stdlib/stdlib.h

   1 /* Copyright (C) 1991,92,93,94,95,96,97,98,99 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
  25 #include <features.h>
  26
  27 /* Get size_t, wchar_t and NULL from <stddef.h>.  */
  28 #define         __need_size_t
  29 #ifndef __need_malloc_and_calloc
  30 # define        __need_wchar_t
  31 # define        __need_NULL
  32 #endif
  33 #include <stddef.h>
  34
  35 __BEGIN_DECLS
  36
  37 #ifndef __need_malloc_and_calloc
  38 #define _STDLIB_H       1
  39
  40 /* Returned by `div'.  */
  41 typedef struct
  42   {
  43     int quot;                   /* Quotient.  */
  44     int rem;                    /* Remainder.  */
  45   } div_t;
  46
  47 /* Returned by `ldiv'.  */
  48 #ifndef __ldiv_t_defined
  49 typedef struct
  50   {
  51     long int quot;              /* Quotient.  */
  52     long int rem;               /* Remainder.  */
  53   } ldiv_t;
  54 # define __ldiv_t_defined       1
  55 #endif
  56
  57 #if defined __USE_ISOC9X && !defined __lldiv_t_defined
  58 /* Returned by `lldiv'.  */
  59 __extension__ typedef struct
  60   {
  61     long long int quot;         /* Quotient.  */
  62     long long int rem;          /* Remainder.  */
  63   } lldiv_t;
  64 # define __lldiv_t_defined      1
  65 #endif
  66
  67
  68 /* The largest number rand will return (same as INT_MAX).  */
  69 #define RAND_MAX        2147483647
  70
  71
  72 /* We define these the same for all machines.
  73    Changes from this to the outside world should be done in `_exit'.  */
  74 #define EXIT_FAILURE    1       /* Failing exit status.  */
  75 #define EXIT_SUCCESS    0       /* Successful exit status.  */
  76
  77
  78 /* Maximum length of a multibyte character in the current locale.  */
  79 #define MB_CUR_MAX      (__ctype_get_mb_cur_max ())
  80 extern size_t __ctype_get_mb_cur_max __P ((void));
  81
  82
  83 /* Convert a string to a floating-point number.  */
  84 extern double atof __P ((__const char *__nptr));
  85 /* Convert a string to an integer.  */
  86 extern int atoi __P ((__const char *__nptr));
  87 /* Convert a string to a long integer.  */
  88 extern long int atol __P ((__const char *__nptr));
  89
  90 #if defined __USE_ISOC9X || (defined __GNUC__ && defined __USE_MISC)
  91 /* These functions will part of the standard C library in ISO C 9X.  */
  92 __extension__ extern long long int atoll __P ((__const char *__nptr));
  93 #endif
  94
  95 /* Convert a string to a floating-point number.  */
  96 extern double strtod __P ((__const char *__restrict __nptr,
  97                            char **__restrict __endptr));
  98
  99 #ifdef  __USE_ISOC9X
 100 /* Likewise for `float' and `long double' sizes of floating-point numbers.  */
 101 extern float strtof __P ((__const char *__restrict __nptr,
 102                           char **__restrict __endptr));
 103
 104 extern __long_double_t strtold __P ((__const char *__restrict __nptr,
 105                                      char **__restrict __endptr));
 106 #endif
 107
 108 /* Convert a string to a long integer.  */
 109 extern long int strtol __P ((__const char *__restrict __nptr,
 110                              char **__restrict __endptr, int __base));
 111 /* Convert a string to an unsigned long integer.  */
 112 extern unsigned long int strtoul __P ((__const char *__restrict __nptr,
 113                                        char **__restrict __endptr,
 114                                        int __base));
 115
 116 #if defined __GNUC__ && defined __USE_BSD
 117 /* Convert a string to a quadword integer.  */
 118 __extension__
 119 extern long long int strtoq __P ((__const char *__restrict __nptr,
 120                                   char **__restrict __endptr, int __base));
 121 /* Convert a string to an unsigned quadword integer.  */
 122 __extension__
 123 extern unsigned long long int strtouq __P ((__const char *__restrict __nptr,
 124                                             char **__restrict __endptr,
 125                                             int __base));
 126 #endif /* GCC and use BSD.  */
 127
 128 #if defined __USE_ISOC9X || (defined __GNUC__ && defined __USE_MISC)
 129 /* These functions will part of the standard C library in ISO C 9X.  */
 130
 131 /* Convert a string to a quadword integer.  */
 132 __extension__
 133 extern long long int strtoll __P ((__const char *__restrict __nptr,
 134                                    char **__restrict __endptr, int __base));
 135 /* Convert a string to an unsigned quadword integer.  */
 136 __extension__
 137 extern unsigned long long int strtoull __P ((__const char *__restrict __nptr,
 138                                              char **__restrict __endptr,
 139                                              int __base));
 140 #endif /* ISO C 9X or GCC and use MISC.  */
 141
 142
 143 #ifdef __USE_GNU
 144 /* The concept of one static locale per category is not very well
 145    thought out.  Many applications will need to process its data using
 146    information from several different locales.  Another application is
 147    the implementation of the internationalization handling in the
 148    upcoming ISO C++ standard library.  To support this another set of
 149    the functions using locale data exist which have an additional
 150    argument.
 151
 152    Attention: all these functions are *not* standardized in any form.
 153    This is a proof-of-concept implementation.  */
 154
 155 /* Structure for reentrant locale using functions.  This is an
 156    (almost) opaque type for the user level programs.  */
 157 # include <xlocale.h>
 158
 159 /* Special versions of the functions above which take the locale to
 160    use as an additional parameter.  */
 161 extern long int __strtol_l __P ((__const char *__restrict __nptr,
 162                                  char **__restrict __endptr, int __base,
 163                                  __locale_t __loc));
 164
 165 extern unsigned long int __strtoul_l __P ((__const char *__restrict __nptr,
 166                                            char **__restrict __endptr,
 167                                            int __base, __locale_t __loc));
 168
 169 __extension__
 170 extern long long int __strtoll_l __P ((__const char *__restrict __nptr,
 171                                        char **__restrict __endptr, int __base,
 172                                        __locale_t __loc));
 173
 174 __extension__
 175 extern unsigned long long int __strtoull_l __P ((__const char *__restrict
 176                                                  __nptr,
 177                                                  char **__restrict __endptr,
 178                                                  int __base,
 179                                                  __locale_t __loc));
 180
 181 extern double __strtod_l __P ((__const char *__restrict __nptr,
 182                                char **__restrict __endptr, __locale_t __loc));
 183
 184 extern float __strtof_l __P ((__const char *__restrict __nptr,
 185                               char **__restrict __endptr, __locale_t __loc));
 186
 187 extern __long_double_t __strtold_l __P ((__const char *__restrict __nptr,
 188                                          char **__restrict __endptr,
 189                                          __locale_t __loc));
 190 #endif /* GNU */
 191
 192
 193 /* The internal entry points for `strtoX' take an extra flag argument
 194    saying whether or not to parse locale-dependent number grouping.  */
 195
 196 extern double __strtod_internal __P ((__const char *__restrict __nptr,
 197                                       char **__restrict __endptr,
 198                                       int __group));
 199 extern float __strtof_internal __P ((__const char *__restrict __nptr,
 200                                      char **__restrict __endptr, int __group));
 201 extern __long_double_t __strtold_internal __P ((__const char *
 202                                                 __restrict __nptr,
 203                                                 char **__restrict __endptr,
 204                                                 int __group));
 205 #ifndef __strtol_internal_defined
 206 extern long int __strtol_internal __P ((__const char *__restrict __nptr,
 207                                         char **__restrict __endptr,
 208                                         int __base, int __group));
 209 # define __strtol_internal_defined      1
 210 #endif
 211 #ifndef __strtoul_internal_defined
 212 extern unsigned long int __strtoul_internal __P ((__const char *
 213                                                   __restrict __nptr,
 214                                                   char **__restrict __endptr,
 215                                                   int __base, int __group));
 216 # define __strtoul_internal_defined     1
 217 #endif
 218 #if defined __GNUC__ || defined __USE_ISOC9X
 219 # ifndef __strtoll_internal_defined
 220 __extension__
 221 extern long long int __strtoll_internal __P ((__const char *__restrict __nptr,
 222                                               char **__restrict __endptr,
 223                                               int __base, int __group));
 224 #  define __strtoll_internal_defined    1
 225 # endif
 226 # ifndef __strtoull_internal_defined
 227 __extension__
 228 extern unsigned long long int __strtoull_internal __P ((__const char *
 229                                                         __restrict __nptr,
 230                                                         char **
 231                                                         __restrict __endptr,
 232                                                         int __base,
 233                                                         int __group));
 234 #  define __strtoull_internal_defined   1
 235 # endif
 236 #endif /* GCC */
 237
 238 #if defined __OPTIMIZE__ && !defined __OPTIMIZE_SIZE__ \
 239     && defined __USE_EXTERN_INLINES
 240 /* Define inline functions which call the internal entry points.  */
 241
 242 extern __inline double
 243 strtod (__const char *__restrict __nptr, char **__restrict __endptr) __THROW
 244 {
 245   return __strtod_internal (__nptr, __endptr, 0);
 246 }
 247 extern __inline long int
 248 strtol (__const char *__restrict __nptr, char **__restrict __endptr,
 249         int __base) __THROW
 250 {
 251   return __strtol_internal (__nptr, __endptr, __base, 0);
 252 }
 253 extern __inline unsigned long int
 254 strtoul (__const char *__restrict __nptr, char **__restrict __endptr,
 255          int __base) __THROW
 256 {
 257   return __strtoul_internal (__nptr, __endptr, __base, 0);
 258 }
 259
 260 # ifdef __USE_ISOC9X
 261 extern __inline float
 262 strtof (__const char *__restrict __nptr, char **__restrict __endptr) __THROW
 263 {
 264   return __strtof_internal (__nptr, __endptr, 0);
 265 }
 266 extern __inline __long_double_t
 267 strtold (__const char *__restrict __nptr, char **__restrict __endptr) __THROW
 268 {
 269   return __strtold_internal (__nptr, __endptr, 0);
 270 }
 271 # endif
 272
 273 # ifdef __USE_BSD
 274 __extension__ extern __inline long long int
 275 strtoq (__const char *__restrict __nptr, char **__restrict __endptr,
 276         int __base) __THROW
 277 {
 278   return __strtoll_internal (__nptr, __endptr, __base, 0);
 279 }
 280 __extension__ extern __inline unsigned long long int
 281 strtouq (__const char *__restrict __nptr, char **__restrict __endptr,
 282          int __base) __THROW
 283 {
 284   return __strtoull_internal (__nptr, __endptr, __base, 0);
 285 }
 286 # endif
 287
 288 # if defined __USE_MISC || defined __USE_ISOC9X
 289 __extension__ extern __inline long long int
 290 strtoll (__const char *__restrict __nptr, char **__restrict __endptr,
 291          int __base) __THROW
 292 {
 293   return __strtoll_internal (__nptr, __endptr, __base, 0);
 294 }
 295 __extension__ extern __inline unsigned long long int
 296 strtoull (__const char * __restrict __nptr, char **__restrict __endptr,
 297           int __base) __THROW
 298 {
 299   return __strtoull_internal (__nptr, __endptr, __base, 0);
 300 }
 301 # endif
 302
 303 extern __inline double
 304 atof (__const char *__nptr) __THROW
 305 {
 306   return strtod (__nptr, (char **) NULL);
 307 }
 308 extern __inline int
 309 atoi (__const char *__nptr) __THROW
 310 {
 311   return (int) strtol (__nptr, (char **) NULL, 10);
 312 }
 313 extern __inline long int
 314 atol (__const char *__nptr) __THROW
 315 {
 316   return strtol (__nptr, (char **) NULL, 10);
 317 }
 318
 319 # if defined __USE_MISC || defined __USE_ISOC9X
 320 __extension__ extern __inline long long int
 321 atoll (__const char *__nptr) __THROW
 322 {
 323   return strtoll (__nptr, (char **) NULL, 10);
 324 }
 325 # endif
 326 #endif /* Optimizing and Inlining.  */
 327
 328
 329 #if defined __USE_SVID || defined __USE_XOPEN_EXTENDED
 330 /* Convert N to base 64 using the digits "./0-9A-Za-z", least-significant
 331    digit first.  Returns a pointer to static storage overwritten by the
 332    next call.  */
 333 extern char *l64a __P ((long int __n));
 334
 335 /* Read a number from a string S in base 64 as above.  */
 336 extern long int a64l __P ((__const char *__s));
 337
 338
 339 # include <sys/types.h> /* we need int32_t... */
 340
 341 /* These are the functions that actually do things.  The `random', `srandom',
 342    `initstate' and `setstate' functions are those from BSD Unices.
 343    The `rand' and `srand' functions are required by the ANSI standard.
 344    We provide both interfaces to the same random number generator.  */
 345 /* Return a random long integer between 0 and RAND_MAX inclusive.  */
 346 extern int32_t random __P ((void));
 347
 348 /* Seed the random number generator with the given number.  */
 349 extern void srandom __P ((unsigned int __seed));
 350
 351 /* Initialize the random number generator to use state buffer STATEBUF,
 352    of length STATELEN, and seed it with SEED.  Optimal lengths are 8, 16,
 353    32, 64, 128 and 256, the bigger the better; values less than 8 will
 354    cause an error and values greater than 256 will be rounded down.  */
 355 extern __ptr_t initstate __P ((unsigned int __seed, __ptr_t __statebuf,
 356                                size_t __statelen));
 357
 358 /* Switch the random number generator to state buffer STATEBUF,
 359    which should have been previously initialized by `initstate'.  */
 360 extern __ptr_t setstate __P ((__ptr_t __statebuf));
 361
 362
 363 # ifdef __USE_MISC
 364 /* Reentrant versions of the `random' family of functions.
 365    These functions all use the following data structure to contain
 366    state, rather than global state variables.  */
 367
 368 struct random_data
 369   {
 370     int32_t *fptr;              /* Front pointer.  */
 371     int32_t *rptr;              /* Rear pointer.  */
 372     int32_t *state;             /* Array of state values.  */
 373     int rand_type;              /* Type of random number generator.  */
 374     int rand_deg;               /* Degree of random number generator.  */
 375     int rand_sep;               /* Distance between front and rear.  */
 376     int32_t *end_ptr;           /* Pointer behind state table.  */
 377   };
 378
 379 extern int random_r __P ((struct random_data *__restrict __buf,
 380                           int32_t *__restrict __result));
 381
 382 extern int srandom_r __P ((unsigned int __seed, struct random_data *__buf));
 383
 384 extern int initstate_r __P ((unsigned int __seed,
 385                              __ptr_t __restrict __statebuf,
 386                              size_t __statelen,
 387                              struct random_data *__restrict __buf));
 388
 389 extern int setstate_r __P ((__ptr_t __restrict __statebuf,
 390                             struct random_data *__restrict __buf));
 391 # endif /* Use misc.  */
 392 #endif  /* Use SVID || extended X/Open.  */
 393
 394
 395 /* Return a random integer between 0 and RAND_MAX inclusive.  */
 396 extern int rand __P ((void));
 397 /* Seed the random number generator with the given number.  */
 398 extern void srand __P ((unsigned int __seed));
 399
 400 #ifdef __USE_POSIX
 401 /* Reentrant interface according to POSIX.1.  */
 402 extern int rand_r __P ((unsigned int *__seed));
 403 #endif
 404
 405
 406 #if defined __USE_SVID || defined __USE_XOPEN
 407 /* System V style 48-bit random number generator functions.  */
 408
 409 /* Return non-negative, double-precision floating-point value in [0.0,1.0).  */
 410 extern double drand48 __P ((void));
 411 extern double erand48 __P ((unsigned short int __xsubi[3]));
 412
 413 /* Return non-negative, long integer in [0,2^31).  */
 414 extern long int lrand48 __P ((void));
 415 extern long int nrand48 __P ((unsigned short int __xsubi[3]));
 416
 417 /* Return signed, long integers in [-2^31,2^31).  */
 418 extern long int mrand48 __P ((void));
 419 extern long int jrand48 __P ((unsigned short int __xsubi[3]));
 420
 421 /* Seed random number generator.  */
 422 extern void srand48 __P ((long int __seedval));
 423 extern unsigned short int *seed48 __P ((unsigned short int __seed16v[3]));
 424 extern void lcong48 __P ((unsigned short int __param[7]));
 425
 426 /* Data structure for communication with thread safe versions.  */
 427 struct drand48_data
 428   {
 429     unsigned short int x[3];    /* Current state.  */
 430     unsigned short int a[3];    /* Factor in congruential formula.  */
 431     unsigned short int c;       /* Additive const. in congruential formula.  */
 432     unsigned short int old_x[3]; /* Old state.  */
 433     int init;                   /* Flag for initializing.  */
 434   };
 435
 436 # ifdef __USE_MISC
 437 /* Return non-negative, double-precision floating-point value in [0.0,1.0).  */
 438 extern int drand48_r __P ((struct drand48_data *__restrict __buffer,
 439                            double *__restrict __result));
 440 extern int erand48_r __P ((unsigned short int __xsubi[3],
 441                            struct drand48_data *__restrict __buffer,
 442                            double *__restrict __result));
 443
 444 /* Return non-negative, long integer in [0,2^31).  */
 445 extern int lrand48_r __P ((struct drand48_data *__restrict __buffer,
 446                            long int *__restrict __result));
 447 extern int nrand48_r __P ((unsigned short int __xsubi[3],
 448                            struct drand48_data *__restrict __buffer,
 449                            long int *__restrict __result));
 450
 451 /* Return signed, long integers in [-2^31,2^31).  */
 452 extern int mrand48_r __P ((struct drand48_data *__restrict __buffer,
 453                            long int *__restrict __result));
 454 extern int jrand48_r __P ((unsigned short int __xsubi[3],
 455                            struct drand48_data *__restrict __buffer,
 456                            long int *__restrict __result));
 457
 458 /* Seed random number generator.  */
 459 extern int srand48_r __P ((long int __seedval, struct drand48_data *__buffer));
 460
 461 extern int seed48_r __P ((unsigned short int __seed16v[3],
 462                           struct drand48_data *__buffer));
 463
 464 extern int lcong48_r __P ((unsigned short int __param[7],
 465                            struct drand48_data *__buffer));
 466 # endif /* Use misc.  */
 467 #endif  /* Use SVID or X/Open.  */
 468
 469 #endif /* don't just need malloc and calloc */
 470
 471 #ifndef __malloc_and_calloc_defined
 472 #define __malloc_and_calloc_defined
 473 /* Allocate SIZE bytes of memory.  */
 474 extern __ptr_t malloc __P ((size_t __size));
 475 /* Allocate NMEMB elements of SIZE bytes each, all initialized to 0.  */
 476 extern __ptr_t calloc __P ((size_t __nmemb, size_t __size));
 477 #endif
 478
 479 #ifndef __need_malloc_and_calloc
 480 /* Re-allocate the previously allocated block
 481    in __ptr_t, making the new block SIZE bytes long.  */
 482 extern __ptr_t realloc __P ((__ptr_t __ptr, size_t __size));
 483 /* Free a block allocated by `malloc', `realloc' or `calloc'.  */
 484 extern void free __P ((__ptr_t __ptr));
 485
 486 #ifdef  __USE_MISC
 487 /* Free a block.  An alias for `free'.  (Sun Unices).  */
 488 extern void cfree __P ((__ptr_t __ptr));
 489 #endif /* Use misc.  */
 490
 491 #if defined __USE_GNU || defined __USE_BSD || defined __USE_MISC
 492 # include <alloca.h>
 493 #endif /* Use GNU, BSD, or misc.  */
 494
 495 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 496 /* Allocate SIZE bytes on a page boundary.  The storage cannot be freed.  */
 497 extern __ptr_t valloc __P ((size_t __size));
 498 #endif
 499
 500
 501 /* Abort execution and generate a core-dump.  */
 502 extern void abort __P ((void)) __attribute__ ((__noreturn__));
 503
 504
 505 /* Register a function to be called when `exit' is called.  */
 506 extern int atexit __P ((void (*__func) (void)));
 507
 508 #ifdef  __USE_MISC
 509 /* Register a function to be called with the status
 510    given to `exit' and the given argument.  */
 511 extern int __on_exit __P ((void (*__func) (int __status, __ptr_t __arg),
 512                            __ptr_t __arg));
 513 extern int on_exit __P ((void (*__func) (int __status, __ptr_t __arg),
 514                          __ptr_t __arg));
 515 #endif
 516
 517 /* Call all functions registered with `atexit' and `on_exit',
 518    in the reverse of the order in which they were registered
 519    perform stdio cleanup, and terminate program execution with STATUS.  */
 520 extern void exit __P ((int __status)) __attribute__ ((__noreturn__));
 521
 522 #ifdef __USE_ISOC9X
 523 /* Terminate the program with STATUS without calling any of the
 524    functions registered with `atexit' or `on_exit'.  */
 525 extern void _Exit __P ((int __status)) __attribute__ ((__noreturn__));
 526 #endif
 527
 528
 529 /* Return the value of envariable NAME, or NULL if it doesn't exist.  */
 530 extern char *getenv __P ((__const char *__name));
 531
 532 /* This function is similar to the above but returns NULL if the
 533    programs is running with SUID or SGID enabled.  */
 534 extern char *__secure_getenv __P ((__const char *__name));
 535
 536 #if defined __USE_SVID || defined __USE_XOPEN
 537 /* The SVID says this is in <stdio.h>, but this seems a better place.   */
 538 /* Put STRING, which is of the form "NAME=VALUE", in the environment.
 539    If there is no `=', remove NAME from the environment.  */
 540 extern int putenv __P ((__const char *__string));
 541 #endif
 542
 543 #ifdef  __USE_BSD
 544 /* Set NAME to VALUE in the environment.
 545    If REPLACE is nonzero, overwrite an existing value.  */
 546 extern int setenv __P ((__const char *__name, __const char *__value,
 547                         int __replace));
 548
 549 /* Remove the variable NAME from the environment.  */
 550 extern void unsetenv __P ((__const char *__name));
 551 #endif
 552
 553 #ifdef  __USE_MISC
 554 /* The `clearenv' was planned to be added to POSIX.1 but probably
 555    never made it.  Nevertheless the POSIX.9 standard (POSIX bindings
 556    for Fortran 77) requires this function.  */
 557 extern int clearenv __P ((void));
 558 #endif
 559
 560
 561 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 562 /* Generate a unique temporary file name from TEMPLATE.
 563    The last six characters of TEMPLATE must be "XXXXXX";
 564    they are replaced with a string that makes the file name unique.
 565    Returns TEMPLATE, or a null pointer if it cannot get a unique file name.  */
 566 extern char *mktemp __P ((char *__template));
 567
 568 /* Generate a unique temporary file name from TEMPLATE.
 569    The last six characters of TEMPLATE must be "XXXXXX";
 570    they are replaced with a string that makes the filename unique.
 571    Returns a file descriptor open on the file for reading and writing,
 572    or -1 if it cannot create a uniquely-named file.  */
 573 extern int mkstemp __P ((char *__template));
 574 #endif
 575
 576
 577 /* Execute the given line as a shell command.  */
 578 extern int system __P ((__const char *__command));
 579
 580
 581 #ifdef  __USE_GNU
 582 /* Return a malloc'd string containing the canonical absolute name of the
 583    named file.  The last file name component need not exist, and may be a
 584    symlink to a nonexistent file.  */
 585 extern char *canonicalize_file_name __P ((__const char *__name));
 586 #endif
 587
 588 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 589 /* Return the canonical absolute name of file NAME.  The last file name
 590    component need not exist, and may be a symlink to a nonexistent file.
 591    If RESOLVED is null, the result is malloc'd; otherwise, if the canonical
 592    name is PATH_MAX chars or more, returns null with `errno' set to
 593    ENAMETOOLONG; if the name fits in fewer than PATH_MAX chars, returns the
 594    name in RESOLVED.  */
 595 extern char *realpath __P ((__const char *__restrict __name,
 596                             char *__restrict __resolved));
 597 #endif
 598
 599
 600 /* Shorthand for type of comparison functions.  */
 601 #ifndef __COMPAR_FN_T
 602 # define __COMPAR_FN_T
 603 typedef int (*__compar_fn_t) __PMT ((__const __ptr_t, __const __ptr_t));
 604
 605 # ifdef __USE_GNU
 606 typedef __compar_fn_t comparison_fn_t;
 607 # endif
 608 #endif
 609
 610 /* Do a binary search for KEY in BASE, which consists of NMEMB elements
 611    of SIZE bytes each, using COMPAR to perform the comparisons.  */
 612 extern __ptr_t bsearch __PMT ((__const __ptr_t __key, __const __ptr_t __base,
 613                                size_t __nmemb, size_t __size,
 614                                __compar_fn_t __compar));
 615
 616 /* Sort NMEMB elements of BASE, of SIZE bytes each,
 617    using COMPAR to perform the comparisons.  */
 618 extern void qsort __PMT ((__ptr_t __base, size_t __nmemb, size_t __size,
 619                           __compar_fn_t __compar));
 620
 621
 622 /* Return the absolute value of X.  */
 623 extern int abs __P ((int __x)) __attribute__ ((__const__));
 624 extern long int labs __P ((long int __x)) __attribute__ ((__const__));
 625 #ifdef __USE_ISOC9X
 626 __extension__ extern long long int llabs __P ((long long int __x))
 627      __attribute__ ((__const__));
 628 #endif
 629
 630
 631 /* Return the `div_t', `ldiv_t' or `lldiv_t' representation
 632    of the value of NUMER over DENOM. */
 633 /* GCC may have built-ins for these someday.  */
 634 extern div_t div __P ((int __numer, int __denom)) __attribute__ ((__const__));
 635 extern ldiv_t ldiv __P ((long int __numer, long int __denom))
 636      __attribute__ ((__const__));
 637 #ifdef __USE_ISOC9X
 638 __extension__ extern lldiv_t lldiv __P ((long long int __numer,
 639                                          long long int __denom))
 640      __attribute__ ((__const__));
 641 #endif
 642
 643
 644 #if defined __USE_SVID || defined __USE_XOPEN_EXTENDED
 645 /* Convert floating point numbers to strings.  The returned values are
 646    valid only until another call to the same function.  */
 647
 648 /* Convert VALUE to a string with NDIGIT digits and return a pointer to
 649    this.  Set *DECPT with the position of the decimal character and *SIGN
 650    with the sign of the number.  */
 651 extern char *ecvt __P ((double __value, int __ndigit, int *__restrict __decpt,
 652                         int *__restrict __sign));
 653
 654 /* Convert VALUE to a string rounded to NDIGIT decimal digits.  Set *DECPT
 655    with the position of the decimal character and *SIGN with the sign of
 656    the number.  */
 657 extern char *fcvt __P ((double __value, int __ndigit, int *__restrict __decpt,
 658                         int *__restrict __sign));
 659
 660 /* If possible convert VALUE to a string with NDIGIT significant digits.
 661    Otherwise use exponential representation.  The resulting string will
 662    be written to BUF.  */
 663 extern char *gcvt __P ((double __value, int __ndigit, char *__buf));
 664
 665 /* Long double versions of above functions.  */
 666 extern char *qecvt __P ((__long_double_t __value, int __ndigit,
 667                          int *__restrict __decpt, int *__restrict __sign));
 668 extern char *qfcvt __P ((__long_double_t __value, int __ndigit,
 669                          int *__restrict __decpt, int *__restrict __sign));
 670 extern char *qgcvt __P ((__long_double_t __value, int __ndigit, char *__buf));
 671
 672
 673 # ifdef __USE_MISC
 674 /* Reentrant version of the functions above which provide their own
 675    buffers.  */
 676 extern int ecvt_r __P ((double __value, int __ndigit, int *__restrict __decpt,
 677                         int *__restrict __sign, char *__restrict __buf,
 678                         size_t __len));
 679 extern int fcvt_r __P ((double __value, int __ndigit, int *__restrict __decpt,
 680                         int *__restrict __sign, char *__restrict __buf,
 681                         size_t __len));
 682
 683 extern int qecvt_r __P ((__long_double_t __value, int __ndigit,
 684                          int *__restrict __decpt, int *__restrict __sign,
 685                          char *__restrict __buf, size_t __len));
 686 extern int qfcvt_r __P ((__long_double_t __value, int __ndigit,
 687                          int *__restrict __decpt, int *__restrict __sign,
 688                          char *__restrict __buf, size_t __len));
 689 # endif /* misc */
 690 #endif  /* use MISC || use X/Open Unix */
 691
 692
 693 /* Return the length of the multibyte character
 694    in S, which is no longer than N.  */
 695 extern int mblen __P ((__const char *__s, size_t __n));
 696 /* Return the length of the given multibyte character,
 697    putting its `wchar_t' representation in *PWC.  */
 698 extern int mbtowc __P ((wchar_t *__restrict __pwc,
 699                         __const char *__restrict __s, size_t __n));
 700 /* Put the multibyte character represented
 701    by WCHAR in S, returning its length.  */
 702 extern int wctomb __P ((char *__s, wchar_t __wchar));
 703
 704
 705 /* Convert a multibyte string to a wide char string.  */
 706 extern size_t mbstowcs __P ((wchar_t *__restrict  __pwcs,
 707                              __const char *__restrict __s, size_t __n));
 708 /* Convert a wide char string to multibyte string.  */
 709 extern size_t wcstombs __P ((char *__restrict __s,
 710                              __const wchar_t *__restrict __pwcs, size_t __n));
 711
 712
 713 #ifdef __USE_SVID
 714 /* Determine whether the string value of RESPONSE matches the affirmation
 715    or negative response expression as specified by the LC_MESSAGES category
 716    in the program's current locale.  Returns 1 if affirmative, 0 if
 717    negative, and -1 if not matching.  */
 718 extern int rpmatch __P ((__const char *__response));
 719 #endif
 720
 721
 722 #ifdef __USE_XOPEN_EXTENDED
 723 /* Parse comma separated suboption from *OPTIONP and match against
 724    strings in TOKENS.  If found return index and set *VALUEP to
 725    optional value introduced by an equal sign.  If the suboption is
 726    not part of TOKENS return in *VALUEP beginning of unknown
 727    suboption.  On exit *OPTIONP is set to the beginning of the next
 728    token or at the terminating NUL character.  */
 729 extern int getsubopt __P ((char **__restrict __optionp,
 730                            __const char *__const *__restrict __tokens,
 731                            char **__restrict __valuep));
 732 #endif
 733
 734
 735 #ifdef __USE_XOPEN
 736
 737 /* Setup DES tables according KEY.  */
 738 extern void setkey __P ((__const char *__key));
 739
 740 /* X/Open pseudo terminal handling.  */
 741
 742 /* The next four functions all take a master pseudo-tty fd and
 743    perform an operation on the associated slave:  */
 744
 745 /* Chown the slave to the calling user.  */
 746 extern int grantpt __P ((int __fd));
 747
 748 /* Release an internal lock so the slave can be opened.
 749    Call after grantpt().  */
 750 extern int unlockpt __P ((int __fd));
 751
 752 /* Return the pathname of the pseudo terminal slave assoicated with
 753    the master FD is open on, or NULL on errors.
 754    The returned storage is good until the next call to this function.  */
 755 extern char *ptsname __P ((int __fd));
 756 #endif
 757
 758 #ifdef __USE_GNU
 759 /* Store at most BUFLEN characters of the pathname of the slave pseudo
 760    terminal associated with the master FD is open on in BUF.
 761    Return 0 on success, otherwise an error number.  */
 762 extern int ptsname_r __P ((int __fd, char *__buf, size_t __buflen));
 763
 764 /* Open a master pseudo terminal and return its file descriptor.  */
 765 extern int getpt __P ((void));
 766 #endif
 767
 768 #endif /* don't just need malloc and calloc */
 769 #undef __need_malloc_and_calloc
 770
 771 __END_DECLS
 772
 773 #endif /* stdlib.h  */