posix/unistd.h

   1 /* Copyright (C) 1991, 92, 93, 94, 95, 96 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
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 /*
  20  *      POSIX Standard: 2.10 Symbolic Constants         <unistd.h>
  21  */
  22
  23 #ifndef _UNISTD_H
  24
  25 #define _UNISTD_H       1
  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 IEEE Std 1003.1 as of August, 1988 and
  34    extended by P1003.1b (aka POSIX.4).  */
  35 #define _POSIX_VERSION  199309L
  36
  37 /* These are not #ifdef __USE_POSIX2 because they are
  38    in the theoretically application-owned namespace.  */
  39
  40 #define _POSIX2_C_VERSION       199912L /* Invalid until 1003.2 is done.  */
  41
  42 /* If defined, the implementation supports the
  43    C Language Bindings Option.  */
  44 #define _POSIX2_C_BIND  1
  45
  46 /* If defined, the implementation supports the
  47    C Language Development Utilities Option.  */
  48 #define _POSIX2_C_DEV   1
  49
  50 /* If defined, the implementation supports the
  51    Software Development Utilities Option.  */
  52 #define _POSIX2_SW_DEV  1
  53
  54 /* If defined, the implementation supports the
  55    creation of locales with the localedef utility.  */
  56 #define _POSIX2_LOCALEDEF       1
  57
  58
  59 /* Get values of POSIX options:
  60
  61    If these symbols are defined, the corresponding features are
  62    always available.  If not, they may be available sometimes.
  63    The current values can be obtained with `sysconf'.
  64
  65    _POSIX_JOB_CONTROL           Job control is supported.
  66    _POSIX_SAVED_IDS             Processes have a saved set-user-ID
  67                                 and a saved set-group-ID.
  68    _POSIX_REALTIME_SIGNALS      Real-time, queued signals are supported.
  69    _POSIX_PRIORITY_SCHEDULING   Priority scheduling is supported.
  70    _POSIX_TIMERS                POSIX.4 clocks and timers are supported.
  71    _POSIX_ASYNCHRONOUS_IO       Asynchronous I/O is supported.
  72    _POSIX_PRIORITIZED_IO        Prioritized asynchronous I/O is supported.
  73    _POSIX_SYNCHRONIZED_IO       Synchronizing file data is supported.
  74    _POSIX_FSYNC                 The fsync function is present.
  75    _POSIX_MAPPED_FILES          Mapping of files to memory is supported.
  76    _POSIX_MEMLOCK               Locking of all memory is supported.
  77    _POSIX_MEMLOCK_RANGE         Locking of ranges of memory is supported.
  78    _POSIX_MEMORY_PROTECTION     Setting of memory protections is supported.
  79    _POSIX_MESSAGE_PASSING       POSIX.4 message queues are supported.
  80    _POSIX_SEMAPHORES            POSIX.4 counting semaphores are supported.
  81    _POSIX_SHARED_MEMORY_OBJECTS POSIX.4 shared memory objects are supported.
  82
  83    If any of these symbols is defined as -1, the corresponding option is not
  84    true for any file.  If any is defined as other than -1, the corresponding
  85    option is true for all files.  If a symbol is not defined at all, the value
  86    for a specific file can be obtained from `pathconf' and `fpathconf'.
  87
  88    _POSIX_CHOWN_RESTRICTED      Only the super user can use `chown' to change
  89                                 the owner of a file.  `chown' can only be used
  90                                 to change the group ID of a file to a group of
  91                                 which the calling process is a member.
  92    _POSIX_NO_TRUNC              Pathname components longer than
  93                                 NAME_MAX generate an error.
  94    _POSIX_VDISABLE              If defined, if the value of an element of the
  95                                 `c_cc' member of `struct termios' is
  96                                 _POSIX_VDISABLE, no character will have the
  97                                 effect associated with that element.
  98    _POSIX_SYNC_IO               Synchronous I/O may be performed.
  99    _POSIX_ASYNC_IO              Asynchronous I/O may be performed.
 100    _POSIX_PRIO_IO               Prioritized Asynchronous I/O may be performed.
 101    */
 102
 103 #include <posix_opt.h>
 104
 105
 106 /* Standard file descriptors.  */
 107 #define STDIN_FILENO    0       /* Standard input.  */
 108 #define STDOUT_FILENO   1       /* Standard output.  */
 109 #define STDERR_FILENO   2       /* Standard error output.  */
 110
 111
 112 /* All functions that are not declared anywhere else.  */
 113
 114 #include <gnu/types.h>
 115
 116 #ifndef ssize_t
 117 #define ssize_t __ssize_t
 118 #endif
 119
 120 #define __need_size_t
 121 #define __need_NULL
 122 #include <stddef.h>
 123
 124
 125 /* Values for the second argument to access.
 126    These may be OR'd together.  */
 127 #define R_OK    4               /* Test for read permission.  */
 128 #define W_OK    2               /* Test for write permission.  */
 129 #define X_OK    1               /* Test for execute permission.  */
 130 #define F_OK    0               /* Test for existence.  */
 131
 132 /* Test for access to NAME using the real UID and real GID.  */
 133 extern int __access __P ((__const char *__name, int __type));
 134 extern int access __P ((__const char *__name, int __type));
 135
 136 #ifdef __USE_GNU
 137 /* Test for access to NAME using the effective UID and GID
 138    (as normal file operations use).  */
 139 extern int euidaccess __P ((__const char *__name, int __type));
 140 #endif
 141
 142
 143 /* Values for the WHENCE argument to lseek.  */
 144 #ifndef _STDIO_H                /* <stdio.h> has the same definitions.  */
 145 #define SEEK_SET        0       /* Seek from beginning of file.  */
 146 #define SEEK_CUR        1       /* Seek from current position.  */
 147 #define SEEK_END        2       /* Seek from end of file.  */
 148 #endif
 149
 150 #if defined (__USE_BSD) && !defined (L_SET)
 151 /* Old BSD names for the same constants; just for compatibility.  */
 152 #define L_SET           SEEK_SET
 153 #define L_INCR          SEEK_CUR
 154 #define L_XTND          SEEK_END
 155 #endif
 156
 157
 158 /* Move FD's file position to OFFSET bytes from the
 159    beginning of the file (if WHENCE is SEEK_SET),
 160    the current position (if WHENCE is SEEK_CUR),
 161    or the end of the file (if WHENCE is SEEK_END).
 162    Return the new file position.  */
 163 extern __off_t __lseek __P ((int __fd, __off_t __offset, int __whence));
 164 extern __off_t lseek __P ((int __fd, __off_t __offset, int __whence));
 165
 166 /* Close the file descriptor FD.  */
 167 extern int __close __P ((int __fd));
 168 extern int close __P ((int __fd));
 169
 170 /* Read NBYTES into BUF from FD.  Return the
 171    number read, -1 for errors or 0 for EOF.  */
 172 extern ssize_t __read __P ((int __fd, __ptr_t __buf, size_t __nbytes));
 173 extern ssize_t read __P ((int __fd, __ptr_t __buf, size_t __nbytes));
 174
 175 /* Write N bytes of BUF to FD.  Return the number written, or -1.  */
 176 extern ssize_t __write __P ((int __fd, __const __ptr_t __buf, size_t __n));
 177 extern ssize_t write __P ((int __fd, __const __ptr_t __buf, size_t __n));
 178
 179
 180 /* Create a one-way communication channel (pipe).
 181    If successul, two file descriptors are stored in PIPEDES;
 182    bytes written on PIPEDES[1] can be read from PIPEDES[0].
 183    Returns 0 if successful, -1 if not.  */
 184 extern int __pipe __P ((int __pipedes[2]));
 185 extern int pipe __P ((int __pipedes[2]));
 186
 187 /* Schedule an alarm.  In SECONDS seconds, the process will get a SIGALRM.
 188    If SECONDS is zero, any currently scheduled alarm will be cancelled.
 189    The function returns the number of seconds remaining until the last
 190    alarm scheduled would have signaled, or zero if there wasn't one.
 191    There is no return value to indicate an error, but you can set `errno'
 192    to 0 and check its value after calling `alarm', and this might tell you.
 193    The signal may come late due to processor scheduling.  */
 194 extern unsigned int alarm __P ((unsigned int __seconds));
 195
 196 /* Make the process sleep for SECONDS seconds, or until a signal arrives
 197    and is not ignored.  The function returns the number of seconds less
 198    than SECONDS which it actually slept (thus zero if it slept the full time).
 199    If a signal handler does a `longjmp' or modifies the handling of the
 200    SIGALRM signal while inside `sleep' call, the handling of the SIGALRM
 201    signal afterwards is undefined.  There is no return value to indicate
 202    error, but if `sleep' returns SECONDS, it probably didn't work.  */
 203 extern unsigned int sleep __P ((unsigned int __seconds));
 204
 205 #ifdef __USE_BSD
 206 /* Sleep USECONDS microseconds, or until a signal arrives that is not blocked
 207    or ignored.  Return value is not necessarily useful.  */
 208 extern unsigned int usleep __P ((unsigned __useconds));
 209 #endif
 210
 211
 212 /* Suspend the process until a signal arrives.
 213    This always returns -1 and sets `errno' to EINTR.  */
 214 extern int pause __P ((void));
 215
 216
 217 /* Change the owner and group of FILE.  */
 218 extern int __chown __P ((__const char *__file,
 219                          __uid_t __owner, __gid_t __group));
 220 extern int chown __P ((__const char *__file,
 221                        __uid_t __owner, __gid_t __group));
 222
 223 #ifdef  __USE_BSD
 224 /* Change the owner and group of the file that FD is open on.  */
 225 extern int __fchown __P ((int __fd,
 226                           __uid_t __owner, __gid_t __group));
 227 extern int fchown __P ((int __fd,
 228                         __uid_t __owner, __gid_t __group));
 229 #endif /* Use BSD.  */
 230
 231 /* Change the process's working directory to PATH.  */
 232 extern int __chdir __P ((__const char *__path));
 233 extern int chdir __P ((__const char *__path));
 234
 235 #ifdef __USE_BSD
 236 /* Change the process's working directory to the one FD is open on.  */
 237 extern int fchdir __P ((int __fd));
 238 #endif
 239
 240 /* Get the pathname of the current working directory,
 241    and put it in SIZE bytes of BUF.  Returns NULL if the
 242    directory couldn't be determined or SIZE was too small.
 243    If successful, returns BUF.  In GNU, if BUF is NULL,
 244    an array is allocated with `malloc'; the array is SIZE
 245    bytes long, unless SIZE <= 0, in which case it is as
 246    big as necessary.  */
 247 extern char *__getcwd __P ((char *__buf, size_t __size));
 248 extern char *getcwd __P ((char *__buf, size_t __size));
 249
 250 #ifdef  __USE_GNU
 251 /* Return a malloc'd string containing the current directory name.
 252    If the environment variable `PWD' is set, and its value is correct,
 253    that value is used.  */
 254 extern char *get_current_dir_name __P ((void));
 255
 256 /* Get the canonical absolute name of the named directory, and put it in SIZE
 257    bytes of BUF.  Returns NULL if the directory couldn't be determined or
 258    SIZE was too small.  If successful, returns BUF.  In GNU, if BUF is
 259    NULL, an array is allocated with `malloc'; the array is SIZE bytes long,
 260    unless SIZE <= 0, in which case it is as big as necessary.  */
 261
 262 char *__canonicalize_directory_name_internal __P ((const char *__thisdir,
 263                                                    char *__buf,
 264                                                    size_t __size));
 265 #endif
 266
 267 #ifdef  __USE_BSD
 268 /* Put the absolute pathname of the current working directory in BUF.
 269    If successful, return BUF.  If not, put an error message in
 270    BUF and return NULL.  BUF should be at least PATH_MAX bytes long.  */
 271 extern char *getwd __P ((char *__buf));
 272 #endif
 273
 274
 275 /* Duplicate FD, returning a new file descriptor on the same file.  */
 276 extern int __dup __P ((int __fd));
 277 extern int dup __P ((int __fd));
 278
 279 /* Duplicate FD to FD2, closing FD2 and making it open on the same file.  */
 280 extern int __dup2 __P ((int __fd, int __fd2));
 281 extern int dup2 __P ((int __fd, int __fd2));
 282
 283 /* NULL-terminated array of "NAME=VALUE" environment variables.  */
 284 extern char **__environ;
 285 extern char **environ;
 286
 287
 288 /* Replace the current process, executing PATH with arguments ARGV and
 289    environment ENVP.  ARGV and ENVP are terminated by NULL pointers.  */
 290 extern int __execve __P ((__const char *__path, char *__const __argv[],
 291                           char *__const __envp[]));
 292 extern int execve __P ((__const char *__path, char *__const __argv[],
 293                         char *__const __envp[]));
 294
 295 #ifdef __USE_GNU
 296 /* Execute the file FD refers to, overlaying the running program image.
 297    ARGV and ENVP are passed to the new program, as for `execve'.  */
 298 extern int fexecve __P ((int __fd,
 299                          char *const __argv[], char *const __envp[]));
 300
 301 #endif
 302
 303
 304 /* Execute PATH with arguments ARGV and environment from `environ'.  */
 305 extern int execv __P ((__const char *__path, char *__const __argv[]));
 306
 307 /* Execute PATH with all arguments after PATH until a NULL pointer,
 308    and the argument after that for environment.  */
 309 extern int execle __P ((__const char *__path, __const char *__arg,...));
 310
 311 /* Execute PATH with all arguments after PATH until
 312    a NULL pointer and environment from `environ'.  */
 313 extern int execl __P ((__const char *__path, __const char *__arg,...));
 314
 315 /* Execute FILE, searching in the `PATH' environment variable if it contains
 316    no slashes, with arguments ARGV and environment from `environ'.  */
 317 extern int execvp __P ((__const char *__file, char *__const __argv[]));
 318
 319 /* Execute FILE, searching in the `PATH' environment variable if
 320    it contains no slashes, with all arguments after FILE until a
 321    NULL pointer and environment from `environ'.  */
 322 extern int execlp __P ((__const char *__file, ...));
 323
 324
 325 /* Terminate program execution with the low-order 8 bits of STATUS.  */
 326 extern void _exit __P ((int __status)) __attribute__ ((__noreturn__));
 327
 328
 329 /* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf';
 330    the `_SC_*' symbols for the NAME argument to `sysconf';
 331    and the `_CS_*' symbols for the NAME argument to `confstr'.  */
 332 #include <confname.h>
 333
 334 /* Get file-specific configuration information about PATH.  */
 335 extern long int __pathconf __P ((__const char *__path, int __name));
 336 extern long int pathconf __P ((__const char *__path, int __name));
 337
 338 /* Get file-specific configuration about descriptor FD.  */
 339 extern long int __fpathconf __P ((int __fd, int __name));
 340 extern long int fpathconf __P ((int __fd, int __name));
 341
 342 /* Get the value of the system variable NAME.  */
 343 extern long int __sysconf __P ((int __name));
 344 extern long int sysconf __P ((int __name));
 345
 346 #ifdef  __USE_POSIX2
 347 /* Get the value of the string-valued system variable NAME.  */
 348 extern size_t confstr __P ((int __name, char *__buf, size_t __len));
 349 #endif
 350
 351
 352 /* Get the process ID of the calling process.  */
 353 extern __pid_t __getpid __P ((void));
 354 extern __pid_t getpid __P ((void));
 355
 356 /* Get the process ID of the calling process's parent.  */
 357 extern __pid_t __getppid __P ((void));
 358 extern __pid_t getppid __P ((void));
 359
 360 /* Get the process group ID of the calling process.  */
 361 extern __pid_t getpgrp __P ((void));
 362
 363 /* Set the process group ID of the process matching PID to PGID.
 364    If PID is zero, the current process's process group ID is set.
 365    If PGID is zero, the process ID of the process is used.  */
 366 extern int setpgid __P ((__pid_t __pid, __pid_t __pgid));
 367
 368 /* Get the process group ID of process PID.  */
 369 extern __pid_t __getpgid __P ((__pid_t __pid));
 370 #ifdef __USE_GNU
 371 extern __pid_t getpgid __P ((__pid_t __pid));
 372 #endif
 373
 374 #if defined (__USE_SVID) || defined (__USE_BSD)
 375 /* Both System V and BSD have `setpgrp' functions, but with different
 376    calling conventions.  The BSD function is the same as POSIX.1 `setpgid'
 377    (above).  The System V function takes no arguments and puts the calling
 378    process in its on group like `setpgid (0, 0)'.
 379
 380    New programs should always use `setpgid' instead.
 381
 382    The default in GNU is to provide the System V function.  The BSD
 383    function is available under -D_BSD_SOURCE with -lbsd-compat.  */
 384
 385 #ifndef __FAVOR_BSD
 386
 387 /* Set the process group ID of the calling process to its own PID.
 388    This is exactly the same as `setpgid (0, 0)'.  */
 389 extern int setpgrp __P ((void));
 390
 391 #else
 392
 393 /* Another name for `setpgid' (above).  */
 394 extern int setpgrp __P ((__pid_t __pid, __pid_t __pgrp));
 395
 396 #endif  /* Favor BSD.  */
 397 #endif  /* Use SVID or BSD.  */
 398
 399 /* Create a new session with the calling process as its leader.
 400    The process group IDs of the session and the calling process
 401    are set to the process ID of the calling process, which is returned.  */
 402 extern __pid_t __setsid __P ((void));
 403 extern __pid_t setsid __P ((void));
 404
 405 #ifdef __USE_GNU
 406 /* Return the session ID of the given process.  */
 407 extern __pid_t getsid __P ((__pid_t));
 408 #endif
 409
 410 /* Get the real user ID of the calling process.  */
 411 extern __uid_t __getuid __P ((void));
 412 extern __uid_t getuid __P ((void));
 413
 414 /* Get the effective user ID of the calling process.  */
 415 extern __uid_t __geteuid __P ((void));
 416 extern __uid_t geteuid __P ((void));
 417
 418 /* Get the real group ID of the calling process.  */
 419 extern __gid_t __getgid __P ((void));
 420 extern __gid_t getgid __P ((void));
 421
 422 /* Get the effective group ID of the calling process.  */
 423 extern __gid_t __getegid __P ((void));
 424 extern __gid_t getegid __P ((void));
 425
 426 /* If SIZE is zero, return the number of supplementary groups
 427    the calling process is in.  Otherwise, fill in the group IDs
 428    of its supplementary groups in LIST and return the number written.  */
 429 extern int __getgroups __P ((int __size, __gid_t __list[]));
 430 extern int getgroups __P ((int __size, __gid_t __list[]));
 431
 432 #ifdef  __USE_GNU
 433 /* Return nonzero iff the calling process is in group GID.  */
 434 extern int __group_member __P ((__gid_t __gid));
 435 extern int group_member __P ((__gid_t __gid));
 436 #endif
 437
 438 /* Set the user ID of the calling process to UID.
 439    If the calling process is the super-user, set the real
 440    and effective user IDs, and the saved set-user-ID to UID;
 441    if not, the effective user ID is set to UID.  */
 442 extern int __setuid __P ((__uid_t __uid));
 443 extern int setuid __P ((__uid_t __uid));
 444
 445 #ifdef  __USE_BSD
 446 /* Set the real user ID of the calling process to RUID,
 447    and the effective user ID of the calling process to EUID.  */
 448 extern int __setreuid __P ((__uid_t __ruid, __uid_t __euid));
 449 extern int setreuid __P ((__uid_t __ruid, __uid_t __euid));
 450
 451 /* Set the effective user ID of the calling process to UID.  */
 452 extern int seteuid __P ((__uid_t __uid));
 453 #endif /* Use BSD.  */
 454
 455 /* Set the group ID of the calling process to GID.
 456    If the calling process is the super-user, set the real
 457    and effective group IDs, and the saved set-group-ID to GID;
 458    if not, the effective group ID is set to GID.  */
 459 extern int __setgid __P ((__gid_t __gid));
 460 extern int setgid __P ((__gid_t __gid));
 461
 462 #ifdef  __USE_BSD
 463 /* Set the real group ID of the calling process to RGID,
 464    and the effective group ID of the calling process to EGID.  */
 465 extern int __setregid __P ((__gid_t __rgid, __gid_t __egid));
 466 extern int setregid __P ((__gid_t __rgid, __gid_t __egid));
 467
 468 /* Set the effective group ID of the calling process to GID.  */
 469 extern int setegid __P ((__gid_t __gid));
 470 #endif /* Use BSD.  */
 471
 472
 473 /* Clone the calling process, creating an exact copy.
 474    Return -1 for errors, 0 to the new process,
 475    and the process ID of the new process to the old process.  */
 476 extern __pid_t __fork __P ((void));
 477 extern __pid_t fork __P ((void));
 478
 479 #ifdef  __USE_BSD
 480 /* Clone the calling process, but without copying the whole address space.
 481    The the calling process is suspended until the the new process exits or is
 482    replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
 483    and the process ID of the new process to the old process.  */
 484 extern __pid_t __vfork __P ((void));
 485 extern __pid_t vfork __P ((void));
 486 #endif /* Use BSD. */
 487
 488
 489 /* Return the pathname of the terminal FD is open on, or NULL on errors.
 490    The returned storage is good only until the next call to this function.  */
 491 extern char *ttyname __P ((int __fd));
 492 #ifdef __USE_REENTRANT
 493 /* Store at most BUFLEN characters of the pathname of the terminal FD is
 494    open on in BUF.  Return 0 on success, -1 otherwise.  */
 495 extern int ttyname_r __P ((int __fd, char *__buf, int __buflen));
 496 #endif
 497
 498 /* Return 1 if FD is a valid descriptor associated
 499    with a terminal, zero if not.  */
 500 extern int __isatty __P ((int __fd));
 501 extern int isatty __P ((int __fd));
 502
 503 #ifdef __USE_BSD
 504 /* Return the index into the active-logins file (utmp) for
 505    the controlling terminal.  */
 506 extern int ttyslot __P ((void));
 507 #endif
 508
 509
 510 /* Make a link to FROM named TO.  */
 511 extern int __link __P ((__const char *__from, __const char *__to));
 512 extern int link __P ((__const char *__from, __const char *__to));
 513
 514 #ifdef  __USE_BSD
 515 /* Make a symbolic link to FROM named TO.  */
 516 extern int __symlink __P ((__const char *__from, __const char *__to));
 517 extern int symlink __P ((__const char *__from, __const char *__to));
 518
 519 /* Read the contents of the symbolic link PATH into no more than
 520    LEN bytes of BUF.  The contents are not null-terminated.
 521    Returns the number of characters read, or -1 for errors.  */
 522 extern int __readlink __P ((__const char *__path, char *__buf, size_t __len));
 523 extern int readlink __P ((__const char *__path, char *__buf, size_t __len));
 524 #endif /* Use BSD.  */
 525
 526 /* Remove the link NAME.  */
 527 extern int __unlink __P ((__const char *__name));
 528 extern int unlink __P ((__const char *__name));
 529
 530 /* Remove the directory PATH.  */
 531 extern int __rmdir __P ((__const char *__path));
 532 extern int rmdir __P ((__const char *__path));
 533
 534
 535 /* Return the foreground process group ID of FD.  */
 536 extern __pid_t tcgetpgrp __P ((int __fd));
 537
 538 /* Set the foreground process group ID of FD set PGRP_ID.  */
 539 extern int tcsetpgrp __P ((int __fd, __pid_t __pgrp_id));
 540
 541
 542 /* Return the login name of the user.  */
 543 extern char *getlogin __P ((void));
 544 #ifdef __USE_REENTRANT
 545 /* Return at most NAME_LEN characters of the login name of the user in NAME.
 546    If it cannot be determined or some other error occured, return the error
 547    code.  Otherwise return 0.  */
 548 extern int getlogin_r __P ((char *__name, size_t __name_len));
 549 #endif
 550
 551 #ifdef  __USE_BSD
 552 /* Set the login name returned by `getlogin'.  */
 553 extern int setlogin __P ((__const char *__name));
 554 #endif
 555
 556
 557 #ifdef  __USE_POSIX2
 558 /* Process the arguments in ARGV (ARGC of them, minus
 559    the program name) for options given in OPTS.
 560
 561    If `opterr' is zero, no messages are generated
 562    for invalid options; it defaults to 1.
 563    `optind' is the current index into ARGV.
 564    `optarg' is the argument corresponding to the current option.
 565    Return the option character from OPTS just read.
 566    Return -1 when there are no more options.
 567    For unrecognized options, or options missing arguments,
 568    `optopt' is set to the option letter, and '?' is returned.
 569
 570    The OPTS string is a list of characters which are recognized option
 571    letters, optionally followed by colons, specifying that that letter
 572    takes an argument, to be placed in `optarg'.
 573
 574    If a letter in OPTS is followed by two colons, its argument is optional.
 575    This behavior is specific to the GNU `getopt'.
 576
 577    The argument `--' causes premature termination of argument scanning,
 578    explicitly telling `getopt' that there are no more options.
 579
 580    If OPTS begins with `--', then non-option arguments
 581    are treated as arguments to the option '\0'.
 582    This behavior is specific to the GNU `getopt'.  */
 583 extern int getopt __P ((int __argc, char *__const * __argv,
 584                         __const char *__opts));
 585 extern int opterr;
 586 extern int optind;
 587 extern int optopt;
 588 extern char *optarg;
 589 #endif
 590
 591
 592 #ifdef  __USE_BSD
 593
 594 /* Put the name of the current host in no more than LEN bytes of NAME.
 595    The result is null-terminated if LEN is large enough for the full
 596    name and the terminator.  */
 597 extern int __gethostname __P ((char *__name, size_t __len));
 598 extern int gethostname __P ((char *__name, size_t __len));
 599
 600 /* Set the name of the current host to NAME, which is LEN bytes long.
 601    This call is restricted to the super-user.  */
 602 extern int sethostname __P ((__const char *__name, size_t __len));
 603
 604 /* Return the current machine's Internet number.  */
 605 extern long int gethostid __P ((void));
 606
 607 /* Set the current machine's Internet number to ID.
 608    This call is restricted to the super-user.  */
 609 extern int sethostid __P ((long int __id));
 610
 611
 612 /* Return the number of bytes in a page.  This is the system's page size,
 613    which is not necessarily the same as the hardware page size.  */
 614 extern size_t __getpagesize __P ((void));
 615 extern size_t getpagesize __P ((void));
 616
 617
 618 /* Return the maximum number of file descriptors
 619    the current process could possibly have.  */
 620 extern int __getdtablesize __P ((void));
 621 extern int getdtablesize __P ((void));
 622
 623
 624 /* Truncate FILE to LENGTH bytes.  */
 625 extern int truncate __P ((__const char *__file, __off_t __length));
 626
 627 /* Truncate the file FD is open on to LENGTH bytes.  */
 628 extern int ftruncate __P ((int __fd, __off_t __length));
 629
 630
 631 /* Make all changes done to FD actually appear on disk.  */
 632 extern int fsync __P ((int __fd));
 633
 634 /* Make all changes done to all files actually appear on disk.  */
 635 extern int sync __P ((void));
 636
 637
 638 /* Revoke access permissions to all processes currently communicating
 639    with the control terminal, and then send a SIGHUP signal to the process
 640    group of the control terminal.  */
 641 extern int vhangup __P ((void));
 642
 643 /* Revoke the access of all descriptors currently open on FILE.  */
 644 extern int revoke __P ((const char *__file));
 645
 646
 647 /* Enable statistical profiling, writing samples of the PC into at most
 648    SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
 649    is enabled, the system examines the user PC and increments
 650    SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536].  If SCALE is zero,
 651    disable profiling.  Returns zero on success, -1 on error.  */
 652 extern int profil __P ((unsigned short int *__sample_buffer, size_t __size,
 653                         size_t __offset, unsigned int __scale));
 654
 655
 656 /* Turn accounting on if NAME is an existing file.  The system will then write
 657    a record for each process as it terminates, to this file.  If NAME is NULL,
 658    turn accounting off.  This call is restricted to the super-user.  */
 659 extern int acct __P ((__const char *__name));
 660
 661 /* Make PATH be the root directory (the starting point for absolute paths).
 662    This call is restricted to the super-user.  */
 663 extern int chroot __P ((__const char *__path));
 664
 665 /* Make the block special device PATH available to the system for swapping.
 666    This call is restricted to the super-user.  */
 667 extern int swapon __P ((__const char *__path));
 668
 669 /* Stop using block special device PATH for swapping.  */
 670 extern int swapoff __P ((__const char *__path));
 671
 672
 673 /* Successive calls return the shells listed in `/etc/shells'.  */
 674 extern char *getusershell __P ((void));
 675 extern void endusershell __P ((void)); /* Discard cached info.  */
 676 extern void setusershell __P ((void)); /* Rewind and re-read the file.  */
 677
 678
 679 /* Prompt with PROMPT and read a string from the terminal without echoing.
 680    Uses /dev/tty if possible; otherwise stderr and stdin.  */
 681 extern char *getpass __P ((const char *__prompt));
 682
 683 /* Put the program in the background, and dissociate from the controlling
 684    terminal.  If NOCHDIR is zero, do `chdir ("/")'.  If NOCLOSE is zero,
 685    redirects stdin, stdout, and stderr to /dev/null.  */
 686 extern int daemon __P ((int __nochdir, int __noclose));
 687
 688 #endif /* Use BSD.  */
 689
 690
 691 #ifdef __USE_MISC
 692
 693 /* Generate a unique temporary file name from TEMPLATE.
 694    The last six characters of TEMPLATE must be "XXXXXX";
 695    they are replaced with a string that makes the file name unique.
 696    Returns TEMPLATE, or a null pointer if it cannot get a unique file name.  */
 697 extern char *mktemp __P ((char *__template));
 698
 699 /* Generate a unique temporary file name from TEMPLATE.
 700    The last six characters of TEMPLATE must be "XXXXXX";
 701    they are replaced with a string that makes the filename unique.
 702    Returns a file descriptor open on the file for reading and writing,
 703    or -1 if it cannot create a uniquely-named file.  */
 704 extern int mkstemp __P ((char *__template));
 705
 706
 707 /* Set the end of accessible data space (aka "the break") to ADDR.
 708    Returns zero on success and -1 for errors (with errno set).  */
 709 extern int __brk __P ((__ptr_t __addr));
 710 extern int brk __P ((__ptr_t __addr));
 711
 712 #define __need_ptrdiff_t
 713 #include <stddef.h>
 714
 715 /* Increase or decrease the end of accessible data space by DELTA bytes.
 716    If successful, returns the address the previous end of data space
 717    (i.e. the beginning of the new space, if DELTA > 0);
 718    returns (void *) -1 for errors (with errno set).  */
 719 extern __ptr_t __sbrk __P ((ptrdiff_t __delta));
 720 extern __ptr_t sbrk __P ((ptrdiff_t __delta));
 721
 722
 723 /* Invoke `system call' number SYSNO, passing it the remaining arguments.
 724    This is completely system-dependent, and not often useful.
 725
 726    In Unix, `syscall' sets `errno' for all errors and most calls return -1
 727    for errors; in many systems you cannot pass arguments or get return
 728    values for all system calls (`pipe', `fork', and `getppid' typically
 729    among them).
 730
 731    In Mach, all system calls take normal arguments and always return an
 732    error code (zero for success).  */
 733 extern int syscall __P ((int __sysno, ...));
 734
 735 #endif  /* Use misc.  */
 736
 737
 738 #if defined (__USE_MISC) && !defined (F_LOCK)
 739 /* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both
 740    files consistent.  Some systems have them there and some here, and some
 741    software depends on the macros being defined without including both.  */
 742
 743 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
 744    LEN is always relative to the current file position.
 745    The CMD argument is one of the following.  */
 746
 747 #define F_ULOCK 0       /* Unlock a previously locked region.  */
 748 #define F_LOCK  1       /* Lock a region for exclusive use.  */
 749 #define F_TLOCK 2       /* Test and lock a region for exclusive use.  */
 750 #define F_TEST  3       /* Test a region for other processes locks.  */
 751
 752 extern int lockf __P ((int __fd, int __cmd, __off_t __len));
 753 #endif /* Use misc and F_LOCK not already defined.  */
 754
 755
 756 #ifdef __USE_GNU
 757
 758 /* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno'
 759    set to EINTR.  */
 760
 761 #define TEMP_FAILURE_RETRY(expression) \
 762   ({ long int __result;                                                       \
 763        do __result = (long int) (expression);                                 \
 764        while (__result == -1L && errno == EINTR);                             \
 765        __result; })
 766
 767 #endif
 768
 769 #ifdef __USE_POSIX
 770 /* Synchronize at least the data part of a file with the underlying
 771    media.  */
 772 extern int fdatasync __P ((int __fildes));
 773 #endif /* Use POSIX */
 774
 775 __END_DECLS
 776
 777 #endif /* unistd.h  */