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