about summary refs log tree commit diff
path: root/sysdeps/posix/sysconf.c
blob: 26136bd9c93e0d7a1441e77079b3608e0b74670a (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
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
/* Copyright (C) 1991-2014 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 Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#include <errno.h>
#include <limits.h>
#include <grp.h>
#include <pwd.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/sysinfo.h>
#include <sys/types.h>
#include <regex.h>


#define NEED_CHECK_SPEC \
  (!defined _XBS5_ILP32_OFF32 || !defined _XBS5_ILP32_OFFBIG \
   || !defined _XBS5_LP64_OFF64 || !defined _XBS5_LPBIG_OFFBIG \
   || !defined _POSIX_V6_ILP32_OFF32 || !defined _POSIX_V6_ILP32_OFFBIG \
   || !defined _POSIX_V6_LP64_OFF64 || !defined _POSIX_V6_LPBIG_OFFBIG \
   || !defined _POSIX_V7_ILP32_OFF32 || !defined _POSIX_V7_ILP32_OFFBIG \
   || !defined _POSIX_V7_LP64_OFF64 || !defined _POSIX_V7_LPBIG_OFFBIG)
#if NEED_CHECK_SPEC
static long int __sysconf_check_spec (const char *spec);
#endif


/* Get the value of the system variable NAME.  */
long int
__sysconf (name)
     int name;
{
  switch (name)
    {
      /* Also add obsolete or unnecessarily added constants here.  */
    case _SC_EQUIV_CLASS_MAX:
    default:
      __set_errno (EINVAL);
      return -1;

    case _SC_ARG_MAX:
#ifdef	ARG_MAX
      return ARG_MAX;
#else
      return -1;
#endif

    case _SC_CHILD_MAX:
#ifdef	CHILD_MAX
      return CHILD_MAX;
#else
      return __get_child_max ();
#endif

    case _SC_CLK_TCK:
      return __getclktck ();

    case _SC_NGROUPS_MAX:
#ifdef	NGROUPS_MAX
      return NGROUPS_MAX;
#else
      return -1;
#endif

    case _SC_OPEN_MAX:
      return __getdtablesize ();

    case _SC_STREAM_MAX:
#ifdef	STREAM_MAX
      return STREAM_MAX;
#else
      return FOPEN_MAX;
#endif

    case _SC_TZNAME_MAX:
      return MAX (__tzname_max (), _POSIX_TZNAME_MAX);

    case _SC_JOB_CONTROL:
#if _POSIX_JOB_CONTROL > 0
      return _POSIX_JOB_CONTROL;
#else
      return -1;
#endif

    case _SC_SAVED_IDS:
#if _POSIX_SAVED_IDS > 0
      return 1;
#else
      return -1;
#endif

    case _SC_REALTIME_SIGNALS:
#if _POSIX_REALTIME_SIGNALS > 0
      return _POSIX_REALTIME_SIGNALS;
#else
      return -1;
#endif

    case _SC_PRIORITY_SCHEDULING:
#if _POSIX_PRIORITY_SCHEDULING > 0
      return _POSIX_PRIORITY_SCHEDULING;
#else
      return -1;
#endif

    case _SC_TIMERS:
#if _POSIX_TIMERS > 0
      return _POSIX_TIMERS;
#else
      return -1;
#endif

    case _SC_ASYNCHRONOUS_IO:
#if _POSIX_ASYNCHRONOUS_IO > 0
      return _POSIX_ASYNCHRONOUS_IO;
#else
      return -1;
#endif

    case _SC_PRIORITIZED_IO:
#if _POSIX_PRIORITIZED_IO > 0
      return _POSIX_PRIORITIZED_IO;
#else
      return -1;
#endif

    case _SC_SYNCHRONIZED_IO:
#if _POSIX_SYNCHRONIZED_IO > 0
      return _POSIX_SYNCHRONIZED_IO;
#else
      return -1;
#endif

    case _SC_FSYNC:
#if _POSIX_FSYNC > 0
      return _POSIX_FSYNC;
#else
      return -1;
#endif

    case _SC_MAPPED_FILES:
#if _POSIX_MAPPED_FILES > 0
      return _POSIX_MAPPED_FILES;
#else
      return -1;
#endif

    case _SC_MEMLOCK:
#if _POSIX_MEMLOCK > 0
      return _POSIX_MEMLOCK;
#else
      return -1;
#endif

    case _SC_MEMLOCK_RANGE:
#if _POSIX_MEMLOCK_RANGE > 0
      return _POSIX_MEMLOCK_RANGE;
#else
      return -1;
#endif

    case _SC_MEMORY_PROTECTION:
#if _POSIX_MEMORY_PROTECTION > 0
      return _POSIX_MEMORY_PROTECTION;
#else
      return -1;
#endif

    case _SC_MESSAGE_PASSING:
#if _POSIX_MESSAGE_PASSING > 0
      return _POSIX_MESSAGE_PASSING;
#else
      return -1;
#endif

    case _SC_SEMAPHORES:
#if _POSIX_SEMAPHORES > 0
      return _POSIX_SEMAPHORES;
#else
      return -1;
#endif

    case _SC_SHARED_MEMORY_OBJECTS:
#if _POSIX_SHARED_MEMORY_OBJECTS > 0
      return _POSIX_SHARED_MEMORY_OBJECTS;
#else
      return -1;
#endif

    case _SC_VERSION:
      return _POSIX_VERSION;

    case _SC_PAGESIZE:
      return __getpagesize ();

    case _SC_AIO_LISTIO_MAX:
#ifdef	AIO_LISTIO_MAX
      return AIO_LISTIO_MAX;
#else
      return -1;
#endif

    case _SC_AIO_MAX:
#ifdef	AIO_MAX
      return AIO_MAX;
#else
      return -1;
#endif

    case _SC_AIO_PRIO_DELTA_MAX:
#ifdef	AIO_PRIO_DELTA_MAX
      return AIO_PRIO_DELTA_MAX;
#else
      return -1;
#endif

    case _SC_DELAYTIMER_MAX:
#ifdef	DELAYTIMER_MAX
      return DELAYTIMER_MAX;
#else
      return -1;
#endif

    case _SC_MQ_OPEN_MAX:
#ifdef	MQ_OPEN_MAX
      return MQ_OPEN_MAX;
#else
      return -1;
#endif

    case _SC_MQ_PRIO_MAX:
#ifdef	MQ_PRIO_MAX
      return MQ_PRIO_MAX;
#else
      return -1;
#endif

    case _SC_RTSIG_MAX:
#ifdef	RTSIG_MAX
      return RTSIG_MAX;
#else
      return -1;
#endif

    case _SC_SEM_NSEMS_MAX:
#ifdef	SEM_NSEMS_MAX
      return SEM_NSEMS_MAX;
#else
      return -1;
#endif

    case _SC_SEM_VALUE_MAX:
#ifdef	SEM_VALUE_MAX
      return SEM_VALUE_MAX;
#else
      return -1;
#endif

    case _SC_SIGQUEUE_MAX:
#ifdef	SIGQUEUE_MAX
      return SIGQUEUE_MAX;
#else
      return -1;
#endif

    case _SC_TIMER_MAX:
#ifdef	TIMER_MAX
      return TIMER_MAX;
#else
      return -1;
#endif

    case _SC_BC_BASE_MAX:
#ifdef	BC_BASE_MAX
      return BC_BASE_MAX;
#else
      return -1;
#endif

    case _SC_BC_DIM_MAX:
#ifdef	BC_DIM_MAX
      return BC_DIM_MAX;
#else
      return -1;
#endif

    case _SC_BC_SCALE_MAX:
#ifdef	BC_SCALE_MAX
      return BC_SCALE_MAX;
#else
      return -1;
#endif

    case _SC_BC_STRING_MAX:
#ifdef	BC_STRING_MAX
      return BC_STRING_MAX;
#else
      return -1;
#endif

    case _SC_COLL_WEIGHTS_MAX:
#ifdef	COLL_WEIGHTS_MAX
      return COLL_WEIGHTS_MAX;
#else
      return -1;
#endif

    case _SC_EXPR_NEST_MAX:
#ifdef	EXPR_NEST_MAX
      return EXPR_NEST_MAX;
#else
      return -1;
#endif

    case _SC_LINE_MAX:
#ifdef	LINE_MAX
      return LINE_MAX;
#else
      return -1;
#endif

    case _SC_RE_DUP_MAX:
#ifdef	RE_DUP_MAX
      return RE_DUP_MAX;
#else
      return -1;
#endif

    case _SC_CHARCLASS_NAME_MAX:
#ifdef	CHARCLASS_NAME_MAX
      return CHARCLASS_NAME_MAX;
#else
      return -1;
#endif

    case _SC_PII:
#if _POSIX_PII > 0
      return 1;
#else
      return -1;
#endif

    case _SC_PII_XTI:
#if _POSIX_PII_XTI > 0
      return 1;
#else
      return -1;
#endif

    case _SC_PII_SOCKET:
#if _POSIX_PII_SOCKET > 0
      return 1;
#else
      return -1;
#endif

    case _SC_PII_INTERNET:
#if _POSIX_PII_INTERNET > 0
      return 1;
#else
      return -1;
#endif

    case _SC_PII_OSI:
#if _POSIX_PII_OSI > 0
      return 1;
#else
      return -1;
#endif

    case _SC_POLL:
#if _POSIX_POLL > 0
      return 1;
#else
      return -1;
#endif

    case _SC_SELECT:
#if _POSIX_SELECT > 0
      return 1;
#else
      return -1;
#endif

      /* The same as _SC_IOV_MAX.  */
    case _SC_UIO_MAXIOV:
#ifdef	UIO_MAXIOV
      return UIO_MAXIOV;
#else
      return -1;
#endif

    case _SC_PII_INTERNET_STREAM:
#if _POSIX_PII_INTERNET_STREAM > 0
      return 1;
#else
      return -1;
#endif

    case _SC_PII_INTERNET_DGRAM:
#if _POSIX_PII_INTERNET_DGRAM > 0
      return 1;
#else
      return -1;
#endif

    case _SC_PII_OSI_COTS:
#if _POSIX_PII_OSI_COTS > 0
      return 1;
#else
      return -1;
#endif

    case _SC_PII_OSI_CLTS:
#if _POSIX_PII_OSI_CLTS > 0
      return 1;
#else
      return -1;
#endif

    case _SC_PII_OSI_M:
#if _POSIX_PII_OSI_M > 0
      return 1;
#else
      return -1;
#endif

    case _SC_T_IOV_MAX:
#ifdef	_T_IOV_MAX
      return _T_IOV_MAX;
#else
      return -1;
#endif

    case _SC_2_VERSION:
      return _POSIX2_VERSION;

    case _SC_2_C_BIND:
#ifdef	_POSIX2_C_BIND
      return _POSIX2_C_BIND;
#else
      return -1;
#endif

    case _SC_2_C_DEV:
#ifdef	_POSIX2_C_DEV
      return _POSIX2_C_DEV;
#else
      return -1;
#endif

    case _SC_2_C_VERSION:
#ifdef	_POSIX2_C_VERSION
      return _POSIX2_C_VERSION;
#else
      return -1;
#endif

    case _SC_2_FORT_DEV:
#ifdef	_POSIX2_FORT_DEV
      return _POSIX2_FORT_DEV;
#else
      return -1;
#endif

    case _SC_2_FORT_RUN:
#ifdef	_POSIX2_FORT_RUN
      return _POSIX2_FORT_RUN;
#else
      return -1;
#endif

    case _SC_2_LOCALEDEF:
#ifdef	_POSIX2_LOCALEDEF
      return _POSIX2_LOCALEDEF;
#else
      return -1;
#endif

    case _SC_2_SW_DEV:
#ifdef	_POSIX2_SW_DEV
      return _POSIX2_SW_DEV;
#else
      return -1;
#endif

    case _SC_2_CHAR_TERM:
#ifdef	_POSIX2_CHAR_TERM
      return _POSIX2_CHAR_TERM;
#else
      return -1;
#endif

    case _SC_2_UPE:
#ifdef	_POSIX2_UPE
      return _POSIX2_UPE;
#else
      return -1;
#endif

      /* POSIX 1003.1c (POSIX Threads).  */
    case _SC_THREADS:
#if _POSIX_THREADS > 0
      return _POSIX_THREADS;
#else
      return -1;
#endif

    case _SC_THREAD_SAFE_FUNCTIONS:
#if _POSIX_THREAD_SAFE_FUNCTIONS > 0
      return _POSIX_THREAD_SAFE_FUNCTIONS;
#else
      return -1;
#endif

    case _SC_GETGR_R_SIZE_MAX:
      return NSS_BUFLEN_GROUP;

    case _SC_GETPW_R_SIZE_MAX:
      return NSS_BUFLEN_PASSWD;

    case _SC_LOGIN_NAME_MAX:
#ifdef	LOGIN_NAME_MAX
      return LOGIN_NAME_MAX;
#else
      return -1;
#endif

    case _SC_TTY_NAME_MAX:
#ifdef	TTY_NAME_MAX
      return TTY_NAME_MAX;
#else
      return -1;
#endif

    case _SC_THREAD_DESTRUCTOR_ITERATIONS:
#if _POSIX_THREAD_DESTRUCTOR_ITERATIONS > 0
      return _POSIX_THREAD_DESTRUCTOR_ITERATIONS;
#else
      return -1;
#endif

    case _SC_THREAD_KEYS_MAX:
#ifdef	PTHREAD_KEYS_MAX
      return PTHREAD_KEYS_MAX;
#else
      return -1;
#endif

    case _SC_THREAD_STACK_MIN:
#ifdef	PTHREAD_STACK_MIN
      return PTHREAD_STACK_MIN;
#else
      return -1;
#endif

    case _SC_THREAD_THREADS_MAX:
#ifdef	PTHREAD_THREADS_MAX
      return PTHREAD_THREADS_MAX;
#else
      return -1;
#endif

    case _SC_THREAD_ATTR_STACKADDR:
#if _POSIX_THREAD_ATTR_STACKADDR > 0
      return _POSIX_THREAD_ATTR_STACKADDR;
#else
      return -1;
#endif

    case _SC_THREAD_ATTR_STACKSIZE:
#if _POSIX_THREAD_ATTR_STACKSIZE > 0
      return _POSIX_THREAD_ATTR_STACKSIZE;
#else
      return -1;
#endif

    case _SC_THREAD_PRIORITY_SCHEDULING:
#if _POSIX_THREAD_PRIORITY_SCHEDULING > 0
      return _POSIX_THREAD_PRIORITY_SCHEDULING;
#else
      return -1;
#endif

    case _SC_THREAD_PRIO_INHERIT:
#if _POSIX_THREAD_PRIO_INHERIT > 0
      return _POSIX_THREAD_PRIO_INHERIT;
#else
      return -1;
#endif

    case _SC_THREAD_PRIO_PROTECT:
#if _POSIX_THREAD_PRIO_PROTECT > 0
      return _POSIX_THREAD_PRIO_PROTECT;
#else
      return -1;
#endif

    case _SC_THREAD_PROCESS_SHARED:
#if _POSIX_THREAD_PROCESS_SHARED > 0
      return _POSIX_THREAD_PROCESS_SHARED;
#else
      return -1;
#endif

    case _SC_NPROCESSORS_CONF:
      return __get_nprocs_conf ();

    case _SC_NPROCESSORS_ONLN:
      return __get_nprocs ();

    case _SC_PHYS_PAGES:
      return __get_phys_pages ();

    case _SC_AVPHYS_PAGES:
      return __get_avphys_pages ();

    case _SC_ATEXIT_MAX:
      /* We have no limit since we use lists.  */
      return INT_MAX;

    case _SC_PASS_MAX:
      /* We have no limit but since the return value might be used to
	 allocate a buffer we restrict the value.  */
      return BUFSIZ;

    case _SC_XOPEN_VERSION:
      return _XOPEN_VERSION;

    case _SC_XOPEN_XCU_VERSION:
      return _XOPEN_XCU_VERSION;

    case _SC_XOPEN_UNIX:
      return _XOPEN_UNIX;

    case _SC_XOPEN_CRYPT:
#ifdef	_XOPEN_CRYPT
      return _XOPEN_CRYPT;
#else
      return -1;
#endif

    case _SC_XOPEN_ENH_I18N:
#ifdef	_XOPEN_ENH_I18N
      return _XOPEN_ENH_I18N;
#else
      return -1;
#endif

    case _SC_XOPEN_SHM:
#ifdef	_XOPEN_SHM
      return _XOPEN_SHM;
#else
      return -1;
#endif

    case _SC_XOPEN_XPG2:
#ifdef	_XOPEN_XPG2
      return _XOPEN_XPG2;
#else
      return -1;
#endif

    case _SC_XOPEN_XPG3:
#ifdef	_XOPEN_XPG3
      return _XOPEN_XPG3;
#else
      return -1;
#endif

    case _SC_XOPEN_XPG4:
#ifdef	_XOPEN_XPG4
      return _XOPEN_XPG4;
#else
      return -1;
#endif

    case _SC_CHAR_BIT:
      return CHAR_BIT;

    case _SC_CHAR_MAX:
      return CHAR_MAX;

    case _SC_CHAR_MIN:
      return CHAR_MIN;

    case _SC_INT_MAX:
      return INT_MAX;

    case _SC_INT_MIN:
      return INT_MIN;

    case _SC_LONG_BIT:
      return sizeof (long int) * CHAR_BIT;

    case _SC_WORD_BIT:
      return sizeof (int) * CHAR_BIT;

    case _SC_MB_LEN_MAX:
      return MB_LEN_MAX;

    case _SC_NZERO:
      return NZERO;

    case _SC_SSIZE_MAX:
      return _POSIX_SSIZE_MAX;

    case _SC_SCHAR_MAX:
      return SCHAR_MAX;

    case _SC_SCHAR_MIN:
      return SCHAR_MIN;

    case _SC_SHRT_MAX:
      return SHRT_MAX;

    case _SC_SHRT_MIN:
      return SHRT_MIN;

    case _SC_UCHAR_MAX:
      return UCHAR_MAX;

    case _SC_UINT_MAX:
      return UINT_MAX;

    case _SC_ULONG_MAX:
      return ULONG_MAX;

    case _SC_USHRT_MAX:
      return USHRT_MAX;

    case _SC_NL_ARGMAX:
#ifdef	NL_ARGMAX
      return NL_ARGMAX;
#else
      return -1;
#endif

    case _SC_NL_LANGMAX:
#ifdef	NL_LANGMAX
      return NL_LANGMAX;
#else
      return -1;
#endif

    case _SC_NL_MSGMAX:
#ifdef	NL_MSGMAX
      return NL_MSGMAX;
#else
      return -1;
#endif

    case _SC_NL_NMAX:
#ifdef	NL_NMAX
      return NL_NMAX;
#else
      return -1;
#endif

    case _SC_NL_SETMAX:
#ifdef	NL_SETMAX
      return NL_SETMAX;
#else
      return -1;
#endif

    case _SC_NL_TEXTMAX:
#ifdef	NL_TEXTMAX
      return NL_TEXTMAX;
#else
      return -1;
#endif

#define START_ENV_GROUP(VERSION)		\
      /* Empty.  */

#define END_ENV_GROUP(VERSION)			\
      /* Empty.  */

#define KNOWN_ABSENT_ENVIRONMENT(SC_PREFIX, ENV_PREFIX, SUFFIX)	\
    case _SC_##SC_PREFIX##_##SUFFIX:				\
      return _##ENV_PREFIX##_##SUFFIX;

#define KNOWN_PRESENT_ENVIRONMENT(SC_PREFIX, ENV_PREFIX, SUFFIX)	\
    case _SC_##SC_PREFIX##_##SUFFIX:					\
      return _##ENV_PREFIX##_##SUFFIX;

#define UNKNOWN_ENVIRONMENT(SC_PREFIX, ENV_PREFIX, SUFFIX)	\
    case _SC_##SC_PREFIX##_##SUFFIX:				\
      return __sysconf_check_spec (#SUFFIX);

#include <posix/posix-envs.def>

#undef START_ENV_GROUP
#undef END_ENV_GROUP
#undef KNOWN_ABSENT_ENVIRONMENT
#undef KNOWN_PRESENT_ENVIRONMENT
#undef UNKNOWN_ENVIRONMENT

    case _SC_XOPEN_LEGACY:
      return _XOPEN_LEGACY;

    case _SC_XOPEN_REALTIME:
#ifdef _XOPEN_REALTIME
      return _XOPEN_REALTIME;
#else
      return -1;
#endif
    case _SC_XOPEN_REALTIME_THREADS:
#ifdef _XOPEN_REALTIME_THREADS
      return _XOPEN_REALTIME_THREADS;
#else
      return -1;
#endif

    case _SC_ADVISORY_INFO:
#if _POSIX_ADVISORY_INFO > 0
      return _POSIX_ADVISORY_INFO;
#else
      return -1;
#endif

    case _SC_BARRIERS:
#if _POSIX_BARRIERS > 0
      return _POSIX_BARRIERS;
#else
      return -1;
#endif

    case _SC_BASE:
#if _POSIX_BASE > 0
      return _POSIX_BASE;
#else
      return -1;
#endif
    case _SC_C_LANG_SUPPORT:
#if _POSIX_C_LANG_SUPPORT > 0
      return _POSIX_C_LANG_SUPPORT;
#else
      return -1;
#endif
    case _SC_C_LANG_SUPPORT_R:
#if _POSIX_C_LANG_SUPPORT_R > 0
      return _POSIX_C_LANG_SUPPORT_R;
#else
      return -1;
#endif

    case _SC_CLOCK_SELECTION:
#if _POSIX_CLOCK_SELECTION > 0
      return _POSIX_CLOCK_SELECTION;
#else
      return -1;
#endif

    case _SC_CPUTIME:
#if _POSIX_CPUTIME > 0
      return _POSIX_CPUTIME;
#else
      return -1;
#endif

    case _SC_DEVICE_IO:
#if _POSIX_DEVICE_IO > 0
      return _POSIX_DEVICE_IO;
#else
      return -1;
#endif
    case _SC_DEVICE_SPECIFIC:
#if _POSIX_DEVICE_SPCIFIC > 0
      return _POSIX_DEVICE_SPECIFIC;
#else
      return -1;
#endif
    case _SC_DEVICE_SPECIFIC_R:
#if _POSIX_DEVICE_SPCIFIC_R > 0
      return _POSIX_DEVICE_SPECIFIC_R;
#else
      return -1;
#endif

    case _SC_FD_MGMT:
#if _POSIX_FD_MGMT > 0
      return _POSIX_FD_MGMT;
#else
      return -1;
#endif

    case _SC_FIFO:
#if _POSIX_FIFO > 0
      return _POSIX_FIFO;
#else
      return -1;
#endif
    case _SC_PIPE:
#if _POSIX_PIPE > 0
      return _POSIX_PIPE;
#else
      return -1;
#endif

    case _SC_FILE_ATTRIBUTES:
#if _POSIX_FILE_ATTRIBUTES > 0
      return _POSIX_FILE_ATTRIBUTES;
#else
      return -1;
#endif
    case _SC_FILE_LOCKING:
#if _POSIX_FILE_LOCKING > 0
      return _POSIX_FILE_LOCKING;
#else
      return -1;
#endif
    case _SC_FILE_SYSTEM:
#if _POSIX_FILE_SYSTEM > 0
      return _POSIX_FILE_SYSTEM;
#else
      return -1;
#endif

    case _SC_MONOTONIC_CLOCK:
#if _POSIX_MONOTONIC_CLOCK
      return _POSIX_MONOTONIC_CLOCK;
#else
      return -1;
#endif

    case _SC_MULTI_PROCESS:
#if _POSIX_MULTI_PROCESS > 0
      return _POSIX_MULTI_PROCESS;
#else
      return -1;
#endif
    case _SC_SINGLE_PROCESS:
#if _POSIX_SINGLE_PROCESS > 0
      return _POSIX_SINGLE_PROCESS;
#else
      return -1;
#endif

    case _SC_NETWORKING:
#if _POSIX_NETWORKING > 0
      return _POSIX_NETWORKING;
#else
      return -1;
#endif

    case _SC_READER_WRITER_LOCKS:
#if _POSIX_READER_WRITER_LOCKS > 0
      return _POSIX_READER_WRITER_LOCKS;
#else
      return -1;
#endif
    case _SC_SPIN_LOCKS:
#if _POSIX_SPIN_LOCKS > 0
      return _POSIX_SPIN_LOCKS;
#else
      return -1;
#endif

    case _SC_REGEXP:
#if _POSIX_REGEXP > 0
      return _POSIX_REGEXP;
#else
      return -1;
#endif
    case _SC_REGEX_VERSION:
#if _POSIX_REGEX_VERSION > 0
      return _POSIX_REGEX_VERSION;
#else
      return -1;
#endif

    case _SC_SHELL:
#if _POSIX_SHELL > 0
      return _POSIX_SHELL;
#else
      return -1;
#endif

    case _SC_SIGNALS:
#ifdef _POSUX_SIGNALS
      return _POSIX_SIGNALS;
#else
      return -1;
#endif

    case _SC_SPAWN:
#if _POSIX_SPAWN > 0
      return _POSIX_SPAWN;
#else
      return -1;
#endif

    case _SC_SPORADIC_SERVER:
#if _POSIX_SPORADIC_SERVER > 0
      return _POSIX_SPORADIC_SERVER;
#else
      return -1;
#endif
    case _SC_THREAD_SPORADIC_SERVER:
#if _POSIX_THREAD_SPORADIC_SERVER > 0
      return _POSIX_THREAD_SPORADIC_SERVER;
#else
      return -1;
#endif

    case _SC_SYSTEM_DATABASE:
#if _POSIX_SYSTEM_DATABASE > 0
      return _POSIX_SYSTEM_DATABASE;
#else
      return -1;
#endif
    case _SC_SYSTEM_DATABASE_R:
#if _POSIX_SYSTEM_DATABASE_R > 0
      return _POSIX_SYSTEM_DATABASE_R;
#else
      return -1;
#endif

    case _SC_THREAD_CPUTIME:
#if _POSIX_THREAD_CPUTIME > 0
      return _POSIX_THREAD_CPUTIME;
#else
      return -1;
#endif

    case _SC_TIMEOUTS:
#if _POSIX_TIMEOUTS > 0
      return _POSIX_TIMEOUTS;
#else
      return -1;
#endif

    case _SC_TYPED_MEMORY_OBJECTS:
#if _POSIX_TYPED_MEMORY_OBJECTS > 0
      return _POSIX_TYPED_MEMORY_OBJECTS;
#else
      return -1;
#endif

    case _SC_USER_GROUPS:
#if _POSIX_USER_GROUPS > 0
      return _POSIX_USER_GROUPS;
#else
      return -1;
#endif
    case _SC_USER_GROUPS_R:
#if _POSIX_USER_GROUPS_R > 0
      return _POSIX_USER_GROUPS_R;
#else
      return -1;
#endif

    case _SC_2_PBS:
#ifdef _POSIX2_PBS
      return _POSIX2_PBS;
#else
      return -1;
#endif
    case _SC_2_PBS_ACCOUNTING:
#ifdef _POSIX2_PBS_ACCOUNTING
      return _POSIX2_PBS_ACCOUNTING;
#else
      return -1;
#endif
    case _SC_2_PBS_CHECKPOINT:
#ifdef _POSIX2_PBS_CHECKPOINT
      return _POSIX2_PBS_CHECKPOINT;
#else
      return -1;
#endif
    case _SC_2_PBS_LOCATE:
#ifdef _POSIX2_PBS_LOCATE
      return _POSIX2_PBS_LOCATE;
#else
      return -1;
#endif
    case _SC_2_PBS_MESSAGE:
#ifdef _POSIX2_PBS_MESSAGE
      return _POSIX2_PBS_MESSAGE;
#else
      return -1;
#endif
    case _SC_2_PBS_TRACK:
#ifdef _POSIX2_PBS_TRACK
      return _POSIX2_PBS_TRACK;
#else
      return -1;
#endif

    case _SC_SYMLOOP_MAX:
#ifdef SYMLOOP_MAX
      return SYMLOOP_MAX;
#else
      return -1;
#endif

    case _SC_STREAMS:
#ifdef _XOPEN_STREAMS
      return _XOPEN_STREAMS;
#else
      return -1;
#endif

    case _SC_HOST_NAME_MAX:
#ifdef HOST_NAME_MAX
      return HOST_NAME_MAX;
#else
      return -1;
#endif

    case _SC_TRACE:
#if _POSIX_TRACE > 0
      return _POSIX_TRACE;
#else
      return -1;
#endif
    case _SC_TRACE_EVENT_FILTER:
#if _POSIX_TRACE_EVENT_FILTER > 0
      return _POSIX_TRACE_EVENT_FILTER;
#else
      return -1;
#endif
    case _SC_TRACE_INHERIT:
#if _POSIX_TRACE_INHERIT > 0
      return _POSIX_TRACE_INHERIT;
#else
      return -1;
#endif
    case _SC_TRACE_LOG:
#if _POSIX_TRACE_LOG > 0
      return _POSIX_TRACE_LOG;
#else
      return -1;
#endif

    case _SC_TRACE_EVENT_NAME_MAX:
    case _SC_TRACE_NAME_MAX:
    case _SC_TRACE_SYS_MAX:
    case _SC_TRACE_USER_EVENT_MAX:
      /* No support for tracing.  */

    case _SC_XOPEN_STREAMS:
      /* No support for STREAMS.  */
      return -1;

    case _SC_LEVEL1_ICACHE_SIZE:
    case _SC_LEVEL1_ICACHE_ASSOC:
    case _SC_LEVEL1_ICACHE_LINESIZE:
    case _SC_LEVEL1_DCACHE_SIZE:
    case _SC_LEVEL1_DCACHE_ASSOC:
    case _SC_LEVEL1_DCACHE_LINESIZE:
    case _SC_LEVEL2_CACHE_SIZE:
    case _SC_LEVEL2_CACHE_ASSOC:
    case _SC_LEVEL2_CACHE_LINESIZE:
    case _SC_LEVEL3_CACHE_SIZE:
    case _SC_LEVEL3_CACHE_ASSOC:
    case _SC_LEVEL3_CACHE_LINESIZE:
    case _SC_LEVEL4_CACHE_SIZE:
    case _SC_LEVEL4_CACHE_ASSOC:
    case _SC_LEVEL4_CACHE_LINESIZE:
      /* In general we cannot determine these values.  Therefore we
	 return zero which indicates that no information is
	 available.  */
      return 0;

    case _SC_IPV6:
#if _POSIX_IPV6 > 0
      return _POSIX_IPV6;
#else
      return -1;
#endif

    case _SC_RAW_SOCKETS:
#if _POSIX_RAW_SOCKETS > 0
      return _POSIX_RAW_SOCKETS;
#else
      return -1;
#endif
    }
}

#undef __sysconf
weak_alias (__sysconf, sysconf)
libc_hidden_def (__sysconf)

#if NEED_CHECK_SPEC
static long int
__sysconf_check_spec (const char *spec)
{
  int save_errno = errno;

  const char *getconf_dir = __libc_secure_getenv ("GETCONF_DIR") ?: GETCONF_DIR;
  size_t getconf_dirlen = strlen (getconf_dir);
  size_t speclen = strlen (spec);

  char name[getconf_dirlen + sizeof ("/POSIX_V6_") + speclen];
  memcpy (mempcpy (mempcpy (name, getconf_dir, getconf_dirlen),
		   "/POSIX_V6_", sizeof ("/POSIX_V6_") - 1),
	  spec, speclen + 1);

  struct stat64 st;
  long int ret = __xstat64 (_STAT_VER, name, &st) >= 0 ? 1 : -1;

  __set_errno (save_errno);
  return ret;
}
#endif