posix/unistd.h

   1 /* Copyright (C) 1991, 92, 93, 94, 95, 96, 97 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 Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    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    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 /*
  20  *      POSIX Standard: 2.10 Symbolic Constants         <unistd.h>
  21  */
  22
  23 #ifndef _UNISTD_H
  24 #define _UNISTD_H       1
  25
  26 #include <features.h>
  27
  28 __BEGIN_DECLS
  29
  30 /* These may be used to determine what facilities are present at compile time.
  31    Their values can be obtained at run time from `sysconf'.  */
  32
  33 /* POSIX Standard approved as ISO/IEC 9945-1 as of August, 1988 and
  34    extended by POSIX-1b (aka POSIX-4) and POSIX-1c (aka POSIX threads).  */
  35 #define _POSIX_VERSION  199506L
  36
  37 /* These are not #ifdef __USE_POSIX2 because they are
  38    in the theoretically application-owned namespace.  */
  39
  40 /* POSIX Standard approved as ISO/IEC 9945-2 as of December, 1993.  */
  41 #define _POSIX2_C_VERSION       199209L
  42
  43 /* If defined, the implementation supports the
  44    C Language Bindings Option.  */
  45 #define _POSIX2_C_BIND  1
  46
  47 /* If defined, the implementation supports the
  48    C Language Development Utilities Option.  */
  49 #define _POSIX2_C_DEV   1
  50
  51 /* If defined, the implementation supports the
  52    Software Development Utilities Option.  */
  53 #define _POSIX2_SW_DEV  1
  54
  55 /* If defined, the implementation supports the
  56    creation of locales with the localedef utility.  */
  57 #define _POSIX2_LOCALEDEF       1
  58
  59 /* Library conforms to X/Open version 4.  */
  60 #define _XOPEN_VERSION  4
  61
  62 /* Commands and utilities from XPG4 are available.  */
  63 #define _XOPEN_XCU_VERSION      4
  64
  65 /* We are compatible with the old published standards as well.  */
  66 #define _XOPEN_XPG2     1
  67 #define _XOPEN_XPG3     1
  68 #define _XOPEN_XPG4     1
  69
  70 /* The X/Open Unix extensions are available.  */
  71 #define _XOPEN_UNIX     1
  72
  73 /* Encryption is present.  */
  74 #define _XOPEN_CRYPT    1
  75
  76 /* The enhanced internationalization capabilities according to XPG4.2
  77    are present.  */
  78 #define _XOPEN_ENH_I18N 1
  79
  80
  81 /* Get values of POSIX options:
  82
  83    If these symbols are defined, the corresponding features are
  84    always available.  If not, they may be available sometimes.
  85    The current values can be obtained with `sysconf'.
  86
  87    _POSIX_JOB_CONTROL           Job control is supported.
  88    _POSIX_SAVED_IDS             Processes have a saved set-user-ID
  89                                 and a saved set-group-ID.
  90    _POSIX_REALTIME_SIGNALS      Real-time, queued signals are supported.
  91    _POSIX_PRIORITY_SCHEDULING   Priority scheduling is supported.
  92    _POSIX_TIMERS                POSIX.4 clocks and timers are supported.
  93    _POSIX_ASYNCHRONOUS_IO       Asynchronous I/O is supported.
  94    _POSIX_PRIORITIZED_IO        Prioritized asynchronous I/O is supported.
  95    _POSIX_SYNCHRONIZED_IO       Synchronizing file data is supported.
  96    _POSIX_FSYNC                 The fsync function is present.
  97    _POSIX_MAPPED_FILES          Mapping of files to memory is supported.
  98    _POSIX_MEMLOCK               Locking of all memory is supported.
  99    _POSIX_MEMLOCK_RANGE         Locking of ranges of memory is supported.
 100    _POSIX_MEMORY_PROTECTION     Setting of memory protections is supported.
 101    _POSIX_MESSAGE_PASSING       POSIX.4 message queues are supported.
 102    _POSIX_SEMAPHORES            POSIX.4 counting semaphores are supported.
 103    _POSIX_SHARED_MEMORY_OBJECTS POSIX.4 shared memory objects are supported.
 104    _POSIX_PII                   Protocol-independent interfaces are supported.
 105    _POSIX_PII_XTI               XTI protocol-indep. interfaces are supported.
 106    _POSIX_PII_SOCKET            Socket protocol-indep. interfaces are supported.
 107    _POSIX_PII_INTERNET          Internet family of protocols supported.
 108    _POSIX_PII_INTERNET_STREAM   Connection-mode Internet protocol supported.
 109    _POSIX_PII_INTERNET_DGRAM    Connectionless Internet protocol supported.
 110    _POSIX_PII_OSI               ISO/OSI family of protocols supported.
 111    _POSIX_PII_OSI_COTS          Connection-mode ISO/OSI service supported.
 112    _POSIX_PII_OSI_CLTS          Connectionless ISO/OSI service supported.
 113    _POSIX_POLL                  Implementation supports `poll' function.
 114    _POSIX_SELECT                Implementation supports `select' and `pselect'.
 115
 116    _XOPEN_SHM                   Shared memory interface according to XPG4.2.
 117
 118    If any of these symbols is defined as -1, the corresponding option is not
 119    true for any file.  If any is defined as other than -1, the corresponding
 120    option is true for all files.  If a symbol is not defined at all, the value
 121    for a specific file can be obtained from `pathconf' and `fpathconf'.
 122
 123    _POSIX_CHOWN_RESTRICTED      Only the super user can use `chown' to change
 124                                 the owner of a file.  `chown' can only be used
 125                                 to change the group ID of a file to a group of
 126                                 which the calling process is a member.
 127    _POSIX_NO_TRUNC              Pathname components longer than
 128                                 NAME_MAX generate an error.
 129    _POSIX_VDISABLE              If defined, if the value of an element of the
 130                                 `c_cc' member of `struct termios' is
 131                                 _POSIX_VDISABLE, no character will have the
 132                                 effect associated with that element.
 133    _POSIX_SYNC_IO               Synchronous I/O may be performed.
 134    _POSIX_ASYNC_IO              Asynchronous I/O may be performed.
 135    _POSIX_PRIO_IO               Prioritized Asynchronous I/O may be performed.
 136
 137    Support for the Large File Support interface is not generally available.
 138    If it is available the following constants are defined to one.
 139    _LFS64_LARGEFILE             Low-level I/O supports large files.
 140    _LFS64_STDIO                 Standard I/O supports large files.
 141    */
 142
 143 #include <bits/posix_opt.h>
 144
 145
 146 /* Standard file descriptors.  */
 147 #define STDIN_FILENO    0       /* Standard input.  */
 148 #define STDOUT_FILENO   1       /* Standard output.  */
 149 #define STDERR_FILENO   2       /* Standard error output.  */
 150
 151
 152 /* All functions that are not declared anywhere else.  */
 153
 154 #include <bits/types.h>
 155
 156 #ifndef ssize_t
 157 typedef __ssize_t ssize_t;
 158 # define ssize_t ssize_t
 159 #endif
 160
 161 #define __need_size_t
 162 #define __need_NULL
 163 #include <stddef.h>
 164
 165 #ifdef __USE_UNIX98
 166 /* The Single Unix specification says that some more types are
 167    available here.  */
 168 # ifndef gid_t
 169 typedef __gid_t gid_t;
 170 #  define gid_t gid_t
 171 # endif
 172
 173 # ifndef uid_t
 174 typedef __uid_t uid_t;
 175 #  define uid_t uid_t
 176 # endif
 177
 178 # ifndef off_t
 179 #  ifndef __USE_FILE_OFFSET64
 180 typedef __off_t off_t;
 181 #  else
 182 typedef __off64_t off_t;
 183 #  endif
 184 #  define off_t off_t
 185 # endif
 186 # if defined __USE_LARGEFILE64 && !defined off64_t
 187 typedef __off64_t off64_t;
 188 #  define off64_t off64_t
 189 # endif
 190
 191 # ifndef pid_t
 192 typedef __pid_t pid_t;
 193 #  define pid_t pid_t
 194 # endif
 195 #endif  /* Unix98 */
 196
 197 /* Values for the second argument to access.
 198    These may be OR'd together.  */
 199 #define R_OK    4               /* Test for read permission.  */
 200 #define W_OK    2               /* Test for write permission.  */
 201 #define X_OK    1               /* Test for execute permission.  */
 202 #define F_OK    0               /* Test for existence.  */
 203
 204 /* Test for access to NAME using the real UID and real GID.  */
 205 extern int __access __P ((__const char *__name, int __type));
 206 extern int access __P ((__const char *__name, int __type));
 207
 208 #ifdef __USE_GNU
 209 /* Test for access to NAME using the effective UID and GID
 210    (as normal file operations use).  */
 211 extern int __euidaccess __P ((__const char *__name, int __type));
 212 extern int euidaccess __P ((__const char *__name, int __type));
 213 #endif
 214
 215
 216 /* Values for the WHENCE argument to lseek.  */
 217 #ifndef _STDIO_H                /* <stdio.h> has the same definitions.  */
 218 # define SEEK_SET       0       /* Seek from beginning of file.  */
 219 # define SEEK_CUR       1       /* Seek from current position.  */
 220 # define SEEK_END       2       /* Seek from end of file.  */
 221 #endif
 222
 223 #if defined __USE_BSD && !defined L_SET
 224 /* Old BSD names for the same constants; just for compatibility.  */
 225 # define L_SET          SEEK_SET
 226 # define L_INCR         SEEK_CUR
 227 # define L_XTND         SEEK_END
 228 #endif
 229
 230
 231 /* Move FD's file position to OFFSET bytes from the
 232    beginning of the file (if WHENCE is SEEK_SET),
 233    the current position (if WHENCE is SEEK_CUR),
 234    or the end of the file (if WHENCE is SEEK_END).
 235    Return the new file position.  */
 236 extern __off_t __lseek __P ((int __fd, __off_t __offset, int __whence));
 237 #ifndef __USE_FILE_OFFSET64
 238 extern __off_t lseek __P ((int __fd, __off_t __offset, int __whence));
 239 #else
 240 extern __off_t lseek __P ((int __fd, __off_t __offset, int __whence))
 241      __asm__ ("lseek64");
 242 #endif
 243 #ifdef __USE_LARGEFILE64
 244 extern __off64_t lseek64 __P ((int __fd, __off64_t __offset, int __whence));
 245 #endif
 246
 247 /* Close the file descriptor FD.  */
 248 extern int __close __P ((int __fd));
 249 extern int close __P ((int __fd));
 250
 251 /* Read NBYTES into BUF from FD.  Return the
 252    number read, -1 for errors or 0 for EOF.  */
 253 extern ssize_t __read __P ((int __fd, __ptr_t __buf, size_t __nbytes));
 254 extern ssize_t read __P ((int __fd, __ptr_t __buf, size_t __nbytes));
 255
 256 /* Write N bytes of BUF to FD.  Return the number written, or -1.  */
 257 extern ssize_t __write __P ((int __fd, __const __ptr_t __buf, size_t __n));
 258 extern ssize_t write __P ((int __fd, __const __ptr_t __buf, size_t __n));
 259
 260 #ifdef __USE_UNIX98
 261 /* Read NBYTES into BUF from FD at the given position OFFSET without
 262    changing the file pointer.  Return the number read, -1 for errors
 263    or 0 for EOF.  */
 264 # ifndef __USE_FILE_OFFSET64
 265 extern ssize_t pread __P ((int __fd, __ptr_t __buf, size_t __nbytes,
 266                            __off_t __offset));
 267 # else
 268 extern ssize_t pread __P ((int __fd, __ptr_t __buf, size_t __nbytes,
 269                            __off_t __offset)) __asm__ ("pread64");
 270 # endif
 271 # ifdef __USE_LARGEFILE64
 272 extern ssize_t pread64 __P ((int __fd, __ptr_t __buf, size_t __nbytes,
 273                              __off64_t __offset));
 274 # endif
 275
 276 /* Write N bytes of BUF to FD at the given position OFFSET without
 277    changing the file pointer.  Return the number written, or -1.  */
 278 # ifndef __USE_FILE_OFFSET64
 279 extern ssize_t pwrite __P ((int __fd, __const __ptr_t __buf, size_t __n,
 280                             __off_t __offset));
 281 # else
 282 extern ssize_t pwrite __P ((int __fd, __const __ptr_t __buf, size_t __n,
 283                             __off_t __offset)) __asm__ ("pwrite64");
 284 # endif
 285 # ifdef __USE_LARGEFILE64
 286 extern ssize_t pwrite64 __P ((int __fd, __const __ptr_t __buf, size_t __n,
 287                               __off64_t __offset));
 288 # endif
 289 #endif
 290
 291
 292 /* Create a one-way communication channel (pipe).
 293    If successful, two file descriptors are stored in PIPEDES;
 294    bytes written on PIPEDES[1] can be read from PIPEDES[0].
 295    Returns 0 if successful, -1 if not.  */
 296 extern int __pipe __P ((int __pipedes[2]));
 297 extern int pipe __P ((int __pipedes[2]));
 298
 299 /* Schedule an alarm.  In SECONDS seconds, the process will get a SIGALRM.
 300    If SECONDS is zero, any currently scheduled alarm will be cancelled.
 301    The function returns the number of seconds remaining until the last
 302    alarm scheduled would have signaled, or zero if there wasn't one.
 303    There is no return value to indicate an error, but you can set `errno'
 304    to 0 and check its value after calling `alarm', and this might tell you.
 305    The signal may come late due to processor scheduling.  */
 306 extern unsigned int alarm __P ((unsigned int __seconds));
 307
 308 /* Make the process sleep for SECONDS seconds, or until a signal arrives
 309    and is not ignored.  The function returns the number of seconds less
 310    than SECONDS which it actually slept (thus zero if it slept the full time).
 311    If a signal handler does a `longjmp' or modifies the handling of the
 312    SIGALRM signal while inside `sleep' call, the handling of the SIGALRM
 313    signal afterwards is undefined.  There is no return value to indicate
 314    error, but if `sleep' returns SECONDS, it probably didn't work.  */
 315 extern unsigned int __sleep __P ((unsigned int __seconds));
 316 extern unsigned int sleep __P ((unsigned int __seconds));
 317
 318 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 319 /* Set an alarm to go off (generating a SIGALRM signal) in VALUE
 320    microseconds.  If INTERVAL is nonzero, when the alarm goes off, the
 321    timer is reset to go off every INTERVAL microseconds thereafter.
 322    Returns the number of microseconds remaining before the alarm.  */
 323 extern unsigned int ualarm __P ((unsigned int __value,
 324                                  unsigned int __interval));
 325
 326 /* Sleep USECONDS microseconds, or until a signal arrives that is not blocked
 327    or ignored.  */
 328 extern void usleep __P ((unsigned int __useconds));
 329 #endif
 330
 331
 332 /* Suspend the process until a signal arrives.
 333    This always returns -1 and sets `errno' to EINTR.  */
 334 extern int pause __P ((void));
 335
 336
 337 /* Change the owner and group of FILE.  */
 338 extern int __chown __P ((__const char *__file,
 339                          __uid_t __owner, __gid_t __group));
 340 extern int chown __P ((__const char *__file,
 341                        __uid_t __owner, __gid_t __group));
 342
 343 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 344 /* Change the owner and group of the file that FD is open on.  */
 345 extern int __fchown __P ((int __fd,
 346                           __uid_t __owner, __gid_t __group));
 347 extern int fchown __P ((int __fd,
 348                         __uid_t __owner, __gid_t __group));
 349
 350
 351 /* Change owner and group of FILE, if it is a symbolic
 352    link the ownership of the symbolic link is changed.  */
 353 extern int __lchown __P ((__const char *__file, __uid_t __owner,
 354                           __gid_t __group));
 355 extern int lchown __P ((__const char *__file, __uid_t __owner,
 356                         __gid_t __group));
 357
 358 #endif /* Use BSD || X/Open Unix.  */
 359
 360 /* Change the process's working directory to PATH.  */
 361 extern int __chdir __P ((__const char *__path));
 362 extern int chdir __P ((__const char *__path));
 363
 364 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 365 /* Change the process's working directory to the one FD is open on.  */
 366 extern int __fchdir __P ((int __fd));
 367 extern int fchdir __P ((int __fd));
 368 #endif
 369
 370 /* Get the pathname of the current working directory,
 371    and put it in SIZE bytes of BUF.  Returns NULL if the
 372    directory couldn't be determined or SIZE was too small.
 373    If successful, returns BUF.  In GNU, if BUF is NULL,
 374    an array is allocated with `malloc'; the array is SIZE
 375    bytes long, unless SIZE == 0, in which case it is as
 376    big as necessary.  */
 377 extern char *__getcwd __P ((char *__buf, size_t __size));
 378 extern char *getcwd __P ((char *__buf, size_t __size));
 379
 380 #ifdef  __USE_GNU
 381 /* Return a malloc'd string containing the current directory name.
 382    If the environment variable `PWD' is set, and its value is correct,
 383    that value is used.  */
 384 extern char *get_current_dir_name __P ((void));
 385
 386 /* Get the canonical absolute name of the named directory, and put it in SIZE
 387    bytes of BUF.  Returns NULL if the directory couldn't be determined or
 388    SIZE was too small.  If successful, returns BUF.  In GNU, if BUF is
 389    NULL, an array is allocated with `malloc'; the array is SIZE bytes long,
 390    unless SIZE <= 0, in which case it is as big as necessary.  */
 391
 392 char *__canonicalize_directory_name_internal __P ((__const char *__thisdir,
 393                                                    char *__buf,
 394                                                    size_t __size));
 395 #endif
 396
 397 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 398 /* Put the absolute pathname of the current working directory in BUF.
 399    If successful, return BUF.  If not, put an error message in
 400    BUF and return NULL.  BUF should be at least PATH_MAX bytes long.  */
 401 extern char *getwd __P ((char *__buf));
 402 #endif
 403
 404
 405 /* Duplicate FD, returning a new file descriptor on the same file.  */
 406 extern int __dup __P ((int __fd));
 407 extern int dup __P ((int __fd));
 408
 409 /* Duplicate FD to FD2, closing FD2 and making it open on the same file.  */
 410 extern int __dup2 __P ((int __fd, int __fd2));
 411 extern int dup2 __P ((int __fd, int __fd2));
 412
 413 /* NULL-terminated array of "NAME=VALUE" environment variables.  */
 414 extern char **__environ;
 415 #ifdef __USE_GNU
 416 extern char **environ;
 417 #endif
 418
 419
 420 /* Replace the current process, executing PATH with arguments ARGV and
 421    environment ENVP.  ARGV and ENVP are terminated by NULL pointers.  */
 422 extern int __execve __P ((__const char *__path, char *__const __argv[],
 423                           char *__const __envp[]));
 424 extern int execve __P ((__const char *__path, char *__const __argv[],
 425                         char *__const __envp[]));
 426
 427 #ifdef __USE_GNU
 428 /* Execute the file FD refers to, overlaying the running program image.
 429    ARGV and ENVP are passed to the new program, as for `execve'.  */
 430 extern int fexecve __P ((int __fd,
 431                          char *__const __argv[], char *__const __envp[]));
 432
 433 #endif
 434
 435
 436 /* Execute PATH with arguments ARGV and environment from `environ'.  */
 437 extern int execv __P ((__const char *__path, char *__const __argv[]));
 438
 439 /* Execute PATH with all arguments after PATH until a NULL pointer,
 440    and the argument after that for environment.  */
 441 extern int execle __P ((__const char *__path, __const char *__arg, ...));
 442
 443 /* Execute PATH with all arguments after PATH until
 444    a NULL pointer and environment from `environ'.  */
 445 extern int execl __P ((__const char *__path, __const char *__arg, ...));
 446
 447 /* Execute FILE, searching in the `PATH' environment variable if it contains
 448    no slashes, with arguments ARGV and environment from `environ'.  */
 449 extern int execvp __P ((__const char *__file, char *__const __argv[]));
 450
 451 /* Execute FILE, searching in the `PATH' environment variable if
 452    it contains no slashes, with all arguments after FILE until a
 453    NULL pointer and environment from `environ'.  */
 454 extern int execlp __P ((__const char *__file, __const char *__arg, ...));
 455
 456
 457 #if defined __USE_MISC || defined __USE_XOPEN
 458 /* Add INC to priority of the current process.  */
 459 extern int nice __P ((int __inc));
 460 #endif
 461
 462
 463 /* Terminate program execution with the low-order 8 bits of STATUS.  */
 464 extern void _exit __P ((int __status)) __attribute__ ((__noreturn__));
 465
 466
 467 /* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf';
 468    the `_SC_*' symbols for the NAME argument to `sysconf';
 469    and the `_CS_*' symbols for the NAME argument to `confstr'.  */
 470 #include <bits/confname.h>
 471
 472 /* Get file-specific configuration information about PATH.  */
 473 extern long int __pathconf __P ((__const char *__path, int __name));
 474 extern long int pathconf __P ((__const char *__path, int __name));
 475
 476 /* Get file-specific configuration about descriptor FD.  */
 477 extern long int __fpathconf __P ((int __fd, int __name));
 478 extern long int fpathconf __P ((int __fd, int __name));
 479
 480 /* Get the value of the system variable NAME.  */
 481 extern long int __sysconf __P ((int __name));
 482 extern long int sysconf __P ((int __name));
 483
 484 #ifdef  __USE_POSIX2
 485 /* Get the value of the string-valued system variable NAME.  */
 486 extern size_t confstr __P ((int __name, char *__buf, size_t __len));
 487 #endif
 488
 489
 490 /* Get the process ID of the calling process.  */
 491 extern __pid_t __getpid __P ((void));
 492 extern __pid_t getpid __P ((void));
 493
 494 /* Get the process ID of the calling process's parent.  */
 495 extern __pid_t __getppid __P ((void));
 496 extern __pid_t getppid __P ((void));
 497
 498 /* Get the process group ID of the calling process.  */
 499 extern __pid_t getpgrp __P ((void));
 500 /* The old BSD definition is a bit different.  */
 501 extern __pid_t __bsd_getpgrp __P ((__pid_t __pid));
 502 #ifdef __FAVOR_BSD
 503 /* When we explicitely compile BSD sources use the BSD definition of this
 504    function.  Please note that we cannot use parameters for the macro.  */
 505 # define getpgrp __bsd_getpgrp
 506 #endif
 507
 508 /* Set the process group ID of the process matching PID to PGID.
 509    If PID is zero, the current process's process group ID is set.
 510    If PGID is zero, the process ID of the process is used.  */
 511 extern int __setpgid __P ((__pid_t __pid, __pid_t __pgid));
 512 extern int setpgid __P ((__pid_t __pid, __pid_t __pgid));
 513
 514 /* Get the process group ID of process PID.  */
 515 extern __pid_t __getpgid __P ((__pid_t __pid));
 516 #ifdef __USE_XOPEN_EXTENDED
 517 extern __pid_t getpgid __P ((__pid_t __pid));
 518 #endif
 519
 520 #if defined __USE_SVID || defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 521 /* Both System V and BSD have `setpgrp' functions, but with different
 522    calling conventions.  The BSD function is the same as POSIX.1 `setpgid'
 523    (above).  The System V function takes no arguments and puts the calling
 524    process in its on group like `setpgid (0, 0)'.
 525
 526    New programs should always use `setpgid' instead.
 527
 528    The default in GNU is to provide the System V function.  The BSD
 529    function is available under -D_BSD_SOURCE with -lbsd-compat.  */
 530
 531 # ifndef __FAVOR_BSD
 532
 533 /* Set the process group ID of the calling process to its own PID.
 534    This is exactly the same as `setpgid (0, 0)'.  */
 535 extern int setpgrp __P ((void));
 536
 537 # else
 538
 539 /* Another name for `setpgid' (above).  */
 540 extern int setpgrp __P ((__pid_t __pid, __pid_t __pgrp));
 541
 542 # endif /* Favor BSD.  */
 543 #endif  /* Use SVID or BSD.  */
 544
 545 /* Create a new session with the calling process as its leader.
 546    The process group IDs of the session and the calling process
 547    are set to the process ID of the calling process, which is returned.  */
 548 extern __pid_t __setsid __P ((void));
 549 extern __pid_t setsid __P ((void));
 550
 551 #ifdef __USE_XOPEN_EXTENDED
 552 /* Return the session ID of the given process.  */
 553 extern __pid_t getsid __P ((__pid_t __pid));
 554 #endif
 555
 556 /* Get the real user ID of the calling process.  */
 557 extern __uid_t __getuid __P ((void));
 558 extern __uid_t getuid __P ((void));
 559
 560 /* Get the effective user ID of the calling process.  */
 561 extern __uid_t __geteuid __P ((void));
 562 extern __uid_t geteuid __P ((void));
 563
 564 /* Get the real group ID of the calling process.  */
 565 extern __gid_t __getgid __P ((void));
 566 extern __gid_t getgid __P ((void));
 567
 568 /* Get the effective group ID of the calling process.  */
 569 extern __gid_t __getegid __P ((void));
 570 extern __gid_t getegid __P ((void));
 571
 572 /* If SIZE is zero, return the number of supplementary groups
 573    the calling process is in.  Otherwise, fill in the group IDs
 574    of its supplementary groups in LIST and return the number written.  */
 575 extern int __getgroups __P ((int __size, __gid_t __list[]));
 576 extern int getgroups __P ((int __size, __gid_t __list[]));
 577
 578 #ifdef  __USE_GNU
 579 /* Return nonzero iff the calling process is in group GID.  */
 580 extern int __group_member __P ((__gid_t __gid));
 581 extern int group_member __P ((__gid_t __gid));
 582 #endif
 583
 584 /* Set the user ID of the calling process to UID.
 585    If the calling process is the super-user, set the real
 586    and effective user IDs, and the saved set-user-ID to UID;
 587    if not, the effective user ID is set to UID.  */
 588 extern int __setuid __P ((__uid_t __uid));
 589 extern int setuid __P ((__uid_t __uid));
 590
 591 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 592 /* Set the real user ID of the calling process to RUID,
 593    and the effective user ID of the calling process to EUID.  */
 594 extern int __setreuid __P ((__uid_t __ruid, __uid_t __euid));
 595 extern int setreuid __P ((__uid_t __ruid, __uid_t __euid));
 596 #endif
 597
 598 #ifdef  __USE_BSD
 599 /* Set the effective user ID of the calling process to UID.  */
 600 extern int seteuid __P ((__uid_t __uid));
 601 #endif /* Use BSD.  */
 602
 603 /* Set the group ID of the calling process to GID.
 604    If the calling process is the super-user, set the real
 605    and effective group IDs, and the saved set-group-ID to GID;
 606    if not, the effective group ID is set to GID.  */
 607 extern int __setgid __P ((__gid_t __gid));
 608 extern int setgid __P ((__gid_t __gid));
 609
 610 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 611 /* Set the real group ID of the calling process to RGID,
 612    and the effective group ID of the calling process to EGID.  */
 613 extern int __setregid __P ((__gid_t __rgid, __gid_t __egid));
 614 extern int setregid __P ((__gid_t __rgid, __gid_t __egid));
 615 #endif
 616
 617 #ifdef __USE_BSD
 618 /* Set the effective group ID of the calling process to GID.  */
 619 extern int setegid __P ((__gid_t __gid));
 620 #endif /* Use BSD.  */
 621
 622
 623 /* Clone the calling process, creating an exact copy.
 624    Return -1 for errors, 0 to the new process,
 625    and the process ID of the new process to the old process.  */
 626 extern __pid_t __fork __P ((void));
 627 extern __pid_t fork __P ((void));
 628
 629 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 630 /* Clone the calling process, but without copying the whole address space.
 631    The the calling process is suspended until the the new process exits or is
 632    replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
 633    and the process ID of the new process to the old process.  */
 634 extern __pid_t __vfork __P ((void));
 635 extern __pid_t vfork __P ((void));
 636 #endif /* Use BSD. */
 637
 638
 639 /* Return the pathname of the terminal FD is open on, or NULL on errors.
 640    The returned storage is good only until the next call to this function.  */
 641 extern char *ttyname __P ((int __fd));
 642
 643 /* Store at most BUFLEN characters of the pathname of the terminal FD is
 644    open on in BUF.  Return 0 on success, otherwise an error number.  */
 645 extern int __ttyname_r __P ((int __fd, char *__buf, size_t __buflen));
 646 extern int ttyname_r __P ((int __fd, char *__buf, size_t __buflen));
 647
 648 /* Return 1 if FD is a valid descriptor associated
 649    with a terminal, zero if not.  */
 650 extern int __isatty __P ((int __fd));
 651 extern int isatty __P ((int __fd));
 652
 653 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 654 /* Return the index into the active-logins file (utmp) for
 655    the controlling terminal.  */
 656 extern int ttyslot __P ((void));
 657 #endif
 658
 659
 660 /* Make a link to FROM named TO.  */
 661 extern int __link __P ((__const char *__from, __const char *__to));
 662 extern int link __P ((__const char *__from, __const char *__to));
 663
 664 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 665 /* Make a symbolic link to FROM named TO.  */
 666 extern int __symlink __P ((__const char *__from, __const char *__to));
 667 extern int symlink __P ((__const char *__from, __const char *__to));
 668
 669 /* Read the contents of the symbolic link PATH into no more than
 670    LEN bytes of BUF.  The contents are not null-terminated.
 671    Returns the number of characters read, or -1 for errors.  */
 672 extern int __readlink __P ((__const char *__path, char *__buf, size_t __len));
 673 extern int readlink __P ((__const char *__path, char *__buf, size_t __len));
 674 #endif /* Use BSD.  */
 675
 676 /* Remove the link NAME.  */
 677 extern int __unlink __P ((__const char *__name));
 678 extern int unlink __P ((__const char *__name));
 679
 680 /* Remove the directory PATH.  */
 681 extern int __rmdir __P ((__const char *__path));
 682 extern int rmdir __P ((__const char *__path));
 683
 684
 685 /* Return the foreground process group ID of FD.  */
 686 extern __pid_t tcgetpgrp __P ((int __fd));
 687
 688 /* Set the foreground process group ID of FD set PGRP_ID.  */
 689 extern int tcsetpgrp __P ((int __fd, __pid_t __pgrp_id));
 690
 691
 692 /* Return the login name of the user.  */
 693 extern char *getlogin __P ((void));
 694 #ifdef __USE_REENTRANT
 695 /* Return at most NAME_LEN characters of the login name of the user in NAME.
 696    If it cannot be determined or some other error occurred, return the error
 697    code.  Otherwise return 0.  */
 698 extern int getlogin_r __P ((char *__name, size_t __name_len));
 699 #endif
 700
 701 #ifdef  __USE_BSD
 702 /* Set the login name returned by `getlogin'.  */
 703 extern int setlogin __P ((__const char *__name));
 704 #endif
 705
 706
 707 #ifdef  __USE_POSIX2
 708 /* Process the arguments in ARGV (ARGC of them, minus
 709    the program name) for options given in OPTS.
 710
 711    If `opterr' is zero, no messages are generated
 712    for invalid options; it defaults to 1.
 713    `optind' is the current index into ARGV.
 714    `optarg' is the argument corresponding to the current option.
 715    Return the option character from OPTS just read.
 716    Return -1 when there are no more options.
 717    For unrecognized options, or options missing arguments,
 718    `optopt' is set to the option letter, and '?' is returned.
 719
 720    The OPTS string is a list of characters which are recognized option
 721    letters, optionally followed by colons, specifying that that letter
 722    takes an argument, to be placed in `optarg'.
 723
 724    If a letter in OPTS is followed by two colons, its argument is optional.
 725    This behavior is specific to the GNU `getopt'.
 726
 727    The argument `--' causes premature termination of argument scanning,
 728    explicitly telling `getopt' that there are no more options.
 729
 730    If OPTS begins with `--', then non-option arguments
 731    are treated as arguments to the option '\0'.
 732    This behavior is specific to the GNU `getopt'.  */
 733 extern int getopt __P ((int __argc, char *__const * __argv,
 734                         __const char *__opts));
 735 extern int opterr;
 736 extern int optind;
 737 extern int optopt;
 738 extern char *optarg;
 739 #endif
 740
 741
 742 #if defined __USE_BSD || defined __USE_XOPEN
 743
 744 /* Put the name of the current host in no more than LEN bytes of NAME.
 745    The result is null-terminated if LEN is large enough for the full
 746    name and the terminator.  */
 747 extern int __gethostname __P ((char *__name, size_t __len));
 748 extern int gethostname __P ((char *__name, size_t __len));
 749
 750 /* Set the name of the current host to NAME, which is LEN bytes long.
 751    This call is restricted to the super-user.  */
 752 extern int sethostname __P ((__const char *__name, size_t __len));
 753
 754 /* Set the current machine's Internet number to ID.
 755    This call is restricted to the super-user.  */
 756 extern int sethostid __P ((long int __id));
 757
 758
 759 /* Get and set the NIS (aka YP) domain name, if any.
 760    Called just like `gethostname' and `sethostname'.
 761    The NIS domain name is usually the empty string when not using NIS.  */
 762 extern int getdomainname __P ((char *__name, size_t __len));
 763 extern int setdomainname __P ((__const char *__name, size_t __len));
 764
 765
 766 /* Make all changes done to FD actually appear on disk.  */
 767 extern int fsync __P ((int __fd));
 768
 769
 770 /* Revoke access permissions to all processes currently communicating
 771    with the control terminal, and then send a SIGHUP signal to the process
 772    group of the control terminal.  */
 773 extern int vhangup __P ((void));
 774
 775 /* Revoke the access of all descriptors currently open on FILE.  */
 776 extern int revoke __P ((__const char *__file));
 777
 778
 779 /* Enable statistical profiling, writing samples of the PC into at most
 780    SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
 781    is enabled, the system examines the user PC and increments
 782    SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536].  If SCALE is zero,
 783    disable profiling.  Returns zero on success, -1 on error.  */
 784 extern int __profil __P ((unsigned short int *__sample_buffer, size_t __size,
 785                           size_t __offset, unsigned int __scale));
 786 extern int profil __P ((unsigned short int *__sample_buffer, size_t __size,
 787                         size_t __offset, unsigned int __scale));
 788
 789
 790 /* Turn accounting on if NAME is an existing file.  The system will then write
 791    a record for each process as it terminates, to this file.  If NAME is NULL,
 792    turn accounting off.  This call is restricted to the super-user.  */
 793 extern int acct __P ((__const char *__name));
 794
 795 /* Make PATH be the root directory (the starting point for absolute paths).
 796    This call is restricted to the super-user.  */
 797 extern int chroot __P ((__const char *__path));
 798
 799
 800 /* Successive calls return the shells listed in `/etc/shells'.  */
 801 extern char *getusershell __P ((void));
 802 extern void endusershell __P ((void)); /* Discard cached info.  */
 803 extern void setusershell __P ((void)); /* Rewind and re-read the file.  */
 804
 805
 806 /* Prompt with PROMPT and read a string from the terminal without echoing.
 807    Uses /dev/tty if possible; otherwise stderr and stdin.  */
 808 extern char *getpass __P ((__const char *__prompt));
 809
 810 /* Put the program in the background, and dissociate from the controlling
 811    terminal.  If NOCHDIR is zero, do `chdir ("/")'.  If NOCLOSE is zero,
 812    redirects stdin, stdout, and stderr to /dev/null.  */
 813 extern int daemon __P ((int __nochdir, int __noclose));
 814
 815 #endif /* Use BSD || X/Open.  */
 816
 817
 818 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 819
 820 /* Return the current machine's Internet number.  */
 821 extern long int gethostid __P ((void));
 822
 823 /* Make all changes done to all files actually appear on disk.  */
 824 extern int sync __P ((void));
 825
 826
 827 /* Return the number of bytes in a page.  This is the system's page size,
 828    which is not necessarily the same as the hardware page size.  */
 829 extern int __getpagesize __P ((void));
 830 extern int getpagesize __P ((void));
 831
 832
 833 /* Truncate FILE to LENGTH bytes.  */
 834 #ifndef __USE_FILE_OFFSET64
 835 extern int truncate __P ((__const char *__file, __off_t __length));
 836 #else
 837 extern int truncate __P ((__const char *__file, __off_t __length))
 838      __asm__ ("truncate64");
 839 #endif
 840 #ifdef __USE_LARGEFILE64
 841 extern int truncate64 __P ((__const char *__file, __off64_t __length));
 842 #endif
 843
 844 /* Truncate the file FD is open on to LENGTH bytes.  */
 845 #ifndef __USE_FILE_OFFSET64
 846 extern int ftruncate __P ((int __fd, __off_t __length));
 847 #else
 848 extern int ftruncate __P ((int __fd, __off_t __length))
 849      __asm__ ("ftruncate64");
 850 #endif
 851 #ifdef __USE_LARGEFILE64
 852 extern int ftruncate64 __P ((int __fd, __off64_t __length));
 853 #endif
 854
 855
 856 /* Return the maximum number of file descriptors
 857    the current process could possibly have.  */
 858 extern int __getdtablesize __P ((void));
 859 extern int getdtablesize __P ((void));
 860
 861 #endif /* Use BSD || X/Open Unix.  */
 862
 863
 864 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 865
 866 /* Set the end of accessible data space (aka "the break") to ADDR.
 867    Returns zero on success and -1 for errors (with errno set).  */
 868 extern int __brk __P ((__ptr_t __addr));
 869 extern int brk __P ((__ptr_t __addr));
 870
 871 # define __need_ptrdiff_t
 872 # include <stddef.h>
 873
 874 /* Increase or decrease the end of accessible data space by DELTA bytes.
 875    If successful, returns the address the previous end of data space
 876    (i.e. the beginning of the new space, if DELTA > 0);
 877    returns (void *) -1 for errors (with errno set).  */
 878 extern __ptr_t __sbrk __P ((ptrdiff_t __delta));
 879 extern __ptr_t sbrk __P ((ptrdiff_t __delta));
 880 #endif
 881
 882
 883 #ifdef __USE_MISC
 884 /* Invoke `system call' number SYSNO, passing it the remaining arguments.
 885    This is completely system-dependent, and not often useful.
 886
 887    In Unix, `syscall' sets `errno' for all errors and most calls return -1
 888    for errors; in many systems you cannot pass arguments or get return
 889    values for all system calls (`pipe', `fork', and `getppid' typically
 890    among them).
 891
 892    In Mach, all system calls take normal arguments and always return an
 893    error code (zero for success).  */
 894 extern long int syscall __P ((long int __sysno, ...));
 895
 896 #endif  /* Use misc.  */
 897
 898
 899 #if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK
 900 /* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both
 901    files consistent.  Some systems have them there and some here, and some
 902    software depends on the macros being defined without including both.  */
 903
 904 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
 905    LEN is always relative to the current file position.
 906    The CMD argument is one of the following.  */
 907
 908 # define F_ULOCK 0      /* Unlock a previously locked region.  */
 909 # define F_LOCK  1      /* Lock a region for exclusive use.  */
 910 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
 911 # define F_TEST  3      /* Test a region for other processes locks.  */
 912
 913 # ifndef __USE_FILE_OFFSET64
 914 extern int lockf __P ((int __fd, int __cmd, __off_t __len));
 915 # else
 916 extern int lockf __P ((int __fd, int __cmd, __off_t __len))
 917      __asm__ ("lockf64");
 918 # endif
 919 # ifdef __USE_LARGEFILE64
 920 extern int lockf64 __P ((int __fd, int __cmd, __off64_t __len));
 921 # endif
 922 #endif /* Use misc and F_LOCK not already defined.  */
 923
 924
 925 #ifdef __USE_GNU
 926
 927 /* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno'
 928    set to EINTR.  */
 929
 930 # define TEMP_FAILURE_RETRY(expression) \
 931   (__extension__                                                              \
 932     ({ long int __result;                                                     \
 933        do __result = (long int) (expression);                                 \
 934        while (__result == -1L && errno == EINTR);                             \
 935        __result; }))                                                          \
 936
 937
 938 /* This variable is set nonzero at startup if the process's effective
 939    IDs differ from its real IDs, or it is otherwise indicated that
 940    extra security should be used.  When this is set the dynamic linker
 941    and some functions contained in the C library ignore various
 942    environment variables that normally affect them.  */
 943 extern int __libc_enable_secure;
 944
 945 #endif
 946
 947 #if defined __USE_POSIX199309 || defined __USE_UNIX98
 948 /* Synchronize at least the data part of a file with the underlying
 949    media.  */
 950 extern int fdatasync __P ((int __fildes));
 951 #endif /* Use POSIX199309 */
 952
 953
 954 /* XPG4.2 specifies that prototypes for the encryption functions must
 955    be defined here.  */
 956 #ifdef  __USE_XOPEN
 957 /* Encrypt at most 8 characters from KEY using salt to perturb DES.  */
 958 extern char *crypt __P ((__const char *__key, __const char *__salt));
 959
 960 /* Setup DES tables according KEY.  */
 961 extern void setkey __P ((__const char *__key));
 962
 963 /* Encrypt data in BLOCK in place if EDFLAG is zero; otherwise decrypt
 964    block in place.  */
 965 extern void encrypt __P ((char *__block, int __edflag));
 966
 967
 968 /* Swab pairs bytes in the first N bytes of the area pointed to by
 969    FROM and copy the result to TO.  The value of TO must not be in the
 970    range [FROM - N + 1, FROM - 1].  If N is odd the first byte in FROM
 971    is without partner.  */
 972 extern void swab __P ((__const __ptr_t __from, __ptr_t __to, ssize_t __n));
 973 #endif
 974
 975
 976 /* The Single Unix specification, version 2, demands these prototypes
 977    to be here.  They are also found in <stdio.h>.  */
 978 #ifdef __USE_UNIX98
 979 /* Return the name of the controlling terminal.  */
 980 extern char *ctermid __P ((char *__s));
 981
 982 /* Return the name of the current user.  */
 983 extern char *cuserid __P ((char *__s));
 984 #endif
 985
 986 __END_DECLS
 987
 988 #endif /* unistd.h  */