stdlib/stdlib.h

   1 /* Copyright (C) 1991, 92, 93, 94, 95, 96, 97 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 /*
  20  *      ISO C Standard: 4.10 GENERAL UTILITIES  <stdlib.h>
  21  */
  22
  23 #ifndef _STDLIB_H
  24
  25 #define _STDLIB_H       1
  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
 132 /* The internal entry points for `strtoX' take an extra flag argument
 133    saying whether or not to parse locale-dependent number grouping.  */
 134
 135 extern double __strtod_internal __P ((__const char *__restrict __nptr,
 136                                       char **__restrict __endptr,
 137                                       int __group));
 138 extern float __strtof_internal __P ((__const char *__restrict __nptr,
 139                                      char **__restrict __endptr, int __group));
 140 extern __long_double_t __strtold_internal __P ((__const char *
 141                                                 __restrict __nptr,
 142                                                 char **__restrict __endptr,
 143                                                 int __group));
 144 extern long int __strtol_internal __P ((__const char *__restrict __nptr,
 145                                         char **__restrict __endptr,
 146                                         int __base, int __group));
 147 extern unsigned long int __strtoul_internal __P ((__const char *
 148                                                   __restrict __nptr,
 149                                                   char **__restrict __endptr,
 150                                                   int __base, int __group));
 151 #ifdef __GNUC__
 152 extern long long int __strtoll_internal __P ((__const char *__restrict __nptr,
 153                                               char **__restrict __endptr,
 154                                               int __base, int __group));
 155 extern unsigned long long int __strtoull_internal __P ((__const char *
 156                                                         __restrict __nptr,
 157                                                         char **
 158                                                         __restrict __endptr,
 159                                                         int __base,
 160                                                         int __group));
 161 #endif /* GCC */
 162
 163 #if defined __OPTIMIZE__ && __GNUC__ >= 2
 164 /* Define inline functions which call the internal entry points.  */
 165
 166 extern __inline double strtod (__const char *__restrict __nptr,
 167                                char **__restrict __endptr)
 168 { return __strtod_internal (__nptr, __endptr, 0); }
 169 extern __inline long int strtol (__const char *__restrict __nptr,
 170                                  char **__restrict __endptr, int __base)
 171 { return __strtol_internal (__nptr, __endptr, __base, 0); }
 172 extern __inline unsigned long int strtoul (__const char *__restrict __nptr,
 173                                            char **__restrict __endptr,
 174                                            int __base)
 175 { return __strtoul_internal (__nptr, __endptr, __base, 0); }
 176
 177 #ifdef __USE_GNU
 178 extern __inline float strtof (__const char *__restrict __nptr,
 179                               char **__restrict __endptr)
 180 { return __strtof_internal (__nptr, __endptr, 0); }
 181 extern __inline __long_double_t strtold (__const char *__restrict __nptr,
 182                                          char **__restrict __endptr)
 183 { return __strtold_internal (__nptr, __endptr, 0); }
 184 #endif
 185
 186 #ifdef __USE_BSD
 187 extern __inline long long int strtoq (__const char *__restrict __nptr,
 188                                       char **__restrict __endptr, int __base)
 189 { return __strtoll_internal (__nptr, __endptr, __base, 0); }
 190 extern __inline unsigned long long int strtouq (__const char *__restrict __nptr,
 191                                                 char **__restrict __endptr,
 192                                                 int __base)
 193 { return __strtoull_internal (__nptr, __endptr, __base, 0); }
 194 #endif
 195
 196 #if defined __USE_MISC || defined __USE_ISOC9X
 197 extern __inline long long int strtoll (__const char *__restrict __nptr,
 198                                        char **__restrict __endptr, int __base)
 199 { return __strtoll_internal (__nptr, __endptr, __base, 0); }
 200 extern __inline unsigned long long int strtoull (__const char *
 201                                                  __restrict __nptr,
 202                                                  char **__restrict __endptr,
 203                                                  int __base)
 204 { return __strtoull_internal (__nptr, __endptr, __base, 0); }
 205 #endif
 206
 207 extern __inline double atof (__const char *__nptr)
 208 { return strtod (__nptr, (char **) NULL); }
 209 extern __inline int atoi (__const char *__nptr)
 210 { return (int) strtol (__nptr, (char **) NULL, 10); }
 211 extern __inline long int atol (__const char *__nptr)
 212 { return strtol (__nptr, (char **) NULL, 10); }
 213
 214 #if defined __USE_ISOC9X && (defined __GNUC__ || defined __USE_MISC)
 215 extern __inline long long int atoll (__const char *__nptr)
 216 { return strtoll (__nptr, (char **) NULL, 10); }
 217 #endif
 218 #endif /* Optimizing GCC >=2.  */
 219
 220
 221 #if defined __USE_SVID || defined __USE_XOPEN_EXTENDED
 222 /* Convert N to base 64 using the digits "./0-9A-Za-z", least-significant
 223    digit first.  Returns a pointer to static storage overwritten by the
 224    next call.  */
 225 extern char *l64a __P ((long int __n));
 226
 227 /* Read a number from a string S in base 64 as above.  */
 228 extern long int a64l __P ((__const char *__s));
 229
 230
 231 #include <sys/types.h>  /* we need int32_t... */
 232
 233 /* These are the functions that actually do things.  The `random', `srandom',
 234    `initstate' and `setstate' functions are those from BSD Unices.
 235    The `rand' and `srand' functions are required by the ANSI standard.
 236    We provide both interfaces to the same random number generator.  */
 237 /* Return a random long integer between 0 and RAND_MAX inclusive.  */
 238 extern int32_t __random __P ((void));
 239 extern int32_t random __P ((void));
 240
 241 /* Seed the random number generator with the given number.  */
 242 extern void __srandom __P ((unsigned int __seed));
 243 extern void srandom __P ((unsigned int __seed));
 244
 245 /* Initialize the random number generator to use state buffer STATEBUF,
 246    of length STATELEN, and seed it with SEED.  Optimal lengths are 8, 16,
 247    32, 64, 128 and 256, the bigger the better; values less than 8 will
 248    cause an error and values greater than 256 will be rounded down.  */
 249 extern __ptr_t __initstate __P ((unsigned int __seed, __ptr_t __statebuf,
 250                                  size_t __statelen));
 251 extern __ptr_t initstate __P ((unsigned int __seed, __ptr_t __statebuf,
 252                                size_t __statelen));
 253
 254 /* Switch the random number generator to state buffer STATEBUF,
 255    which should have been previously initialized by `initstate'.  */
 256 extern __ptr_t __setstate __P ((__ptr_t __statebuf));
 257 extern __ptr_t setstate __P ((__ptr_t __statebuf));
 258
 259
 260 #ifdef __USE_MISC
 261 /* Reentrant versions of the `random' family of functions.
 262    These functions all use the following data structure to contain
 263    state, rather than global state variables.  */
 264
 265 struct random_data
 266   {
 267     int32_t *fptr;              /* Front pointer.  */
 268     int32_t *rptr;              /* Rear pointer.  */
 269     int32_t *state;             /* Array of state values.  */
 270     int rand_type;              /* Type of random number generator.  */
 271     int rand_deg;               /* Degree of random number generator.  */
 272     int rand_sep;               /* Distance between front and rear.  */
 273     int32_t *end_ptr;           /* Pointer behind state table.  */
 274   };
 275
 276 extern int __random_r __P ((struct random_data *__buf, int32_t *__result));
 277 extern int random_r __P ((struct random_data *__buf, int32_t *__result));
 278
 279 extern int __srandom_r __P ((unsigned int __seed, struct random_data *__buf));
 280 extern int srandom_r __P ((unsigned int __seed, struct random_data *__buf));
 281
 282 extern int __initstate_r __P ((unsigned int __seed, __ptr_t __statebuf,
 283                                size_t __statelen, struct random_data *__buf));
 284 extern int initstate_r __P ((unsigned int __seed, __ptr_t __statebuf,
 285                              size_t __statelen, struct random_data *__buf));
 286
 287 extern int __setstate_r __P ((__ptr_t __statebuf, struct random_data *__buf));
 288 extern int setstate_r __P ((__ptr_t __statebuf, struct random_data *__buf));
 289 #endif  /* Use misc.  */
 290 #endif  /* Use SVID || extended X/Open.  */
 291
 292
 293 /* Return a random integer between 0 and RAND_MAX inclusive.  */
 294 extern int rand __P ((void));
 295 /* Seed the random number generator with the given number.  */
 296 extern void srand __P ((unsigned int __seed));
 297
 298 #ifdef __USE_MISC
 299 /* Reentrant interface according to POSIX.1.  */
 300 extern int __rand_r __P ((unsigned int *__seed));
 301 extern int rand_r __P ((unsigned int *__seed));
 302 #endif
 303
 304
 305 #if defined __USE_SVID || defined __USE_XOPEN
 306 /* System V style 48-bit random number generator functions.  */
 307
 308 /* Return non-negative, double-precision floating-point value in [0.0,1.0).  */
 309 extern double drand48 __P ((void));
 310 extern double erand48 __P ((unsigned short int __xsubi[3]));
 311
 312 /* Return non-negative, long integer in [0,2^31).  */
 313 extern long lrand48 __P ((void));
 314 extern long nrand48 __P ((unsigned short int __xsubi[3]));
 315
 316 /* Return signed, long integers in [-2^31,2^31).  */
 317 extern long mrand48 __P ((void));
 318 extern long jrand48 __P ((unsigned short int __xsubi[3]));
 319
 320 /* Seed random number generator.  */
 321 extern void srand48 __P ((long __seedval));
 322 extern unsigned short int *seed48 __P ((unsigned short int __seed16v[3]));
 323 extern void lcong48 __P ((unsigned short int __param[7]));
 324
 325 /* Data structure for communication with thread safe versions.  */
 326 struct drand48_data
 327   {
 328     unsigned short int X[3];    /* Current state.  */
 329     unsigned short int a[3];    /* Factor in congruential formula.  */
 330     unsigned short int c;       /* Additive const. in congruential formula.  */
 331     unsigned short int old_X[3]; /* Old state.  */
 332     int init;                   /* Flag for initializing.  */
 333   };
 334
 335 #ifdef __USE_MISC
 336 /* Return non-negative, double-precision floating-point value in [0.0,1.0).  */
 337 extern int drand48_r __P ((struct drand48_data *__buffer, double *__result));
 338 extern int erand48_r __P ((unsigned short int __xsubi[3],
 339                            struct drand48_data *__buffer, double *__result));
 340
 341 /* Return non-negative, long integer in [0,2^31).  */
 342 extern int lrand48_r __P ((struct drand48_data *__buffer, long *__result));
 343 extern int nrand48_r __P ((unsigned short int __xsubi[3],
 344                            struct drand48_data *__buffer, long *__result));
 345
 346 /* Return signed, long integers in [-2^31,2^31).  */
 347 extern int mrand48_r __P ((struct drand48_data *__buffer, long *__result));
 348 extern int jrand48_r __P ((unsigned short int __xsubi[3],
 349                            struct drand48_data *__buffer, long *__result));
 350
 351 /* Seed random number generator.  */
 352 extern int srand48_r __P ((long __seedval, struct drand48_data *__buffer));
 353 extern int seed48_r __P ((unsigned short int __seed16v[3],
 354                           struct drand48_data *__buffer));
 355 extern int lcong48_r __P ((unsigned short int __param[7],
 356                            struct drand48_data *__buffer));
 357 #endif  /* Use misc.  */
 358
 359 /* Internal function to compute next state of the generator.  */
 360 extern int __drand48_iterate __P ((unsigned short int __xsubi[3],
 361                                    struct drand48_data *__buffer));
 362 #endif  /* Use SVID or X/Open.  */
 363
 364
 365 /* Allocate SIZE bytes of memory.  */
 366 extern __ptr_t malloc __P ((size_t __size));
 367 /* Re-allocate the previously allocated block
 368    in __ptr_t, making the new block SIZE bytes long.  */
 369 extern __ptr_t realloc __P ((__ptr_t __ptr, size_t __size));
 370 /* Allocate NMEMB elements of SIZE bytes each, all initialized to 0.  */
 371 extern __ptr_t calloc __P ((size_t __nmemb, size_t __size));
 372 /* Free a block allocated by `malloc', `realloc' or `calloc'.  */
 373 extern void free __P ((__ptr_t __ptr));
 374
 375 #ifdef  __USE_MISC
 376 /* Free a block.  An alias for `free'.  (Sun Unices).  */
 377 extern void cfree __P ((__ptr_t __ptr));
 378 #endif /* Use misc.  */
 379
 380 #if defined __USE_GNU || defined __USE_BSD || defined __USE_MISC
 381 #include <alloca.h>
 382 #endif /* Use GNU, BSD, or misc.  */
 383
 384 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 385 /* Allocate SIZE bytes on a page boundary.  The storage cannot be freed.  */
 386 extern __ptr_t valloc __P ((size_t __size));
 387 #endif
 388
 389
 390 /* Abort execution and generate a core-dump.  */
 391 extern void abort __P ((void)) __attribute__ ((__noreturn__));
 392
 393
 394 /* Register a function to be called when `exit' is called.  */
 395 extern int atexit __P ((void (*__func) (void)));
 396
 397 #ifdef  __USE_MISC
 398 /* Register a function to be called with the status
 399    given to `exit' and the given argument.  */
 400 extern int __on_exit __P ((void (*__func) (int __status, __ptr_t __arg),
 401                            __ptr_t __arg));
 402 extern int on_exit __P ((void (*__func) (int __status, __ptr_t __arg),
 403                          __ptr_t __arg));
 404 #endif
 405
 406 /* Call all functions registered with `atexit' and `on_exit',
 407    in the reverse of the order in which they were registered
 408    perform stdio cleanup, and terminate program execution with STATUS.  */
 409 extern void exit __P ((int __status)) __attribute__ ((__noreturn__));
 410
 411
 412 /* Return the value of envariable NAME, or NULL if it doesn't exist.  */
 413 extern char *getenv __P ((__const char *__name));
 414
 415 /* This function is similar to the above but returns NULL if the
 416    programs is running with SUID or SGID enabled.  */
 417 extern char *__secure_getenv __P ((__const char *__name));
 418
 419 #if defined __USE_SVID || defined __USE_XOPEN
 420 /* The SVID says this is in <stdio.h>, but this seems a better place.   */
 421 /* Put STRING, which is of the form "NAME=VALUE", in the environment.
 422    If there is no `=', remove NAME from the environment.  */
 423 extern int putenv __P ((__const char *__string));
 424 #endif
 425
 426 #ifdef  __USE_BSD
 427 /* Set NAME to VALUE in the environment.
 428    If REPLACE is nonzero, overwrite an existing value.  */
 429 extern int setenv __P ((__const char *__name, __const char *__value,
 430                         int __replace));
 431
 432 /* Remove the variable NAME from the environment.  */
 433 extern void unsetenv __P ((__const char *__name));
 434 #endif
 435
 436 #ifdef  __USE_MISC
 437 /* The `clearenv' was planned to be added to POSIX.1 but probably
 438    never made it.  Nevertheless the POSIX.9 standard (POSIX bindings
 439    for Fortran 77) requires this function.  */
 440 extern int __clearenv __P ((void));
 441 extern int clearenv __P ((void));
 442 #endif
 443
 444
 445 #if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
 446 /* Generate a unique temporary file name from TEMPLATE.
 447    The last six characters of TEMPLATE must be "XXXXXX";
 448    they are replaced with a string that makes the file name unique.
 449    Returns TEMPLATE, or a null pointer if it cannot get a unique file name.  */
 450 extern char *mktemp __P ((char *__template));
 451
 452 /* Generate a unique temporary file name from TEMPLATE.
 453    The last six characters of TEMPLATE must be "XXXXXX";
 454    they are replaced with a string that makes the filename unique.
 455    Returns a file descriptor open on the file for reading and writing,
 456    or -1 if it cannot create a uniquely-named file.  */
 457 extern int mkstemp __P ((char *__template));
 458 #endif
 459
 460
 461 /* Execute the given line as a shell command.  */
 462 extern int system __P ((__const char *__command));
 463
 464
 465 #ifdef  __USE_GNU
 466 /* Return a malloc'd string containing the canonical absolute name of the
 467    named file.  The last file name component need not exist, and may be a
 468    symlink to a nonexistent file.  */
 469 extern char *canonicalize_file_name __P ((__const char *__name));
 470 #endif
 471
 472 #if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
 473 /* Return the canonical absolute name of file NAME.  The last file name
 474    component need not exist, and may be a symlink to a nonexistent file.
 475    If RESOLVED is null, the result is malloc'd; otherwise, if the canonical
 476    name is PATH_MAX chars or more, returns null with `errno' set to
 477    ENAMETOOLONG; if the name fits in fewer than PATH_MAX chars, returns the
 478    name in RESOLVED.  */
 479 extern char *realpath __P ((__const char *__name, char *__resolved));
 480 #endif
 481
 482
 483 /* Shorthand for type of comparison functions.  */
 484 #ifndef __COMPAR_FN_T
 485 #define __COMPAR_FN_T
 486 typedef int (*__compar_fn_t) __P ((__const __ptr_t, __const __ptr_t));
 487 #endif
 488
 489 #ifdef  __USE_GNU
 490 typedef __compar_fn_t comparison_fn_t;
 491 #endif
 492
 493 /* Do a binary search for KEY in BASE, which consists of NMEMB elements
 494    of SIZE bytes each, using COMPAR to perform the comparisons.  */
 495 extern __ptr_t bsearch __P ((__const __ptr_t __key, __const __ptr_t __base,
 496                              size_t __nmemb, size_t __size,
 497                              __compar_fn_t __compar));
 498
 499 /* Sort NMEMB elements of BASE, of SIZE bytes each,
 500    using COMPAR to perform the comparisons.  */
 501 extern void qsort __P ((__ptr_t __base, size_t __nmemb, size_t __size,
 502                         __compar_fn_t __compar));
 503
 504
 505 /* Return the absolute value of X.  */
 506 extern int abs __P ((int __x)) __attribute__ ((__const__));
 507 extern long int labs __P ((long int __x)) __attribute__ ((__const__));
 508 #if defined __USE_ISOC9X
 509 extern long long int llabs __P ((long long int __x))
 510      __attribute__ ((__const__));
 511 #endif
 512
 513
 514 /* Return the `div_t', `ldiv_t' or `lldiv_t' representation
 515    of the value of NUMER over DENOM. */
 516 /* GCC may have built-ins for these someday.  */
 517 extern div_t div __P ((int __numer, int __denom)) __attribute__ ((__const__));
 518 extern ldiv_t ldiv __P ((long int __numer, long int __denom))
 519      __attribute__ ((__const__));
 520 #ifdef __USE_ISOC9X
 521 extern lldiv_t lldiv __P ((long long int __numer, long long int __denom))
 522      __attribute__ ((__const__));
 523 #endif
 524
 525
 526 #if defined __USE_SVID || defined __USE_XOPEN_EXTENDED
 527 /* Convert floating point numbers to strings.  The returned values are
 528    valid only until another call to the same function.  */
 529
 530 /* Convert VALUE to a string with NDIGIT digits and return a pointer to
 531    this.  Set *DECPT with the position of the decimal character and *SIGN
 532    with the sign of the number.  */
 533 extern char *ecvt __P ((double __value, int __ndigit, int *__decpt,
 534                         int *__sign));
 535
 536 /* Convert VALUE to a string rounded to NDIGIT decimal digits.  Set *DECPT
 537    with the position of the decimal character and *SIGN with the sign of
 538    the number.  */
 539 extern char *fcvt __P ((double __value, int __ndigit, int *__decpt,
 540                         int *__sign));
 541
 542 /* If possible convert VALUE to a string with NDIGIT significant digits.
 543    Otherwise use exponential representation.  The resulting string will
 544    be written to BUF.  */
 545 extern char *gcvt __P ((double __value, int __ndigit, char *__buf));
 546
 547 /* Long double versions of above functions.  */
 548 extern char *qecvt __P ((__long_double_t __value, int __ndigit, int *__decpt,
 549                          int *__sign));
 550 extern char *qfcvt __P ((__long_double_t __value, int __ndigit, int *__decpt,
 551                          int *__sign));
 552 extern char *qgcvt __P ((__long_double_t __value, int __ndigit, char *__buf));
 553
 554
 555 #ifdef __USE_MISC
 556 /* Reentrant version of the functions above which provide their own
 557    buffers.  */
 558 extern int ecvt_r __P ((double __value, int __ndigit, int *__decpt,
 559                         int *__sign, char *__buf, size_t __len));
 560 extern int fcvt_r __P ((double __value, int __ndigit, int *__decpt,
 561                         int *__sign, char *__buf, size_t __len));
 562
 563 extern int qecvt_r __P ((__long_double_t __value, int __ndigit, int *__decpt,
 564                          int *__sign, char *__buf, size_t __len));
 565 extern int qfcvt_r __P ((__long_double_t __value, int __ndigit, int *__decpt,
 566                          int *__sign, char *__buf, size_t __len));
 567 #endif  /* misc */
 568 #endif  /* use MISC || use X/Open Unix */
 569
 570
 571 /* Return the length of the multibyte character
 572    in S, which is no longer than N.  */
 573 extern int mblen __P ((__const char *__s, size_t __n));
 574 /* Return the length of the given multibyte character,
 575    putting its `wchar_t' representation in *PWC.  */
 576 extern int mbtowc __P ((wchar_t *__restrict __pwc,
 577                         __const char *__restrict __s, size_t __n));
 578 /* Put the multibyte character represented
 579    by WCHAR in S, returning its length.  */
 580 extern int wctomb __P ((char *__s, wchar_t __wchar));
 581
 582 #if defined __OPTIMIZE__ && __GNUC__ >= 2
 583 extern __inline int mblen (__const char *__s, size_t __n)
 584 { return mbtowc ((wchar_t *) NULL, __s, __n); }
 585 #endif /* Optimizing GCC >=2.  */
 586
 587
 588 /* Convert a multibyte string to a wide char string.  */
 589 extern size_t mbstowcs __P ((wchar_t *__restrict  __pwcs,
 590                              __const char *__restrict __s, size_t __n));
 591 /* Convert a wide char string to multibyte string.  */
 592 extern size_t wcstombs __P ((char *__restrict __s,
 593                              __const wchar_t *__restrict __pwcs, size_t __n));
 594
 595
 596 #ifdef __USE_SVID
 597 /* Determine whether the string value of RESPONSE matches the affirmation
 598    or negative response expression as specified by the LC_MESSAGES category
 599    in the program's current locale.  Returns 1 if affirmative, 0 if
 600    negative, and -1 if not matching.  */
 601 extern int rpmatch __P ((__const char *__response));
 602 #endif
 603
 604
 605 #ifdef __USE_XOPEN_EXTENDED
 606 /* Parse comma separated suboption from *OPTIONP and match against
 607    strings in TOKENS.  If found return index and set *VALUEP to
 608    optional value introduced by an equal sign.  If the suboption is
 609    not part of TOKENS return in *VALUEP beginning of unknown
 610    suboption.  On exit *OPTIONP is set to the beginning of the next
 611    otken or at the terminating NUL character.  */
 612 extern int getsubopt __P ((char **__optionp, __const char *__const *__tokens,
 613                            char **__valuep));
 614 #endif
 615
 616
 617 #ifdef __USE_XOPEN
 618
 619 /* Setup DES tables according KEY.  */
 620 extern void setkey __P ((__const char *__key));
 621 #endif
 622
 623
 624 __END_DECLS
 625
 626 #endif /* stdlib.h  */