posix/unistd.h

   1 /* Copyright (C) 1991-2006, 2007, 2008 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 /*
  20  *      POSIX Standard: 2.10 Symbolic Constants         <unistd.h>
  21  */
  22
  23 #ifndef _UNISTD_H
  24 #define _UNISTD_H       1
  25
  26 #include <features.h>
  27
  28 __BEGIN_DECLS
  29
  30 /* These may be used to determine what facilities are present at compile time.
  31    Their values can be obtained at run time from `sysconf'.  */
  32
  33 /* POSIX Standard approved as ISO/IEC 9945-1 as of December 2001.  */
  34 #define _POSIX_VERSION  200112L
  35
  36 /* These are not #ifdef __USE_POSIX2 because they are
  37    in the theoretically application-owned namespace.  */
  38
  39 /* The utilities on GNU systems also correspond to this version.  */
  40 #define _POSIX2_VERSION 200112L
  41
  42 /* If defined, the implementation supports the
  43    C Language Bindings Option.  */
  44 #define _POSIX2_C_BIND  200112L
  45
  46 /* If defined, the implementation supports the
  47    C Language Development Utilities Option.  */
  48 #define _POSIX2_C_DEV   200112L
  49
  50 /* If defined, the implementation supports the
  51    Software Development Utilities Option.  */
  52 #define _POSIX2_SW_DEV  200112L
  53
  54 /* If defined, the implementation supports the
  55    creation of locales with the localedef utility.  */
  56 #define _POSIX2_LOCALEDEF       200112L
  57
  58 /* X/Open version number to which the library conforms.  It is selectable.  */
  59 #ifdef __USE_XOPEN2K
  60 # define _XOPEN_VERSION 600
  61 #elif defined __USE_UNIX98
  62 # define _XOPEN_VERSION 500
  63 #else
  64 # define _XOPEN_VERSION 4
  65 #endif
  66
  67 /* Commands and utilities from XPG4 are available.  */
  68 #define _XOPEN_XCU_VERSION      4
  69
  70 /* We are compatible with the old published standards as well.  */
  71 #define _XOPEN_XPG2     1
  72 #define _XOPEN_XPG3     1
  73 #define _XOPEN_XPG4     1
  74
  75 /* The X/Open Unix extensions are available.  */
  76 #define _XOPEN_UNIX     1
  77
  78 /* Encryption is present.  */
  79 #define _XOPEN_CRYPT    1
  80
  81 /* The enhanced internationalization capabilities according to XPG4.2
  82    are present.  */
  83 #define _XOPEN_ENH_I18N 1
  84
  85 /* The legacy interfaces are also available.  */
  86 #define _XOPEN_LEGACY   1
  87
  88
  89 /* Get values of POSIX options:
  90
  91    If these symbols are defined, the corresponding features are
  92    always available.  If not, they may be available sometimes.
  93    The current values can be obtained with `sysconf'.
  94
  95    _POSIX_JOB_CONTROL           Job control is supported.
  96    _POSIX_SAVED_IDS             Processes have a saved set-user-ID
  97                                 and a saved set-group-ID.
  98    _POSIX_REALTIME_SIGNALS      Real-time, queued signals are supported.
  99    _POSIX_PRIORITY_SCHEDULING   Priority scheduling is supported.
 100    _POSIX_TIMERS                POSIX.4 clocks and timers are supported.
 101    _POSIX_ASYNCHRONOUS_IO       Asynchronous I/O is supported.
 102    _POSIX_PRIORITIZED_IO        Prioritized asynchronous I/O is supported.
 103    _POSIX_SYNCHRONIZED_IO       Synchronizing file data is supported.
 104    _POSIX_FSYNC                 The fsync function is present.
 105    _POSIX_MAPPED_FILES          Mapping of files to memory is supported.
 106    _POSIX_MEMLOCK               Locking of all memory is supported.
 107    _POSIX_MEMLOCK_RANGE         Locking of ranges of memory is supported.
 108    _POSIX_MEMORY_PROTECTION     Setting of memory protections is supported.
 109    _POSIX_MESSAGE_PASSING       POSIX.4 message queues are supported.
 110    _POSIX_SEMAPHORES            POSIX.4 counting semaphores are supported.
 111    _POSIX_SHARED_MEMORY_OBJECTS POSIX.4 shared memory objects are supported.
 112    _POSIX_THREADS               POSIX.1c pthreads are supported.
 113    _POSIX_THREAD_ATTR_STACKADDR Thread stack address attribute option supported.
 114    _POSIX_THREAD_ATTR_STACKSIZE Thread stack size attribute option supported.
 115    _POSIX_THREAD_SAFE_FUNCTIONS Thread-safe functions are supported.
 116    _POSIX_THREAD_PRIORITY_SCHEDULING
 117                                 POSIX.1c thread execution scheduling supported.
 118    _POSIX_THREAD_PRIO_INHERIT   Thread priority inheritance option supported.
 119    _POSIX_THREAD_PRIO_PROTECT   Thread priority protection option supported.
 120    _POSIX_THREAD_PROCESS_SHARED Process-shared synchronization supported.
 121    _POSIX_PII                   Protocol-independent interfaces are supported.
 122    _POSIX_PII_XTI               XTI protocol-indep. interfaces are supported.
 123    _POSIX_PII_SOCKET            Socket protocol-indep. interfaces are supported.
 124    _POSIX_PII_INTERNET          Internet family of protocols supported.
 125    _POSIX_PII_INTERNET_STREAM   Connection-mode Internet protocol supported.
 126    _POSIX_PII_INTERNET_DGRAM    Connectionless Internet protocol supported.
 127    _POSIX_PII_OSI               ISO/OSI family of protocols supported.
 128    _POSIX_PII_OSI_COTS          Connection-mode ISO/OSI service supported.
 129    _POSIX_PII_OSI_CLTS          Connectionless ISO/OSI service supported.
 130    _POSIX_POLL                  Implementation supports `poll' function.
 131    _POSIX_SELECT                Implementation supports `select' and `pselect'.
 132
 133    _XOPEN_REALTIME              X/Open realtime support is available.
 134    _XOPEN_REALTIME_THREADS      X/Open realtime thread support is available.
 135    _XOPEN_SHM                   Shared memory interface according to XPG4.2.
 136
 137    _XBS5_ILP32_OFF32            Implementation provides environment with 32-bit
 138                                 int, long, pointer, and off_t types.
 139    _XBS5_ILP32_OFFBIG           Implementation provides environment with 32-bit
 140                                 int, long, and pointer and off_t with at least
 141                                 64 bits.
 142    _XBS5_LP64_OFF64             Implementation provides environment with 32-bit
 143                                 int, and 64-bit long, pointer, and off_t types.
 144    _XBS5_LPBIG_OFFBIG           Implementation provides environment with at
 145                                 least 32 bits int and long, pointer, and off_t
 146                                 with at least 64 bits.
 147
 148    If any of these symbols is defined as -1, the corresponding option is not
 149    true for any file.  If any is defined as other than -1, the corresponding
 150    option is true for all files.  If a symbol is not defined at all, the value
 151    for a specific file can be obtained from `pathconf' and `fpathconf'.
 152
 153    _POSIX_CHOWN_RESTRICTED      Only the super user can use `chown' to change
 154                                 the owner of a file.  `chown' can only be used
 155                                 to change the group ID of a file to a group of
 156                                 which the calling process is a member.
 157    _POSIX_NO_TRUNC              Pathname components longer than
 158                                 NAME_MAX generate an error.
 159    _POSIX_VDISABLE              If defined, if the value of an element of the
 160                                 `c_cc' member of `struct termios' is
 161                                 _POSIX_VDISABLE, no character will have the
 162                                 effect associated with that element.
 163    _POSIX_SYNC_IO               Synchronous I/O may be performed.
 164    _POSIX_ASYNC_IO              Asynchronous I/O may be performed.
 165    _POSIX_PRIO_IO               Prioritized Asynchronous I/O may be performed.
 166
 167    Support for the Large File Support interface is not generally available.
 168    If it is available the following constants are defined to one.
 169    _LFS64_LARGEFILE             Low-level I/O supports large files.
 170    _LFS64_STDIO                 Standard I/O supports large files.
 171    */
 172
 173 #include <bits/posix_opt.h>
 174
 175 /* Get the environment definitions from Unix98.  */
 176 #ifdef __USE_UNIX98
 177 # include <bits/environments.h>
 178 #endif
 179
 180 /* Standard file descriptors.  */
 181 #define STDIN_FILENO    0       /* Standard input.  */
 182 #define STDOUT_FILENO   1       /* Standard output.  */
 183 #define STDERR_FILENO   2       /* Standard error output.  */
 184
 185
 186 /* All functions that are not declared anywhere else.  */
 187
 188 #include <bits/types.h>
 189
 190 #ifndef __ssize_t_defined
 191 typedef __ssize_t ssize_t;
 192 # define __ssize_t_defined
 193 #endif
 194
 195 #define __need_size_t
 196 #define __need_NULL
 197 #include <stddef.h>
 198
 199 #if defined __USE_XOPEN || defined __USE_XOPEN2K
 200 /* The Single Unix specification says that some more types are
 201    available here.  */
 202 # ifndef __gid_t_defined
 203 typedef __gid_t gid_t;
 204 #  define __gid_t_defined
 205 # endif
 206
 207 # ifndef __uid_t_defined
 208 typedef __uid_t uid_t;
 209 #  define __uid_t_defined
 210 # endif
 211
 212 # ifndef __off_t_defined
 213 #  ifndef __USE_FILE_OFFSET64
 214 typedef __off_t off_t;
 215 #  else
 216 typedef __off64_t off_t;
 217 #  endif
 218 #  define __off_t_defined
 219 # endif
 220 # if defined __USE_LARGEFILE64 && !defined __off64_t_defined
 221 typedef __off64_t off64_t;
 222 #  define __off64_t_defined
 223 # endif
 224
 225 # ifndef __useconds_t_defined
 226 typedef __useconds_t useconds_t;
 227 #  define __useconds_t_defined
 228 # endif
 229
 230 # ifndef __pid_t_defined
 231 typedef __pid_t pid_t;
 232 #  define __pid_t_defined
 233 # endif
 234 #endif  /* X/Open */
 235
 236 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 237 # ifndef __intptr_t_defined
 238 typedef __intptr_t intptr_t;
 239 #  define __intptr_t_defined
 240 # endif
 241 #endif
 242
 243 #if defined __USE_BSD || defined __USE_XOPEN
 244 # ifndef __socklen_t_defined
 245 typedef __socklen_t socklen_t;
 246 #  define __socklen_t_defined
 247 # endif
 248 #endif
 249
 250 /* Values for the second argument to access.
 251    These may be OR'd together.  */
 252 #define R_OK    4               /* Test for read permission.  */
 253 #define W_OK    2               /* Test for write permission.  */
 254 #define X_OK    1               /* Test for execute permission.  */
 255 #define F_OK    0               /* Test for existence.  */
 256
 257 /* Test for access to NAME using the real UID and real GID.  */
 258 extern int access (__const char *__name, int __type) __THROW __nonnull ((1));
 259
 260 #ifdef __USE_GNU
 261 /* Test for access to NAME using the effective UID and GID
 262    (as normal file operations use).  */
 263 extern int euidaccess (__const char *__name, int __type)
 264      __THROW __nonnull ((1));
 265
 266 /* An alias for `euidaccess', used by some other systems.  */
 267 extern int eaccess (__const char *__name, int __type)
 268      __THROW __nonnull ((1));
 269 #endif
 270
 271 #ifdef __USE_ATFILE
 272 /* Test for access to FILE relative to the directory FD is open on.
 273    If AT_EACCESS is set in FLAG, then use effective IDs like `eaccess',
 274    otherwise use real IDs like `access'.  */
 275 extern int faccessat (int __fd, __const char *__file, int __type, int __flag)
 276      __THROW __nonnull ((2)) __wur;
 277 #endif /* Use GNU.  */
 278
 279
 280 /* Values for the WHENCE argument to lseek.  */
 281 #ifndef _STDIO_H                /* <stdio.h> has the same definitions.  */
 282 # define SEEK_SET       0       /* Seek from beginning of file.  */
 283 # define SEEK_CUR       1       /* Seek from current position.  */
 284 # define SEEK_END       2       /* Seek from end of file.  */
 285 #endif
 286
 287 #if defined __USE_BSD && !defined L_SET
 288 /* Old BSD names for the same constants; just for compatibility.  */
 289 # define L_SET          SEEK_SET
 290 # define L_INCR         SEEK_CUR
 291 # define L_XTND         SEEK_END
 292 #endif
 293
 294
 295 /* Move FD's file position to OFFSET bytes from the
 296    beginning of the file (if WHENCE is SEEK_SET),
 297    the current position (if WHENCE is SEEK_CUR),
 298    or the end of the file (if WHENCE is SEEK_END).
 299    Return the new file position.  */
 300 #ifndef __USE_FILE_OFFSET64
 301 extern __off_t lseek (int __fd, __off_t __offset, int __whence) __THROW;
 302 #else
 303 # ifdef __REDIRECT_NTH
 304 extern __off64_t __REDIRECT_NTH (lseek,
 305                                  (int __fd, __off64_t __offset, int __whence),
 306                                  lseek64);
 307 # else
 308 #  define lseek lseek64
 309 # endif
 310 #endif
 311 #ifdef __USE_LARGEFILE64
 312 extern __off64_t lseek64 (int __fd, __off64_t __offset, int __whence)
 313      __THROW;
 314 #endif
 315
 316 /* Close the file descriptor FD.
 317
 318    This function is a cancellation point and therefore not marked with
 319    __THROW.  */
 320 extern int close (int __fd);
 321
 322 /* Read NBYTES into BUF from FD.  Return the
 323    number read, -1 for errors or 0 for EOF.
 324
 325    This function is a cancellation point and therefore not marked with
 326    __THROW.  */
 327 extern ssize_t read (int __fd, void *__buf, size_t __nbytes) __wur;
 328
 329 /* Write N bytes of BUF to FD.  Return the number written, or -1.
 330
 331    This function is a cancellation point and therefore not marked with
 332    __THROW.  */
 333 extern ssize_t write (int __fd, __const void *__buf, size_t __n) __wur;
 334
 335 #ifdef __USE_UNIX98
 336 # ifndef __USE_FILE_OFFSET64
 337 /* Read NBYTES into BUF from FD at the given position OFFSET without
 338    changing the file pointer.  Return the number read, -1 for errors
 339    or 0 for EOF.
 340
 341    This function is a cancellation point and therefore not marked with
 342    __THROW.  */
 343 extern ssize_t pread (int __fd, void *__buf, size_t __nbytes,
 344                       __off_t __offset) __wur;
 345
 346 /* Write N bytes of BUF to FD at the given position OFFSET without
 347    changing the file pointer.  Return the number written, or -1.
 348
 349    This function is a cancellation point and therefore not marked with
 350    __THROW.  */
 351 extern ssize_t pwrite (int __fd, __const void *__buf, size_t __n,
 352                        __off_t __offset) __wur;
 353 # else
 354 #  ifdef __REDIRECT
 355 extern ssize_t __REDIRECT (pread, (int __fd, void *__buf, size_t __nbytes,
 356                                    __off64_t __offset),
 357                            pread64) __wur;
 358 extern ssize_t __REDIRECT (pwrite, (int __fd, __const void *__buf,
 359                                     size_t __nbytes, __off64_t __offset),
 360                            pwrite64) __wur;
 361 #  else
 362 #   define pread pread64
 363 #   define pwrite pwrite64
 364 #  endif
 365 # endif
 366
 367 # ifdef __USE_LARGEFILE64
 368 /* Read NBYTES into BUF from FD at the given position OFFSET without
 369    changing the file pointer.  Return the number read, -1 for errors
 370    or 0 for EOF.  */
 371 extern ssize_t pread64 (int __fd, void *__buf, size_t __nbytes,
 372                         __off64_t __offset) __wur;
 373 /* Write N bytes of BUF to FD at the given position OFFSET without
 374    changing the file pointer.  Return the number written, or -1.  */
 375 extern ssize_t pwrite64 (int __fd, __const void *__buf, size_t __n,
 376                          __off64_t __offset) __wur;
 377 # endif
 378 #endif
 379
 380 /* Create a one-way communication channel (pipe).
 381    If successful, two file descriptors are stored in PIPEDES;
 382    bytes written on PIPEDES[1] can be read from PIPEDES[0].
 383    Returns 0 if successful, -1 if not.  */
 384 extern int pipe (int __pipedes[2]) __THROW __wur;
 385
 386 #ifdef __USE_GNU
 387 /* Same as pipe but apply flags passed in FLAGS to the new file
 388    descriptors.  */
 389 extern int pipe2 (int __pipedes[2], int __flags) __THROW __wur;
 390 #endif
 391
 392 /* Schedule an alarm.  In SECONDS seconds, the process will get a SIGALRM.
 393    If SECONDS is zero, any currently scheduled alarm will be cancelled.
 394    The function returns the number of seconds remaining until the last
 395    alarm scheduled would have signaled, or zero if there wasn't one.
 396    There is no return value to indicate an error, but you can set `errno'
 397    to 0 and check its value after calling `alarm', and this might tell you.
 398    The signal may come late due to processor scheduling.  */
 399 extern unsigned int alarm (unsigned int __seconds) __THROW;
 400
 401 /* Make the process sleep for SECONDS seconds, or until a signal arrives
 402    and is not ignored.  The function returns the number of seconds less
 403    than SECONDS which it actually slept (thus zero if it slept the full time).
 404    If a signal handler does a `longjmp' or modifies the handling of the
 405    SIGALRM signal while inside `sleep' call, the handling of the SIGALRM
 406    signal afterwards is undefined.  There is no return value to indicate
 407    error, but if `sleep' returns SECONDS, it probably didn't work.
 408
 409    This function is a cancellation point and therefore not marked with
 410    __THROW.  */
 411 extern unsigned int sleep (unsigned int __seconds);
 412
 413 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 414 /* Set an alarm to go off (generating a SIGALRM signal) in VALUE
 415    microseconds.  If INTERVAL is nonzero, when the alarm goes off, the
 416    timer is reset to go off every INTERVAL microseconds thereafter.
 417    Returns the number of microseconds remaining before the alarm.  */
 418 extern __useconds_t ualarm (__useconds_t __value, __useconds_t __interval)
 419      __THROW;
 420
 421 /* Sleep USECONDS microseconds, or until a signal arrives that is not blocked
 422    or ignored.
 423
 424    This function is a cancellation point and therefore not marked with
 425    __THROW.  */
 426 extern int usleep (__useconds_t __useconds);
 427 #endif
 428
 429
 430 /* Suspend the process until a signal arrives.
 431    This always returns -1 and sets `errno' to EINTR.
 432
 433    This function is a cancellation point and therefore not marked with
 434    __THROW.  */
 435 extern int pause (void);
 436
 437
 438 /* Change the owner and group of FILE.  */
 439 extern int chown (__const char *__file, __uid_t __owner, __gid_t __group)
 440      __THROW __nonnull ((1)) __wur;
 441
 442 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 443 /* Change the owner and group of the file that FD is open on.  */
 444 extern int fchown (int __fd, __uid_t __owner, __gid_t __group) __THROW __wur;
 445
 446
 447 /* Change owner and group of FILE, if it is a symbolic
 448    link the ownership of the symbolic link is changed.  */
 449 extern int lchown (__const char *__file, __uid_t __owner, __gid_t __group)
 450      __THROW __nonnull ((1)) __wur;
 451
 452 #endif /* Use BSD || X/Open Unix.  */
 453
 454 #ifdef __USE_ATFILE
 455 /* Change the owner and group of FILE relative to the directory FD is open
 456    on.  */
 457 extern int fchownat (int __fd, __const char *__file, __uid_t __owner,
 458                      __gid_t __group, int __flag)
 459      __THROW __nonnull ((2)) __wur;
 460 #endif /* Use GNU.  */
 461
 462 /* Change the process's working directory to PATH.  */
 463 extern int chdir (__const char *__path) __THROW __nonnull ((1)) __wur;
 464
 465 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 466 /* Change the process's working directory to the one FD is open on.  */
 467 extern int fchdir (int __fd) __THROW __wur;
 468 #endif
 469
 470 /* Get the pathname of the current working directory,
 471    and put it in SIZE bytes of BUF.  Returns NULL if the
 472    directory couldn't be determined or SIZE was too small.
 473    If successful, returns BUF.  In GNU, if BUF is NULL,
 474    an array is allocated with `malloc'; the array is SIZE
 475    bytes long, unless SIZE == 0, in which case it is as
 476    big as necessary.  */
 477 extern char *getcwd (char *__buf, size_t __size) __THROW __wur;
 478
 479 #ifdef  __USE_GNU
 480 /* Return a malloc'd string containing the current directory name.
 481    If the environment variable `PWD' is set, and its value is correct,
 482    that value is used.  */
 483 extern char *get_current_dir_name (void) __THROW;
 484 #endif
 485
 486 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 487 /* Put the absolute pathname of the current working directory in BUF.
 488    If successful, return BUF.  If not, put an error message in
 489    BUF and return NULL.  BUF should be at least PATH_MAX bytes long.  */
 490 extern char *getwd (char *__buf)
 491      __THROW __nonnull ((1)) __attribute_deprecated__ __wur;
 492 #endif
 493
 494
 495 /* Duplicate FD, returning a new file descriptor on the same file.  */
 496 extern int dup (int __fd) __THROW __wur;
 497
 498 /* Duplicate FD to FD2, closing FD2 and making it open on the same file.  */
 499 extern int dup2 (int __fd, int __fd2) __THROW;
 500
 501 #ifdef __USE_GNU
 502 /* Duplicate FD to FD2, closing FD2 and making it open on the same
 503    file while setting flags according to FLAGS.  */
 504 extern int dup3 (int __fd, int __fd2, int __flags) __THROW;
 505 #endif
 506
 507 /* NULL-terminated array of "NAME=VALUE" environment variables.  */
 508 extern char **__environ;
 509 #ifdef __USE_GNU
 510 extern char **environ;
 511 #endif
 512
 513
 514 /* Replace the current process, executing PATH with arguments ARGV and
 515    environment ENVP.  ARGV and ENVP are terminated by NULL pointers.  */
 516 extern int execve (__const char *__path, char *__const __argv[],
 517                    char *__const __envp[]) __THROW __nonnull ((1));
 518
 519 #ifdef __USE_GNU
 520 /* Execute the file FD refers to, overlaying the running program image.
 521    ARGV and ENVP are passed to the new program, as for `execve'.  */
 522 extern int fexecve (int __fd, char *__const __argv[], char *__const __envp[])
 523      __THROW;
 524 #endif
 525
 526
 527 /* Execute PATH with arguments ARGV and environment from `environ'.  */
 528 extern int execv (__const char *__path, char *__const __argv[])
 529      __THROW __nonnull ((1));
 530
 531 /* Execute PATH with all arguments after PATH until a NULL pointer,
 532    and the argument after that for environment.  */
 533 extern int execle (__const char *__path, __const char *__arg, ...)
 534      __THROW __nonnull ((1));
 535
 536 /* Execute PATH with all arguments after PATH until
 537    a NULL pointer and environment from `environ'.  */
 538 extern int execl (__const char *__path, __const char *__arg, ...)
 539      __THROW __nonnull ((1));
 540
 541 /* Execute FILE, searching in the `PATH' environment variable if it contains
 542    no slashes, with arguments ARGV and environment from `environ'.  */
 543 extern int execvp (__const char *__file, char *__const __argv[])
 544      __THROW __nonnull ((1));
 545
 546 /* Execute FILE, searching in the `PATH' environment variable if
 547    it contains no slashes, with all arguments after FILE until a
 548    NULL pointer and environment from `environ'.  */
 549 extern int execlp (__const char *__file, __const char *__arg, ...)
 550      __THROW __nonnull ((1));
 551
 552
 553 #if defined __USE_MISC || defined __USE_XOPEN
 554 /* Add INC to priority of the current process.  */
 555 extern int nice (int __inc) __THROW __wur;
 556 #endif
 557
 558
 559 /* Terminate program execution with the low-order 8 bits of STATUS.  */
 560 extern void _exit (int __status) __attribute__ ((__noreturn__));
 561
 562
 563 /* Get the `_PC_*' symbols for the NAME argument to `pathconf' and `fpathconf';
 564    the `_SC_*' symbols for the NAME argument to `sysconf';
 565    and the `_CS_*' symbols for the NAME argument to `confstr'.  */
 566 #include <bits/confname.h>
 567
 568 /* Get file-specific configuration information about PATH.  */
 569 extern long int pathconf (__const char *__path, int __name)
 570      __THROW __nonnull ((1));
 571
 572 /* Get file-specific configuration about descriptor FD.  */
 573 extern long int fpathconf (int __fd, int __name) __THROW;
 574
 575 /* Get the value of the system variable NAME.  */
 576 extern long int sysconf (int __name) __THROW;
 577
 578 #ifdef  __USE_POSIX2
 579 /* Get the value of the string-valued system variable NAME.  */
 580 extern size_t confstr (int __name, char *__buf, size_t __len) __THROW;
 581 #endif
 582
 583
 584 /* Get the process ID of the calling process.  */
 585 extern __pid_t getpid (void) __THROW;
 586
 587 /* Get the process ID of the calling process's parent.  */
 588 extern __pid_t getppid (void) __THROW;
 589
 590 /* Get the process group ID of the calling process.
 591    This function is different on old BSD. */
 592 #ifndef __FAVOR_BSD
 593 extern __pid_t getpgrp (void) __THROW;
 594 #else
 595 # ifdef __REDIRECT_NTH
 596 extern __pid_t __REDIRECT_NTH (getpgrp, (__pid_t __pid), __getpgid);
 597 # else
 598 #  define getpgrp __getpgid
 599 # endif
 600 #endif
 601
 602 /* Get the process group ID of process PID.  */
 603 extern __pid_t __getpgid (__pid_t __pid) __THROW;
 604 #ifdef __USE_XOPEN_EXTENDED
 605 extern __pid_t getpgid (__pid_t __pid) __THROW;
 606 #endif
 607
 608
 609 /* Set the process group ID of the process matching PID to PGID.
 610    If PID is zero, the current process's process group ID is set.
 611    If PGID is zero, the process ID of the process is used.  */
 612 extern int setpgid (__pid_t __pid, __pid_t __pgid) __THROW;
 613
 614 #if defined __USE_SVID || defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 615 /* Both System V and BSD have `setpgrp' functions, but with different
 616    calling conventions.  The BSD function is the same as POSIX.1 `setpgid'
 617    (above).  The System V function takes no arguments and puts the calling
 618    process in its on group like `setpgid (0, 0)'.
 619
 620    New programs should always use `setpgid' instead.
 621
 622    The default in GNU is to provide the System V function.  The BSD
 623    function is available under -D_BSD_SOURCE.  */
 624
 625 # ifndef __FAVOR_BSD
 626
 627 /* Set the process group ID of the calling process to its own PID.
 628    This is exactly the same as `setpgid (0, 0)'.  */
 629 extern int setpgrp (void) __THROW;
 630
 631 # else
 632
 633 /* Another name for `setpgid' (above).  */
 634 #  ifdef __REDIRECT_NTH
 635 extern int __REDIRECT_NTH (setpgrp, (__pid_t __pid, __pid_t __pgrp), setpgid);
 636 #  else
 637 #   define setpgrp setpgid
 638 #  endif
 639
 640 # endif /* Favor BSD.  */
 641 #endif  /* Use SVID or BSD.  */
 642
 643 /* Create a new session with the calling process as its leader.
 644    The process group IDs of the session and the calling process
 645    are set to the process ID of the calling process, which is returned.  */
 646 extern __pid_t setsid (void) __THROW;
 647
 648 #ifdef __USE_XOPEN_EXTENDED
 649 /* Return the session ID of the given process.  */
 650 extern __pid_t getsid (__pid_t __pid) __THROW;
 651 #endif
 652
 653 /* Get the real user ID of the calling process.  */
 654 extern __uid_t getuid (void) __THROW;
 655
 656 /* Get the effective user ID of the calling process.  */
 657 extern __uid_t geteuid (void) __THROW;
 658
 659 /* Get the real group ID of the calling process.  */
 660 extern __gid_t getgid (void) __THROW;
 661
 662 /* Get the effective group ID of the calling process.  */
 663 extern __gid_t getegid (void) __THROW;
 664
 665 /* If SIZE is zero, return the number of supplementary groups
 666    the calling process is in.  Otherwise, fill in the group IDs
 667    of its supplementary groups in LIST and return the number written.  */
 668 extern int getgroups (int __size, __gid_t __list[]) __THROW __wur;
 669
 670 #ifdef  __USE_GNU
 671 /* Return nonzero iff the calling process is in group GID.  */
 672 extern int group_member (__gid_t __gid) __THROW;
 673 #endif
 674
 675 /* Set the user ID of the calling process to UID.
 676    If the calling process is the super-user, set the real
 677    and effective user IDs, and the saved set-user-ID to UID;
 678    if not, the effective user ID is set to UID.  */
 679 extern int setuid (__uid_t __uid) __THROW;
 680
 681 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 682 /* Set the real user ID of the calling process to RUID,
 683    and the effective user ID of the calling process to EUID.  */
 684 extern int setreuid (__uid_t __ruid, __uid_t __euid) __THROW;
 685 #endif
 686
 687 #if defined __USE_BSD || defined __USE_XOPEN2K
 688 /* Set the effective user ID of the calling process to UID.  */
 689 extern int seteuid (__uid_t __uid) __THROW;
 690 #endif /* Use BSD.  */
 691
 692 /* Set the group ID of the calling process to GID.
 693    If the calling process is the super-user, set the real
 694    and effective group IDs, and the saved set-group-ID to GID;
 695    if not, the effective group ID is set to GID.  */
 696 extern int setgid (__gid_t __gid) __THROW;
 697
 698 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 699 /* Set the real group ID of the calling process to RGID,
 700    and the effective group ID of the calling process to EGID.  */
 701 extern int setregid (__gid_t __rgid, __gid_t __egid) __THROW;
 702 #endif
 703
 704 #if defined __USE_BSD || defined __USE_XOPEN2K
 705 /* Set the effective group ID of the calling process to GID.  */
 706 extern int setegid (__gid_t __gid) __THROW;
 707 #endif /* Use BSD.  */
 708
 709 #ifdef __USE_GNU
 710 /* Fetch the real user ID, effective user ID, and saved-set user ID,
 711    of the calling process.  */
 712 extern int getresuid (__uid_t *__ruid, __uid_t *__euid, __uid_t *__suid)
 713      __THROW;
 714
 715 /* Fetch the real group ID, effective group ID, and saved-set group ID,
 716    of the calling process.  */
 717 extern int getresgid (__gid_t *__rgid, __gid_t *__egid, __gid_t *__sgid)
 718      __THROW;
 719
 720 /* Set the real user ID, effective user ID, and saved-set user ID,
 721    of the calling process to RUID, EUID, and SUID, respectively.  */
 722 extern int setresuid (__uid_t __ruid, __uid_t __euid, __uid_t __suid)
 723      __THROW;
 724
 725 /* Set the real group ID, effective group ID, and saved-set group ID,
 726    of the calling process to RGID, EGID, and SGID, respectively.  */
 727 extern int setresgid (__gid_t __rgid, __gid_t __egid, __gid_t __sgid)
 728      __THROW;
 729 #endif
 730
 731
 732 /* Clone the calling process, creating an exact copy.
 733    Return -1 for errors, 0 to the new process,
 734    and the process ID of the new process to the old process.  */
 735 extern __pid_t fork (void) __THROW;
 736
 737 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 738 /* Clone the calling process, but without copying the whole address space.
 739    The calling process is suspended until the new process exits or is
 740    replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
 741    and the process ID of the new process to the old process.  */
 742 extern __pid_t vfork (void) __THROW;
 743 #endif /* Use BSD. */
 744
 745
 746 /* Return the pathname of the terminal FD is open on, or NULL on errors.
 747    The returned storage is good only until the next call to this function.  */
 748 extern char *ttyname (int __fd) __THROW;
 749
 750 /* Store at most BUFLEN characters of the pathname of the terminal FD is
 751    open on in BUF.  Return 0 on success, otherwise an error number.  */
 752 extern int ttyname_r (int __fd, char *__buf, size_t __buflen)
 753      __THROW __nonnull ((2)) __wur;
 754
 755 /* Return 1 if FD is a valid descriptor associated
 756    with a terminal, zero if not.  */
 757 extern int isatty (int __fd) __THROW;
 758
 759 #if defined __USE_BSD \
 760     || (defined __USE_XOPEN_EXTENDED && !defined __USE_UNIX98)
 761 /* Return the index into the active-logins file (utmp) for
 762    the controlling terminal.  */
 763 extern int ttyslot (void) __THROW;
 764 #endif
 765
 766
 767 /* Make a link to FROM named TO.  */
 768 extern int link (__const char *__from, __const char *__to)
 769      __THROW __nonnull ((1, 2)) __wur;
 770
 771 #ifdef __USE_ATFILE
 772 /* Like link but relative paths in TO and FROM are interpreted relative
 773    to FROMFD and TOFD respectively.  */
 774 extern int linkat (int __fromfd, __const char *__from, int __tofd,
 775                    __const char *__to, int __flags)
 776      __THROW __nonnull ((2, 4)) __wur;
 777 #endif
 778
 779 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
 780 /* Make a symbolic link to FROM named TO.  */
 781 extern int symlink (__const char *__from, __const char *__to)
 782      __THROW __nonnull ((1, 2)) __wur;
 783
 784 /* Read the contents of the symbolic link PATH into no more than
 785    LEN bytes of BUF.  The contents are not null-terminated.
 786    Returns the number of characters read, or -1 for errors.  */
 787 extern ssize_t readlink (__const char *__restrict __path,
 788                          char *__restrict __buf, size_t __len)
 789      __THROW __nonnull ((1, 2)) __wur;
 790 #endif /* Use BSD.  */
 791
 792 #ifdef __USE_ATFILE
 793 /* Like symlink but a relative path in TO is interpreted relative to TOFD.  */
 794 extern int symlinkat (__const char *__from, int __tofd,
 795                       __const char *__to) __THROW __nonnull ((1, 3)) __wur;
 796
 797 /* Like readlink but a relative PATH is interpreted relative to FD.  */
 798 extern ssize_t readlinkat (int __fd, __const char *__restrict __path,
 799                            char *__restrict __buf, size_t __len)
 800      __THROW __nonnull ((2, 3)) __wur;
 801 #endif
 802
 803 /* Remove the link NAME.  */
 804 extern int unlink (__const char *__name) __THROW __nonnull ((1));
 805
 806 #ifdef __USE_ATFILE
 807 /* Remove the link NAME relative to FD.  */
 808 extern int unlinkat (int __fd, __const char *__name, int __flag)
 809      __THROW __nonnull ((2));
 810 #endif
 811
 812 /* Remove the directory PATH.  */
 813 extern int rmdir (__const char *__path) __THROW __nonnull ((1));
 814
 815
 816 /* Return the foreground process group ID of FD.  */
 817 extern __pid_t tcgetpgrp (int __fd) __THROW;
 818
 819 /* Set the foreground process group ID of FD set PGRP_ID.  */
 820 extern int tcsetpgrp (int __fd, __pid_t __pgrp_id) __THROW;
 821
 822
 823 /* Return the login name of the user.
 824
 825    This function is a possible cancellation points and therefore not
 826    marked with __THROW.  */
 827 extern char *getlogin (void);
 828 #if defined __USE_REENTRANT || defined __USE_POSIX199506
 829 /* Return at most NAME_LEN characters of the login name of the user in NAME.
 830    If it cannot be determined or some other error occurred, return the error
 831    code.  Otherwise return 0.
 832
 833    This function is a possible cancellation points and therefore not
 834    marked with __THROW.  */
 835 extern int getlogin_r (char *__name, size_t __name_len) __nonnull ((1));
 836 #endif
 837
 838 #ifdef  __USE_BSD
 839 /* Set the login name returned by `getlogin'.  */
 840 extern int setlogin (__const char *__name) __THROW __nonnull ((1));
 841 #endif
 842
 843
 844 #ifdef  __USE_POSIX2
 845 /* Get definitions and prototypes for functions to process the
 846    arguments in ARGV (ARGC of them, minus the program name) for
 847    options given in OPTS.  */
 848 # define __need_getopt
 849 # include <getopt.h>
 850 #endif
 851
 852
 853 #if defined __USE_BSD || defined __USE_UNIX98
 854 /* Put the name of the current host in no more than LEN bytes of NAME.
 855    The result is null-terminated if LEN is large enough for the full
 856    name and the terminator.  */
 857 extern int gethostname (char *__name, size_t __len) __THROW __nonnull ((1));
 858 #endif
 859
 860
 861 #if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_UNIX98)
 862 /* Set the name of the current host to NAME, which is LEN bytes long.
 863    This call is restricted to the super-user.  */
 864 extern int sethostname (__const char *__name, size_t __len)
 865      __THROW __nonnull ((1)) __wur;
 866
 867 /* Set the current machine's Internet number to ID.
 868    This call is restricted to the super-user.  */
 869 extern int sethostid (long int __id) __THROW __wur;
 870
 871
 872 /* Get and set the NIS (aka YP) domain name, if any.
 873    Called just like `gethostname' and `sethostname'.
 874    The NIS domain name is usually the empty string when not using NIS.  */
 875 extern int getdomainname (char *__name, size_t __len)
 876      __THROW __nonnull ((1)) __wur;
 877 extern int setdomainname (__const char *__name, size_t __len)
 878      __THROW __nonnull ((1)) __wur;
 879
 880
 881 /* Revoke access permissions to all processes currently communicating
 882    with the control terminal, and then send a SIGHUP signal to the process
 883    group of the control terminal.  */
 884 extern int vhangup (void) __THROW;
 885
 886 /* Revoke the access of all descriptors currently open on FILE.  */
 887 extern int revoke (__const char *__file) __THROW __nonnull ((1)) __wur;
 888
 889
 890 /* Enable statistical profiling, writing samples of the PC into at most
 891    SIZE bytes of SAMPLE_BUFFER; every processor clock tick while profiling
 892    is enabled, the system examines the user PC and increments
 893    SAMPLE_BUFFER[((PC - OFFSET) / 2) * SCALE / 65536].  If SCALE is zero,
 894    disable profiling.  Returns zero on success, -1 on error.  */
 895 extern int profil (unsigned short int *__sample_buffer, size_t __size,
 896                    size_t __offset, unsigned int __scale)
 897      __THROW __nonnull ((1));
 898
 899
 900 /* Turn accounting on if NAME is an existing file.  The system will then write
 901    a record for each process as it terminates, to this file.  If NAME is NULL,
 902    turn accounting off.  This call is restricted to the super-user.  */
 903 extern int acct (__const char *__name) __THROW;
 904
 905
 906 /* Successive calls return the shells listed in `/etc/shells'.  */
 907 extern char *getusershell (void) __THROW;
 908 extern void endusershell (void) __THROW; /* Discard cached info.  */
 909 extern void setusershell (void) __THROW; /* Rewind and re-read the file.  */
 910
 911
 912 /* Put the program in the background, and dissociate from the controlling
 913    terminal.  If NOCHDIR is zero, do `chdir ("/")'.  If NOCLOSE is zero,
 914    redirects stdin, stdout, and stderr to /dev/null.  */
 915 extern int daemon (int __nochdir, int __noclose) __THROW __wur;
 916 #endif /* Use BSD || X/Open.  */
 917
 918
 919 #if defined __USE_BSD || (defined __USE_XOPEN && !defined __USE_XOPEN2K)
 920 /* Make PATH be the root directory (the starting point for absolute paths).
 921    This call is restricted to the super-user.  */
 922 extern int chroot (__const char *__path) __THROW __nonnull ((1)) __wur;
 923
 924 /* Prompt with PROMPT and read a string from the terminal without echoing.
 925    Uses /dev/tty if possible; otherwise stderr and stdin.  */
 926 extern char *getpass (__const char *__prompt) __nonnull ((1));
 927 #endif /* Use BSD || X/Open.  */
 928
 929
 930 #if defined __USE_BSD || defined __USE_XOPEN || defined __USE_XOPEN2K
 931 /* Make all changes done to FD actually appear on disk.
 932
 933    This function is a cancellation point and therefore not marked with
 934    __THROW.  */
 935 extern int fsync (int __fd);
 936 #endif /* Use BSD || X/Open || Unix98.  */
 937
 938
 939 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 940
 941 /* Return identifier for the current host.  */
 942 extern long int gethostid (void);
 943
 944 /* Make all changes done to all files actually appear on disk.  */
 945 extern void sync (void) __THROW;
 946
 947
 948 /* Return the number of bytes in a page.  This is the system's page size,
 949    which is not necessarily the same as the hardware page size.  */
 950 extern int getpagesize (void)  __THROW __attribute__ ((__const__));
 951
 952
 953 /* Return the maximum number of file descriptors
 954    the current process could possibly have.  */
 955 extern int getdtablesize (void) __THROW;
 956
 957
 958 /* Truncate FILE to LENGTH bytes.  */
 959 # ifndef __USE_FILE_OFFSET64
 960 extern int truncate (__const char *__file, __off_t __length)
 961      __THROW __nonnull ((1)) __wur;
 962 # else
 963 #  ifdef __REDIRECT_NTH
 964 extern int __REDIRECT_NTH (truncate,
 965                            (__const char *__file, __off64_t __length),
 966                            truncate64) __nonnull ((1)) __wur;
 967 #  else
 968 #   define truncate truncate64
 969 #  endif
 970 # endif
 971 # ifdef __USE_LARGEFILE64
 972 extern int truncate64 (__const char *__file, __off64_t __length)
 973      __THROW __nonnull ((1)) __wur;
 974 # endif
 975
 976 #endif /* Use BSD || X/Open Unix.  */
 977
 978 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED || defined __USE_XOPEN2K
 979
 980 /* Truncate the file FD is open on to LENGTH bytes.  */
 981 # ifndef __USE_FILE_OFFSET64
 982 extern int ftruncate (int __fd, __off_t __length) __THROW __wur;
 983 # else
 984 #  ifdef __REDIRECT_NTH
 985 extern int __REDIRECT_NTH (ftruncate, (int __fd, __off64_t __length),
 986                            ftruncate64) __wur;
 987 #  else
 988 #   define ftruncate ftruncate64
 989 #  endif
 990 # endif
 991 # ifdef __USE_LARGEFILE64
 992 extern int ftruncate64 (int __fd, __off64_t __length) __THROW __wur;
 993 # endif
 994
 995 #endif /* Use BSD || X/Open Unix || POSIX 2003.  */
 996
 997
 998 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 999
1000 /* Set the end of accessible data space (aka "the break") to ADDR.
1001    Returns zero on success and -1 for errors (with errno set).  */
1002 extern int brk (void *__addr) __THROW __wur;
1003
1004 /* Increase or decrease the end of accessible data space by DELTA bytes.
1005    If successful, returns the address the previous end of data space
1006    (i.e. the beginning of the new space, if DELTA > 0);
1007    returns (void *) -1 for errors (with errno set).  */
1008 extern void *sbrk (intptr_t __delta) __THROW;
1009 #endif
1010
1011
1012 #ifdef __USE_MISC
1013 /* Invoke `system call' number SYSNO, passing it the remaining arguments.
1014    This is completely system-dependent, and not often useful.
1015
1016    In Unix, `syscall' sets `errno' for all errors and most calls return -1
1017    for errors; in many systems you cannot pass arguments or get return
1018    values for all system calls (`pipe', `fork', and `getppid' typically
1019    among them).
1020
1021    In Mach, all system calls take normal arguments and always return an
1022    error code (zero for success).  */
1023 extern long int syscall (long int __sysno, ...) __THROW;
1024
1025 #endif  /* Use misc.  */
1026
1027
1028 #if (defined __USE_MISC || defined __USE_XOPEN_EXTENDED) && !defined F_LOCK
1029 /* NOTE: These declarations also appear in <fcntl.h>; be sure to keep both
1030    files consistent.  Some systems have them there and some here, and some
1031    software depends on the macros being defined without including both.  */
1032
1033 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
1034    LEN is always relative to the current file position.
1035    The CMD argument is one of the following.
1036
1037    This function is a cancellation point and therefore not marked with
1038    __THROW.  */
1039
1040 # define F_ULOCK 0      /* Unlock a previously locked region.  */
1041 # define F_LOCK  1      /* Lock a region for exclusive use.  */
1042 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
1043 # define F_TEST  3      /* Test a region for other processes locks.  */
1044
1045 # ifndef __USE_FILE_OFFSET64
1046 extern int lockf (int __fd, int __cmd, __off_t __len) __wur;
1047 # else
1048 #  ifdef __REDIRECT
1049 extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len),
1050                        lockf64) __wur;
1051 #  else
1052 #   define lockf lockf64
1053 #  endif
1054 # endif
1055 # ifdef __USE_LARGEFILE64
1056 extern int lockf64 (int __fd, int __cmd, __off64_t __len) __wur;
1057 # endif
1058 #endif /* Use misc and F_LOCK not already defined.  */
1059
1060
1061 #ifdef __USE_GNU
1062
1063 /* Evaluate EXPRESSION, and repeat as long as it returns -1 with `errno'
1064    set to EINTR.  */
1065
1066 # define TEMP_FAILURE_RETRY(expression) \
1067   (__extension__                                                              \
1068     ({ long int __result;                                                     \
1069        do __result = (long int) (expression);                                 \
1070        while (__result == -1L && errno == EINTR);                             \
1071        __result; }))
1072 #endif
1073
1074 #if defined __USE_POSIX199309 || defined __USE_UNIX98
1075 /* Synchronize at least the data part of a file with the underlying
1076    media.  */
1077 extern int fdatasync (int __fildes);
1078 #endif /* Use POSIX199309 */
1079
1080
1081 /* XPG4.2 specifies that prototypes for the encryption functions must
1082    be defined here.  */
1083 #ifdef  __USE_XOPEN
1084 /* Encrypt at most 8 characters from KEY using salt to perturb DES.  */
1085 extern char *crypt (__const char *__key, __const char *__salt)
1086      __THROW __nonnull ((1, 2));
1087
1088 /* Encrypt data in BLOCK in place if EDFLAG is zero; otherwise decrypt
1089    block in place.  */
1090 extern void encrypt (char *__block, int __edflag) __THROW __nonnull ((1));
1091
1092
1093 /* Swab pairs bytes in the first N bytes of the area pointed to by
1094    FROM and copy the result to TO.  The value of TO must not be in the
1095    range [FROM - N + 1, FROM - 1].  If N is odd the first byte in FROM
1096    is without partner.  */
1097 extern void swab (__const void *__restrict __from, void *__restrict __to,
1098                   ssize_t __n) __THROW __nonnull ((1, 2));
1099 #endif
1100
1101
1102 /* The Single Unix specification demands this prototype to be here.
1103    It is also found in <stdio.h>.  */
1104 #ifdef __USE_XOPEN
1105 /* Return the name of the controlling terminal.  */
1106 extern char *ctermid (char *__s) __THROW;
1107 #endif
1108
1109
1110 /* Define some macros helping to catch buffer overflows.  */
1111 #if __USE_FORTIFY_LEVEL > 0 && defined __extern_always_inline
1112 # include <bits/unistd.h>
1113 #endif
1114
1115 __END_DECLS
1116
1117 #endif /* unistd.h  */