
 942 extern int brk (void *__addr) __THROW __wur;
 943
 944 /* Increase or decrease the end of accessible data space by DELTA bytes.
 945    If successful, returns the address the previous end of data space
 946    (i.e. the beginning of the new space, if DELTA > 0);
 947    returns (void *) -1 for errors (with errno set).  */
 948 extern void *sbrk (intptr_t __delta) __THROW;
 949 #endif
 950
 951
 952 #ifdef __USE_MISC
 953 /* Invoke `system call' number SYSNO, passing it the remaining arguments.
 954    This is completely system-dependent, and not often useful.
 955
 956    In Unix, `syscall' sets `errno' for all errors and most calls return -1
 957    for errors; in many systems you cannot pass arguments or get return
 958    values for all system calls (`pipe', `fork', and `getppid' typically
 959    among them).
 960
 961    In Mach, all system calls take normal arguments and always return an
 962    error code (zero for success).  */
 963 extern long int syscall (long int __sysno, ...) __THROW;
 964
 965 #endif  /* Use misc.  */
 966
 967
 968 #if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK
 969 /* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both
 970    files consistent.  Some systems have them there and some here, and some
 971    software depends on the macros being defined without including both.  */
 972
 973 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
 974    LEN is always relative to the current file position.
 975    The CMD argument is one of the following.
 976
 977    This function is a cancellation point and therefore not marked with
 978    __THROW.  */
 979
 980 # define F_ULOCK 0      /* Unlock a previously locked region.  */
 981 # define F_LOCK  1      /* Lock a region for exclusive use.  */
 982 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
 983 # define F_TEST  3      /* Test a region for other processes locks.  */
 984
 985 # ifndef __USE_FILE_OFFSET64
 986 extern int lockf (int __fd, int __cmd, __off_t __len) __wur;
 987 # else
 988 #  ifdef __REDIRECT
 989 extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len),
 990                        lockf64) __wur;
 991 #  else
 992 #   define lockf lockf64
 993 #  endif
 994 # endif
 995 # ifdef __USE_LARGEFILE64
 996 extern int lockf64 (int __fd, int __cmd, __off64_t __len) __wur;
 997 # endif
 998 #endif /* Use misc and F_LOCK not already defined.  */
 999
1000
1001 #ifdef __USE_GNU
1002
1003 /* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno'
1004    set to EINTR.  */
1005
1006 # define TEMP_FAILURE_RETRY(expression) \
1007   (__extension__                                                              \
1008     ({ long int __result;                                                     \
1009        do __result = (long int) (expression);                                 \
1010        while (__result == -1L && errno == EINTR);                             \
1011        __result; }))
1012 #endif
1013
1014 #if defined __USE_POSIX199309 || defined __USE_UNIX98
1015 /* Synchronize at least the data part of a file with the underlying
1016    media.  */
1017 extern int fdatasync (int __fildes) __THROW;
1018 #endif /* Use POSIX199309 */
1019
1020
1021 /* XPG4.2 specifies that prototypes for the encryption functions must
1022    be defined here.  */
1023 #ifdef  __USE_XOPEN
1024 /* Encrypt at most 8 characters from KEY using salt to perturb DES.  */
1025 extern char *crypt (__const char *__key, __const char *__salt)
1026      __THROW __nonnull ((1, 2));
1027
1028 /* Encrypt data in BLOCK in place if EDFLAG is zero; otherwise decrypt
1029    block in place.  */
1030 extern void encrypt (char *__block, int __edflag) __THROW __nonnull ((1));
1031
1032
1033 /* Swab pairs bytes in the first N bytes of the area pointed to by
1034    FROM and copy the result to TO.  The value of TO must not be in the
1035    range [FROM - N + 1, FROM - 1].  If N is odd the first byte in FROM
1036    is without partner.  */
1037 extern void swab (__const void *__restrict __from, void *__restrict __to,
1038                   ssize_t __n) __THROW __nonnull ((1, 2));
1039 #endif
1040
1041
1042 /* The Single Unix specification demands this prototype to be here.
1043    It is also found in <stdio.h>.  */
1044 #ifdef __USE_XOPEN
1045 /* Return the name of the controlling terminal.  */
1046 extern char *ctermid (char *__s) __THROW __nonnull ((1));
1047 #endif
1048
1049 __END_DECLS
1050
1051 #endif /* unistd.h  */