posix/unistd.h

   1 /* Copyright (C) 1991-2002, 2003 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 #ifdef __USE_XOPEN
 198 /* The Single Unix specification says that some more types are
 199    available here.  */
 200 # ifndef __gid_t_defined
 201 typedef __gid_t gid_t;
 202 #  define __gid_t_defined
 203 # endif
 204
 205 # ifndef __uid_t_defined
 206 typedef __uid_t uid_t;
 207 #  define __uid_t_defined
 208 # endif
 209
 210 # ifndef __off_t_defined
 211 #  ifndef __USE_FILE_OFFSET64
 212 typedef __off_t off_t;
 213 #  else
 214 typedef __off64_t off_t;
 215 #  endif
 216 #  define __off_t_defined
 217 # endif
 218 # if defined __USE_LARGEFILE64 && !defined __off64_t_defined
 219 typedef __off64_t off64_t;
 220 #  define __off64_t_defined
 221 # endif
 222
 223 # ifndef __useconds_t_defined
 224 typedef __useconds_t useconds_t;
 225 #  define __useconds_t_defined
 226 # endif
 227
 228 # ifndef __pid_t_defined
 229 typedef __pid_t pid_t;
 230 #  define __pid_t_defined
 231 # endif
 232 #endif  /* X/Open */
 233
 234 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 235 # ifndef __intptr_t_defined
 236 typedef __intptr_t intptr_t;
 237 #  define __intptr_t_defined
 238 # endif
 239 #endif
 240
 241 #if defined __USE_BSD || defined __USE_XOPEN
 242 # ifndef __socklen_t_defined
 243 typedef __socklen_t socklen_t;
 244 #  define __socklen_t_defined
 245 # endif
 246 #endif
 247
 248 /* Values for the second argument to access.
 249    These may be OR'd together.  */
 250 #define R_OK    4               /* Test for read permission.  */
 251 #define W_OK    2               /* Test for write permission.  */
 252 #define X_OK    1               /* Test for execute permission.  */
 253 #define F_OK    0               /* Test for existence.  */
 254
 255 /* Test for access to NAME using the real UID and real GID.  */
 256 extern int access (__const char *__name, int __type) __THROW;
 257
 258 #ifdef __USE_GNU
 259 /* Test for access to NAME using the effective UID and GID
 260    (as normal file operations use).  */
 261 extern int euidaccess (__const char *__name, int __type) __THROW;
 262 #endif
 263
 264
 265 /* Values for the WHENCE argument to lseek.  */
 266 #ifndef _STDIO_H                /* <stdio.h> has the same definitions.  */
 267 # define SEEK_SET       0       /* Seek from beginning of file.  */
 268 # define SEEK_CUR       1       /* Seek from current position.  */
 269 # define SEEK_END       2       /* Seek from end of file.  */
 270 #endif
 271
 272 #if defined __USE_BSD && !defined L_SET
 273 /* Old BSD names for the same constants; just for compatibility.  */
 274 # define L_SET          SEEK_SET
 275 # define L_INCR         SEEK_CUR
 276 # define L_XTND         SEEK_END
 277 #endif
 278
 279
 280 /* Move FD's file position to OFFSET bytes from the
 281    beginning of the file (if WHENCE is SEEK_SET),
 282    the current position (if WHENCE is SEEK_CUR),
 283    or the end of the file (if WHENCE is SEEK_END).
 284    Return the new file position.  */
 285 #ifndef __USE_FILE_OFFSET64
 286 extern __off_t lseek (int __fd, __off_t __offset, int __whence) __THROW;
 287 #else
 288 # ifdef __REDIRECT
 289 extern __off64_t __REDIRECT (lseek,
 290                              (int __fd, __off64_t __offset, int __whence)
 291                              __THROW,
 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;
 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;
 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;
 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;
 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;
 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[]) __THROW;
 493
 494 /* Execute PATH with all arguments after PATH until a NULL pointer,
 495    and the argument after that for environment.  */
 496 extern int execle (__const char *__path, __const char *__arg, ...) __THROW;
 497
 498 /* Execute PATH with all arguments after PATH until
 499    a NULL pointer and environment from `environ'.  */
 500 extern int execl (__const char *__path, __const char *__arg, ...) __THROW;
 501
 502 /* Execute FILE, searching in the `PATH' environment variable if it contains
 503    no slashes, with arguments ARGV and environment from `environ'.  */
 504 extern int execvp (__const char *__file, char *__const __argv[]) __THROW;
 505
 506 /* Execute FILE, searching in the `PATH' environment variable if
 507    it contains no slashes, with all arguments after FILE until a
 508    NULL pointer and environment from `environ'.  */
 509 extern int execlp (__const char *__file, __const char *__arg, ...) __THROW;
 510
 511
 512 #if defined __USE_MISC || defined __USE_XOPEN
 513 /* Add INC to priority of the current process.  */
 514 extern int nice (int __inc) __THROW;
 515 #endif
 516
 517
 518 /* Terminate program execution with the low-order 8 bits of STATUS.  */
 519 extern void _exit (int __status) __attribute__ ((__noreturn__));
 520
 521
 522 /* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf';
 523    the `_SC_*' symbols for the NAME argument to `sysconf';
 524    and the `_CS_*' symbols for the NAME argument to `confstr'.  */
 525 #include <bits/confname.h>
 526
 527 /* Get file-specific configuration information about PATH.  */
 528 extern long int pathconf (__const char *__path, int __name) __THROW;
 529
 530 /* Get file-specific configuration about descriptor FD.  */
 531 extern long int fpathconf (int __fd, int __name) __THROW;
 532
 533 /* Get the value of the system variable NAME.  */
 534 extern long int sysconf (int __name) __THROW __attribute__ ((__const__));
 535
 536 #ifdef  __USE_POSIX2
 537 /* Get the value of the string-valued system variable NAME.  */
 538 extern size_t confstr (int __name, char *__buf, size_t __len) __THROW;
 539 #endif
 540
 541
 542 /* Get the process ID of the calling process.  */
 543 extern __pid_t getpid (void) __THROW;
 544
 545 /* Get the process ID of the calling process's parent.  */
 546 extern __pid_t getppid (void) __THROW;
 547
 548 /* Get the process group ID of the calling process.
 549    This function is different on old BSD. */
 550 #ifndef __FAVOR_BSD
 551 extern __pid_t getpgrp (void) __THROW;
 552 #else
 553 # ifdef __REDIRECT
 554 extern __pid_t __REDIRECT (getpgrp, (__pid_t __pid) __THROW, __getpgid);
 555 # else
 556 #  define getpgrp __getpgid
 557 # endif
 558 #endif
 559
 560 /* Get the process group ID of process PID.  */
 561 extern __pid_t __getpgid (__pid_t __pid) __THROW;
 562 #ifdef __USE_XOPEN_EXTENDED
 563 extern __pid_t getpgid (__pid_t __pid) __THROW;
 564 #endif
 565
 566
 567 /* Set the process group ID of the process matching PID to PGID.
 568    If PID is zero, the current process's process group ID is set.
 569    If PGID is zero, the process ID of the process is used.  */
 570 extern int setpgid (__pid_t __pid, __pid_t __pgid) __THROW;
 571
 572 #if defined __USE_SVID || defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 573 /* Both System V and BSD have `setpgrp' functions, but with different
 574    calling conventions.  The BSD function is the same as POSIX.1 `setpgid'
 575    (above).  The System V function takes no arguments and puts the calling
 576    process in its on group like `setpgid (0, 0)'.
 577
 578    New programs should always use `setpgid' instead.
 579
 580    The default in GNU is to provide the System V function.  The BSD
 581    function is available under -D_BSD_SOURCE.  */
 582
 583 # ifndef __FAVOR_BSD
 584
 585 /* Set the process group ID of the calling process to its own PID.
 586    This is exactly the same as `setpgid (0, 0)'.  */
 587 extern int setpgrp (void) __THROW;
 588
 589 # else
 590
 591 /* Another name for `setpgid' (above).  */
 592 #  ifdef __REDIRECT
 593 extern int __REDIRECT (setpgrp, (__pid_t __pid, __pid_t __pgrp) __THROW,
 594                        setpgid);
 595 #  else
 596 #   define setpgrp setpgid
 597 #  endif
 598
 599 # endif /* Favor BSD.  */
 600 #endif  /* Use SVID or BSD.  */
 601
 602 /* Create a new session with the calling process as its leader.
 603    The process group IDs of the session and the calling process
 604    are set to the process ID of the calling process, which is returned.  */
 605 extern __pid_t setsid (void) __THROW;
 606
 607 #ifdef __USE_XOPEN_EXTENDED
 608 /* Return the session ID of the given process.  */
 609 extern __pid_t getsid (__pid_t __pid) __THROW;
 610 #endif
 611
 612 /* Get the real user ID of the calling process.  */
 613 extern __uid_t getuid (void) __THROW;
 614
 615 /* Get the effective user ID of the calling process.  */
 616 extern __uid_t geteuid (void) __THROW;
 617
 618 /* Get the real group ID of the calling process.  */
 619 extern __gid_t getgid (void) __THROW;
 620
 621 /* Get the effective group ID of the calling process.  */
 622 extern __gid_t getegid (void) __THROW;
 623
 624 /* If SIZE is zero, return the number of supplementary groups
 625    the calling process is in.  Otherwise, fill in the group IDs
 626    of its supplementary groups in LIST and return the number written.  */
 627 extern int getgroups (int __size, __gid_t __list[]) __THROW;
 628
 629 #ifdef  __USE_GNU
 630 /* Return nonzero iff the calling process is in group GID.  */
 631 extern int group_member (__gid_t __gid) __THROW;
 632 #endif
 633
 634 /* Set the user ID of the calling process to UID.
 635    If the calling process is the super-user, set the real
 636    and effective user IDs, and the saved set-user-ID to UID;
 637    if not, the effective user ID is set to UID.  */
 638 extern int setuid (__uid_t __uid) __THROW;
 639
 640 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 641 /* Set the real user ID of the calling process to RUID,
 642    and the effective user ID of the calling process to EUID.  */
 643 extern int setreuid (__uid_t __ruid, __uid_t __euid) __THROW;
 644 #endif
 645
 646 #if defined __USE_BSD || defined __USE_XOPEN2K
 647 /* Set the effective user ID of the calling process to UID.  */
 648 extern int seteuid (__uid_t __uid) __THROW;
 649 #endif /* Use BSD.  */
 650
 651 /* Set the group ID of the calling process to GID.
 652    If the calling process is the super-user, set the real
 653    and effective group IDs, and the saved set-group-ID to GID;
 654    if not, the effective group ID is set to GID.  */
 655 extern int setgid (__gid_t __gid) __THROW;
 656
 657 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 658 /* Set the real group ID of the calling process to RGID,
 659    and the effective group ID of the calling process to EGID.  */
 660 extern int setregid (__gid_t __rgid, __gid_t __egid) __THROW;
 661 #endif
 662
 663 #if defined __USE_BSD || defined __USE_XOPEN2K
 664 /* Set the effective group ID of the calling process to GID.  */
 665 extern int setegid (__gid_t __gid) __THROW;
 666 #endif /* Use BSD.  */
 667
 668 #ifdef __USE_GNU
 669 /* Fetch the effective user ID, real user ID, and saved-set user ID,
 670    of the calling process.  */
 671 extern int getresuid (__uid_t *__euid, __uid_t *__ruid, __uid_t *__suid);
 672
 673 /* Fetch the effective group ID, real group ID, and saved-set group ID,
 674    of the calling process.  */
 675 extern int getresgid (__gid_t *__egid, __gid_t *__rgid, __gid_t *__sgid);
 676
 677 /* Set the effective user ID, real user ID, and saved-set user ID,
 678    of the calling process to EUID, RUID, and SUID, respectively.  */
 679 extern int setresuid (__uid_t __euid, __uid_t __ruid, __uid_t __suid);
 680
 681 /* Set the effective group ID, real group ID, and saved-set group ID,
 682    of the calling process to EGID, RGID, and SGID, respectively.  */
 683 extern int setresgid (__gid_t __egid, __gid_t __rgid, __gid_t __sgid);
 684 #endif
 685
 686
 687 /* Clone the calling process, creating an exact copy.
 688    Return -1 for errors, 0 to the new process,
 689    and the process ID of the new process to the old process.  */
 690 extern __pid_t fork (void) __THROW;
 691
 692 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 693 /* Clone the calling process, but without copying the whole address space.
 694    The calling process is suspended until the new process exits or is
 695    replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
 696    and the process ID of the new process to the old process.  */
 697 extern __pid_t vfork (void) __THROW;
 698 #endif /* Use BSD. */
 699
 700
 701 /* Return the pathname of the terminal FD is open on, or NULL on errors.
 702    The returned storage is good only until the next call to this function.
 703
 704    This function is a possible cancellation points and therefore not
 705    marked with __THROW.  */
 706 extern char *ttyname (int __fd);
 707
 708 /* Store at most BUFLEN characters of the pathname of the terminal FD is
 709    open on in BUF.  Return 0 on success, otherwise an error number.
 710
 711    This function is a possible cancellation points and therefore not
 712    marked with __THROW.  */
 713 extern int ttyname_r (int __fd, char *__buf, size_t __buflen);
 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) __THROW;
 729
 730 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 731 /* Make a symbolic link to FROM named TO.  */
 732 extern int symlink (__const char *__from, __const char *__to) __THROW;
 733
 734 /* Read the contents of the symbolic link PATH into no more than
 735    LEN bytes of BUF.  The contents are not null-terminated.
 736    Returns the number of characters read, or -1 for errors.  */
 737 extern int readlink (__const char *__restrict __path, char *__restrict __buf,
 738                      size_t __len) __THROW;
 739 #endif /* Use BSD.  */
 740
 741 /* Remove the link NAME.  */
 742 extern int unlink (__const char *__name) __THROW;
 743
 744 /* Remove the directory PATH.  */
 745 extern int rmdir (__const char *__path) __THROW;
 746
 747
 748 /* Return the foreground process group ID of FD.  */
 749 extern __pid_t tcgetpgrp (int __fd) __THROW;
 750
 751 /* Set the foreground process group ID of FD set PGRP_ID.  */
 752 extern int tcsetpgrp (int __fd, __pid_t __pgrp_id) __THROW;
 753
 754
 755 /* Return the login name of the user.
 756
 757    This function is a possible cancellation points and therefore not
 758    marked with __THROW.  */
 759 extern char *getlogin (void);
 760 #if defined __USE_REENTRANT || defined __USE_UNIX98
 761 /* Return at most NAME_LEN characters of the login name of the user in NAME.
 762    If it cannot be determined or some other error occurred, return the error
 763    code.  Otherwise return 0.
 764
 765    This function is a possible cancellation points and therefore not
 766    marked with __THROW.  */
 767 extern int getlogin_r (char *__name, size_t __name_len);
 768 #endif
 769
 770 #ifdef  __USE_BSD
 771 /* Set the login name returned by `getlogin'.  */
 772 extern int setlogin (__const char *__name) __THROW;
 773 #endif
 774
 775
 776 #ifdef  __USE_POSIX2
 777 /* Get definitions and prototypes for functions to process the
 778    arguments in ARGV (ARGC of them, minus the program name) for
 779    options given in OPTS.  */
 780 # define __need_getopt
 781 # include <getopt.h>
 782 #endif
 783
 784
 785 #if defined __USE_BSD || defined __USE_UNIX98
 786 /* Put the name of the current host in no more than LEN bytes of NAME.
 787    The result is null-terminated if LEN is large enough for the full
 788    name and the terminator.  */
 789 extern int gethostname (char *__name, size_t __len) __THROW;
 790 #endif
 791
 792
 793 #if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_UNIX98)
 794 /* Set the name of the current host to NAME, which is LEN bytes long.
 795    This call is restricted to the super-user.  */
 796 extern int sethostname (__const char *__name, size_t __len) __THROW;
 797
 798 /* Set the current machine's Internet number to ID.
 799    This call is restricted to the super-user.  */
 800 extern int sethostid (long int __id) __THROW;
 801
 802
 803 /* Get and set the NIS (aka YP) domain name, if any.
 804    Called just like `gethostname' and `sethostname'.
 805    The NIS domain name is usually the empty string when not using NIS.  */
 806 extern int getdomainname (char *__name, size_t __len) __THROW;
 807 extern int setdomainname (__const char *__name, size_t __len) __THROW;
 808
 809
 810 /* Revoke access permissions to all processes currently communicating
 811    with the control terminal, and then send a SIGHUP signal to the process
 812    group of the control terminal.  */
 813 extern int vhangup (void) __THROW;
 814
 815 /* Revoke the access of all descriptors currently open on FILE.  */
 816 extern int revoke (__const char *__file) __THROW;
 817
 818
 819 /* Enable statistical profiling, writing samples of the PC into at most
 820    SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
 821    is enabled, the system examines the user PC and increments
 822    SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536].  If SCALE is zero,
 823    disable profiling.  Returns zero on success, -1 on error.  */
 824 extern int profil (unsigned short int *__sample_buffer, size_t __size,
 825                    size_t __offset, unsigned int __scale) __THROW;
 826
 827
 828 /* Turn accounting on if NAME is an existing file.  The system will then write
 829    a record for each process as it terminates, to this file.  If NAME is NULL,
 830    turn accounting off.  This call is restricted to the super-user.  */
 831 extern int acct (__const char *__name) __THROW;
 832
 833
 834 /* Successive calls return the shells listed in `/etc/shells'.  */
 835 extern char *getusershell (void) __THROW;
 836 extern void endusershell (void) __THROW; /* Discard cached info.  */
 837 extern void setusershell (void) __THROW; /* Rewind and re-read the file.  */
 838
 839
 840 /* Put the program in the background, and dissociate from the controlling
 841    terminal.  If NOCHDIR is zero, do `chdir ("/")'.  If NOCLOSE is zero,
 842    redirects stdin, stdout, and stderr to /dev/null.  */
 843 extern int daemon (int __nochdir, int __noclose) __THROW;
 844 #endif /* Use BSD || X/Open.  */
 845
 846
 847 #if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_XOPEN2K)
 848 /* Make PATH be the root directory (the starting point for absolute paths).
 849    This call is restricted to the super-user.  */
 850 extern int chroot (__const char *__path) __THROW;
 851
 852 /* Prompt with PROMPT and read a string from the terminal without echoing.
 853    Uses /dev/tty if possible; otherwise stderr and stdin.  */
 854 extern char *getpass (__const char *__prompt) __THROW;
 855 #endif /* Use BSD || X/Open.  */
 856
 857
 858 #if defined __USE_BSD || defined __USE_XOPEN
 859 /* Make all changes done to FD actually appear on disk.
 860
 861    This function is a cancellation point and therefore not marked with
 862    __THROW.  */
 863 extern int fsync (int __fd);
 864 #endif /* Use BSD || X/Open.  */
 865
 866
 867 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 868
 869 /* Return the current machine's Internet number.  */
 870 extern long int gethostid (void) __THROW;
 871
 872 /* Make all changes done to all files actually appear on disk.  */
 873 extern void sync (void) __THROW;
 874
 875
 876 /* Return the number of bytes in a page.  This is the system's page size,
 877    which is not necessarily the same as the hardware page size.  */
 878 extern int getpagesize (void)  __THROW __attribute__ ((__const__));
 879
 880
 881 /* Truncate FILE to LENGTH bytes.  */
 882 # ifndef __USE_FILE_OFFSET64
 883 extern int truncate (__const char *__file, __off_t __length) __THROW;
 884 # else
 885 #  ifdef __REDIRECT
 886 extern int __REDIRECT (truncate,
 887                        (__const char *__file, __off64_t __length) __THROW,
 888                        truncate64);
 889 #  else
 890 #   define truncate truncate64
 891 #  endif
 892 # endif
 893 # ifdef __USE_LARGEFILE64
 894 extern int truncate64 (__const char *__file, __off64_t __length) __THROW;
 895 # endif
 896
 897 /* Truncate the file FD is open on to LENGTH bytes.  */
 898 # ifndef __USE_FILE_OFFSET64
 899 extern int ftruncate (int __fd, __off_t __length) __THROW;
 900 # else
 901 #  ifdef __REDIRECT
 902 extern int __REDIRECT (ftruncate, (int __fd, __off64_t __length) __THROW,
 903                        ftruncate64);
 904 #  else
 905 #   define ftruncate ftruncate64
 906 #  endif
 907 # endif
 908 # ifdef __USE_LARGEFILE64
 909 extern int ftruncate64 (int __fd, __off64_t __length) __THROW;
 910 # endif
 911
 912
 913 /* Return the maximum number of file descriptors
 914    the current process could possibly have.  */
 915 extern int getdtablesize (void) __THROW;
 916
 917 #endif /* Use BSD || X/Open Unix.  */
 918
 919
 920 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 921
 922 /* Set the end of accessible data space (aka "the break") to ADDR.
 923    Returns zero on success and -1 for errors (with errno set).  */
 924 extern int brk (void *__addr) __THROW;
 925
 926 /* Increase or decrease the end of accessible data space by DELTA bytes.
 927    If successful, returns the address the previous end of data space
 928    (i.e. the beginning of the new space, if DELTA > 0);
 929    returns (void *) -1 for errors (with errno set).  */
 930 extern void *sbrk (intptr_t __delta) __THROW;
 931 #endif
 932
 933
 934 #ifdef __USE_MISC
 935 /* Invoke `system call' number SYSNO, passing it the remaining arguments.
 936    This is completely system-dependent, and not often useful.
 937
 938    In Unix, `syscall' sets `errno' for all errors and most calls return -1
 939    for errors; in many systems you cannot pass arguments or get return
 940    values for all system calls (`pipe', `fork', and `getppid' typically
 941    among them).
 942
 943    In Mach, all system calls take normal arguments and always return an
 944    error code (zero for success).  */
 945 extern long int syscall (long int __sysno, ...) __THROW;
 946
 947 #endif  /* Use misc.  */
 948
 949
 950 #if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK
 951 /* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both
 952    files consistent.  Some systems have them there and some here, and some
 953    software depends on the macros being defined without including both.  */
 954
 955 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
 956    LEN is always relative to the current file position.
 957    The CMD argument is one of the following.
 958
 959    This function is a cancellation point and therefore not marked with
 960    __THROW.  */
 961
 962 # define F_ULOCK 0      /* Unlock a previously locked region.  */
 963 # define F_LOCK  1      /* Lock a region for exclusive use.  */
 964 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
 965 # define F_TEST  3      /* Test a region for other processes locks.  */
 966
 967 # ifndef __USE_FILE_OFFSET64
 968 extern int lockf (int __fd, int __cmd, __off_t __len);
 969 # else
 970 #  ifdef __REDIRECT
 971 extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len),
 972                        lockf64);
 973 #  else
 974 #   define lockf lockf64
 975 #  endif
 976 # endif
 977 # ifdef __USE_LARGEFILE64
 978 extern int lockf64 (int __fd, int __cmd, __off64_t __len);
 979 # endif
 980 #endif /* Use misc and F_LOCK not already defined.  */
 981
 982
 983 #ifdef __USE_GNU
 984
 985 /* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno'
 986    set to EINTR.  */
 987
 988 # define TEMP_FAILURE_RETRY(expression) \
 989   (__extension__                                                              \
 990     ({ long int __result;                                                     \
 991        do __result = (long int) (expression);                                 \
 992        while (__result == -1L && errno == EINTR);                             \
 993        __result; }))
 994 #endif
 995
 996 #if defined __USE_POSIX199309 || defined __USE_UNIX98
 997 /* Synchronize at least the data part of a file with the underlying
 998    media.  */
 999 extern int fdatasync (int __fildes) __THROW;
1000 #endif /* Use POSIX199309 */
1001
1002
1003 /* XPG4.2 specifies that prototypes for the encryption functions must
1004    be defined here.  */
1005 #ifdef  __USE_XOPEN
1006 /* Encrypt at most 8 characters from KEY using salt to perturb DES.  */
1007 extern char *crypt (__const char *__key, __const char *__salt) __THROW;
1008
1009 /* Encrypt data in BLOCK in place if EDFLAG is zero; otherwise decrypt
1010    block in place.  */
1011 extern void encrypt (char *__block, int __edflag) __THROW;
1012
1013
1014 /* Swab pairs bytes in the first N bytes of the area pointed to by
1015    FROM and copy the result to TO.  The value of TO must not be in the
1016    range [FROM - N + 1, FROM - 1].  If N is odd the first byte in FROM
1017    is without partner.  */
1018 extern void swab (__const void *__restrict __from, void *__restrict __to,
1019                   ssize_t __n) __THROW;
1020 #endif
1021
1022
1023 /* The Single Unix specification demands this prototype to be here.
1024    It is also found in <stdio.h>.  */
1025 #ifdef __USE_XOPEN
1026 /* Return the name of the controlling terminal.  */
1027 extern char *ctermid (char *__s) __THROW;
1028 #endif
1029
1030 __END_DECLS
1031
1032 #endif /* unistd.h  */