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__ && __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 extern int32_t random __P ((void));
 331
 332 /* Seed the random number generator with the given number.  */
 333 extern void __srandom __P ((unsigned int __seed));
 334 extern void srandom __P ((unsigned int __seed));
 335
 336 /* Initialize the random number generator to use state buffer STATEBUF,
 337    of length STATELEN, and seed it with SEED.  Optimal lengths are 8, 16,
 338    32, 64, 128 and 256, the bigger the better; values less than 8 will
 339    cause an error and values greater than 256 will be rounded down.  */
 340 extern __ptr_t __initstate __P ((unsigned int __seed, __ptr_t __statebuf,
 341                                  size_t __statelen));
 342 extern __ptr_t initstate __P ((unsigned int __seed, __ptr_t __statebuf,
 343                                size_t __statelen));
 344
 345 /* Switch the random number generator to state buffer STATEBUF,
 346    which should have been previously initialized by `initstate'.  */
 347 extern __ptr_t __setstate __P ((__ptr_t __statebuf));
 348 extern __ptr_t setstate __P ((__ptr_t __statebuf));
 349
 350
 351 # ifdef __USE_MISC
 352 /* Reentrant versions of the `random' family of functions.
 353    These functions all use the following data structure to contain
 354    state, rather than global state variables.  */
 355
 356 struct random_data
 357   {
 358     int32_t *fptr;              /* Front pointer.  */
 359     int32_t *rptr;              /* Rear pointer.  */
 360     int32_t *state;             /* Array of state values.  */
 361     int rand_type;              /* Type of random number generator.  */
 362     int rand_deg;               /* Degree of random number generator.  */
 363     int rand_sep;               /* Distance between front and rear.  */
 364     int32_t *end_ptr;           /* Pointer behind state table.  */
 365   };
 366
 367 extern int __random_r __P ((struct random_data *__buf, int32_t *__result));
 368 extern int random_r __P ((struct random_data *__buf, int32_t *__result));
 369
 370 extern int __srandom_r __P ((unsigned int __seed, struct random_data *__buf));
 371 extern int srandom_r __P ((unsigned int __seed, struct random_data *__buf));
 372
 373 extern int __initstate_r __P ((unsigned int __seed, __ptr_t __statebuf,
 374                                size_t __statelen, struct random_data *__buf));
 375 extern int initstate_r __P ((unsigned int __seed, __ptr_t __statebuf,
 376                              size_t __statelen, struct random_data *__buf));
 377
 378 extern int __setstate_r __P ((__ptr_t __statebuf, struct random_data *__buf));
 379 extern int setstate_r __P ((__ptr_t __statebuf, struct random_data *__buf));
 380 # endif /* Use misc.  */
 381 #endif  /* Use SVID || extended X/Open.  */
 382
 383
 384 /* Return a random integer between 0 and RAND_MAX inclusive.  */
 385 extern int rand __P ((void));
 386 /* Seed the random number generator with the given number.  */
 387 extern void srand __P ((unsigned int __seed));
 388
 389 #ifdef __USE_POSIX
 390 /* Reentrant interface according to POSIX.1.  */
 391 extern int __rand_r __P ((unsigned int *__seed));
 392 extern int rand_r __P ((unsigned int *__seed));
 393 #endif
 394
 395
 396 #if defined __USE_SVID || defined __USE_XOPEN
 397 /* System V style 48-bit random number generator functions.  */
 398
 399 /* Return non-negative, double-precision floating-point value in [0.0,1.0).  */
 400 extern double drand48 __P ((void));
 401 extern double erand48 __P ((unsigned short int __xsubi[3]));
 402
 403 /* Return non-negative, long integer in [0,2^31).  */
 404 extern long int lrand48 __P ((void));
 405 extern long int nrand48 __P ((unsigned short int __xsubi[3]));
 406
 407 /* Return signed, long integers in [-2^31,2^31).  */
 408 extern long int mrand48 __P ((void));
 409 extern long int jrand48 __P ((unsigned short int __xsubi[3]));
 410
 411 /* Seed random number generator.  */
 412 extern void srand48 __P ((long int __seedval));
 413 extern unsigned short int *seed48 __P ((unsigned short int __seed16v[3]));
 414 extern void lcong48 __P ((unsigned short int __param[7]));
 415
 416 /* Data structure for communication with thread safe versions.  */
 417 struct drand48_data
 418   {
 419     unsigned short int x[3];    /* Current state.  */
 420     unsigned short int a[3];    /* Factor in congruential formula.  */
 421     unsigned short int c;       /* Additive const. in congruential formula.  */
 422     unsigned short int old_x[3]; /* Old state.  */
 423     int init;                   /* Flag for initializing.  */
 424   };
 425
 426 # ifdef __USE_MISC
 427 /* Return non-negative, double-precision floating-point value in [0.0,1.0).  */
 428 extern int drand48_r __P ((struct drand48_data *__buffer, double *__result));
 429 extern int __erand48_r __P ((unsigned short int __xsubi[3],
 430                              struct drand48_data *__buffer, double *__result));
 431 extern int erand48_r __P ((unsigned short int __xsubi[3],
 432                            struct drand48_data *__buffer, double *__result));
 433
 434 /* Return non-negative, long integer in [0,2^31).  */
 435 extern int lrand48_r __P ((struct drand48_data *__buffer, long int *__result));
 436 extern int __nrand48_r __P ((unsigned short int __xsubi[3],
 437                              struct drand48_data *__buffer,
 438                              long int *__result));
 439 extern int nrand48_r __P ((unsigned short int __xsubi[3],
 440                            struct drand48_data *__buffer, long int *__result));
 441
 442 /* Return signed, long integers in [-2^31,2^31).  */
 443 extern int mrand48_r __P ((struct drand48_data *__buffer, long int *__result));
 444 extern int __jrand48_r __P ((unsigned short int __xsubi[3],
 445                              struct drand48_data *__buffer,
 446                              long int *__result));
 447 extern int jrand48_r __P ((unsigned short int __xsubi[3],
 448                            struct drand48_data *__buffer, long int *__result));
 449
 450 /* Seed random number generator.  */
 451 extern int __srand48_r __P ((long int __seedval,
 452                              struct drand48_data *__buffer));
 453 extern int srand48_r __P ((long int __seedval, struct drand48_data *__buffer));
 454
 455 extern int __seed48_r __P ((unsigned short int __seed16v[3],
 456                             struct drand48_data *__buffer));
 457 extern int seed48_r __P ((unsigned short int __seed16v[3],
 458                           struct drand48_data *__buffer));
 459
 460 extern int __lcong48_r __P ((unsigned short int __param[7],
 461                              struct drand48_data *__buffer));
 462 extern int lcong48_r __P ((unsigned short int __param[7],
 463                            struct drand48_data *__buffer));
 464 # endif /* Use misc.  */
 465
 466 /* Internal function to compute next state of the generator.  */
 467 extern int __drand48_iterate __P ((unsigned short int __xsubi[3],
 468                                    struct drand48_data *__buffer));
 469 #endif  /* Use SVID or X/Open.  */
 470
 471
 472 /* Allocate SIZE bytes of memory.  */
 473 extern __ptr_t malloc __P ((size_t __size));
 474 /* Re-allocate the previously allocated block
 475    in __ptr_t, making the new block SIZE bytes long.  */
 476 extern __ptr_t realloc __P ((__ptr_t __ptr, size_t __size));
 477 /* Allocate NMEMB elements of SIZE bytes each, all initialized to 0.  */
 478 extern __ptr_t calloc __P ((size_t __nmemb, size_t __size));
 479 /* Free a block allocated by `malloc', `realloc' or `calloc'.  */
 480 extern void free __P ((__ptr_t __ptr));
 481
 482 #ifdef  __USE_MISC
 483 /* Free a block.  An alias for `free'.  (Sun Unices).  */
 484 extern void cfree __P ((__ptr_t __ptr));
 485 #endif /* Use misc.  */
 486
 487 #if defined __USE_GNU || defined __USE_BSD || defined __USE_MISC
 488 # include <alloca.h>
 489 #endif /* Use GNU, BSD, or misc.  */
 490
 491 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 492 /* Allocate SIZE bytes on a page boundary.  The storage cannot be freed.  */
 493 extern __ptr_t valloc __P ((size_t __size));
 494 #endif
 495
 496
 497 /* Abort execution and generate a core-dump.  */
 498 extern void abort __P ((void)) __attribute__ ((__noreturn__));
 499
 500
 501 /* Register a function to be called when `exit' is called.  */
 502 extern int atexit __P ((void (*__func) (void)));
 503
 504 #ifdef  __USE_MISC
 505 /* Register a function to be called with the status
 506    given to `exit' and the given argument.  */
 507 extern int __on_exit __P ((void (*__func) (int __status, __ptr_t __arg),
 508                            __ptr_t __arg));
 509 extern int on_exit __P ((void (*__func) (int __status, __ptr_t __arg),
 510                          __ptr_t __arg));
 511 #endif
 512
 513 /* Call all functions registered with `atexit' and `on_exit',
 514    in the reverse of the order in which they were registered
 515    perform stdio cleanup, and terminate program execution with STATUS.  */
 516 extern void exit __P ((int __status)) __attribute__ ((__noreturn__));
 517
 518
 519 /* Return the value of envariable NAME, or NULL if it doesn't exist.  */
 520 extern char *getenv __P ((__const char *__name));
 521
 522 /* This function is similar to the above but returns NULL if the
 523    programs is running with SUID or SGID enabled.  */
 524 extern char *__secure_getenv __P ((__const char *__name));
 525
 526 #if defined __USE_SVID || defined __USE_XOPEN
 527 /* The SVID says this is in <stdio.h>, but this seems a better place.   */
 528 /* Put STRING, which is of the form "NAME=VALUE", in the environment.
 529    If there is no `=', remove NAME from the environment.  */
 530 extern int putenv __P ((__const char *__string));
 531 #endif
 532
 533 #ifdef  __USE_BSD
 534 /* Set NAME to VALUE in the environment.
 535    If REPLACE is nonzero, overwrite an existing value.  */
 536 extern int __setenv __P ((__const char *__name, __const char *__value,
 537                           int __replace));
 538 extern int setenv __P ((__const char *__name, __const char *__value,
 539                         int __replace));
 540
 541 /* Remove the variable NAME from the environment.  */
 542 extern void __unsetenv __P ((__const char *__name));
 543 extern void unsetenv __P ((__const char *__name));
 544 #endif
 545
 546 #ifdef  __USE_MISC
 547 /* The `clearenv' was planned to be added to POSIX.1 but probably
 548    never made it.  Nevertheless the POSIX.9 standard (POSIX bindings
 549    for Fortran 77) requires this function.  */
 550 extern int __clearenv __P ((void));
 551 extern int clearenv __P ((void));
 552 #endif
 553
 554
 555 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 556 /* Generate a unique temporary file name from TEMPLATE.
 557    The last six characters of TEMPLATE must be "XXXXXX";
 558    they are replaced with a string that makes the file name unique.
 559    Returns TEMPLATE, or a null pointer if it cannot get a unique file name.  */
 560 extern char *mktemp __P ((char *__template));
 561
 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 filename unique.
 565    Returns a file descriptor open on the file for reading and writing,
 566    or -1 if it cannot create a uniquely-named file.  */
 567 extern int mkstemp __P ((char *__template));
 568 #endif
 569
 570
 571 /* Execute the given line as a shell command.  */
 572 extern int system __P ((__const char *__command));
 573
 574
 575 #ifdef  __USE_GNU
 576 /* Return a malloc'd string containing the canonical absolute name of the
 577    named file.  The last file name component need not exist, and may be a
 578    symlink to a nonexistent file.  */
 579 extern char *__canonicalize_file_name __P ((__const char *__name));
 580 extern char *canonicalize_file_name __P ((__const char *__name));
 581 #endif
 582
 583 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 584 /* Return the canonical absolute name of file NAME.  The last file name
 585    component need not exist, and may be a symlink to a nonexistent file.
 586    If RESOLVED is null, the result is malloc'd; otherwise, if the canonical
 587    name is PATH_MAX chars or more, returns null with `errno' set to
 588    ENAMETOOLONG; if the name fits in fewer than PATH_MAX chars, returns the
 589    name in RESOLVED.  */
 590 extern char *__realpath __P ((__const char *__name, char *__resolved));
 591 extern char *realpath __P ((__const char *__name, char *__resolved));
 592 #endif
 593
 594
 595 /* Shorthand for type of comparison functions.  */
 596 #ifndef __COMPAR_FN_T
 597 # define __COMPAR_FN_T
 598 typedef int (*__compar_fn_t) __PMT ((__const __ptr_t, __const __ptr_t));
 599
 600 # ifdef __USE_GNU
 601 typedef __compar_fn_t comparison_fn_t;
 602 # endif
 603 #endif
 604
 605 /* Do a binary search for KEY in BASE, which consists of NMEMB elements
 606    of SIZE bytes each, using COMPAR to perform the comparisons.  */
 607 extern __ptr_t bsearch __PMT ((__const __ptr_t __key, __const __ptr_t __base,
 608                                size_t __nmemb, size_t __size,
 609                                __compar_fn_t __compar));
 610
 611 /* Sort NMEMB elements of BASE, of SIZE bytes each,
 612    using COMPAR to perform the comparisons.  */
 613 extern void qsort __PMT ((__ptr_t __base, size_t __nmemb, size_t __size,
 614                           __compar_fn_t __compar));
 615
 616
 617 /* Return the absolute value of X.  */
 618 extern int abs __P ((int __x)) __attribute__ ((__const__));
 619 extern long int labs __P ((long int __x)) __attribute__ ((__const__));
 620 #ifdef __USE_ISOC9X
 621 extern long long int llabs __P ((long long int __x))
 622      __attribute__ ((__const__));
 623 #endif
 624
 625
 626 /* Return the `div_t', `ldiv_t' or `lldiv_t' representation
 627    of the value of NUMER over DENOM. */
 628 /* GCC may have built-ins for these someday.  */
 629 extern div_t div __P ((int __numer, int __denom)) __attribute__ ((__const__));
 630 extern ldiv_t ldiv __P ((long int __numer, long int __denom))
 631      __attribute__ ((__const__));
 632 #ifdef __USE_ISOC9X
 633 extern lldiv_t lldiv __P ((long long int __numer, long long int __denom))
 634      __attribute__ ((__const__));
 635 #endif
 636
 637
 638 #if defined __USE_SVID || defined __USE_XOPEN_EXTENDED
 639 /* Convert floating point numbers to strings.  The returned values are
 640    valid only until another call to the same function.  */
 641
 642 /* Convert VALUE to a string with NDIGIT digits and return a pointer to
 643    this.  Set *DECPT with the position of the decimal character and *SIGN
 644    with the sign of the number.  */
 645 extern char *ecvt __P ((double __value, int __ndigit, int *__decpt,
 646                         int *__sign));
 647
 648 /* Convert VALUE to a string rounded to NDIGIT decimal digits.  Set *DECPT
 649    with the position of the decimal character and *SIGN with the sign of
 650    the number.  */
 651 extern char *fcvt __P ((double __value, int __ndigit, int *__decpt,
 652                         int *__sign));
 653
 654 /* If possible convert VALUE to a string with NDIGIT significant digits.
 655    Otherwise use exponential representation.  The resulting string will
 656    be written to BUF.  */
 657 extern char *gcvt __P ((double __value, int __ndigit, char *__buf));
 658
 659 /* Long double versions of above functions.  */
 660 extern char *qecvt __P ((__long_double_t __value, int __ndigit, int *__decpt,
 661                          int *__sign));
 662 extern char *qfcvt __P ((__long_double_t __value, int __ndigit, int *__decpt,
 663                          int *__sign));
 664 extern char *qgcvt __P ((__long_double_t __value, int __ndigit, char *__buf));
 665
 666
 667 # ifdef __USE_MISC
 668 /* Reentrant version of the functions above which provide their own
 669    buffers.  */
 670 extern int ecvt_r __P ((double __value, int __ndigit, int *__decpt,
 671                         int *__sign, char *__buf, size_t __len));
 672 extern int fcvt_r __P ((double __value, int __ndigit, int *__decpt,
 673                         int *__sign, char *__buf, size_t __len));
 674
 675 extern int qecvt_r __P ((__long_double_t __value, int __ndigit, int *__decpt,
 676                          int *__sign, char *__buf, size_t __len));
 677 extern int qfcvt_r __P ((__long_double_t __value, int __ndigit, int *__decpt,
 678                          int *__sign, char *__buf, size_t __len));
 679 # endif /* misc */
 680 #endif  /* use MISC || use X/Open Unix */
 681
 682
 683 /* Return the length of the multibyte character
 684    in S, which is no longer than N.  */
 685 extern int mblen __P ((__const char *__s, size_t __n));
 686 /* Return the length of the given multibyte character,
 687    putting its `wchar_t' representation in *PWC.  */
 688 extern int mbtowc __P ((wchar_t *__restrict __pwc,
 689                         __const char *__restrict __s, size_t __n));
 690 /* Put the multibyte character represented
 691    by WCHAR in S, returning its length.  */
 692 extern int wctomb __P ((char *__s, wchar_t __wchar));
 693
 694
 695 /* Convert a multibyte string to a wide char string.  */
 696 extern size_t mbstowcs __P ((wchar_t *__restrict  __pwcs,
 697                              __const char *__restrict __s, size_t __n));
 698 /* Convert a wide char string to multibyte string.  */
 699 extern size_t wcstombs __P ((char *__restrict __s,
 700                              __const wchar_t *__restrict __pwcs, size_t __n));
 701
 702
 703 #ifdef __USE_SVID
 704 /* Determine whether the string value of RESPONSE matches the affirmation
 705    or negative response expression as specified by the LC_MESSAGES category
 706    in the program's current locale.  Returns 1 if affirmative, 0 if
 707    negative, and -1 if not matching.  */
 708 extern int rpmatch __P ((__const char *__response));
 709 #endif
 710
 711
 712 #ifdef __USE_XOPEN_EXTENDED
 713 /* Parse comma separated suboption from *OPTIONP and match against
 714    strings in TOKENS.  If found return index and set *VALUEP to
 715    optional value introduced by an equal sign.  If the suboption is
 716    not part of TOKENS return in *VALUEP beginning of unknown
 717    suboption.  On exit *OPTIONP is set to the beginning of the next
 718    token or at the terminating NUL character.  */
 719 extern int getsubopt __P ((char **__optionp, __const char *__const *__tokens,
 720                            char **__valuep));
 721 #endif
 722
 723
 724 #ifdef __USE_XOPEN
 725
 726 /* Setup DES tables according KEY.  */
 727 extern void setkey __P ((__const char *__key));
 728
 729 /* X/Open pseudo terminal handling.  */
 730
 731 /* The next four functions all take a master pseudo-tty fd and
 732    perform an operation on the associated slave:  */
 733
 734 /* Chown the slave to the calling user.  */
 735 extern int grantpt __P ((int __fd));
 736
 737 /* Release an internal lock so the slave can be opened.
 738    Call after grantpt().  */
 739 extern int unlockpt __P ((int __fd));
 740
 741 /* Return the pathname of the pseudo terminal slave assoicated with
 742    the master FD is open on, or NULL on errors.
 743    The returned storage is good until the next call to this function.  */
 744 extern char *ptsname __P ((int __fd));
 745 #endif
 746
 747 #ifdef __USE_GNU
 748 /* Store at most BUFLEN characters of the pathname of the slave pseudo
 749    terminal associated with the master FD is open on in BUF.
 750    Return 0 on success, otherwise an error number.  */
 751 extern int __ptsname_r __P ((int __fd, char *__buf, size_t __buflen));
 752 extern int ptsname_r __P ((int __fd, char *__buf, size_t __buflen));
 753
 754 /* Open a master pseudo terminal and return its file descriptor.  */
 755 extern int __getpt __P ((void));
 756 extern int getpt __P ((void));
 757 #endif
 758
 759 __END_DECLS
 760
 761 #endif /* stdlib.h  */