stdlib/stdlib.h

   1 /* Copyright (C) 1991, 92, 93, 94, 95, 96 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 S 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 #define __need_Emath
  35 #include <errno.h>
  36
  37 __BEGIN_DECLS
  38
  39 /* Returned by `div'.  */
  40 typedef struct
  41   {
  42     int quot;                   /* Quotient.  */
  43     int rem;                    /* Remainder.  */
  44   } div_t;
  45
  46 /* Returned by `ldiv'.  */
  47 typedef struct
  48   {
  49     long int quot;              /* Quotient.  */
  50     long int rem;               /* Remainder.  */
  51   } ldiv_t;
  52
  53 #ifdef __USE_GNU
  54 /* Returned by `lldiv'.  */
  55 typedef struct
  56   {
  57     long long int quot;         /* Quotient.  */
  58     long long int rem;          /* Remainder.  */
  59   } lldiv_t;
  60 #endif
  61
  62
  63 /* The largest number rand will return (same as INT_MAX).  */
  64 #define RAND_MAX        2147483647
  65
  66
  67 /* We define these the same for all machines.
  68    Changes from this to the outside world should be done in `_exit'.  */
  69 #define EXIT_FAILURE    1       /* Failing exit status.  */
  70 #define EXIT_SUCCESS    0       /* Successful exit status.  */
  71
  72
  73 /* Maximum length of a multibyte character in the current locale.  */
  74 #define MB_CUR_MAX      (__ctype_get_mb_cur_max ())
  75 extern int __ctype_get_mb_cur_max __P ((void));
  76
  77
  78 /* Convert a string to a floating-point number.  */
  79 extern double atof __P ((__const char *__nptr));
  80 /* Convert a string to an integer.  */
  81 extern int atoi __P ((__const char *__nptr));
  82 /* Convert a string to a long integer.  */
  83 extern long int atol __P ((__const char *__nptr));
  84
  85 /* Convert a string to a floating-point number.  */
  86 extern double strtod __P ((__const char *__nptr, char **__endptr));
  87
  88 #ifdef  __USE_GNU
  89 /* Likewise for `float' and `long double' sizes of floating-point numbers.  */
  90 extern float strtof __P ((__const char *__nptr, char **__endptr));
  91 extern __long_double_t strtold __P ((__const char *__nptr, char **__endptr));
  92 #endif
  93
  94 /* Convert a string to a long integer.  */
  95 extern long int strtol __P ((__const char *__nptr, char **__endptr,
  96                              int __base));
  97 /* Convert a string to an unsigned long integer.  */
  98 extern unsigned long int strtoul __P ((__const char *__nptr,
  99                                        char **__endptr, int __base));
 100
 101 #if defined (__GNUC__) && defined (__USE_BSD)
 102 /* Convert a string to a quadword integer.  */
 103 extern long long int strtoq __P ((__const char *__nptr, char **__endptr,
 104                                   int __base));
 105 /* Convert a string to an unsigned quadword integer.  */
 106 extern unsigned long long int strtouq __P ((__const char *__nptr,
 107                                             char **__endptr, int __base));
 108 #endif /* GCC and use BSD.  */
 109
 110 #if defined (__GNUC__) && defined (__USE_MISC)
 111 /* Convert a string to a quadword integer.  */
 112 extern long long int strtoll __P ((__const char *__nptr, char **__endptr,
 113                                    int __base));
 114 /* Convert a string to an unsigned quadword integer.  */
 115 extern unsigned long long int strtoull __P ((__const char *__nptr,
 116                                              char **__endptr, int __base));
 117 #endif /* GCC and use MISC.  */
 118
 119
 120
 121 /* The internal entry points for `strtoX' take an extra flag argument
 122    saying whether or not to parse locale-dependent number grouping.  */
 123
 124 extern double __strtod_internal __P ((__const char *__nptr,
 125                                       char **__endptr, int __group));
 126 extern float __strtof_internal __P ((__const char *__nptr, char **__endptr,
 127                                      int __group));
 128 extern __long_double_t __strtold_internal __P ((__const char *__nptr,
 129                                                 char **__endptr, int __group));
 130 extern long int __strtol_internal __P ((__const char *__nptr, char **__endptr,
 131                                         int __base, int __group));
 132 extern unsigned long int __strtoul_internal __P ((__const char *__nptr,
 133                                                   char **__endptr, int __base,
 134                                                   int __group));
 135 #ifdef __GNUC__
 136 extern long long int __strtoq_internal __P ((__const char *__nptr,
 137                                              char **__endptr, int __base,
 138                                              int __group));
 139 extern unsigned long long int __strtouq_internal __P ((__const char *__nptr,
 140                                                        char **__endptr,
 141                                                        int __base,
 142                                                        int __group));
 143 #endif /* GCC */
 144
 145 #if defined (__OPTIMIZE__) && __GNUC__ >= 2
 146 /* Define inline functions which call the internal entry points.  */
 147
 148 extern __inline double strtod (__const char *__nptr, char **__endptr)
 149 { return __strtod_internal (__nptr, __endptr, 0); }
 150 extern __inline long int strtol (__const char *__nptr,
 151                                  char **__endptr, int __base)
 152 { return __strtol_internal (__nptr, __endptr, __base, 0); }
 153 extern __inline unsigned long int strtoul (__const char *__nptr,
 154                                            char **__endptr, int __base)
 155 { return __strtoul_internal (__nptr, __endptr, __base, 0); }
 156
 157 #ifdef __USE_GNU
 158 extern __inline float strtof (__const char *__nptr, char **__endptr)
 159 { return __strtof_internal (__nptr, __endptr, 0); }
 160 extern __inline __long_double_t strtold (__const char *__nptr, char **__endptr)
 161 { return __strtold_internal (__nptr, __endptr, 0); }
 162 #endif
 163
 164 #ifdef __USE_BSD
 165 extern __inline long long int strtoq (__const char *__nptr, char **__endptr,
 166                                       int __base)
 167 { return __strtoq_internal (__nptr, __endptr, __base, 0); }
 168 extern __inline unsigned long long int strtouq (__const char *__nptr,
 169                                                 char **__endptr, int __base)
 170 { return __strtouq_internal (__nptr, __endptr, __base, 0); }
 171 #endif
 172
 173 #ifdef __USE_MISC
 174 extern __inline long long int strtoll (__const char *__nptr, char **__endptr,
 175                                        int __base)
 176 { return __strtoq_internal (__nptr, __endptr, __base, 0); }
 177 extern __inline unsigned long long int strtoull (__const char *__nptr,
 178                                                  char **__endptr, int __base)
 179 { return __strtouq_internal (__nptr, __endptr, __base, 0); }
 180 #endif
 181
 182 extern __inline double atof (__const char *__nptr)
 183 { return strtod (__nptr, (char **) NULL); }
 184 extern __inline int atoi (__const char *__nptr)
 185 { return (int) strtol (__nptr, (char **) NULL, 10); }
 186 extern __inline long int atol (__const char *__nptr)
 187 { return strtol (__nptr, (char **) NULL, 10); }
 188 #endif /* Optimizing GCC >=2.  */
 189
 190
 191 #if defined(__USE_SVID) || defined(__USE_XOPEN_EXTENDED)
 192 /* Convert N to base 64 using the digits "./0-9A-Za-z", least-significant
 193    digit first.  Returns a pointer to static storage overwritten by the
 194    next call.  */
 195 extern char *l64a __P ((long int __n));
 196
 197 /* Read a number from a string S in base 64 as above.  */
 198 extern long int a64l __P ((__const char *__s));
 199
 200
 201 #include <sys/types.h>  /* we need int32_t... */
 202
 203 /* These are the functions that actually do things.  The `random', `srandom',
 204    `initstate' and `setstate' functions are those from BSD Unices.
 205    The `rand' and `srand' functions are required by the ANSI standard.
 206    We provide both interfaces to the same random number generator.  */
 207 /* Return a random long integer between 0 and RAND_MAX inclusive.  */
 208 extern int32_t __random __P ((void));
 209 extern int32_t random __P ((void));
 210
 211 /* Seed the random number generator with the given number.  */
 212 extern void __srandom __P ((unsigned int __seed));
 213 extern void srandom __P ((unsigned int __seed));
 214
 215 /* Initialize the random number generator to use state buffer STATEBUF,
 216    of length STATELEN, and seed it with SEED.  Optimal lengths are 8, 16,
 217    32, 64, 128 and 256, the bigger the better; values less than 8 will
 218    cause an error and values greater than 256 will be rounded down.  */
 219 extern __ptr_t __initstate __P ((unsigned int __seed, __ptr_t __statebuf,
 220                                  size_t __statelen));
 221 extern __ptr_t initstate __P ((unsigned int __seed, __ptr_t __statebuf,
 222                                size_t __statelen));
 223
 224 /* Switch the random number generator to state buffer STATEBUF,
 225    which should have been previously initialized by `initstate'.  */
 226 extern __ptr_t __setstate __P ((__ptr_t __statebuf));
 227 extern __ptr_t setstate __P ((__ptr_t __statebuf));
 228
 229
 230 #ifdef __USE_REENTRANT
 231 /* Reentrant versions of the `random' family of functions.
 232    These functions all use the following data structure to contain
 233    state, rather than global state variables.  */
 234
 235 struct random_data
 236   {
 237     int32_t *fptr;              /* Front pointer.  */
 238     int32_t *rptr;              /* Rear pointer.  */
 239     int32_t *state;             /* Array of state values.  */
 240     int rand_type;              /* Type of random number generator.  */
 241     int rand_deg;               /* Degree of random number generator.  */
 242     int rand_sep;               /* Distance between front and rear.  */
 243     int32_t *end_ptr;           /* Pointer behind state table.  */
 244   };
 245
 246 extern int __random_r __P ((struct random_data *__buf, int32_t *__result));
 247 extern int random_r __P ((struct random_data *__buf, int32_t *__result));
 248
 249 extern int __srandom_r __P ((unsigned int __seed, struct random_data *__buf));
 250 extern int srandom_r __P ((unsigned int __seed, struct random_data *__buf));
 251
 252 extern int __initstate_r __P ((unsigned int __seed, __ptr_t __statebuf,
 253                                size_t __statelen, struct random_data *__buf));
 254 extern int initstate_r __P ((unsigned int __seed, __ptr_t __statebuf,
 255                              size_t __statelen, struct random_data *__buf));
 256
 257 extern int __setstate_r __P ((__ptr_t __statebuf, struct random_data *__buf));
 258 extern int setstate_r __P ((__ptr_t __statebuf, struct random_data *__buf));
 259 #endif  /* Use reentrant.  */
 260 #endif  /* Use BSD.  */
 261
 262
 263 /* Return a random integer between 0 and RAND_MAX inclusive.  */
 264 extern int rand __P ((void));
 265 /* Seed the random number generator with the given number.  */
 266 extern void srand __P ((unsigned int __seed));
 267
 268 #ifdef __USE_REENTRANT
 269 /* Reentrant interface according to POSIX.1.  */
 270 extern int __rand_r __P ((unsigned int *__seed));
 271 extern int rand_r __P ((unsigned int *__seed));
 272 #endif
 273
 274
 275 #if defined(__USE_SVID) || defined(__USE_XOPEN)
 276 /* System V style 48-bit random number generator functions.  */
 277
 278 /* Return non-negative, double-precision floating-point value in [0.0,1.0).  */
 279 extern double drand48 __P ((void));
 280 extern double erand48 __P ((unsigned short int __xsubi[3]));
 281
 282 /* Return non-negative, long integer in [0,2^31).  */
 283 extern long lrand48 __P ((void));
 284 extern long nrand48 __P ((unsigned short int __xsubi[3]));
 285
 286 /* Return signed, long integers in [-2^31,2^31).  */
 287 extern long mrand48 __P ((void));
 288 extern long jrand48 __P ((unsigned short int __xsubi[3]));
 289
 290 /* Seed random number generator.  */
 291 extern void srand48 __P ((long __seedval));
 292 extern unsigned short int *seed48 __P ((unsigned short int __seed16v[3]));
 293 extern void lcong48 __P ((unsigned short int __param[7]));
 294
 295 /* Data structure for communication with thread safe versions.  */
 296 struct drand48_data
 297   {
 298     unsigned short int X[3];    /* Current state.  */
 299     unsigned short int a[3];    /* Factor in congruential formula.  */
 300     unsigned short int c;       /* Additive const. in congruential formula.  */
 301     unsigned short int old_X[3]; /* Old state.  */
 302     int init;                   /* Flag for initializing.  */
 303   };
 304
 305 #ifdef __USE_REENTRANT
 306 /* Return non-negative, double-precision floating-point value in [0.0,1.0).  */
 307 extern int drand48_r __P ((struct drand48_data *__buffer, double *__result));
 308 extern int erand48_r __P ((unsigned short int __xsubi[3],
 309                            struct drand48_data *__buffer, double *__result));
 310
 311 /* Return non-negative, long integer in [0,2^31).  */
 312 extern int lrand48_r __P ((struct drand48_data *__buffer, long *__result));
 313 extern int nrand48_r __P ((unsigned short int __xsubi[3],
 314                            struct drand48_data *__buffer, long *__result));
 315
 316 /* Return signed, long integers in [-2^31,2^31).  */
 317 extern int mrand48_r __P ((struct drand48_data *__buffer, long *__result));
 318 extern int jrand48_r __P ((unsigned short int __xsubi[3],
 319                            struct drand48_data *__buffer, long *__result));
 320
 321 /* Seed random number generator.  */
 322 extern int srand48_r __P ((long __seedval, struct drand48_data *__buffer));
 323 extern int seed48_r __P ((unsigned short int __seed16v[3],
 324                           struct drand48_data *__buffer));
 325 extern int lcong48_r __P ((unsigned short int __param[7],
 326                            struct drand48_data *__buffer));
 327 #endif  /* Use reentrant.  */
 328
 329 /* Internal function to compute next state of the generator.  */
 330 extern int __drand48_iterate __P ((unsigned short int __xsubi[3],
 331                                    struct drand48_data *__buffer));
 332 #endif  /* Use SVID or X/Open.  */
 333
 334
 335 /* Allocate SIZE bytes of memory.  */
 336 extern __ptr_t malloc __P ((size_t __size));
 337 /* Re-allocate the previously allocated block
 338    in __ptr_t, making the new block SIZE bytes long.  */
 339 extern __ptr_t realloc __P ((__ptr_t __ptr, size_t __size));
 340 /* Allocate NMEMB elements of SIZE bytes each, all initialized to 0.  */
 341 extern __ptr_t calloc __P ((size_t __nmemb, size_t __size));
 342 /* Free a block allocated by `malloc', `realloc' or `calloc'.  */
 343 extern void free __P ((__ptr_t __ptr));
 344
 345 #ifdef  __USE_MISC
 346 /* Free a block.  An alias for `free'.  (Sun Unices).  */
 347 extern void cfree __P ((__ptr_t __ptr));
 348 #endif /* Use misc.  */
 349
 350 #if defined(__USE_GNU) || defined(__USE_BSD) || defined(__USE_MISC)
 351 #include <alloca.h>
 352 #endif /* Use GNU, BSD, or misc.  */
 353
 354 #if defined(__USE_BSD) || defined(__USE_XOPEN_EXTENDED)
 355 /* Allocate SIZE bytes on a page boundary.  The storage cannot be freed.  */
 356 extern __ptr_t valloc __P ((size_t __size));
 357 #endif
 358
 359
 360 /* Abort execution and generate a core-dump.  */
 361 extern void abort __P ((void)) __attribute__ ((__noreturn__));
 362
 363
 364 /* Register a function to be called when `exit' is called.  */
 365 extern int atexit __P ((void (*__func) (void)));
 366
 367 #ifdef  __USE_MISC
 368 /* Register a function to be called with the status
 369    given to `exit' and the given argument.  */
 370 extern int on_exit __P ((void (*__func) (int __status, __ptr_t __arg),
 371                          __ptr_t __arg));
 372 #endif
 373
 374 /* Call all functions registered with `atexit' and `on_exit',
 375    in the reverse of the order in which they were registered
 376    perform stdio cleanup, and terminate program execution with STATUS.  */
 377 extern void exit __P ((int __status)) __attribute__ ((__noreturn__));
 378
 379
 380 /* Return the value of envariable NAME, or NULL if it doesn't exist.  */
 381 extern char *getenv __P ((__const char *__name));
 382
 383 /* This function is similar to the above but returns NULL if the
 384    programs is running with SUID or SGID enabled.  */
 385 extern char *__secure_getenv __P ((__const char *__name));
 386
 387 #if defined(__USE_SVID) || defined(__USE_XOPEN)
 388 /* The SVID says this is in <stdio.h>, but this seems a better place.   */
 389 /* Put STRING, which is of the form "NAME=VALUE", in the environment.
 390    If there is no `=', remove NAME from the environment.  */
 391 extern int putenv __P ((__const char *__string));
 392 #endif
 393
 394 #ifdef  __USE_BSD
 395 /* Set NAME to VALUE in the environment.
 396    If REPLACE is nonzero, overwrite an existing value.  */
 397 extern int setenv __P ((__const char *__name, __const char *__value,
 398                         int __replace));
 399
 400 /* Remove the variable NAME from the environment.  */
 401 extern void unsetenv __P ((__const char *__name));
 402 #endif
 403
 404 #ifdef  __USE_MISC
 405 /* The `clearenv' was planned to be added to POSIX.1 but probably
 406    never made it.  Nevertheless the POSIX.9 standard (POSIX bindings
 407    for Fortran 77) requires this function.  */
 408 extern int clearenv __P ((void));
 409 #endif
 410
 411
 412 #if defined(__USE_MISC) || defined(__USE_XOPEN_EXTENDED)
 413 /* Generate a unique temporary file name from TEMPLATE.
 414    The last six characters of TEMPLATE must be "XXXXXX";
 415    they are replaced with a string that makes the file name unique.
 416    Returns TEMPLATE, or a null pointer if it cannot get a unique file name.  */
 417 extern char *mktemp __P ((char *__template));
 418
 419 /* Generate a unique temporary file name from TEMPLATE.
 420    The last six characters of TEMPLATE must be "XXXXXX";
 421    they are replaced with a string that makes the filename unique.
 422    Returns a file descriptor open on the file for reading and writing,
 423    or -1 if it cannot create a uniquely-named file.  */
 424 extern int mkstemp __P ((char *__template));
 425 #endif
 426
 427
 428 /* Execute the given line as a shell command.  */
 429 extern int system __P ((__const char *__command));
 430
 431
 432 #ifdef  __USE_GNU
 433 /* Return a malloc'd string containing the canonical absolute name of the
 434    named file.  The last file name component need not exist, and may be a
 435    symlink to a nonexistent file.  */
 436 extern char *canonicalize_file_name __P ((__const char *__name));
 437 #endif
 438
 439 #if defined(__USE_BSD) || defined(__USE_XOPEN_EXTENDED)
 440 /* Return the canonical absolute name of file NAME.  The last file name
 441    component need not exist, and may be a symlink to a nonexistent file.
 442    If RESOLVED is null, the result is malloc'd; otherwise, if the canonical
 443    name is PATH_MAX chars or more, returns null with `errno' set to
 444    ENAMETOOLONG; if the name fits in fewer than PATH_MAX chars, returns the
 445    name in RESOLVED.  */
 446 extern char *realpath __P ((__const char *__name, char *__resolved));
 447 #endif
 448
 449
 450 /* Shorthand for type of comparison functions.  */
 451 #ifndef __COMPAR_FN_T
 452 #define __COMPAR_FN_T
 453 typedef int (*__compar_fn_t) __P ((__const __ptr_t, __const __ptr_t));
 454 #endif
 455
 456 #ifdef  __USE_GNU
 457 typedef __compar_fn_t comparison_fn_t;
 458 #endif
 459
 460 /* Do a binary search for KEY in BASE, which consists of NMEMB elements
 461    of SIZE bytes each, using COMPAR to perform the comparisons.  */
 462 extern __ptr_t bsearch __P ((__const __ptr_t __key, __const __ptr_t __base,
 463                              size_t __nmemb, size_t __size,
 464                              __compar_fn_t __compar));
 465
 466 /* Sort NMEMB elements of BASE, of SIZE bytes each,
 467    using COMPAR to perform the comparisons.  */
 468 extern void qsort __P ((__ptr_t __base, size_t __nmemb, size_t __size,
 469                         __compar_fn_t __compar));
 470
 471
 472 /* Return the absolute value of X.  */
 473 extern int abs __P ((int __x)) __attribute__ ((__const__));
 474 extern long int labs __P ((long int __x)) __attribute__ ((__const__));
 475 #ifdef __USE_GNU
 476 extern long long int llabs __P ((long long int __x)) __attribute__ ((__const__));
 477 #endif
 478
 479
 480 /* Return the `div_t', `ldiv_t' or `lldiv_t' representation
 481    of the value of NUMER over DENOM. */
 482 /* GCC may have built-ins for these someday.  */
 483 extern div_t div __P ((int __numer, int __denom)) __attribute__ ((__const__));
 484 extern ldiv_t ldiv __P ((long int __numer, long int __denom)) __attribute__ ((__const__));
 485 #ifdef __USE_GNU
 486 extern lldiv_t lldiv __P ((long long int __numer, long long int __denom)) __attribute__ ((__const__));
 487 #endif
 488
 489
 490 #if defined(__USE_SVID) || defined(__USE_XOPEN_EXTENDED)
 491 /* Convert floating point numbers to strings.  The returned values are
 492    valid only until another call to the same function.  */
 493
 494 /* Convert VALUE to a string with NDIGIT digits and return a pointer to
 495    this.  Set *DECPT with the position of the decimal character and *SIGN
 496    with the sign of the number.  */
 497 extern char *ecvt __P ((double __value, int __ndigit, int *__decpt,
 498                         int *__sign));
 499
 500 /* Convert VALUE to a string rounded to NDIGIT decimal digits.  Set *DECPT
 501    with the position of the decimal character and *SIGN with the sign of
 502    the number.  */
 503 extern char *fcvt __P ((double __value, int __ndigit, int *__decpt,
 504                         int *__sign));
 505
 506 /* If possible convert VALUE to a string with NDIGIT significant digits.
 507    Otherwise use exponential representation.  The resulting string will
 508    be written to BUF.  */
 509 extern char *gcvt __P ((double __value, int __ndigit, char *__buf));
 510
 511 /* Long double versions of above functions.  */
 512 extern char *qecvt __P ((__long_double_t __value, int __ndigit, int *__decpt,
 513                          int *__sign));
 514 extern char *qfcvt __P ((__long_double_t __value, int __ndigit, int *__decpt,
 515                          int *__sign));
 516 extern char *qgcvt __P ((__long_double_t __value, int __ndigit, char *__buf));
 517
 518
 519 #ifdef __USE_REENTRANT
 520 /* Reentrant version of the functions above which provide their own
 521    buffers.  */
 522 extern int ecvt_r __P ((double __value, int __ndigit, int *__decpt,
 523                         int *__sign, char *__buf, size_t __len));
 524 extern int fcvt_r __P ((double __value, int __ndigit, int *__decpt,
 525                         int *__sign, char *__buf, size_t __len));
 526
 527 extern int qecvt_r __P ((__long_double_t __value, int __ndigit, int *__decpt,
 528                          int *__sign, char *__buf, size_t __len));
 529 extern int qfcvt_r __P ((__long_double_t __value, int __ndigit, int *__decpt,
 530                          int *__sign, char *__buf, size_t __len));
 531 #endif  /* reentrant */
 532 #endif  /* use MISC || use X/Open Unix */
 533
 534
 535 /* Return the length of the multibyte character
 536    in S, which is no longer than N.  */
 537 extern int mblen __P ((__const char *__s, size_t __n));
 538 /* Return the length of the given multibyte character,
 539    putting its `wchar_t' representation in *PWC.  */
 540 extern int mbtowc __P ((wchar_t *__pwc, __const char *__s, size_t __n));
 541 /* Put the multibyte character represented
 542    by WCHAR in S, returning its length.  */
 543 extern int wctomb __P ((char *__s, wchar_t __wchar));
 544
 545 #if defined (__OPTIMIZE__) && __GNUC__ >= 2
 546 extern __inline int mblen (__const char *__s, size_t __n)
 547 { return mbtowc ((wchar_t *) NULL, __s, __n); }
 548 #endif /* Optimizing GCC >=2.  */
 549
 550
 551 /* Convert a multibyte string to a wide char string.  */
 552 extern size_t mbstowcs __P ((wchar_t *__pwcs, __const char *__s, size_t __n));
 553 /* Convert a wide char string to multibyte string.  */
 554 extern size_t wcstombs __P ((char *__s, __const wchar_t *__pwcs, size_t __n));
 555
 556
 557 #ifdef __USE_SVID
 558 /* Determine whether the string value of RESPONSE matches the affirmation
 559    or negative response expression as specified by the LC_MESSAGES category
 560    in the program's current locale.  Returns 1 if affirmative, 0 if
 561    negative, and -1 if not matching.  */
 562 extern int rpmatch __P ((__const char *__response));
 563 #endif
 564
 565
 566 #ifdef __USE_XOPEN_EXTENDED
 567 /* Parse comma separated suboption from *OPTIONP and match against
 568    strings in TOKENS.  If found return index and set *VALUEP to
 569    optional value introduced by an equal sign.  If the suboption is
 570    not part of TOKENS return in *VALUEP beginning of unknown
 571    suboption.  On exit *OPTIONP is set to the beginning of the next
 572    otken or at the terminating NUL character.  */
 573 extern int getsubopt __P ((char **__optionp, __const char *__const *__tokens,
 574                            char **__valuep));
 575 #endif
 576
 577
 578 #ifdef __USE_XOPEN
 579
 580 /* Setup DES tables according KEY.  */
 581 extern void setkey __P ((__const char *__key));
 582 #endif
 583
 584
 585 __END_DECLS
 586
 587 #endif /* stdlib.h  */