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 /* The utilities on GNU systems also correspond to this version.  */
  44 #define _POSIX2_VERSION 199209L
  45
  46 /* If defined, the implementation supports the
  47    C Language Bindings Option.  */
  48 #define _POSIX2_C_BIND  1
  49
  50 /* If defined, the implementation supports the
  51    C Language Development Utilities Option.  */
  52 #define _POSIX2_C_DEV   1
  53
  54 /* If defined, the implementation supports the
  55    Software Development Utilities Option.  */
  56 #define _POSIX2_SW_DEV  1
  57
  58 /* If defined, the implementation supports the
  59    creation of locales with the localedef utility.  */
  60 #define _POSIX2_LOCALEDEF       1
  61
  62 /* X/Open version number to which the library conforms.  It is selectable.  */
  63 #ifdef __USE_UNIX98
  64 # define _XOPEN_VERSION 500
  65 #else
  66 # define _XOPEN_VERSION 4
  67 #endif
  68
  69 /* Commands and utilities from XPG4 are available.  */
  70 #define _XOPEN_XCU_VERSION      4
  71
  72 /* We are compatible with the old published standards as well.  */
  73 #define _XOPEN_XPG2     1
  74 #define _XOPEN_XPG3     1
  75 #define _XOPEN_XPG4     1
  76
  77 /* The X/Open Unix extensions are available.  */
  78 #define _XOPEN_UNIX     1
  79
  80 /* Encryption is present.  */
  81 #define _XOPEN_CRYPT    1
  82
  83 /* The enhanced internationalization capabilities according to XPG4.2
  84    are present.  */
  85 #define _XOPEN_ENH_I18N 1
  86
  87 /* The legacy interfaces are also available.  */
  88 #define _XOPEN_LEGACY   1
  89
  90
  91 /* Get values of POSIX options:
  92
  93    If these symbols are defined, the corresponding features are
  94    always available.  If not, they may be available sometimes.
  95    The current values can be obtained with `sysconf'.
  96
  97    _POSIX_JOB_CONTROL           Job control is supported.
  98    _POSIX_SAVED_IDS             Processes have a saved set-user-ID
  99                                 and a saved set-group-ID.
 100    _POSIX_REALTIME_SIGNALS      Real-time, queued signals are supported.
 101    _POSIX_PRIORITY_SCHEDULING   Priority scheduling is supported.
 102    _POSIX_TIMERS                POSIX.4 clocks and timers are supported.
 103    _POSIX_ASYNCHRONOUS_IO       Asynchronous I/O is supported.
 104    _POSIX_PRIORITIZED_IO        Prioritized asynchronous I/O is supported.
 105    _POSIX_SYNCHRONIZED_IO       Synchronizing file data is supported.
 106    _POSIX_FSYNC                 The fsync function is present.
 107    _POSIX_MAPPED_FILES          Mapping of files to memory is supported.
 108    _POSIX_MEMLOCK               Locking of all memory is supported.
 109    _POSIX_MEMLOCK_RANGE         Locking of ranges of memory is supported.
 110    _POSIX_MEMORY_PROTECTION     Setting of memory protections is supported.
 111    _POSIX_MESSAGE_PASSING       POSIX.4 message queues are supported.
 112    _POSIX_SEMAPHORES            POSIX.4 counting semaphores are supported.
 113    _POSIX_SHARED_MEMORY_OBJECTS POSIX.4 shared memory objects are supported.
 114    _POSIX_THREADS               POSIX.1c pthreads are supported.
 115    _POSIX_THREAD_ATTR_STACKADDR Thread stack address attribute option supported.
 116    _POSIX_THREAD_ATTR_STACKSIZE Thread stack size attribute option supported.
 117    _POSIX_THREAD_SAFE_FUNCTIONS Thread-safe functions are supported.
 118    _POSIX_THREAD_PRIORITY_SCHEDULING
 119                                 POSIX.1c thread execution scheduling supported.
 120    _POSIX_THREAD_PRIO_INHERIT   Thread priority inheritance option supported.
 121    _POSIX_THREAD_PRIO_PROTECT   Thread priority protection option supported.
 122    _POSIX_THREAD_PROCESS_SHARED Process-shared synchronization supported.
 123    _POSIX_PII                   Protocol-independent interfaces are supported.
 124    _POSIX_PII_XTI               XTI protocol-indep. interfaces are supported.
 125    _POSIX_PII_SOCKET            Socket protocol-indep. interfaces are supported.
 126    _POSIX_PII_INTERNET          Internet family of protocols supported.
 127    _POSIX_PII_INTERNET_STREAM   Connection-mode Internet protocol supported.
 128    _POSIX_PII_INTERNET_DGRAM    Connectionless Internet protocol supported.
 129    _POSIX_PII_OSI               ISO/OSI family of protocols supported.
 130    _POSIX_PII_OSI_COTS          Connection-mode ISO/OSI service supported.
 131    _POSIX_PII_OSI_CLTS          Connectionless ISO/OSI service supported.
 132    _POSIX_POLL                  Implementation supports `poll' function.
 133    _POSIX_SELECT                Implementation supports `select' and `pselect'.
 134
 135    _XOPEN_REALTIME              X/Open realtime support is available.
 136    _XOPEN_REALTIME_THREADS      X/Open realtime thread support is available.
 137    _XOPEN_SHM                   Shared memory interface according to XPG4.2.
 138
 139    _XBS5_ILP32_OFF32            Implementation provides environment with 32-bit
 140                                 int, long, pointer, and off_t types.
 141    _XBS5_ILP32_OFFBIG           Implementation provides environment with 32-bit
 142                                 int, long, and pointer and off_t with at least
 143                                 64 bits.
 144    _XBS5_LP64_OFF64             Implementation provides environment with 32-bit
 145                                 int, and 64-bit long, pointer, and off_t types.
 146    _XBS5_LPBIG_OFFBIG           Implementation provides environment with at
 147                                 least 32 bits int and long, pointer, and off_t
 148                                 with at least 64 bits.
 149
 150    If any of these symbols is defined as -1, the corresponding option is not
 151    true for any file.  If any is defined as other than -1, the corresponding
 152    option is true for all files.  If a symbol is not defined at all, the value
 153    for a specific file can be obtained from `pathconf' and `fpathconf'.
 154
 155    _POSIX_CHOWN_RESTRICTED      Only the super user can use `chown' to change
 156                                 the owner of a file.  `chown' can only be used
 157                                 to change the group ID of a file to a group of
 158                                 which the calling process is a member.
 159    _POSIX_NO_TRUNC              Pathname components longer than
 160                                 NAME_MAX generate an error.
 161    _POSIX_VDISABLE              If defined, if the value of an element of the
 162                                 `c_cc' member of `struct termios' is
 163                                 _POSIX_VDISABLE, no character will have the
 164                                 effect associated with that element.
 165    _POSIX_SYNC_IO               Synchronous I/O may be performed.
 166    _POSIX_ASYNC_IO              Asynchronous I/O may be performed.
 167    _POSIX_PRIO_IO               Prioritized Asynchronous I/O may be performed.
 168
 169    Support for the Large File Support interface is not generally available.
 170    If it is available the following constants are defined to one.
 171    _LFS64_LARGEFILE             Low-level I/O supports large files.
 172    _LFS64_STDIO                 Standard I/O supports large files.
 173    */
 174
 175 #include <bits/posix_opt.h>
 176
 177 /* Get the environment definitions from Unix98.  */
 178 #ifdef __USE_UNIX98
 179 # include <bits/environments.h>
 180 #endif
 181
 182 /* Standard file descriptors.  */
 183 #define STDIN_FILENO    0       /* Standard input.  */
 184 #define STDOUT_FILENO   1       /* Standard output.  */
 185 #define STDERR_FILENO   2       /* Standard error output.  */
 186
 187
 188 /* All functions that are not declared anywhere else.  */
 189
 190 #include <bits/types.h>
 191
 192 #ifndef ssize_t
 193 typedef __ssize_t ssize_t;
 194 # define ssize_t ssize_t
 195 #endif
 196
 197 #define __need_size_t
 198 #define __need_NULL
 199 #include <stddef.h>
 200
 201 #ifdef __USE_UNIX98
 202 /* The Single Unix specification says that some more types are
 203    available here.  */
 204 # ifndef gid_t
 205 typedef __gid_t gid_t;
 206 #  define gid_t gid_t
 207 # endif
 208
 209 # ifndef uid_t
 210 typedef __uid_t uid_t;
 211 #  define uid_t uid_t
 212 # endif
 213
 214 # ifndef off_t
 215 #  ifndef __USE_FILE_OFFSET64
 216 typedef __off_t off_t;
 217 #  else
 218 typedef __off64_t off_t;
 219 #  endif
 220 #  define off_t off_t
 221 # endif
 222 # if defined __USE_LARGEFILE64 && !defined off64_t
 223 typedef __off64_t off64_t;
 224 #  define off64_t off64_t
 225 # endif
 226
 227 # ifndef pid_t
 228 typedef __pid_t pid_t;
 229 #  define pid_t pid_t
 230 # endif
 231 #endif  /* Unix98 */
 232
 233 /* Values for the second argument to access.
 234    These may be OR'd together.  */
 235 #define R_OK    4               /* Test for read permission.  */
 236 #define W_OK    2               /* Test for write permission.  */
 237 #define X_OK    1               /* Test for execute permission.  */
 238 #define F_OK    0               /* Test for existence.  */
 239
 240 /* Test for access to NAME using the real UID and real GID.  */
 241 extern int __access __P ((__const char *__name, int __type));
 242 extern int access __P ((__const char *__name, int __type));
 243
 244 #ifdef __USE_GNU
 245 /* Test for access to NAME using the effective UID and GID
 246    (as normal file operations use).  */
 247 extern int __euidaccess __P ((__const char *__name, int __type));
 248 extern int euidaccess __P ((__const char *__name, int __type));
 249 #endif
 250
 251
 252 /* Values for the WHENCE argument to lseek.  */
 253 #ifndef _STDIO_H                /* <stdio.h> has the same definitions.  */
 254 # define SEEK_SET       0       /* Seek from beginning of file.  */
 255 # define SEEK_CUR       1       /* Seek from current position.  */
 256 # define SEEK_END       2       /* Seek from end of file.  */
 257 #endif
 258
 259 #if defined __USE_BSD && !defined L_SET
 260 /* Old BSD names for the same constants; just for compatibility.  */
 261 # define L_SET          SEEK_SET
 262 # define L_INCR         SEEK_CUR
 263 # define L_XTND         SEEK_END
 264 #endif
 265
 266
 267 /* Move FD's file position to OFFSET bytes from the
 268    beginning of the file (if WHENCE is SEEK_SET),
 269    the current position (if WHENCE is SEEK_CUR),
 270    or the end of the file (if WHENCE is SEEK_END).
 271    Return the new file position.  */
 272 extern __off_t __lseek __P ((int __fd, __off_t __offset, int __whence));
 273 #ifndef __USE_FILE_OFFSET64
 274 extern __off_t lseek __P ((int __fd, __off_t __offset, int __whence));
 275 #else
 276 extern __off_t lseek __P ((int __fd, __off64_t __offset, int __whence))
 277      __asm__ ("lseek64");
 278 #endif
 279 #ifdef __USE_LARGEFILE64
 280 extern __off64_t lseek64 __P ((int __fd, __off64_t __offset, int __whence));
 281 #endif
 282
 283 /* Close the file descriptor FD.  */
 284 extern int __close __P ((int __fd));
 285 extern int close __P ((int __fd));
 286
 287 /* Read NBYTES into BUF from FD.  Return the
 288    number read, -1 for errors or 0 for EOF.  */
 289 extern ssize_t __read __P ((int __fd, __ptr_t __buf, size_t __nbytes));
 290 extern ssize_t read __P ((int __fd, __ptr_t __buf, size_t __nbytes));
 291
 292 /* Write N bytes of BUF to FD.  Return the number written, or -1.  */
 293 extern ssize_t __write __P ((int __fd, __const __ptr_t __buf, size_t __n));
 294 extern ssize_t write __P ((int __fd, __const __ptr_t __buf, size_t __n));
 295
 296 #ifdef __USE_UNIX98
 297 /* Read NBYTES into BUF from FD at the given position OFFSET without
 298    changing the file pointer.  Return the number read, -1 for errors
 299    or 0 for EOF.  */
 300 extern ssize_t __pread __P ((int __fd, __ptr_t __buf, size_t __nbytes,
 301                              __off_t __offset));
 302 # ifndef __USE_FILE_OFFSET64
 303 extern ssize_t pread __P ((int __fd, __ptr_t __buf, size_t __nbytes,
 304                            __off_t __offset));
 305 # else
 306 extern ssize_t pread __P ((int __fd, __ptr_t __buf, size_t __nbytes,
 307                            __off64_t __offset)) __asm__ ("pread64");
 308 # endif
 309 extern ssize_t __pread64 __P ((int __fd, __ptr_t __buf, size_t __nbytes,
 310                                __off64_t __offset));
 311 # ifdef __USE_LARGEFILE64
 312 extern ssize_t pread64 __P ((int __fd, __ptr_t __buf, size_t __nbytes,
 313                              __off64_t __offset));
 314 # endif
 315
 316 /* Write N bytes of BUF to FD at the given position OFFSET without
 317    changing the file pointer.  Return the number written, or -1.  */
 318 extern ssize_t __pwrite __P ((int __fd, __const __ptr_t __buf, size_t __n,
 319                               __off_t __offset));
 320 # ifndef __USE_FILE_OFFSET64
 321 extern ssize_t pwrite __P ((int __fd, __const __ptr_t __buf, size_t __n,
 322                             __off_t __offset));
 323 # else
 324 extern ssize_t pwrite __P ((int __fd, __const __ptr_t __buf, size_t __n,
 325                             __off64_t __offset)) __asm__ ("pwrite64");
 326 # endif
 327 extern ssize_t __pwrite64 __P ((int __fd, __const __ptr_t __buf, size_t __n,
 328                                 __off64_t __offset));
 329 # ifdef __USE_LARGEFILE64
 330 extern ssize_t pwrite64 __P ((int __fd, __const __ptr_t __buf, size_t __n,
 331                               __off64_t __offset));
 332 # endif
 333 #endif
 334
 335
 336 /* Create a one-way communication channel (pipe).
 337    If successful, two file descriptors are stored in PIPEDES;
 338    bytes written on PIPEDES[1] can be read from PIPEDES[0].
 339    Returns 0 if successful, -1 if not.  */
 340 extern int __pipe __P ((int __pipedes[2]));
 341 extern int pipe __P ((int __pipedes[2]));
 342
 343 /* Schedule an alarm.  In SECONDS seconds, the process will get a SIGALRM.
 344    If SECONDS is zero, any currently scheduled alarm will be cancelled.
 345    The function returns the number of seconds remaining until the last
 346    alarm scheduled would have signaled, or zero if there wasn't one.
 347    There is no return value to indicate an error, but you can set `errno'
 348    to 0 and check its value after calling `alarm', and this might tell you.
 349    The signal may come late due to processor scheduling.  */
 350 extern unsigned int alarm __P ((unsigned int __seconds));
 351
 352 /* Make the process sleep for SECONDS seconds, or until a signal arrives
 353    and is not ignored.  The function returns the number of seconds less
 354    than SECONDS which it actually slept (thus zero if it slept the full time).
 355    If a signal handler does a `longjmp' or modifies the handling of the
 356    SIGALRM signal while inside `sleep' call, the handling of the SIGALRM
 357    signal afterwards is undefined.  There is no return value to indicate
 358    error, but if `sleep' returns SECONDS, it probably didn't work.  */
 359 extern unsigned int __sleep __P ((unsigned int __seconds));
 360 extern unsigned int sleep __P ((unsigned int __seconds));
 361
 362 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 363 /* Set an alarm to go off (generating a SIGALRM signal) in VALUE
 364    microseconds.  If INTERVAL is nonzero, when the alarm goes off, the
 365    timer is reset to go off every INTERVAL microseconds thereafter.
 366    Returns the number of microseconds remaining before the alarm.  */
 367 extern unsigned int ualarm __P ((unsigned int __value,
 368                                  unsigned int __interval));
 369
 370 /* Sleep USECONDS microseconds, or until a signal arrives that is not blocked
 371    or ignored.  */
 372 extern void usleep __P ((unsigned int __useconds));
 373 #endif
 374
 375
 376 /* Suspend the process until a signal arrives.
 377    This always returns -1 and sets `errno' to EINTR.  */
 378 extern int pause __P ((void));
 379
 380
 381 /* Change the owner and group of FILE.  */
 382 extern int __chown __P ((__const char *__file,
 383                          __uid_t __owner, __gid_t __group));
 384 extern int chown __P ((__const char *__file,
 385                        __uid_t __owner, __gid_t __group));
 386
 387 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 388 /* Change the owner and group of the file that FD is open on.  */
 389 extern int __fchown __P ((int __fd,
 390                           __uid_t __owner, __gid_t __group));
 391 extern int fchown __P ((int __fd,
 392                         __uid_t __owner, __gid_t __group));
 393
 394
 395 /* Change owner and group of FILE, if it is a symbolic
 396    link the ownership of the symbolic link is changed.  */
 397 extern int __lchown __P ((__const char *__file, __uid_t __owner,
 398                           __gid_t __group));
 399 extern int lchown __P ((__const char *__file, __uid_t __owner,
 400                         __gid_t __group));
 401
 402 #endif /* Use BSD || X/Open Unix.  */
 403
 404 /* Change the process's working directory to PATH.  */
 405 extern int __chdir __P ((__const char *__path));
 406 extern int chdir __P ((__const char *__path));
 407
 408 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 409 /* Change the process's working directory to the one FD is open on.  */
 410 extern int __fchdir __P ((int __fd));
 411 extern int fchdir __P ((int __fd));
 412 #endif
 413
 414 /* Get the pathname of the current working directory,
 415    and put it in SIZE bytes of BUF.  Returns NULL if the
 416    directory couldn't be determined or SIZE was too small.
 417    If successful, returns BUF.  In GNU, if BUF is NULL,
 418    an array is allocated with `malloc'; the array is SIZE
 419    bytes long, unless SIZE == 0, in which case it is as
 420    big as necessary.  */
 421 extern char *__getcwd __P ((char *__buf, size_t __size));
 422 extern char *getcwd __P ((char *__buf, size_t __size));
 423
 424 #ifdef  __USE_GNU
 425 /* Return a malloc'd string containing the current directory name.
 426    If the environment variable `PWD' is set, and its value is correct,
 427    that value is used.  */
 428 extern char *get_current_dir_name __P ((void));
 429
 430 /* Get the canonical absolute name of the named directory, and put it in SIZE
 431    bytes of BUF.  Returns NULL if the directory couldn't be determined or
 432    SIZE was too small.  If successful, returns BUF.  In GNU, if BUF is
 433    NULL, an array is allocated with `malloc'; the array is SIZE bytes long,
 434    unless SIZE <= 0, in which case it is as big as necessary.  */
 435
 436 char *__canonicalize_directory_name_internal __P ((__const char *__thisdir,
 437                                                    char *__buf,
 438                                                    size_t __size));
 439 #endif
 440
 441 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 442 /* Put the absolute pathname of the current working directory in BUF.
 443    If successful, return BUF.  If not, put an error message in
 444    BUF and return NULL.  BUF should be at least PATH_MAX bytes long.  */
 445 extern char *getwd __P ((char *__buf));
 446 #endif
 447
 448
 449 /* Duplicate FD, returning a new file descriptor on the same file.  */
 450 extern int __dup __P ((int __fd));
 451 extern int dup __P ((int __fd));
 452
 453 /* Duplicate FD to FD2, closing FD2 and making it open on the same file.  */
 454 extern int __dup2 __P ((int __fd, int __fd2));
 455 extern int dup2 __P ((int __fd, int __fd2));
 456
 457 /* NULL-terminated array of "NAME=VALUE" environment variables.  */
 458 extern char **__environ;
 459 #ifdef __USE_GNU
 460 extern char **environ;
 461 #endif
 462
 463
 464 /* Replace the current process, executing PATH with arguments ARGV and
 465    environment ENVP.  ARGV and ENVP are terminated by NULL pointers.  */
 466 extern int __execve __P ((__const char *__path, char *__const __argv[],
 467                           char *__const __envp[]));
 468 extern int execve __P ((__const char *__path, char *__const __argv[],
 469                         char *__const __envp[]));
 470
 471 #ifdef __USE_GNU
 472 /* Execute the file FD refers to, overlaying the running program image.
 473    ARGV and ENVP are passed to the new program, as for `execve'.  */
 474 extern int fexecve __P ((int __fd,
 475                          char *__const __argv[], char *__const __envp[]));
 476
 477 #endif
 478
 479
 480 /* Execute PATH with arguments ARGV and environment from `environ'.  */
 481 extern int execv __P ((__const char *__path, char *__const __argv[]));
 482
 483 /* Execute PATH with all arguments after PATH until a NULL pointer,
 484    and the argument after that for environment.  */
 485 extern int execle __P ((__const char *__path, __const char *__arg, ...));
 486
 487 /* Execute PATH with all arguments after PATH until
 488    a NULL pointer and environment from `environ'.  */
 489 extern int execl __P ((__const char *__path, __const char *__arg, ...));
 490
 491 /* Execute FILE, searching in the `PATH' environment variable if it contains
 492    no slashes, with arguments ARGV and environment from `environ'.  */
 493 extern int execvp __P ((__const char *__file, char *__const __argv[]));
 494
 495 /* Execute FILE, searching in the `PATH' environment variable if
 496    it contains no slashes, with all arguments after FILE until a
 497    NULL pointer and environment from `environ'.  */
 498 extern int execlp __P ((__const char *__file, __const char *__arg, ...));
 499
 500
 501 #if defined __USE_MISC || defined __USE_XOPEN
 502 /* Add INC to priority of the current process.  */
 503 extern int nice __P ((int __inc));
 504 #endif
 505
 506
 507 /* Terminate program execution with the low-order 8 bits of STATUS.  */
 508 extern void _exit __P ((int __status)) __attribute__ ((__noreturn__));
 509
 510
 511 /* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf';
 512    the `_SC_*' symbols for the NAME argument to `sysconf';
 513    and the `_CS_*' symbols for the NAME argument to `confstr'.  */
 514 #include <bits/confname.h>
 515
 516 /* Get file-specific configuration information about PATH.  */
 517 extern long int __pathconf __P ((__const char *__path, int __name));
 518 extern long int pathconf __P ((__const char *__path, int __name));
 519
 520 /* Get file-specific configuration about descriptor FD.  */
 521 extern long int __fpathconf __P ((int __fd, int __name));
 522 extern long int fpathconf __P ((int __fd, int __name));
 523
 524 /* Get the value of the system variable NAME.  */
 525 extern long int __sysconf __P ((int __name));
 526 extern long int sysconf __P ((int __name));
 527
 528 #ifdef  __USE_POSIX2
 529 /* Get the value of the string-valued system variable NAME.  */
 530 extern size_t confstr __P ((int __name, char *__buf, size_t __len));
 531 #endif
 532
 533
 534 /* Get the process ID of the calling process.  */
 535 extern __pid_t __getpid __P ((void));
 536 extern __pid_t getpid __P ((void));
 537
 538 /* Get the process ID of the calling process's parent.  */
 539 extern __pid_t __getppid __P ((void));
 540 extern __pid_t getppid __P ((void));
 541
 542 /* Get the process group ID of the calling process.  */
 543 extern __pid_t getpgrp __P ((void));
 544 /* The old BSD definition is a bit different.  */
 545 extern __pid_t __bsd_getpgrp __P ((__pid_t __pid));
 546 #ifdef __FAVOR_BSD
 547 /* When we explicitely compile BSD sources use the BSD definition of this
 548    function.  Please note that we cannot use parameters for the macro.  */
 549 # define getpgrp __bsd_getpgrp
 550 #endif
 551
 552 /* Set the process group ID of the process matching PID to PGID.
 553    If PID is zero, the current process's process group ID is set.
 554    If PGID is zero, the process ID of the process is used.  */
 555 extern int __setpgid __P ((__pid_t __pid, __pid_t __pgid));
 556 extern int setpgid __P ((__pid_t __pid, __pid_t __pgid));
 557
 558 /* Get the process group ID of process PID.  */
 559 extern __pid_t __getpgid __P ((__pid_t __pid));
 560 #ifdef __USE_XOPEN_EXTENDED
 561 extern __pid_t getpgid __P ((__pid_t __pid));
 562 #endif
 563
 564 #if defined __USE_SVID || defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 565 /* Both System V and BSD have `setpgrp' functions, but with different
 566    calling conventions.  The BSD function is the same as POSIX.1 `setpgid'
 567    (above).  The System V function takes no arguments and puts the calling
 568    process in its on group like `setpgid (0, 0)'.
 569
 570    New programs should always use `setpgid' instead.
 571
 572    The default in GNU is to provide the System V function.  The BSD
 573    function is available under -D_BSD_SOURCE with -lbsd-compat.  */
 574
 575 # ifndef __FAVOR_BSD
 576
 577 /* Set the process group ID of the calling process to its own PID.
 578    This is exactly the same as `setpgid (0, 0)'.  */
 579 extern int setpgrp __P ((void));
 580
 581 # else
 582
 583 /* Another name for `setpgid' (above).  */
 584 extern int setpgrp __P ((__pid_t __pid, __pid_t __pgrp));
 585
 586 # endif /* Favor BSD.  */
 587 #endif  /* Use SVID or BSD.  */
 588
 589 /* Create a new session with the calling process as its leader.
 590    The process group IDs of the session and the calling process
 591    are set to the process ID of the calling process, which is returned.  */
 592 extern __pid_t __setsid __P ((void));
 593 extern __pid_t setsid __P ((void));
 594
 595 #ifdef __USE_XOPEN_EXTENDED
 596 /* Return the session ID of the given process.  */
 597 extern __pid_t getsid __P ((__pid_t __pid));
 598 #endif
 599
 600 /* Get the real user ID of the calling process.  */
 601 extern __uid_t __getuid __P ((void));
 602 extern __uid_t getuid __P ((void));
 603
 604 /* Get the effective user ID of the calling process.  */
 605 extern __uid_t __geteuid __P ((void));
 606 extern __uid_t geteuid __P ((void));
 607
 608 /* Get the real group ID of the calling process.  */
 609 extern __gid_t __getgid __P ((void));
 610 extern __gid_t getgid __P ((void));
 611
 612 /* Get the effective group ID of the calling process.  */
 613 extern __gid_t __getegid __P ((void));
 614 extern __gid_t getegid __P ((void));
 615
 616 /* If SIZE is zero, return the number of supplementary groups
 617    the calling process is in.  Otherwise, fill in the group IDs
 618    of its supplementary groups in LIST and return the number written.  */
 619 extern int __getgroups __P ((int __size, __gid_t __list[]));
 620 extern int getgroups __P ((int __size, __gid_t __list[]));
 621
 622 #ifdef  __USE_GNU
 623 /* Return nonzero iff the calling process is in group GID.  */
 624 extern int __group_member __P ((__gid_t __gid));
 625 extern int group_member __P ((__gid_t __gid));
 626 #endif
 627
 628 /* Set the user ID of the calling process to UID.
 629    If the calling process is the super-user, set the real
 630    and effective user IDs, and the saved set-user-ID to UID;
 631    if not, the effective user ID is set to UID.  */
 632 extern int __setuid __P ((__uid_t __uid));
 633 extern int setuid __P ((__uid_t __uid));
 634
 635 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 636 /* Set the real user ID of the calling process to RUID,
 637    and the effective user ID of the calling process to EUID.  */
 638 extern int __setreuid __P ((__uid_t __ruid, __uid_t __euid));
 639 extern int setreuid __P ((__uid_t __ruid, __uid_t __euid));
 640 #endif
 641
 642 #ifdef  __USE_BSD
 643 /* Set the effective user ID of the calling process to UID.  */
 644 extern int seteuid __P ((__uid_t __uid));
 645 #endif /* Use BSD.  */
 646
 647 /* Set the group ID of the calling process to GID.
 648    If the calling process is the super-user, set the real
 649    and effective group IDs, and the saved set-group-ID to GID;
 650    if not, the effective group ID is set to GID.  */
 651 extern int __setgid __P ((__gid_t __gid));
 652 extern int setgid __P ((__gid_t __gid));
 653
 654 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 655 /* Set the real group ID of the calling process to RGID,
 656    and the effective group ID of the calling process to EGID.  */
 657 extern int __setregid __P ((__gid_t __rgid, __gid_t __egid));
 658 extern int setregid __P ((__gid_t __rgid, __gid_t __egid));
 659 #endif
 660
 661 #ifdef __USE_BSD
 662 /* Set the effective group ID of the calling process to GID.  */
 663 extern int setegid __P ((__gid_t __gid));
 664 #endif /* Use BSD.  */
 665
 666
 667 /* Clone the calling process, creating an exact copy.
 668    Return -1 for errors, 0 to the new process,
 669    and the process ID of the new process to the old process.  */
 670 extern __pid_t __fork __P ((void));
 671 extern __pid_t fork __P ((void));
 672
 673 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 674 /* Clone the calling process, but without copying the whole address space.
 675    The the calling process is suspended until the the new process exits or is
 676    replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
 677    and the process ID of the new process to the old process.  */
 678 extern __pid_t __vfork __P ((void));
 679 extern __pid_t vfork __P ((void));
 680 #endif /* Use BSD. */
 681
 682
 683 /* Return the pathname of the terminal FD is open on, or NULL on errors.
 684    The returned storage is good only until the next call to this function.  */
 685 extern char *ttyname __P ((int __fd));
 686
 687 /* Store at most BUFLEN characters of the pathname of the terminal FD is
 688    open on in BUF.  Return 0 on success, otherwise an error number.  */
 689 extern int __ttyname_r __P ((int __fd, char *__buf, size_t __buflen));
 690 extern int ttyname_r __P ((int __fd, char *__buf, size_t __buflen));
 691
 692 /* Return 1 if FD is a valid descriptor associated
 693    with a terminal, zero if not.  */
 694 extern int __isatty __P ((int __fd));
 695 extern int isatty __P ((int __fd));
 696
 697 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 698 /* Return the index into the active-logins file (utmp) for
 699    the controlling terminal.  */
 700 extern int ttyslot __P ((void));
 701 #endif
 702
 703
 704 /* Make a link to FROM named TO.  */
 705 extern int __link __P ((__const char *__from, __const char *__to));
 706 extern int link __P ((__const char *__from, __const char *__to));
 707
 708 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 709 /* Make a symbolic link to FROM named TO.  */
 710 extern int __symlink __P ((__const char *__from, __const char *__to));
 711 extern int symlink __P ((__const char *__from, __const char *__to));
 712
 713 /* Read the contents of the symbolic link PATH into no more than
 714    LEN bytes of BUF.  The contents are not null-terminated.
 715    Returns the number of characters read, or -1 for errors.  */
 716 extern int __readlink __P ((__const char *__path, char *__buf, size_t __len));
 717 extern int readlink __P ((__const char *__path, char *__buf, size_t __len));
 718 #endif /* Use BSD.  */
 719
 720 /* Remove the link NAME.  */
 721 extern int __unlink __P ((__const char *__name));
 722 extern int unlink __P ((__const char *__name));
 723
 724 /* Remove the directory PATH.  */
 725 extern int __rmdir __P ((__const char *__path));
 726 extern int rmdir __P ((__const char *__path));
 727
 728
 729 /* Return the foreground process group ID of FD.  */
 730 extern __pid_t tcgetpgrp __P ((int __fd));
 731
 732 /* Set the foreground process group ID of FD set PGRP_ID.  */
 733 extern int tcsetpgrp __P ((int __fd, __pid_t __pgrp_id));
 734
 735
 736 /* Return the login name of the user.  */
 737 extern char *getlogin __P ((void));
 738 #ifdef __USE_REENTRANT
 739 /* Return at most NAME_LEN characters of the login name of the user in NAME.
 740    If it cannot be determined or some other error occurred, return the error
 741    code.  Otherwise return 0.  */
 742 extern int getlogin_r __P ((char *__name, size_t __name_len));
 743 #endif
 744
 745 #ifdef  __USE_BSD
 746 /* Set the login name returned by `getlogin'.  */
 747 extern int setlogin __P ((__const char *__name));
 748 #endif
 749
 750
 751 #ifdef  __USE_POSIX2
 752 /* Process the arguments in ARGV (ARGC of them, minus
 753    the program name) for options given in OPTS.
 754
 755    If `opterr' is zero, no messages are generated
 756    for invalid options; it defaults to 1.
 757    `optind' is the current index into ARGV.
 758    `optarg' is the argument corresponding to the current option.
 759    Return the option character from OPTS just read.
 760    Return -1 when there are no more options.
 761    For unrecognized options, or options missing arguments,
 762    `optopt' is set to the option letter, and '?' is returned.
 763
 764    The OPTS string is a list of characters which are recognized option
 765    letters, optionally followed by colons, specifying that that letter
 766    takes an argument, to be placed in `optarg'.
 767
 768    If a letter in OPTS is followed by two colons, its argument is optional.
 769    This behavior is specific to the GNU `getopt'.
 770
 771    The argument `--' causes premature termination of argument scanning,
 772    explicitly telling `getopt' that there are no more options.
 773
 774    If OPTS begins with `--', then non-option arguments
 775    are treated as arguments to the option '\0'.
 776    This behavior is specific to the GNU `getopt'.  */
 777 extern int getopt __P ((int __argc, char *__const * __argv,
 778                         __const char *__opts));
 779 extern int opterr;
 780 extern int optind;
 781 extern int optopt;
 782 extern char *optarg;
 783 #endif
 784
 785
 786 #if defined __USE_BSD || defined __USE_XOPEN
 787
 788 /* Put the name of the current host in no more than LEN bytes of NAME.
 789    The result is null-terminated if LEN is large enough for the full
 790    name and the terminator.  */
 791 extern int __gethostname __P ((char *__name, size_t __len));
 792 extern int gethostname __P ((char *__name, size_t __len));
 793
 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 __P ((__const char *__name, size_t __len));
 797
 798 /* Set the current machine's Internet number to ID.
 799    This call is restricted to the super-user.  */
 800 extern int sethostid __P ((long int __id));
 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 __P ((char *__name, size_t __len));
 807 extern int setdomainname __P ((__const char *__name, size_t __len));
 808
 809
 810 /* Make all changes done to FD actually appear on disk.  */
 811 extern int fsync __P ((int __fd));
 812
 813
 814 /* Revoke access permissions to all processes currently communicating
 815    with the control terminal, and then send a SIGHUP signal to the process
 816    group of the control terminal.  */
 817 extern int vhangup __P ((void));
 818
 819 /* Revoke the access of all descriptors currently open on FILE.  */
 820 extern int revoke __P ((__const char *__file));
 821
 822
 823 /* Enable statistical profiling, writing samples of the PC into at most
 824    SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
 825    is enabled, the system examines the user PC and increments
 826    SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536].  If SCALE is zero,
 827    disable profiling.  Returns zero on success, -1 on error.  */
 828 extern int __profil __P ((unsigned short int *__sample_buffer, size_t __size,
 829                           size_t __offset, unsigned int __scale));
 830 extern int profil __P ((unsigned short int *__sample_buffer, size_t __size,
 831                         size_t __offset, unsigned int __scale));
 832
 833
 834 /* Turn accounting on if NAME is an existing file.  The system will then write
 835    a record for each process as it terminates, to this file.  If NAME is NULL,
 836    turn accounting off.  This call is restricted to the super-user.  */
 837 extern int acct __P ((__const char *__name));
 838
 839 /* Make PATH be the root directory (the starting point for absolute paths).
 840    This call is restricted to the super-user.  */
 841 extern int chroot __P ((__const char *__path));
 842
 843
 844 /* Successive calls return the shells listed in `/etc/shells'.  */
 845 extern char *getusershell __P ((void));
 846 extern void endusershell __P ((void)); /* Discard cached info.  */
 847 extern void setusershell __P ((void)); /* Rewind and re-read the file.  */
 848
 849
 850 /* Prompt with PROMPT and read a string from the terminal without echoing.
 851    Uses /dev/tty if possible; otherwise stderr and stdin.  */
 852 extern char *getpass __P ((__const char *__prompt));
 853
 854 /* Put the program in the background, and dissociate from the controlling
 855    terminal.  If NOCHDIR is zero, do `chdir ("/")'.  If NOCLOSE is zero,
 856    redirects stdin, stdout, and stderr to /dev/null.  */
 857 extern int daemon __P ((int __nochdir, int __noclose));
 858
 859 #endif /* Use BSD || X/Open.  */
 860
 861
 862 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 863
 864 /* Return the current machine's Internet number.  */
 865 extern long int gethostid __P ((void));
 866
 867 /* Make all changes done to all files actually appear on disk.  */
 868 extern int sync __P ((void));
 869
 870
 871 /* Return the number of bytes in a page.  This is the system's page size,
 872    which is not necessarily the same as the hardware page size.  */
 873 extern int __getpagesize __P ((void));
 874 extern int getpagesize __P ((void));
 875
 876
 877 /* Truncate FILE to LENGTH bytes.  */
 878 #ifndef __USE_FILE_OFFSET64
 879 extern int truncate __P ((__const char *__file, __off_t __length));
 880 #else
 881 extern int truncate __P ((__const char *__file, __off64_t __length))
 882      __asm__ ("truncate64");
 883 #endif
 884 #ifdef __USE_LARGEFILE64
 885 extern int truncate64 __P ((__const char *__file, __off64_t __length));
 886 #endif
 887
 888 /* Truncate the file FD is open on to LENGTH bytes.  */
 889 #ifndef __USE_FILE_OFFSET64
 890 extern int ftruncate __P ((int __fd, __off_t __length));
 891 #else
 892 extern int ftruncate __P ((int __fd, __off64_t __length))
 893      __asm__ ("ftruncate64");
 894 #endif
 895 #ifdef __USE_LARGEFILE64
 896 extern int ftruncate64 __P ((int __fd, __off64_t __length));
 897 #endif
 898
 899
 900 /* Return the maximum number of file descriptors
 901    the current process could possibly have.  */
 902 extern int __getdtablesize __P ((void));
 903 extern int getdtablesize __P ((void));
 904
 905 #endif /* Use BSD || X/Open Unix.  */
 906
 907
 908 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 909
 910 /* Set the end of accessible data space (aka "the break") to ADDR.
 911    Returns zero on success and -1 for errors (with errno set).  */
 912 extern int __brk __P ((__ptr_t __addr));
 913 extern int brk __P ((__ptr_t __addr));
 914
 915 # define __need_ptrdiff_t
 916 # include <stddef.h>
 917
 918 /* Increase or decrease the end of accessible data space by DELTA bytes.
 919    If successful, returns the address the previous end of data space
 920    (i.e. the beginning of the new space, if DELTA > 0);
 921    returns (void *) -1 for errors (with errno set).  */
 922 extern __ptr_t __sbrk __P ((ptrdiff_t __delta));
 923 extern __ptr_t sbrk __P ((ptrdiff_t __delta));
 924 #endif
 925
 926
 927 #ifdef __USE_MISC
 928 /* Invoke `system call' number SYSNO, passing it the remaining arguments.
 929    This is completely system-dependent, and not often useful.
 930
 931    In Unix, `syscall' sets `errno' for all errors and most calls return -1
 932    for errors; in many systems you cannot pass arguments or get return
 933    values for all system calls (`pipe', `fork', and `getppid' typically
 934    among them).
 935
 936    In Mach, all system calls take normal arguments and always return an
 937    error code (zero for success).  */
 938 extern long int syscall __P ((long int __sysno, ...));
 939
 940 #endif  /* Use misc.  */
 941
 942
 943 #if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK
 944 /* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both
 945    files consistent.  Some systems have them there and some here, and some
 946    software depends on the macros being defined without including both.  */
 947
 948 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
 949    LEN is always relative to the current file position.
 950    The CMD argument is one of the following.  */
 951
 952 # define F_ULOCK 0      /* Unlock a previously locked region.  */
 953 # define F_LOCK  1      /* Lock a region for exclusive use.  */
 954 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
 955 # define F_TEST  3      /* Test a region for other processes locks.  */
 956
 957 # ifndef __USE_FILE_OFFSET64
 958 extern int lockf __P ((int __fd, int __cmd, __off_t __len));
 959 # else
 960 extern int lockf __P ((int __fd, int __cmd, __off64_t __len))
 961      __asm__ ("lockf64");
 962 # endif
 963 # ifdef __USE_LARGEFILE64
 964 extern int lockf64 __P ((int __fd, int __cmd, __off64_t __len));
 965 # endif
 966 #endif /* Use misc and F_LOCK not already defined.  */
 967
 968
 969 #ifdef __USE_GNU
 970
 971 /* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno'
 972    set to EINTR.  */
 973
 974 # define TEMP_FAILURE_RETRY(expression) \
 975   (__extension__                                                              \
 976     ({ long int __result;                                                     \
 977        do __result = (long int) (expression);                                 \
 978        while (__result == -1L && errno == EINTR);                             \
 979        __result; }))                                                          \
 980
 981
 982 /* This variable is set nonzero at startup if the process's effective
 983    IDs differ from its real IDs, or it is otherwise indicated that
 984    extra security should be used.  When this is set the dynamic linker
 985    and some functions contained in the C library ignore various
 986    environment variables that normally affect them.  */
 987 extern int __libc_enable_secure;
 988
 989 #endif
 990
 991 #if defined __USE_POSIX199309 || defined __USE_UNIX98
 992 /* Synchronize at least the data part of a file with the underlying
 993    media.  */
 994 extern int fdatasync __P ((int __fildes));
 995 #endif /* Use POSIX199309 */
 996
 997
 998 /* XPG4.2 specifies that prototypes for the encryption functions must
 999    be defined here.  */
1000 #ifdef  __USE_XOPEN
1001 /* Encrypt at most 8 characters from KEY using salt to perturb DES.  */
1002 extern char *crypt __P ((__const char *__key, __const char *__salt));
1003
1004 /* Setup DES tables according KEY.  */
1005 extern void setkey __P ((__const char *__key));
1006
1007 /* Encrypt data in BLOCK in place if EDFLAG is zero; otherwise decrypt
1008    block in place.  */
1009 extern void encrypt __P ((char *__block, int __edflag));
1010
1011
1012 /* Swab pairs bytes in the first N bytes of the area pointed to by
1013    FROM and copy the result to TO.  The value of TO must not be in the
1014    range [FROM - N + 1, FROM - 1].  If N is odd the first byte in FROM
1015    is without partner.  */
1016 extern void swab __P ((__const __ptr_t __from, __ptr_t __to, ssize_t __n));
1017 #endif
1018
1019
1020 /* The Single Unix specification, version 2, demands these prototypes
1021    to be here.  They are also found in <stdio.h>.  */
1022 #ifdef __USE_UNIX98
1023 /* Return the name of the controlling terminal.  */
1024 extern char *ctermid __P ((char *__s));
1025
1026 /* Return the name of the current user.  */
1027 extern char *cuserid __P ((char *__s));
1028 #endif
1029
1030 __END_DECLS
1031
1032 #endif /* unistd.h  */