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 #ifdef __USE_SVID
 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 #endif
 200
 201
 202 /* Return a random integer between 0 and RAND_MAX inclusive.  */
 203 extern int rand __P ((void));
 204 /* Seed the random number generator with the given number.  */
 205 extern void srand __P ((unsigned int __seed));
 206
 207 #ifdef  __USE_BSD
 208
 209 #include <sys/types.h>  /* we need int32_t... */
 210
 211 /* These are the functions that actually do things.  The `random', `srandom',
 212    `initstate' and `setstate' functions are those from BSD Unices.
 213    The `rand' and `srand' functions are required by the ANSI standard.
 214    We provide both interfaces to the same random number generator.  */
 215 /* Return a random long integer between 0 and RAND_MAX inclusive.  */
 216 extern int32_t __random __P ((void));
 217 extern int32_t random __P ((void));
 218
 219 /* Seed the random number generator with the given number.  */
 220 extern void __srandom __P ((unsigned int __seed));
 221 extern void srandom __P ((unsigned int __seed));
 222
 223 /* Initialize the random number generator to use state buffer STATEBUF,
 224    of length STATELEN, and seed it with SEED.  Optimal lengths are 8, 16,
 225    32, 64, 128 and 256, the bigger the better; values less than 8 will
 226    cause an error and values greater than 256 will be rounded down.  */
 227 extern __ptr_t __initstate __P ((unsigned int __seed, __ptr_t __statebuf,
 228                                  size_t __statelen));
 229 extern __ptr_t initstate __P ((unsigned int __seed, __ptr_t __statebuf,
 230                                size_t __statelen));
 231
 232 /* Switch the random number generator to state buffer STATEBUF,
 233    which should have been previously initialized by `initstate'.  */
 234 extern __ptr_t __setstate __P ((__ptr_t __statebuf));
 235 extern __ptr_t setstate __P ((__ptr_t __statebuf));
 236
 237
 238 #ifdef __USE_REENTRANT
 239 /* Reentrant versions of the `random' family of functions.
 240    These functions all use the following data structure to contain
 241    state, rather than global state variables.  */
 242
 243 struct random_data
 244   {
 245     int32_t *fptr;              /* Front pointer.  */
 246     int32_t *rptr;              /* Rear pointer.  */
 247     int32_t *state;             /* Array of state values.  */
 248     int rand_type;              /* Type of random number generator.  */
 249     int rand_deg;               /* Degree of random number generator.  */
 250     int rand_sep;               /* Distance between front and rear.  */
 251     int32_t *end_ptr;           /* Pointer behind state table.  */
 252   };
 253
 254 extern int __random_r __P ((struct random_data *__buf, int32_t *__result));
 255 extern int random_r __P ((struct random_data *__buf, int32_t *__result));
 256 extern int __srandom_r __P ((unsigned int __seed, struct random_data *__buf));
 257 extern int __initstate_r __P ((unsigned int __seed, __ptr_t __statebuf,
 258                                size_t __statelen, struct random_data *__buf));
 259 extern int __setstate_r __P ((__ptr_t __statebuf, struct random_data *__buf));
 260
 261 extern int srandom_r __P ((unsigned int __seed, struct random_data *__buf));
 262 extern int initstate_r __P ((unsigned int __seed, __ptr_t __statebuf,
 263                              size_t __statelen, struct random_data *__buf));
 264 extern int setstate_r __P ((__ptr_t __statebuf, struct random_data *__buf));
 265 #endif  /* __USE_REENTRANT.  */
 266 #endif  /* Use BSD.  */
 267
 268
 269 #ifdef  __USE_SVID
 270 /* System V style 48-bit random number generator functions.  */
 271
 272 /* Data structure for communication with thread safe versions.  */
 273 struct drand48_data
 274   {
 275     unsigned short int X[3];    /* Current state.  */
 276     unsigned short int a[3];    /* Factor in congruential formula.  */
 277     unsigned short int c;       /* Additive const. in congruential formula.  */
 278     unsigned short int old_X[3]; /* Old state.  */
 279     int init;                   /* Flag for initializing.  */
 280   };
 281
 282 /* Return non-negative, double-precision floating-point value in [0.0,1.0).  */
 283 extern double drand48 __P ((void));
 284 extern int drand48_r __P ((struct drand48_data *__buffer, double *__result));
 285 extern double erand48 __P ((unsigned short int __xsubi[3]));
 286 extern int erand48_r __P ((unsigned short int __xsubi[3],
 287                            struct drand48_data *__buffer, double *__result));
 288 /* Return non-negative, long integer in [0,2^31).  */
 289 extern long lrand48 __P ((void));
 290 extern int lrand48_r __P ((struct drand48_data *__buffer, long *__result));
 291 extern long nrand48 __P ((unsigned short int __xsubi[3]));
 292 extern int nrand48_r __P ((unsigned short int __xsubi[3],
 293                            struct drand48_data *__buffer, long *__result));
 294 /* Return signed, long integers in [-2^31,2^31).  */
 295 extern long mrand48 __P ((void));
 296 extern int mrand48_r __P ((struct drand48_data *__buffer, long *__result));
 297 extern long jrand48 __P ((unsigned short int __xsubi[3]));
 298 extern int jrand48_r __P ((unsigned short int __xsubi[3],
 299                            struct drand48_data *__buffer, long *__result));
 300 /* Seed random number generator.  */
 301 extern void srand48 __P ((long __seedval));
 302 extern int srand48_r __P ((long __seedval, struct drand48_data *__buffer));
 303 extern unsigned short int *seed48 __P ((unsigned short int __seed16v[3]));
 304 extern int seed48_r __P ((unsigned short int __seed16v[3],
 305                           struct drand48_data *__buffer));
 306 extern void lcong48 __P ((unsigned short int __param[7]));
 307 extern int lcong48_r __P ((unsigned short int __param[7],
 308                            struct drand48_data *__buffer));
 309
 310 /* Internal function to compute next state of the generator.  */
 311 extern int __drand48_iterate __P ((unsigned short int __xsubi[3],
 312                                    struct drand48_data *__buffer));
 313 #endif  /* __USE_SVID.  */
 314
 315
 316 /* Allocate SIZE bytes of memory.  */
 317 extern __ptr_t malloc __P ((size_t __size));
 318 /* Re-allocate the previously allocated block
 319    in __ptr_t, making the new block SIZE bytes long.  */
 320 extern __ptr_t realloc __P ((__ptr_t __ptr, size_t __size));
 321 /* Allocate NMEMB elements of SIZE bytes each, all initialized to 0.  */
 322 extern __ptr_t calloc __P ((size_t __nmemb, size_t __size));
 323 /* Free a block allocated by `malloc', `realloc' or `calloc'.  */
 324 extern void free __P ((__ptr_t __ptr));
 325
 326 #ifdef  __USE_MISC
 327 /* Free a block.  An alias for `free'.  (Sun Unices).  */
 328 extern void cfree __P ((__ptr_t __ptr));
 329 #endif /* Use misc.  */
 330
 331 #if defined(__USE_GNU) || defined(__USE_BSD) || defined(__USE_MISC)
 332 #include <alloca.h>
 333 #endif /* Use GNU, BSD, or misc.  */
 334
 335 #ifdef  __USE_BSD
 336 /* Allocate SIZE bytes on a page boundary.  The storage cannot be freed.  */
 337 extern __ptr_t valloc __P ((size_t __size));
 338 #endif
 339
 340
 341 /* Abort execution and generate a core-dump.  */
 342 extern void abort __P ((void)) __attribute__ ((__noreturn__));
 343
 344
 345 /* Register a function to be called when `exit' is called.  */
 346 extern int atexit __P ((void (*__func) (void)));
 347
 348 #ifdef  __USE_MISC
 349 /* Register a function to be called with the status
 350    given to `exit' and the given argument.  */
 351 extern int on_exit __P ((void (*__func) (int __status, __ptr_t __arg),
 352                          __ptr_t __arg));
 353 #endif
 354
 355 /* Call all functions registered with `atexit' and `on_exit',
 356    in the reverse of the order in which they were registered
 357    perform stdio cleanup, and terminate program execution with STATUS.  */
 358 extern void exit __P ((int __status)) __attribute__ ((__noreturn__));
 359
 360
 361 /* Return the value of envariable NAME, or NULL if it doesn't exist.  */
 362 extern char *getenv __P ((__const char *__name));
 363
 364 /* This function is similar to the above but returns NULL if the
 365    programs is running with SUID or SGID enabled.  */
 366 extern char *__secure_getenv __P ((__const char *__name));
 367
 368 #ifdef  __USE_SVID
 369 /* The SVID says this is in <stdio.h>, but this seems a better place.   */
 370 /* Put STRING, which is of the form "NAME=VALUE", in the environment.
 371    If there is no `=', remove NAME from the environment.  */
 372 extern int putenv __P ((__const char *__string));
 373 #endif
 374
 375 #ifdef  __USE_BSD
 376 /* Set NAME to VALUE in the environment.
 377    If REPLACE is nonzero, overwrite an existing value.  */
 378 extern int setenv __P ((__const char *__name, __const char *__value,
 379                         int __replace));
 380
 381 /* Remove the variable NAME from the environment.  */
 382 extern void unsetenv __P ((__const char *__name));
 383 #endif
 384
 385 #ifdef  __USE_MISC
 386 /* The `clearenv' was planned to be added to POSIX.1 but probably
 387    never made it.  Nevertheless the POSIX.9 standard (POSIX bindings
 388    for Fortran 77) requires this function.  */
 389 extern int clearenv __P ((void));
 390 #endif
 391
 392 /* Execute the given line as a shell command.  */
 393 extern int system __P ((__const char *__command));
 394
 395
 396 #ifdef  __USE_GNU
 397 /* Return a malloc'd string containing the canonical absolute name of the
 398    named file.  The last file name component need not exist, and may be a
 399    symlink to a nonexistent file.  */
 400 extern char *canonicalize_file_name __P ((__const char *__name));
 401 #endif
 402
 403 #ifdef  __USE_BSD
 404 /* Return the canonical absolute name of file NAME.  The last file name
 405    component need not exist, and may be a symlink to a nonexistent file.
 406    If RESOLVED is null, the result is malloc'd; otherwise, if the canonical
 407    name is PATH_MAX chars or more, returns null with `errno' set to
 408    ENAMETOOLONG; if the name fits in fewer than PATH_MAX chars, returns the
 409    name in RESOLVED.  */
 410 extern char *realpath __P ((__const char *__name, char *__resolved));
 411 #endif
 412
 413
 414 /* Shorthand for type of comparison functions.  */
 415 #ifndef __COMPAR_FN_T
 416 #define __COMPAR_FN_T
 417 typedef int (*__compar_fn_t) __P ((__const __ptr_t, __const __ptr_t));
 418 #endif
 419
 420 #ifdef  __USE_GNU
 421 typedef __compar_fn_t comparison_fn_t;
 422 #endif
 423
 424 /* Do a binary search for KEY in BASE, which consists of NMEMB elements
 425    of SIZE bytes each, using COMPAR to perform the comparisons.  */
 426 extern __ptr_t bsearch __P ((__const __ptr_t __key, __const __ptr_t __base,
 427                              size_t __nmemb, size_t __size,
 428                              __compar_fn_t __compar));
 429
 430 /* Sort NMEMB elements of BASE, of SIZE bytes each,
 431    using COMPAR to perform the comparisons.  */
 432 extern void qsort __P ((__ptr_t __base, size_t __nmemb, size_t __size,
 433                         __compar_fn_t __compar));
 434
 435
 436 /* Return the absolute value of X.  */
 437 extern int abs __P ((int __x)) __attribute__ ((__const__));
 438 extern long int labs __P ((long int __x)) __attribute__ ((__const__));
 439 #ifdef __USE_GNU
 440 extern long long int llabs __P ((long long int __x)) __attribute__ ((__const__));
 441 #endif
 442
 443
 444 /* Return the `div_t', `ldiv_t' or `lldiv_t' representation
 445    of the value of NUMER over DENOM. */
 446 /* GCC may have built-ins for these someday.  */
 447 extern div_t div __P ((int __numer, int __denom)) __attribute__ ((__const__));
 448 extern ldiv_t ldiv __P ((long int __numer, long int __denom)) __attribute__ ((__const__));
 449 #ifdef __USE_GNU
 450 extern lldiv_t lldiv __P ((long long int __numer, long long int __denom)) __attribute__ ((__const__));
 451 #endif
 452
 453
 454 #ifdef __USE_SVID
 455 /* Convert floating point numbers to strings.  The returned values are
 456    valid only until another call to the same function.  */
 457
 458 /* Convert VALUE to a string with NDIGIT digits and return a pointer to
 459    this.  Set *DECPT with the position of the decimal character and *SIGN
 460    with the sign of the number.  */
 461 char *ecvt __P ((double __value, int __ndigit, int *__decpt, int *__sign));
 462
 463 /* Convert VALUE to a string rounded to NDIGIT decimal digits.  Set *DECPT
 464    with the position of the decimal character and *SIGN with the sign of
 465    the number.  */
 466 char *fcvt __P ((double __value, int __ndigit, int *__decpt, int *__sign));
 467
 468 /* If possible convert VALUE to a string with NDIGIT significant digits.
 469    Otherwise use exponential representation.  The resulting string will
 470    be written to BUF.  */
 471 char *gcvt __P ((double __value, int __ndigit, char *__buf));
 472
 473 /* Long double versions of above functions.  */
 474 char *qecvt __P ((__long_double_t __value, int __ndigit, int *__decpt,
 475                   int *__sign));
 476 char *qfcvt __P ((__long_double_t __value, int __ndigit, int *__decpt,
 477                   int *__sign));
 478 char *qgcvt __P ((__long_double_t __value, int __ndigit, char *__buf));
 479
 480
 481 #ifdef __USE_REENTRANT
 482 /* Reentrant version of the functions above which provide their own
 483    buffers.  */
 484 int ecvt_r __P ((double __value, int __ndigit, int *__decpt, int *__sign,
 485                  char *__buf, size_t __len));
 486 int fcvt_r __P ((double __value, int __ndigit, int *__decpt, int *__sign,
 487                  char *__buf, size_t __len));
 488
 489 int qecvt_r __P ((__long_double_t __value, int __ndigit, int *__decpt,
 490                   int *__sign, char *__buf, size_t __len));
 491 int qfcvt_r __P ((__long_double_t __value, int __ndigit, int *__decpt,
 492                   int *__sign, char *__buf, size_t __len));
 493 #endif
 494 #endif
 495
 496
 497 /* Return the length of the multibyte character
 498    in S, which is no longer than N.  */
 499 extern int mblen __P ((__const char *__s, size_t __n));
 500 /* Return the length of the given multibyte character,
 501    putting its `wchar_t' representation in *PWC.  */
 502 extern int mbtowc __P ((wchar_t *__pwc, __const char *__s, size_t __n));
 503 /* Put the multibyte character represented
 504    by WCHAR in S, returning its length.  */
 505 extern int wctomb __P ((char *__s, wchar_t __wchar));
 506
 507 #if defined (__OPTIMIZE__) && __GNUC__ >= 2
 508 extern __inline int mblen (__const char *__s, size_t __n)
 509 { return mbtowc ((wchar_t *) NULL, __s, __n); }
 510 #endif /* Optimizing GCC >=2.  */
 511
 512
 513 /* Convert a multibyte string to a wide char string.  */
 514 extern size_t mbstowcs __P ((wchar_t *__pwcs, __const char *__s, size_t __n));
 515 /* Convert a wide char string to multibyte string.  */
 516 extern size_t wcstombs __P ((char *__s, __const wchar_t *__pwcs, size_t __n));
 517
 518
 519 #ifdef __USE_SVID
 520 /* Determine whether the string value of RESPONSE matches the affirmation
 521    or negative response expression as specified by the LC_MESSAGES category
 522    in the program's current locale.  Returns 1 if affirmative, 0 if
 523    negative, and -1 if not matching.  */
 524 extern int rpmatch __P ((__const char *__response));
 525 #endif
 526
 527
 528 #ifdef __USE_MISC
 529 /* Parse comma separated suboption from *OPTIONP and match against
 530    strings in TOKENS.  If found return index and set *VALUEP to
 531    optional value introduced by an equal sign.  If the suboption is
 532    not part of TOKENS return in *VALUEP beginning of unknown
 533    suboption.  On exit *OPTIONP is set to the beginning of the next
 534    otken or at the terminating NUL character.  */
 535 extern int getsubopt __P ((char **__optionp, __const char *__const *__tokens,
 536                            char **__valuep));
 537 #endif
 538
 539
 540 __END_DECLS
 541
 542 #endif /* stdlib.h  */