stdlib/stdlib.h

   1 /* Copyright (C) 1991,92,93,94,95,96,97,98 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  *      ISO C Standard: 4.10 GENERAL UTILITIES  <stdlib.h>
  21  */
  22
  23 #ifndef _STDLIB_H
  24 #define _STDLIB_H       1
  25
  26 #include <features.h>
  27
  28 /* Get size_t, wchar_t and NULL from <stddef.h>.  */
  29 #define __need_size_t
  30 #define __need_wchar_t
  31 #define __need_NULL
  32 #include <stddef.h>
  33
  34 __BEGIN_DECLS
  35
  36 /* Returned by `div'.  */
  37 typedef struct
  38   {
  39     int quot;                   /* Quotient.  */
  40     int rem;                    /* Remainder.  */
  41   } div_t;
  42
  43 /* Returned by `ldiv'.  */
  44 typedef struct
  45   {
  46     long int quot;              /* Quotient.  */
  47     long int rem;               /* Remainder.  */
  48   } ldiv_t;
  49
  50 #ifdef __USE_ISOC9X
  51 /* Returned by `lldiv'.  */
  52 typedef struct
  53   {
  54     long long int quot;         /* Quotient.  */
  55     long long int rem;          /* Remainder.  */
  56   } lldiv_t;
  57 #endif
  58
  59
  60 /* The largest number rand will return (same as INT_MAX).  */
  61 #define RAND_MAX        2147483647
  62
  63
  64 /* We define these the same for all machines.
  65    Changes from this to the outside world should be done in `_exit'.  */
  66 #define EXIT_FAILURE    1       /* Failing exit status.  */
  67 #define EXIT_SUCCESS    0       /* Successful exit status.  */
  68
  69
  70 /* Maximum length of a multibyte character in the current locale.  */
  71 #define MB_CUR_MAX      (__ctype_get_mb_cur_max ())
  72 extern int __ctype_get_mb_cur_max __P ((void));
  73
  74
  75 /* Convert a string to a floating-point number.  */
  76 extern double atof __P ((__const char *__nptr));
  77 /* Convert a string to an integer.  */
  78 extern int atoi __P ((__const char *__nptr));
  79 /* Convert a string to a long integer.  */
  80 extern long int atol __P ((__const char *__nptr));
  81
  82 #if defined __USE_ISOC9X || (defined __GNUC__ && defined __USE_MISC)
  83 /* These functions will part of the standard C library in ISO C 9X.  */
  84 extern long long int atoll __P ((__const char *__nptr));
  85 #endif
  86
  87 /* Convert a string to a floating-point number.  */
  88 extern double strtod __P ((__const char *__restrict __nptr,
  89                            char **__restrict __endptr));
  90
  91 #ifdef  __USE_GNU
  92 /* Likewise for `float' and `long double' sizes of floating-point numbers.  */
  93 extern float strtof __P ((__const char *__restrict __nptr,
  94                           char **__restrict __endptr));
  95
  96 extern __long_double_t strtold __P ((__const char *__restrict __nptr,
  97                                      char **__restrict __endptr));
  98 #endif
  99
 100 /* Convert a string to a long integer.  */
 101 extern long int strtol __P ((__const char *__restrict __nptr,
 102                              char **__restrict __endptr, int __base));
 103 /* Convert a string to an unsigned long integer.  */
 104 extern unsigned long int strtoul __P ((__const char *__restrict __nptr,
 105                                        char **__restrict __endptr,
 106                                        int __base));
 107
 108 #if defined __GNUC__ && defined __USE_BSD
 109 /* Convert a string to a quadword integer.  */
 110 extern long long int strtoq __P ((__const char *__restrict __nptr,
 111                                   char **__restrict __endptr, int __base));
 112 /* Convert a string to an unsigned quadword integer.  */
 113 extern unsigned long long int strtouq __P ((__const char *__restrict __nptr,
 114                                             char **__restrict __endptr,
 115                                             int __base));
 116 #endif /* GCC and use BSD.  */
 117
 118 #if defined __USE_ISOC9X || (defined __GNUC__ && defined __USE_MISC)
 119 /* These functions will part of the standard C library in ISO C 9X.  */
 120
 121 /* Convert a string to a quadword integer.  */
 122 extern long long int strtoll __P ((__const char *__restrict __nptr,
 123                                    char **__restrict __endptr, int __base));
 124 /* Convert a string to an unsigned quadword integer.  */
 125 extern unsigned long long int strtoull __P ((__const char *__restrict __nptr,
 126                                              char **__restrict __endptr,
 127                                              int __base));
 128 #endif /* ISO C 9X or GCC and use MISC.  */
 129
 130
 131 #ifdef __USE_GNU
 132 /* The concept of one static locale per category is not very well
 133    thought out.  Many applications will need to process its data using
 134    information from several different locales.  Another application is
 135    the implementation of the internationalization handling in the
 136    upcoming ISO C++ standard library.  To support this another set of
 137    the functions using locale data exist which have an additional
 138    argument.
 139
 140    Attention: all these functions are *not* standardized in any form.
 141    This is a proof-of-concept implementation.  */
 142
 143 /* Structure for reentrant locale using functions.  This is an
 144    (almost) opaque type for the user level programs.  */
 145 # include <xlocale.h>
 146
 147 /* Special versions of the functions above which take the locale to
 148    use as an additional parameter.  */
 149 extern long int __strtol_l __P ((__const char *__restrict __nptr,
 150                                  char **__restrict __endptr, int __base,
 151                                  __locale_t __loc));
 152
 153 extern unsigned long int __strtoul_l __P ((__const char *__restrict __nptr,
 154                                            char **__restrict __endptr,
 155                                            int __base, __locale_t __loc));
 156
 157 extern long long int __strtoll_l __P ((__const char *__restrict __nptr,
 158                                        char **__restrict __endptr, int __base,
 159                                        __locale_t __loc));
 160
 161 extern unsigned long long int __strtoull_l __P ((__const char *__restrict
 162                                                  __nptr,
 163                                                  char **__restrict __endptr,
 164                                                  int __base,
 165                                                  __locale_t __loc));
 166
 167 extern double __strtod_l __P ((__const char *__restrict __nptr,
 168                                char **__restrict __endptr, __locale_t __loc));
 169
 170 extern float __strtof_l __P ((__const char *__restrict __nptr,
 171                               char **__restrict __endptr, __locale_t __loc));
 172
 173 extern __long_double_t __strtold_l __P ((__const char *__restrict __nptr,
 174                                          char **__restrict __endptr,
 175                                          __locale_t __loc));
 176 #endif /* GNU */
 177
 178
 179 /* The internal entry points for `strtoX' take an extra flag argument
 180    saying whether or not to parse locale-dependent number grouping.  */
 181
 182 extern double __strtod_internal __P ((__const char *__restrict __nptr,
 183                                       char **__restrict __endptr,
 184                                       int __group));
 185 extern float __strtof_internal __P ((__const char *__restrict __nptr,
 186                                      char **__restrict __endptr, int __group));
 187 extern __long_double_t __strtold_internal __P ((__const char *
 188                                                 __restrict __nptr,
 189                                                 char **__restrict __endptr,
 190                                                 int __group));
 191 #ifndef __strtol_internal_defined
 192 extern long int __strtol_internal __P ((__const char *__restrict __nptr,
 193                                         char **__restrict __endptr,
 194                                         int __base, int __group));
 195 # define __strtol_internal_defined      1
 196 #endif
 197 #ifndef __strtoul_internal_defined
 198 extern unsigned long int __strtoul_internal __P ((__const char *
 199                                                   __restrict __nptr,
 200                                                   char **__restrict __endptr,
 201                                                   int __base, int __group));
 202 # define __strtoul_internal_defined     1
 203 #endif
 204 #if defined __GNUC__ || defined __USE_ISOC9X
 205 # ifndef __strtoll_internal_defined
 206 extern long long int __strtoll_internal __P ((__const char *__restrict __nptr,
 207                                               char **__restrict __endptr,
 208                                               int __base, int __group));
 209 #  define __strtoll_internal_defined    1
 210 # endif
 211 # ifndef __strtoull_internal_defined
 212 extern unsigned long long int __strtoull_internal __P ((__const char *
 213                                                         __restrict __nptr,
 214                                                         char **
 215                                                         __restrict __endptr,
 216                                                         int __base,
 217                                                         int __group));
 218 #  define __strtoull_internal_defined   1
 219 # endif
 220 #endif /* GCC */
 221
 222 #if defined __OPTIMIZE__ && !defined __OPTIMIZE_SIZE__ && __GNUC__ >= 2
 223 /* Define inline functions which call the internal entry points.  */
 224
 225 extern __inline double
 226 strtod (__const char *__restrict __nptr, char **__restrict __endptr)
 227 {
 228   return __strtod_internal (__nptr, __endptr, 0);
 229 }
 230 extern __inline long int
 231 strtol (__const char *__restrict __nptr, char **__restrict __endptr,
 232         int __base)
 233 {
 234   return __strtol_internal (__nptr, __endptr, __base, 0);
 235 }
 236 extern __inline unsigned long int
 237 strtoul (__const char *__restrict __nptr, char **__restrict __endptr,
 238          int __base)
 239 {
 240   return __strtoul_internal (__nptr, __endptr, __base, 0);
 241 }
 242
 243 # ifdef __USE_GNU
 244 extern __inline float
 245 strtof (__const char *__restrict __nptr, char **__restrict __endptr)
 246 {
 247   return __strtof_internal (__nptr, __endptr, 0);
 248 }
 249 extern __inline __long_double_t
 250 strtold (__const char *__restrict __nptr, char **__restrict __endptr)
 251 {
 252   return __strtold_internal (__nptr, __endptr, 0);
 253 }
 254 # endif
 255
 256 # ifdef __USE_BSD
 257 extern __inline long long int
 258 strtoq (__const char *__restrict __nptr, char **__restrict __endptr,
 259         int __base)
 260 {
 261   return __strtoll_internal (__nptr, __endptr, __base, 0);
 262 }
 263 extern __inline unsigned long long int
 264 strtouq (__const char *__restrict __nptr, char **__restrict __endptr,
 265          int __base)
 266 {
 267   return __strtoull_internal (__nptr, __endptr, __base, 0);
 268 }
 269 # endif
 270
 271 # if defined __USE_MISC || defined __USE_ISOC9X
 272 extern __inline long long int
 273 strtoll (__const char *__restrict __nptr, char **__restrict __endptr,
 274          int __base)
 275 {
 276   return __strtoll_internal (__nptr, __endptr, __base, 0);
 277 }
 278 extern __inline unsigned long long int
 279 strtoull (__const char * __restrict __nptr, char **__restrict __endptr,
 280           int __base)
 281 {
 282   return __strtoull_internal (__nptr, __endptr, __base, 0);
 283 }
 284 # endif
 285
 286 extern __inline double
 287 atof (__const char *__nptr)
 288 {
 289   return strtod (__nptr, (char **) NULL);
 290 }
 291 extern __inline int
 292 atoi (__const char *__nptr)
 293 {
 294   return (int) strtol (__nptr, (char **) NULL, 10);
 295 }
 296 extern __inline long int
 297 atol (__const char *__nptr)
 298 {
 299   return strtol (__nptr, (char **) NULL, 10);
 300 }
 301
 302 # if defined __USE_MISC || defined __USE_ISOC9X
 303 extern __inline long long int
 304 atoll (__const char *__nptr)
 305 {
 306   return strtoll (__nptr, (char **) NULL, 10);
 307 }
 308 # endif
 309 #endif /* Optimizing GCC >=2.  */
 310
 311
 312 #if defined __USE_SVID || defined __USE_XOPEN_EXTENDED
 313 /* Convert N to base 64 using the digits "./0-9A-Za-z", least-significant
 314    digit first.  Returns a pointer to static storage overwritten by the
 315    next call.  */
 316 extern char *l64a __P ((long int __n));
 317
 318 /* Read a number from a string S in base 64 as above.  */
 319 extern long int a64l __P ((__const char *__s));
 320
 321
 322 # include <sys/types.h> /* we need int32_t... */
 323
 324 /* These are the functions that actually do things.  The `random', `srandom',
 325    `initstate' and `setstate' functions are those from BSD Unices.
 326    The `rand' and `srand' functions are required by the ANSI standard.
 327    We provide both interfaces to the same random number generator.  */
 328 /* Return a random long integer between 0 and RAND_MAX inclusive.  */
 329 extern int32_t random __P ((void));
 330
 331 /* Seed the random number generator with the given number.  */
 332 extern void srandom __P ((unsigned int __seed));
 333
 334 /* Initialize the random number generator to use state buffer STATEBUF,
 335    of length STATELEN, and seed it with SEED.  Optimal lengths are 8, 16,
 336    32, 64, 128 and 256, the bigger the better; values less than 8 will
 337    cause an error and values greater than 256 will be rounded down.  */
 338 extern __ptr_t initstate __P ((unsigned int __seed, __ptr_t __statebuf,
 339                                size_t __statelen));
 340
 341 /* Switch the random number generator to state buffer STATEBUF,
 342    which should have been previously initialized by `initstate'.  */
 343 extern __ptr_t setstate __P ((__ptr_t __statebuf));
 344
 345
 346 # ifdef __USE_MISC
 347 /* Reentrant versions of the `random' family of functions.
 348    These functions all use the following data structure to contain
 349    state, rather than global state variables.  */
 350
 351 struct random_data
 352   {
 353     int32_t *fptr;              /* Front pointer.  */
 354     int32_t *rptr;              /* Rear pointer.  */
 355     int32_t *state;             /* Array of state values.  */
 356     int rand_type;              /* Type of random number generator.  */
 357     int rand_deg;               /* Degree of random number generator.  */
 358     int rand_sep;               /* Distance between front and rear.  */
 359     int32_t *end_ptr;           /* Pointer behind state table.  */
 360   };
 361
 362 extern int random_r __P ((struct random_data *__buf, int32_t *__result));
 363
 364 extern int srandom_r __P ((unsigned int __seed, struct random_data *__buf));
 365
 366 extern int initstate_r __P ((unsigned int __seed, __ptr_t __statebuf,
 367                              size_t __statelen, struct random_data *__buf));
 368
 369 extern int setstate_r __P ((__ptr_t __statebuf, struct random_data *__buf));
 370 # endif /* Use misc.  */
 371 #endif  /* Use SVID || extended X/Open.  */
 372
 373
 374 /* Return a random integer between 0 and RAND_MAX inclusive.  */
 375 extern int rand __P ((void));
 376 /* Seed the random number generator with the given number.  */
 377 extern void srand __P ((unsigned int __seed));
 378
 379 #ifdef __USE_POSIX
 380 /* Reentrant interface according to POSIX.1.  */
 381 extern int rand_r __P ((unsigned int *__seed));
 382 #endif
 383
 384
 385 #if defined __USE_SVID || defined __USE_XOPEN
 386 /* System V style 48-bit random number generator functions.  */
 387
 388 /* Return non-negative, double-precision floating-point value in [0.0,1.0).  */
 389 extern double drand48 __P ((void));
 390 extern double erand48 __P ((unsigned short int __xsubi[3]));
 391
 392 /* Return non-negative, long integer in [0,2^31).  */
 393 extern long int lrand48 __P ((void));
 394 extern long int nrand48 __P ((unsigned short int __xsubi[3]));
 395
 396 /* Return signed, long integers in [-2^31,2^31).  */
 397 extern long int mrand48 __P ((void));
 398 extern long int jrand48 __P ((unsigned short int __xsubi[3]));
 399
 400 /* Seed random number generator.  */
 401 extern void srand48 __P ((long int __seedval));
 402 extern unsigned short int *seed48 __P ((unsigned short int __seed16v[3]));
 403 extern void lcong48 __P ((unsigned short int __param[7]));
 404
 405 /* Data structure for communication with thread safe versions.  */
 406 struct drand48_data
 407   {
 408     unsigned short int x[3];    /* Current state.  */
 409     unsigned short int a[3];    /* Factor in congruential formula.  */
 410     unsigned short int c;       /* Additive const. in congruential formula.  */
 411     unsigned short int old_x[3]; /* Old state.  */
 412     int init;                   /* Flag for initializing.  */
 413   };
 414
 415 # ifdef __USE_MISC
 416 /* Return non-negative, double-precision floating-point value in [0.0,1.0).  */
 417 extern int drand48_r __P ((struct drand48_data *__buffer, double *__result));
 418 extern int erand48_r __P ((unsigned short int __xsubi[3],
 419                            struct drand48_data *__buffer, double *__result));
 420
 421 /* Return non-negative, long integer in [0,2^31).  */
 422 extern int lrand48_r __P ((struct drand48_data *__buffer, long int *__result));
 423 extern int nrand48_r __P ((unsigned short int __xsubi[3],
 424                            struct drand48_data *__buffer, long int *__result));
 425
 426 /* Return signed, long integers in [-2^31,2^31).  */
 427 extern int mrand48_r __P ((struct drand48_data *__buffer, long int *__result));
 428 extern int jrand48_r __P ((unsigned short int __xsubi[3],
 429                            struct drand48_data *__buffer, long int *__result));
 430
 431 /* Seed random number generator.  */
 432 extern int srand48_r __P ((long int __seedval, struct drand48_data *__buffer));
 433
 434 extern int seed48_r __P ((unsigned short int __seed16v[3],
 435                           struct drand48_data *__buffer));
 436
 437 extern int lcong48_r __P ((unsigned short int __param[7],
 438                            struct drand48_data *__buffer));
 439 # endif /* Use misc.  */
 440 #endif  /* Use SVID or X/Open.  */
 441
 442
 443 /* Allocate SIZE bytes of memory.  */
 444 extern __ptr_t malloc __P ((size_t __size));
 445 /* Re-allocate the previously allocated block
 446    in __ptr_t, making the new block SIZE bytes long.  */
 447 extern __ptr_t realloc __P ((__ptr_t __ptr, size_t __size));
 448 /* Allocate NMEMB elements of SIZE bytes each, all initialized to 0.  */
 449 extern __ptr_t calloc __P ((size_t __nmemb, size_t __size));
 450 /* Free a block allocated by `malloc', `realloc' or `calloc'.  */
 451 extern void free __P ((__ptr_t __ptr));
 452
 453 #ifdef  __USE_MISC
 454 /* Free a block.  An alias for `free'.  (Sun Unices).  */
 455 extern void cfree __P ((__ptr_t __ptr));
 456 #endif /* Use misc.  */
 457
 458 #if defined __USE_GNU || defined __USE_BSD || defined __USE_MISC
 459 # include <alloca.h>
 460 #endif /* Use GNU, BSD, or misc.  */
 461
 462 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 463 /* Allocate SIZE bytes on a page boundary.  The storage cannot be freed.  */
 464 extern __ptr_t valloc __P ((size_t __size));
 465 #endif
 466
 467
 468 /* Abort execution and generate a core-dump.  */
 469 extern void abort __P ((void)) __attribute__ ((__noreturn__));
 470
 471
 472 /* Register a function to be called when `exit' is called.  */
 473 extern int atexit __P ((void (*__func) (void)));
 474
 475 #ifdef  __USE_MISC
 476 /* Register a function to be called with the status
 477    given to `exit' and the given argument.  */
 478 extern int __on_exit __P ((void (*__func) (int __status, __ptr_t __arg),
 479                            __ptr_t __arg));
 480 extern int on_exit __P ((void (*__func) (int __status, __ptr_t __arg),
 481                          __ptr_t __arg));
 482 #endif
 483
 484 /* Call all functions registered with `atexit' and `on_exit',
 485    in the reverse of the order in which they were registered
 486    perform stdio cleanup, and terminate program execution with STATUS.  */
 487 extern void exit __P ((int __status)) __attribute__ ((__noreturn__));
 488
 489
 490 /* Return the value of envariable NAME, or NULL if it doesn't exist.  */
 491 extern char *getenv __P ((__const char *__name));
 492
 493 /* This function is similar to the above but returns NULL if the
 494    programs is running with SUID or SGID enabled.  */
 495 extern char *__secure_getenv __P ((__const char *__name));
 496
 497 #if defined __USE_SVID || defined __USE_XOPEN
 498 /* The SVID says this is in <stdio.h>, but this seems a better place.   */
 499 /* Put STRING, which is of the form "NAME=VALUE", in the environment.
 500    If there is no `=', remove NAME from the environment.  */
 501 extern int putenv __P ((__const char *__string));
 502 #endif
 503
 504 #ifdef  __USE_BSD
 505 /* Set NAME to VALUE in the environment.
 506    If REPLACE is nonzero, overwrite an existing value.  */
 507 extern int setenv __P ((__const char *__name, __const char *__value,
 508                         int __replace));
 509
 510 /* Remove the variable NAME from the environment.  */
 511 extern void unsetenv __P ((__const char *__name));
 512 #endif
 513
 514 #ifdef  __USE_MISC
 515 /* The `clearenv' was planned to be added to POSIX.1 but probably
 516    never made it.  Nevertheless the POSIX.9 standard (POSIX bindings
 517    for Fortran 77) requires this function.  */
 518 extern int clearenv __P ((void));
 519 #endif
 520
 521
 522 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 523 /* Generate a unique temporary file name from TEMPLATE.
 524    The last six characters of TEMPLATE must be "XXXXXX";
 525    they are replaced with a string that makes the file name unique.
 526    Returns TEMPLATE, or a null pointer if it cannot get a unique file name.  */
 527 extern char *mktemp __P ((char *__template));
 528
 529 /* Generate a unique temporary file name from TEMPLATE.
 530    The last six characters of TEMPLATE must be "XXXXXX";
 531    they are replaced with a string that makes the filename unique.
 532    Returns a file descriptor open on the file for reading and writing,
 533    or -1 if it cannot create a uniquely-named file.  */
 534 extern int mkstemp __P ((char *__template));
 535 #endif
 536
 537
 538 /* Execute the given line as a shell command.  */
 539 extern int system __P ((__const char *__command));
 540
 541
 542 #ifdef  __USE_GNU
 543 /* Return a malloc'd string containing the canonical absolute name of the
 544    named file.  The last file name component need not exist, and may be a
 545    symlink to a nonexistent file.  */
 546 extern char *canonicalize_file_name __P ((__const char *__name));
 547 #endif
 548
 549 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 550 /* Return the canonical absolute name of file NAME.  The last file name
 551    component need not exist, and may be a symlink to a nonexistent file.
 552    If RESOLVED is null, the result is malloc'd; otherwise, if the canonical
 553    name is PATH_MAX chars or more, returns null with `errno' set to
 554    ENAMETOOLONG; if the name fits in fewer than PATH_MAX chars, returns the
 555    name in RESOLVED.  */
 556 extern char *realpath __P ((__const char *__name, char *__resolved));
 557 #endif
 558
 559
 560 /* Shorthand for type of comparison functions.  */
 561 #ifndef __COMPAR_FN_T
 562 # define __COMPAR_FN_T
 563 typedef int (*__compar_fn_t) __PMT ((__const __ptr_t, __const __ptr_t));
 564
 565 # ifdef __USE_GNU
 566 typedef __compar_fn_t comparison_fn_t;
 567 # endif
 568 #endif
 569
 570 /* Do a binary search for KEY in BASE, which consists of NMEMB elements
 571    of SIZE bytes each, using COMPAR to perform the comparisons.  */
 572 extern __ptr_t bsearch __PMT ((__const __ptr_t __key, __const __ptr_t __base,
 573                                size_t __nmemb, size_t __size,
 574                                __compar_fn_t __compar));
 575
 576 /* Sort NMEMB elements of BASE, of SIZE bytes each,
 577    using COMPAR to perform the comparisons.  */
 578 extern void qsort __PMT ((__ptr_t __base, size_t __nmemb, size_t __size,
 579                           __compar_fn_t __compar));
 580
 581
 582 /* Return the absolute value of X.  */
 583 extern int abs __P ((int __x)) __attribute__ ((__const__));
 584 extern long int labs __P ((long int __x)) __attribute__ ((__const__));
 585 #ifdef __USE_ISOC9X
 586 extern long long int llabs __P ((long long int __x))
 587      __attribute__ ((__const__));
 588 #endif
 589
 590
 591 /* Return the `div_t', `ldiv_t' or `lldiv_t' representation
 592    of the value of NUMER over DENOM. */
 593 /* GCC may have built-ins for these someday.  */
 594 extern div_t div __P ((int __numer, int __denom)) __attribute__ ((__const__));
 595 extern ldiv_t ldiv __P ((long int __numer, long int __denom))
 596      __attribute__ ((__const__));
 597 #ifdef __USE_ISOC9X
 598 extern lldiv_t lldiv __P ((long long int __numer, long long int __denom))
 599      __attribute__ ((__const__));
 600 #endif
 601
 602
 603 #if defined __USE_SVID || defined __USE_XOPEN_EXTENDED
 604 /* Convert floating point numbers to strings.  The returned values are
 605    valid only until another call to the same function.  */
 606
 607 /* Convert VALUE to a string with NDIGIT digits and return a pointer to
 608    this.  Set *DECPT with the position of the decimal character and *SIGN
 609    with the sign of the number.  */
 610 extern char *ecvt __P ((double __value, int __ndigit, int *__decpt,
 611                         int *__sign));
 612
 613 /* Convert VALUE to a string rounded to NDIGIT decimal digits.  Set *DECPT
 614    with the position of the decimal character and *SIGN with the sign of
 615    the number.  */
 616 extern char *fcvt __P ((double __value, int __ndigit, int *__decpt,
 617                         int *__sign));
 618
 619 /* If possible convert VALUE to a string with NDIGIT significant digits.
 620    Otherwise use exponential representation.  The resulting string will
 621    be written to BUF.  */
 622 extern char *gcvt __P ((double __value, int __ndigit, char *__buf));
 623
 624 /* Long double versions of above functions.  */
 625 extern char *qecvt __P ((__long_double_t __value, int __ndigit, int *__decpt,
 626                          int *__sign));
 627 extern char *qfcvt __P ((__long_double_t __value, int __ndigit, int *__decpt,
 628                          int *__sign));
 629 extern char *qgcvt __P ((__long_double_t __value, int __ndigit, char *__buf));
 630
 631
 632 # ifdef __USE_MISC
 633 /* Reentrant version of the functions above which provide their own
 634    buffers.  */
 635 extern int ecvt_r __P ((double __value, int __ndigit, int *__decpt,
 636                         int *__sign, char *__buf, size_t __len));
 637 extern int fcvt_r __P ((double __value, int __ndigit, int *__decpt,
 638                         int *__sign, char *__buf, size_t __len));
 639
 640 extern int qecvt_r __P ((__long_double_t __value, int __ndigit, int *__decpt,
 641                          int *__sign, char *__buf, size_t __len));
 642 extern int qfcvt_r __P ((__long_double_t __value, int __ndigit, int *__decpt,
 643                          int *__sign, char *__buf, size_t __len));
 644 # endif /* misc */
 645 #endif  /* use MISC || use X/Open Unix */
 646
 647
 648 /* Return the length of the multibyte character
 649    in S, which is no longer than N.  */
 650 extern int mblen __P ((__const char *__s, size_t __n));
 651 /* Return the length of the given multibyte character,
 652    putting its `wchar_t' representation in *PWC.  */
 653 extern int mbtowc __P ((wchar_t *__restrict __pwc,
 654                         __const char *__restrict __s, size_t __n));
 655 /* Put the multibyte character represented
 656    by WCHAR in S, returning its length.  */
 657 extern int wctomb __P ((char *__s, wchar_t __wchar));
 658
 659
 660 /* Convert a multibyte string to a wide char string.  */
 661 extern size_t mbstowcs __P ((wchar_t *__restrict  __pwcs,
 662                              __const char *__restrict __s, size_t __n));
 663 /* Convert a wide char string to multibyte string.  */
 664 extern size_t wcstombs __P ((char *__restrict __s,
 665                              __const wchar_t *__restrict __pwcs, size_t __n));
 666
 667
 668 #ifdef __USE_SVID
 669 /* Determine whether the string value of RESPONSE matches the affirmation
 670    or negative response expression as specified by the LC_MESSAGES category
 671    in the program's current locale.  Returns 1 if affirmative, 0 if
 672    negative, and -1 if not matching.  */
 673 extern int rpmatch __P ((__const char *__response));
 674 #endif
 675
 676
 677 #ifdef __USE_XOPEN_EXTENDED
 678 /* Parse comma separated suboption from *OPTIONP and match against
 679    strings in TOKENS.  If found return index and set *VALUEP to
 680    optional value introduced by an equal sign.  If the suboption is
 681    not part of TOKENS return in *VALUEP beginning of unknown
 682    suboption.  On exit *OPTIONP is set to the beginning of the next
 683    token or at the terminating NUL character.  */
 684 extern int getsubopt __P ((char **__optionp, __const char *__const *__tokens,
 685                            char **__valuep));
 686 #endif
 687
 688
 689 #ifdef __USE_XOPEN
 690
 691 /* Setup DES tables according KEY.  */
 692 extern void setkey __P ((__const char *__key));
 693
 694 /* X/Open pseudo terminal handling.  */
 695
 696 /* The next four functions all take a master pseudo-tty fd and
 697    perform an operation on the associated slave:  */
 698
 699 /* Chown the slave to the calling user.  */
 700 extern int grantpt __P ((int __fd));
 701
 702 /* Release an internal lock so the slave can be opened.
 703    Call after grantpt().  */
 704 extern int unlockpt __P ((int __fd));
 705
 706 /* Return the pathname of the pseudo terminal slave assoicated with
 707    the master FD is open on, or NULL on errors.
 708    The returned storage is good until the next call to this function.  */
 709 extern char *ptsname __P ((int __fd));
 710 #endif
 711
 712 #ifdef __USE_GNU
 713 /* Store at most BUFLEN characters of the pathname of the slave pseudo
 714    terminal associated with the master FD is open on in BUF.
 715    Return 0 on success, otherwise an error number.  */
 716 extern int ptsname_r __P ((int __fd, char *__buf, size_t __buflen));
 717
 718 /* Open a master pseudo terminal and return its file descriptor.  */
 719 extern int getpt __P ((void));
 720 #endif
 721
 722 __END_DECLS
 723
 724 #endif /* stdlib.h  */