about summary refs log tree commit diff
path: root/stdlib/stdlib.h
blob: bf7b2638d2be3cb16ed6954076bad149bc1fa25e (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
/* Copyright (C) 1991,92,93,94,95,96,97,98 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public License as
   published by the Free Software Foundation; either version 2 of the
   License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with the GNU C Library; see the file COPYING.LIB.  If not,
   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, USA.  */

/*
 *	ISO C Standard: 4.10 GENERAL UTILITIES	<stdlib.h>
 */

#ifndef	_STDLIB_H
#define	_STDLIB_H	1

#include <features.h>

/* Get size_t, wchar_t and NULL from <stddef.h>.  */
#define	__need_size_t
#define	__need_wchar_t
#define	__need_NULL
#include <stddef.h>

__BEGIN_DECLS

/* Returned by `div'.  */
typedef struct
  {
    int quot;			/* Quotient.  */
    int rem;			/* Remainder.  */
  } div_t;

/* Returned by `ldiv'.  */
typedef struct
  {
    long int quot;		/* Quotient.  */
    long int rem;		/* Remainder.  */
  } ldiv_t;

#ifdef __USE_ISOC9X
/* Returned by `lldiv'.  */
typedef struct
  {
    long long int quot;		/* Quotient.  */
    long long int rem;		/* Remainder.  */
  } lldiv_t;
#endif


/* The largest number rand will return (same as INT_MAX).  */
#define	RAND_MAX	2147483647


/* We define these the same for all machines.
   Changes from this to the outside world should be done in `_exit'.  */
#define	EXIT_FAILURE	1	/* Failing exit status.  */
#define	EXIT_SUCCESS	0	/* Successful exit status.  */


/* Maximum length of a multibyte character in the current locale.  */
#define	MB_CUR_MAX	(__ctype_get_mb_cur_max ())
extern int __ctype_get_mb_cur_max __P ((void));


/* Convert a string to a floating-point number.  */
extern double atof __P ((__const char *__nptr));
/* Convert a string to an integer.  */
extern int atoi __P ((__const char *__nptr));
/* Convert a string to a long integer.  */
extern long int atol __P ((__const char *__nptr));

#if defined __USE_ISOC9X || (defined __GNUC__ && defined __USE_MISC)
/* These functions will part of the standard C library in ISO C 9X.  */
extern long long int atoll __P ((__const char *__nptr));
#endif

/* Convert a string to a floating-point number.  */
extern double strtod __P ((__const char *__restrict __nptr,
			   char **__restrict __endptr));

#ifdef	__USE_GNU
/* Likewise for `float' and `long double' sizes of floating-point numbers.  */
extern float strtof __P ((__const char *__restrict __nptr,
			  char **__restrict __endptr));

extern __long_double_t strtold __P ((__const char *__restrict __nptr,
				     char **__restrict __endptr));
#endif

/* Convert a string to a long integer.  */
extern long int strtol __P ((__const char *__restrict __nptr,
			     char **__restrict __endptr, int __base));
/* Convert a string to an unsigned long integer.  */
extern unsigned long int strtoul __P ((__const char *__restrict __nptr,
				       char **__restrict __endptr,
				       int __base));

#if defined __GNUC__ && defined __USE_BSD
/* Convert a string to a quadword integer.  */
extern long long int strtoq __P ((__const char *__restrict __nptr,
				  char **__restrict __endptr, int __base));
/* Convert a string to an unsigned quadword integer.  */
extern unsigned long long int strtouq __P ((__const char *__restrict __nptr,
					    char **__restrict __endptr,
					    int __base));
#endif /* GCC and use BSD.  */

#if defined __USE_ISOC9X || (defined __GNUC__ && defined __USE_MISC)
/* These functions will part of the standard C library in ISO C 9X.  */

/* Convert a string to a quadword integer.  */
extern long long int strtoll __P ((__const char *__restrict __nptr,
				   char **__restrict __endptr, int __base));
/* Convert a string to an unsigned quadword integer.  */
extern unsigned long long int strtoull __P ((__const char *__restrict __nptr,
					     char **__restrict __endptr,
					     int __base));
#endif /* ISO C 9X or GCC and use MISC.  */


#ifdef __USE_GNU
/* The concept of one static locale per category is not very well
   thought out.  Many applications will need to process its data using
   information from several different locales.  Another application is
   the implementation of the internationalization handling in the
   upcoming ISO C++ standard library.  To support this another set of
   the functions using locale data exist which have an additional
   argument.

   Attention: all these functions are *not* standardized in any form.
   This is a proof-of-concept implementation.  */

/* Structure for reentrant locale using functions.  This is an
   (almost) opaque type for the user level programs.  */
# include <xlocale.h>

/* Special versions of the functions above which take the locale to
   use as an additional parameter.  */
extern long int __strtol_l __P ((__const char *__restrict __nptr,
				 char **__restrict __endptr, int __base,
				 __locale_t __loc));

extern unsigned long int __strtoul_l __P ((__const char *__restrict __nptr,
					   char **__restrict __endptr,
					   int __base, __locale_t __loc));

extern long long int __strtoll_l __P ((__const char *__restrict __nptr,
				       char **__restrict __endptr, int __base,
				       __locale_t __loc));

extern unsigned long long int __strtoull_l __P ((__const char *__restrict
						 __nptr,
						 char **__restrict __endptr,
						 int __base,
						 __locale_t __loc));

extern double __strtod_l __P ((__const char *__restrict __nptr,
			       char **__restrict __endptr, __locale_t __loc));

extern float __strtof_l __P ((__const char *__restrict __nptr,
			      char **__restrict __endptr, __locale_t __loc));

extern __long_double_t __strtold_l __P ((__const char *__restrict __nptr,
					 char **__restrict __endptr,
					 __locale_t __loc));
#endif /* GNU */


/* The internal entry points for `strtoX' take an extra flag argument
   saying whether or not to parse locale-dependent number grouping.  */

extern double __strtod_internal __P ((__const char *__restrict __nptr,
				      char **__restrict __endptr,
				      int __group));
extern float __strtof_internal __P ((__const char *__restrict __nptr,
				     char **__restrict __endptr, int __group));
extern __long_double_t __strtold_internal __P ((__const char *
						__restrict __nptr,
						char **__restrict __endptr,
						int __group));
#ifndef __strtol_internal_defined
extern long int __strtol_internal __P ((__const char *__restrict __nptr,
					char **__restrict __endptr,
					int __base, int __group));
# define __strtol_internal_defined	1
#endif
#ifndef __strtoul_internal_defined
extern unsigned long int __strtoul_internal __P ((__const char *
						  __restrict __nptr,
						  char **__restrict __endptr,
						  int __base, int __group));
# define __strtoul_internal_defined	1
#endif
#if defined __GNUC__ || defined __USE_ISOC9X
# ifndef __strtoll_internal_defined
extern long long int __strtoll_internal __P ((__const char *__restrict __nptr,
					      char **__restrict __endptr,
					      int __base, int __group));
#  define __strtoll_internal_defined	1
# endif
# ifndef __strtoull_internal_defined
extern unsigned long long int __strtoull_internal __P ((__const char *
							__restrict __nptr,
							char **
							__restrict __endptr,
							int __base,
							int __group));
#  define __strtoull_internal_defined	1
# endif
#endif /* GCC */

#if defined __OPTIMIZE__ && __GNUC__ >= 2
/* Define inline functions which call the internal entry points.  */

extern __inline double
strtod (__const char *__restrict __nptr, char **__restrict __endptr)
{
  return __strtod_internal (__nptr, __endptr, 0);
}
extern __inline long int
strtol (__const char *__restrict __nptr, char **__restrict __endptr,
	int __base)
{
  return __strtol_internal (__nptr, __endptr, __base, 0);
}
extern __inline unsigned long int
strtoul (__const char *__restrict __nptr, char **__restrict __endptr,
	 int __base)
{
  return __strtoul_internal (__nptr, __endptr, __base, 0);
}

# ifdef __USE_GNU
extern __inline float
strtof (__const char *__restrict __nptr, char **__restrict __endptr)
{
  return __strtof_internal (__nptr, __endptr, 0);
}
extern __inline __long_double_t
strtold (__const char *__restrict __nptr, char **__restrict __endptr)
{
  return __strtold_internal (__nptr, __endptr, 0);
}
# endif

# ifdef __USE_BSD
extern __inline long long int
strtoq (__const char *__restrict __nptr, char **__restrict __endptr,
	int __base)
{
  return __strtoll_internal (__nptr, __endptr, __base, 0);
}
extern __inline unsigned long long int
strtouq (__const char *__restrict __nptr, char **__restrict __endptr,
	 int __base)
{
  return __strtoull_internal (__nptr, __endptr, __base, 0);
}
# endif

# if defined __USE_MISC || defined __USE_ISOC9X
extern __inline long long int
strtoll (__const char *__restrict __nptr, char **__restrict __endptr,
	 int __base)
{
  return __strtoll_internal (__nptr, __endptr, __base, 0);
}
extern __inline unsigned long long int
strtoull (__const char * __restrict __nptr, char **__restrict __endptr,
	  int __base)
{
  return __strtoull_internal (__nptr, __endptr, __base, 0);
}
# endif

extern __inline double
atof (__const char *__nptr)
{
  return strtod (__nptr, (char **) NULL);
}
extern __inline int
atoi (__const char *__nptr)
{
  return (int) strtol (__nptr, (char **) NULL, 10);
}
extern __inline long int
atol (__const char *__nptr)
{
  return strtol (__nptr, (char **) NULL, 10);
}

# if defined __USE_MISC || defined __USE_ISOC9X
extern __inline long long int
atoll (__const char *__nptr)
{
  return strtoll (__nptr, (char **) NULL, 10);
}
# endif
#endif /* Optimizing GCC >=2.  */


#if defined __USE_SVID || defined __USE_XOPEN_EXTENDED
/* Convert N to base 64 using the digits "./0-9A-Za-z", least-significant
   digit first.  Returns a pointer to static storage overwritten by the
   next call.  */
extern char *l64a __P ((long int __n));

/* Read a number from a string S in base 64 as above.  */
extern long int a64l __P ((__const char *__s));


# include <sys/types.h>	/* we need int32_t... */

/* These are the functions that actually do things.  The `random', `srandom',
   `initstate' and `setstate' functions are those from BSD Unices.
   The `rand' and `srand' functions are required by the ANSI standard.
   We provide both interfaces to the same random number generator.  */
/* Return a random long integer between 0 and RAND_MAX inclusive.  */
extern int32_t __random __P ((void));
extern int32_t random __P ((void));

/* Seed the random number generator with the given number.  */
extern void __srandom __P ((unsigned int __seed));
extern void srandom __P ((unsigned int __seed));

/* Initialize the random number generator to use state buffer STATEBUF,
   of length STATELEN, and seed it with SEED.  Optimal lengths are 8, 16,
   32, 64, 128 and 256, the bigger the better; values less than 8 will
   cause an error and values greater than 256 will be rounded down.  */
extern __ptr_t __initstate __P ((unsigned int __seed, __ptr_t __statebuf,
				 size_t __statelen));
extern __ptr_t initstate __P ((unsigned int __seed, __ptr_t __statebuf,
			       size_t __statelen));

/* Switch the random number generator to state buffer STATEBUF,
   which should have been previously initialized by `initstate'.  */
extern __ptr_t __setstate __P ((__ptr_t __statebuf));
extern __ptr_t setstate __P ((__ptr_t __statebuf));


# ifdef __USE_MISC
/* Reentrant versions of the `random' family of functions.
   These functions all use the following data structure to contain
   state, rather than global state variables.  */

struct random_data
  {
    int32_t *fptr;		/* Front pointer.  */
    int32_t *rptr;		/* Rear pointer.  */
    int32_t *state;		/* Array of state values.  */
    int rand_type;		/* Type of random number generator.  */
    int rand_deg;		/* Degree of random number generator.  */
    int rand_sep;		/* Distance between front and rear.  */
    int32_t *end_ptr;		/* Pointer behind state table.  */
  };

extern int __random_r __P ((struct random_data *__buf, int32_t *__result));
extern int random_r __P ((struct random_data *__buf, int32_t *__result));

extern int __srandom_r __P ((unsigned int __seed, struct random_data *__buf));
extern int srandom_r __P ((unsigned int __seed, struct random_data *__buf));

extern int __initstate_r __P ((unsigned int __seed, __ptr_t __statebuf,
			       size_t __statelen, struct random_data *__buf));
extern int initstate_r __P ((unsigned int __seed, __ptr_t __statebuf,
			     size_t __statelen, struct random_data *__buf));

extern int __setstate_r __P ((__ptr_t __statebuf, struct random_data *__buf));
extern int setstate_r __P ((__ptr_t __statebuf, struct random_data *__buf));
# endif	/* Use misc.  */
#endif	/* Use SVID || extended X/Open.  */


/* Return a random integer between 0 and RAND_MAX inclusive.  */
extern int rand __P ((void));
/* Seed the random number generator with the given number.  */
extern void srand __P ((unsigned int __seed));

#ifdef __USE_MISC
/* Reentrant interface according to POSIX.1.  */
extern int __rand_r __P ((unsigned int *__seed));
extern int rand_r __P ((unsigned int *__seed));
#endif


#if defined __USE_SVID || defined __USE_XOPEN
/* System V style 48-bit random number generator functions.  */

/* Return non-negative, double-precision floating-point value in [0.0,1.0).  */
extern double drand48 __P ((void));
extern double erand48 __P ((unsigned short int __xsubi[3]));

/* Return non-negative, long integer in [0,2^31).  */
extern long int lrand48 __P ((void));
extern long int nrand48 __P ((unsigned short int __xsubi[3]));

/* Return signed, long integers in [-2^31,2^31).  */
extern long int mrand48 __P ((void));
extern long int jrand48 __P ((unsigned short int __xsubi[3]));

/* Seed random number generator.  */
extern void srand48 __P ((long int __seedval));
extern unsigned short int *seed48 __P ((unsigned short int __seed16v[3]));
extern void lcong48 __P ((unsigned short int __param[7]));

/* Data structure for communication with thread safe versions.  */
struct drand48_data
  {
    unsigned short int x[3];	/* Current state.  */
    unsigned short int a[3];	/* Factor in congruential formula.  */
    unsigned short int c;	/* Additive const. in congruential formula.  */
    unsigned short int old_x[3]; /* Old state.  */
    int init;			/* Flag for initializing.  */
  };

# ifdef __USE_MISC
/* Return non-negative, double-precision floating-point value in [0.0,1.0).  */
extern int drand48_r __P ((struct drand48_data *__buffer, double *__result));
extern int __erand48_r __P ((unsigned short int __xsubi[3],
			     struct drand48_data *__buffer, double *__result));
extern int erand48_r __P ((unsigned short int __xsubi[3],
			   struct drand48_data *__buffer, double *__result));

/* Return non-negative, long integer in [0,2^31).  */
extern int lrand48_r __P ((struct drand48_data *__buffer, long int *__result));
extern int __nrand48_r __P ((unsigned short int __xsubi[3],
			     struct drand48_data *__buffer,
			     long int *__result));
extern int nrand48_r __P ((unsigned short int __xsubi[3],
			   struct drand48_data *__buffer, long int *__result));

/* Return signed, long integers in [-2^31,2^31).  */
extern int mrand48_r __P ((struct drand48_data *__buffer, long int *__result));
extern int __jrand48_r __P ((unsigned short int __xsubi[3],
			     struct drand48_data *__buffer,
			     long int *__result));
extern int jrand48_r __P ((unsigned short int __xsubi[3],
			   struct drand48_data *__buffer, long int *__result));

/* Seed random number generator.  */
extern int __srand48_r __P ((long int __seedval,
			     struct drand48_data *__buffer));
extern int srand48_r __P ((long int __seedval, struct drand48_data *__buffer));

extern int __seed48_r __P ((unsigned short int __seed16v[3],
			    struct drand48_data *__buffer));
extern int seed48_r __P ((unsigned short int __seed16v[3],
			  struct drand48_data *__buffer));

extern int __lcong48_r __P ((unsigned short int __param[7],
			     struct drand48_data *__buffer));
extern int lcong48_r __P ((unsigned short int __param[7],
			   struct drand48_data *__buffer));
# endif	/* Use misc.  */

/* Internal function to compute next state of the generator.  */
extern int __drand48_iterate __P ((unsigned short int __xsubi[3],
				   struct drand48_data *__buffer));
#endif	/* Use SVID or X/Open.  */


/* Allocate SIZE bytes of memory.  */
extern __ptr_t malloc __P ((size_t __size));
/* Re-allocate the previously allocated block
   in __ptr_t, making the new block SIZE bytes long.  */
extern __ptr_t realloc __P ((__ptr_t __ptr, size_t __size));
/* Allocate NMEMB elements of SIZE bytes each, all initialized to 0.  */
extern __ptr_t calloc __P ((size_t __nmemb, size_t __size));
/* Free a block allocated by `malloc', `realloc' or `calloc'.  */
extern void free __P ((__ptr_t __ptr));

#ifdef	__USE_MISC
/* Free a block.  An alias for `free'.	(Sun Unices).  */
extern void cfree __P ((__ptr_t __ptr));
#endif /* Use misc.  */

#if defined __USE_GNU || defined __USE_BSD || defined __USE_MISC
# include <alloca.h>
#endif /* Use GNU, BSD, or misc.  */

#if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
/* Allocate SIZE bytes on a page boundary.  The storage cannot be freed.  */
extern __ptr_t valloc __P ((size_t __size));
#endif


/* Abort execution and generate a core-dump.  */
extern void abort __P ((void)) __attribute__ ((__noreturn__));


/* Register a function to be called when `exit' is called.  */
extern int atexit __P ((void (*__func) (void)));

#ifdef	__USE_MISC
/* Register a function to be called with the status
   given to `exit' and the given argument.  */
extern int __on_exit __P ((void (*__func) (int __status, __ptr_t __arg),
			   __ptr_t __arg));
extern int on_exit __P ((void (*__func) (int __status, __ptr_t __arg),
			 __ptr_t __arg));
#endif

/* Call all functions registered with `atexit' and `on_exit',
   in the reverse of the order in which they were registered
   perform stdio cleanup, and terminate program execution with STATUS.  */
extern void exit __P ((int __status)) __attribute__ ((__noreturn__));


/* Return the value of envariable NAME, or NULL if it doesn't exist.  */
extern char *getenv __P ((__const char *__name));

/* This function is similar to the above but returns NULL if the
   programs is running with SUID or SGID enabled.  */
extern char *__secure_getenv __P ((__const char *__name));

#if defined __USE_SVID || defined __USE_XOPEN
/* The SVID says this is in <stdio.h>, but this seems a better place.	*/
/* Put STRING, which is of the form "NAME=VALUE", in the environment.
   If there is no `=', remove NAME from the environment.  */
extern int putenv __P ((__const char *__string));
#endif

#ifdef	__USE_BSD
/* Set NAME to VALUE in the environment.
   If REPLACE is nonzero, overwrite an existing value.  */
extern int setenv __P ((__const char *__name, __const char *__value,
			int __replace));

/* Remove the variable NAME from the environment.  */
extern void unsetenv __P ((__const char *__name));
#endif

#ifdef	__USE_MISC
/* The `clearenv' was planned to be added to POSIX.1 but probably
   never made it.  Nevertheless the POSIX.9 standard (POSIX bindings
   for Fortran 77) requires this function.  */
extern int __clearenv __P ((void));
extern int clearenv __P ((void));
#endif


#if defined __USE_MISC || defined __USE_XOPEN_EXTENDED
/* Generate a unique temporary file name from TEMPLATE.
   The last six characters of TEMPLATE must be "XXXXXX";
   they are replaced with a string that makes the file name unique.
   Returns TEMPLATE, or a null pointer if it cannot get a unique file name.  */
extern char *mktemp __P ((char *__template));

/* Generate a unique temporary file name from TEMPLATE.
   The last six characters of TEMPLATE must be "XXXXXX";
   they are replaced with a string that makes the filename unique.
   Returns a file descriptor open on the file for reading and writing,
   or -1 if it cannot create a uniquely-named file.  */
extern int mkstemp __P ((char *__template));
#endif


/* Execute the given line as a shell command.  */
extern int system __P ((__const char *__command));


#ifdef	__USE_GNU
/* Return a malloc'd string containing the canonical absolute name of the
   named file.  The last file name component need not exist, and may be a
   symlink to a nonexistent file.  */
extern char *canonicalize_file_name __P ((__const char *__name));
#endif

#if defined __USE_BSD || defined __USE_XOPEN_EXTENDED
/* Return the canonical absolute name of file NAME.  The last file name
   component need not exist, and may be a symlink to a nonexistent file.
   If RESOLVED is null, the result is malloc'd; otherwise, if the canonical
   name is PATH_MAX chars or more, returns null with `errno' set to
   ENAMETOOLONG; if the name fits in fewer than PATH_MAX chars, returns the
   name in RESOLVED.  */
extern char *realpath __P ((__const char *__name, char *__resolved));
#endif


/* Shorthand for type of comparison functions.  */
#ifndef __COMPAR_FN_T
# define __COMPAR_FN_T
typedef int (*__compar_fn_t) __P ((__const __ptr_t, __const __ptr_t));

# ifdef	__USE_GNU
typedef __compar_fn_t comparison_fn_t;
# endif
#endif

/* Do a binary search for KEY in BASE, which consists of NMEMB elements
   of SIZE bytes each, using COMPAR to perform the comparisons.  */
extern __ptr_t bsearch __P ((__const __ptr_t __key, __const __ptr_t __base,
			     size_t __nmemb, size_t __size,
			     __compar_fn_t __compar));

/* Sort NMEMB elements of BASE, of SIZE bytes each,
   using COMPAR to perform the comparisons.  */
extern void qsort __P ((__ptr_t __base, size_t __nmemb, size_t __size,
			__compar_fn_t __compar));


/* Return the absolute value of X.  */
extern int abs __P ((int __x)) __attribute__ ((__const__));
extern long int labs __P ((long int __x)) __attribute__ ((__const__));
#ifdef __USE_ISOC9X
extern long long int llabs __P ((long long int __x))
     __attribute__ ((__const__));
#endif


/* Return the `div_t', `ldiv_t' or `lldiv_t' representation
   of the value of NUMER over DENOM. */
/* GCC may have built-ins for these someday.  */
extern div_t div __P ((int __numer, int __denom)) __attribute__ ((__const__));
extern ldiv_t ldiv __P ((long int __numer, long int __denom))
     __attribute__ ((__const__));
#ifdef __USE_ISOC9X
extern lldiv_t lldiv __P ((long long int __numer, long long int __denom))
     __attribute__ ((__const__));
#endif


#if defined __USE_SVID || defined __USE_XOPEN_EXTENDED
/* Convert floating point numbers to strings.  The returned values are
   valid only until another call to the same function.  */

/* Convert VALUE to a string with NDIGIT digits and return a pointer to
   this.  Set *DECPT with the position of the decimal character and *SIGN
   with the sign of the number.  */
extern char *ecvt __P ((double __value, int __ndigit, int *__decpt,
			int *__sign));

/* Convert VALUE to a string rounded to NDIGIT decimal digits.  Set *DECPT
   with the position of the decimal character and *SIGN with the sign of
   the number.  */
extern char *fcvt __P ((double __value, int __ndigit, int *__decpt,
			int *__sign));

/* If possible convert VALUE to a string with NDIGIT significant digits.
   Otherwise use exponential representation.  The resulting string will
   be written to BUF.  */
extern char *gcvt __P ((double __value, int __ndigit, char *__buf));

/* Long double versions of above functions.  */
extern char *qecvt __P ((__long_double_t __value, int __ndigit, int *__decpt,
			 int *__sign));
extern char *qfcvt __P ((__long_double_t __value, int __ndigit, int *__decpt,
			 int *__sign));
extern char *qgcvt __P ((__long_double_t __value, int __ndigit, char *__buf));


# ifdef __USE_MISC
/* Reentrant version of the functions above which provide their own
   buffers.  */
extern int ecvt_r __P ((double __value, int __ndigit, int *__decpt,
			int *__sign, char *__buf, size_t __len));
extern int fcvt_r __P ((double __value, int __ndigit, int *__decpt,
			int *__sign, char *__buf, size_t __len));

extern int qecvt_r __P ((__long_double_t __value, int __ndigit, int *__decpt,
			 int *__sign, char *__buf, size_t __len));
extern int qfcvt_r __P ((__long_double_t __value, int __ndigit, int *__decpt,
			 int *__sign, char *__buf, size_t __len));
# endif	/* misc */
#endif	/* use MISC || use X/Open Unix */


/* Return the length of the multibyte character
   in S, which is no longer than N.  */
extern int mblen __P ((__const char *__s, size_t __n));
/* Return the length of the given multibyte character,
   putting its `wchar_t' representation in *PWC.  */
extern int mbtowc __P ((wchar_t *__restrict __pwc,
			__const char *__restrict __s, size_t __n));
/* Put the multibyte character represented
   by WCHAR in S, returning its length.  */
extern int wctomb __P ((char *__s, wchar_t __wchar));


/* Convert a multibyte string to a wide char string.  */
extern size_t mbstowcs __P ((wchar_t *__restrict  __pwcs,
			     __const char *__restrict __s, size_t __n));
/* Convert a wide char string to multibyte string.  */
extern size_t wcstombs __P ((char *__restrict __s,
			     __const wchar_t *__restrict __pwcs, size_t __n));


#ifdef __USE_SVID
/* Determine whether the string value of RESPONSE matches the affirmation
   or negative response expression as specified by the LC_MESSAGES category
   in the program's current locale.  Returns 1 if affirmative, 0 if
   negative, and -1 if not matching.  */
extern int rpmatch __P ((__const char *__response));
#endif


#ifdef __USE_XOPEN_EXTENDED
/* Parse comma separated suboption from *OPTIONP and match against
   strings in TOKENS.  If found return index and set *VALUEP to
   optional value introduced by an equal sign.  If the suboption is
   not part of TOKENS return in *VALUEP beginning of unknown
   suboption.  On exit *OPTIONP is set to the beginning of the next
   token or at the terminating NUL character.  */
extern int getsubopt __P ((char **__optionp, __const char *__const *__tokens,
			   char **__valuep));
#endif


#ifdef __USE_XOPEN

/* Setup DES tables according KEY.  */
extern void setkey __P ((__const char *__key));

/* X/Open pseudo terminal handling.  */

/* The next four functions all take a master pseudo-tty fd and
   perform an operation on the associated slave:  */

/* Chown the slave to the calling user.  */
extern int grantpt __P ((int __fd));

/* Release an internal lock so the slave can be opened.
   Call after grantpt().  */
extern int unlockpt __P ((int __fd));

/* Return the pathname of the pseudo terminal slave assoicated with
   the master FD is open on, or NULL on errors.
   The returned storage is good until the next call to this function.  */
extern char *ptsname __P ((int __fd));
#endif

#ifdef __USE_GNU
/* Store at most BUFLEN characters of the pathname of the slave pseudo
   terminal associated with the master FD is open on in BUF.
   Return 0 on success, otherwise an error number.  */
extern int __ptsname_r __P ((int __fd, char *__buf, size_t __buflen));
extern int ptsname_r __P ((int __fd, char *__buf, size_t __buflen));

/* Open a master pseudo terminal and return its file descriptor.  */
extern int __getpt __P ((void));
extern int getpt __P ((void));
#endif

__END_DECLS

#endif /* stdlib.h  */