sysdeps/posix/sysconf.c

   1 /* Copyright (C) 1991-2014 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 Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the 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    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <limits.h>
  20 #include <grp.h>
  21 #include <pwd.h>
  22 #include <stddef.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <time.h>
  27 #include <unistd.h>
  28 #include <sys/param.h>
  29 #include <sys/stat.h>
  30 #include <sys/sysinfo.h>
  31 #include <sys/types.h>
  32 #include <regex.h>
  33
  34
  35 #define NEED_CHECK_SPEC \
  36   (!defined _XBS5_ILP32_OFF32 || !defined _XBS5_ILP32_OFFBIG \
  37    || !defined _XBS5_LP64_OFF64 || !defined _XBS5_LPBIG_OFFBIG \
  38    || !defined _POSIX_V6_ILP32_OFF32 || !defined _POSIX_V6_ILP32_OFFBIG \
  39    || !defined _POSIX_V6_LP64_OFF64 || !defined _POSIX_V6_LPBIG_OFFBIG \
  40    || !defined _POSIX_V7_ILP32_OFF32 || !defined _POSIX_V7_ILP32_OFFBIG \
  41    || !defined _POSIX_V7_LP64_OFF64 || !defined _POSIX_V7_LPBIG_OFFBIG)
  42 #if NEED_CHECK_SPEC
  43 static long int __sysconf_check_spec (const char *spec);
  44 #endif
  45
  46
  47 /* Get the value of the system variable NAME.  */
  48 long int
  49 __sysconf (name)
  50      int name;
  51 {
  52   switch (name)
  53     {
  54       /* Also add obsolete or unnecessarily added constants here.  */
  55     case _SC_EQUIV_CLASS_MAX:
  56     default:
  57       __set_errno (EINVAL);
  58       return -1;
  59
  60     case _SC_ARG_MAX:
  61 #ifdef  ARG_MAX
  62       return ARG_MAX;
  63 #else
  64       return -1;
  65 #endif
  66
  67     case _SC_CHILD_MAX:
  68 #ifdef  CHILD_MAX
  69       return CHILD_MAX;
  70 #else
  71       return __get_child_max ();
  72 #endif
  73
  74     case _SC_CLK_TCK:
  75       return __getclktck ();
  76
  77     case _SC_NGROUPS_MAX:
  78 #ifdef  NGROUPS_MAX
  79       return NGROUPS_MAX;
  80 #else
  81       return -1;
  82 #endif
  83
  84     case _SC_OPEN_MAX:
  85       return __getdtablesize ();
  86
  87     case _SC_STREAM_MAX:
  88 #ifdef  STREAM_MAX
  89       return STREAM_MAX;
  90 #else
  91       return FOPEN_MAX;
  92 #endif
  93
  94     case _SC_TZNAME_MAX:
  95       return MAX (__tzname_max (), _POSIX_TZNAME_MAX);
  96
  97     case _SC_JOB_CONTROL:
  98 #if _POSIX_JOB_CONTROL > 0
  99       return _POSIX_JOB_CONTROL;
 100 #else
 101       return -1;
 102 #endif
 103
 104     case _SC_SAVED_IDS:
 105 #if _POSIX_SAVED_IDS > 0
 106       return 1;
 107 #else
 108       return -1;
 109 #endif
 110
 111     case _SC_REALTIME_SIGNALS:
 112 #if _POSIX_REALTIME_SIGNALS > 0
 113       return _POSIX_REALTIME_SIGNALS;
 114 #else
 115       return -1;
 116 #endif
 117
 118     case _SC_PRIORITY_SCHEDULING:
 119 #if _POSIX_PRIORITY_SCHEDULING > 0
 120       return _POSIX_PRIORITY_SCHEDULING;
 121 #else
 122       return -1;
 123 #endif
 124
 125     case _SC_TIMERS:
 126 #if _POSIX_TIMERS > 0
 127       return _POSIX_TIMERS;
 128 #else
 129       return -1;
 130 #endif
 131
 132     case _SC_ASYNCHRONOUS_IO:
 133 #if _POSIX_ASYNCHRONOUS_IO > 0
 134       return _POSIX_ASYNCHRONOUS_IO;
 135 #else
 136       return -1;
 137 #endif
 138
 139     case _SC_PRIORITIZED_IO:
 140 #if _POSIX_PRIORITIZED_IO > 0
 141       return _POSIX_PRIORITIZED_IO;
 142 #else
 143       return -1;
 144 #endif
 145
 146     case _SC_SYNCHRONIZED_IO:
 147 #if _POSIX_SYNCHRONIZED_IO > 0
 148       return _POSIX_SYNCHRONIZED_IO;
 149 #else
 150       return -1;
 151 #endif
 152
 153     case _SC_FSYNC:
 154 #if _POSIX_FSYNC > 0
 155       return _POSIX_FSYNC;
 156 #else
 157       return -1;
 158 #endif
 159
 160     case _SC_MAPPED_FILES:
 161 #if _POSIX_MAPPED_FILES > 0
 162       return _POSIX_MAPPED_FILES;
 163 #else
 164       return -1;
 165 #endif
 166
 167     case _SC_MEMLOCK:
 168 #if _POSIX_MEMLOCK > 0
 169       return _POSIX_MEMLOCK;
 170 #else
 171       return -1;
 172 #endif
 173
 174     case _SC_MEMLOCK_RANGE:
 175 #if _POSIX_MEMLOCK_RANGE > 0
 176       return _POSIX_MEMLOCK_RANGE;
 177 #else
 178       return -1;
 179 #endif
 180
 181     case _SC_MEMORY_PROTECTION:
 182 #if _POSIX_MEMORY_PROTECTION > 0
 183       return _POSIX_MEMORY_PROTECTION;
 184 #else
 185       return -1;
 186 #endif
 187
 188     case _SC_MESSAGE_PASSING:
 189 #if _POSIX_MESSAGE_PASSING > 0
 190       return _POSIX_MESSAGE_PASSING;
 191 #else
 192       return -1;
 193 #endif
 194
 195     case _SC_SEMAPHORES:
 196 #if _POSIX_SEMAPHORES > 0
 197       return _POSIX_SEMAPHORES;
 198 #else
 199       return -1;
 200 #endif
 201
 202     case _SC_SHARED_MEMORY_OBJECTS:
 203 #if _POSIX_SHARED_MEMORY_OBJECTS > 0
 204       return _POSIX_SHARED_MEMORY_OBJECTS;
 205 #else
 206       return -1;
 207 #endif
 208
 209     case _SC_VERSION:
 210       return _POSIX_VERSION;
 211
 212     case _SC_PAGESIZE:
 213       return __getpagesize ();
 214
 215     case _SC_AIO_LISTIO_MAX:
 216 #ifdef  AIO_LISTIO_MAX
 217       return AIO_LISTIO_MAX;
 218 #else
 219       return -1;
 220 #endif
 221
 222     case _SC_AIO_MAX:
 223 #ifdef  AIO_MAX
 224       return AIO_MAX;
 225 #else
 226       return -1;
 227 #endif
 228
 229     case _SC_AIO_PRIO_DELTA_MAX:
 230 #ifdef  AIO_PRIO_DELTA_MAX
 231       return AIO_PRIO_DELTA_MAX;
 232 #else
 233       return -1;
 234 #endif
 235
 236     case _SC_DELAYTIMER_MAX:
 237 #ifdef  DELAYTIMER_MAX
 238       return DELAYTIMER_MAX;
 239 #else
 240       return -1;
 241 #endif
 242
 243     case _SC_MQ_OPEN_MAX:
 244 #ifdef  MQ_OPEN_MAX
 245       return MQ_OPEN_MAX;
 246 #else
 247       return -1;
 248 #endif
 249
 250     case _SC_MQ_PRIO_MAX:
 251 #ifdef  MQ_PRIO_MAX
 252       return MQ_PRIO_MAX;
 253 #else
 254       return -1;
 255 #endif
 256
 257     case _SC_RTSIG_MAX:
 258 #ifdef  RTSIG_MAX
 259       return RTSIG_MAX;
 260 #else
 261       return -1;
 262 #endif
 263
 264     case _SC_SEM_NSEMS_MAX:
 265 #ifdef  SEM_NSEMS_MAX
 266       return SEM_NSEMS_MAX;
 267 #else
 268       return -1;
 269 #endif
 270
 271     case _SC_SEM_VALUE_MAX:
 272 #ifdef  SEM_VALUE_MAX
 273       return SEM_VALUE_MAX;
 274 #else
 275       return -1;
 276 #endif
 277
 278     case _SC_SIGQUEUE_MAX:
 279 #ifdef  SIGQUEUE_MAX
 280       return SIGQUEUE_MAX;
 281 #else
 282       return -1;
 283 #endif
 284
 285     case _SC_TIMER_MAX:
 286 #ifdef  TIMER_MAX
 287       return TIMER_MAX;
 288 #else
 289       return -1;
 290 #endif
 291
 292     case _SC_BC_BASE_MAX:
 293 #ifdef  BC_BASE_MAX
 294       return BC_BASE_MAX;
 295 #else
 296       return -1;
 297 #endif
 298
 299     case _SC_BC_DIM_MAX:
 300 #ifdef  BC_DIM_MAX
 301       return BC_DIM_MAX;
 302 #else
 303       return -1;
 304 #endif
 305
 306     case _SC_BC_SCALE_MAX:
 307 #ifdef  BC_SCALE_MAX
 308       return BC_SCALE_MAX;
 309 #else
 310       return -1;
 311 #endif
 312
 313     case _SC_BC_STRING_MAX:
 314 #ifdef  BC_STRING_MAX
 315       return BC_STRING_MAX;
 316 #else
 317       return -1;
 318 #endif
 319
 320     case _SC_COLL_WEIGHTS_MAX:
 321 #ifdef  COLL_WEIGHTS_MAX
 322       return COLL_WEIGHTS_MAX;
 323 #else
 324       return -1;
 325 #endif
 326
 327     case _SC_EXPR_NEST_MAX:
 328 #ifdef  EXPR_NEST_MAX
 329       return EXPR_NEST_MAX;
 330 #else
 331       return -1;
 332 #endif
 333
 334     case _SC_LINE_MAX:
 335 #ifdef  LINE_MAX
 336       return LINE_MAX;
 337 #else
 338       return -1;
 339 #endif
 340
 341     case _SC_RE_DUP_MAX:
 342 #ifdef  RE_DUP_MAX
 343       return RE_DUP_MAX;
 344 #else
 345       return -1;
 346 #endif
 347
 348     case _SC_CHARCLASS_NAME_MAX:
 349 #ifdef  CHARCLASS_NAME_MAX
 350       return CHARCLASS_NAME_MAX;
 351 #else
 352       return -1;
 353 #endif
 354
 355     case _SC_PII:
 356 #if _POSIX_PII > 0
 357       return 1;
 358 #else
 359       return -1;
 360 #endif
 361
 362     case _SC_PII_XTI:
 363 #if _POSIX_PII_XTI > 0
 364       return 1;
 365 #else
 366       return -1;
 367 #endif
 368
 369     case _SC_PII_SOCKET:
 370 #if _POSIX_PII_SOCKET > 0
 371       return 1;
 372 #else
 373       return -1;
 374 #endif
 375
 376     case _SC_PII_INTERNET:
 377 #if _POSIX_PII_INTERNET > 0
 378       return 1;
 379 #else
 380       return -1;
 381 #endif
 382
 383     case _SC_PII_OSI:
 384 #if _POSIX_PII_OSI > 0
 385       return 1;
 386 #else
 387       return -1;
 388 #endif
 389
 390     case _SC_POLL:
 391 #if _POSIX_POLL > 0
 392       return 1;
 393 #else
 394       return -1;
 395 #endif
 396
 397     case _SC_SELECT:
 398 #if _POSIX_SELECT > 0
 399       return 1;
 400 #else
 401       return -1;
 402 #endif
 403
 404       /* The same as _SC_IOV_MAX.  */
 405     case _SC_UIO_MAXIOV:
 406 #ifdef  UIO_MAXIOV
 407       return UIO_MAXIOV;
 408 #else
 409       return -1;
 410 #endif
 411
 412     case _SC_PII_INTERNET_STREAM:
 413 #if _POSIX_PII_INTERNET_STREAM > 0
 414       return 1;
 415 #else
 416       return -1;
 417 #endif
 418
 419     case _SC_PII_INTERNET_DGRAM:
 420 #if _POSIX_PII_INTERNET_DGRAM > 0
 421       return 1;
 422 #else
 423       return -1;
 424 #endif
 425
 426     case _SC_PII_OSI_COTS:
 427 #if _POSIX_PII_OSI_COTS > 0
 428       return 1;
 429 #else
 430       return -1;
 431 #endif
 432
 433     case _SC_PII_OSI_CLTS:
 434 #if _POSIX_PII_OSI_CLTS > 0
 435       return 1;
 436 #else
 437       return -1;
 438 #endif
 439
 440     case _SC_PII_OSI_M:
 441 #if _POSIX_PII_OSI_M > 0
 442       return 1;
 443 #else
 444       return -1;
 445 #endif
 446
 447     case _SC_T_IOV_MAX:
 448 #ifdef  _T_IOV_MAX
 449       return _T_IOV_MAX;
 450 #else
 451       return -1;
 452 #endif
 453
 454     case _SC_2_VERSION:
 455       return _POSIX2_VERSION;
 456
 457     case _SC_2_C_BIND:
 458 #ifdef  _POSIX2_C_BIND
 459       return _POSIX2_C_BIND;
 460 #else
 461       return -1;
 462 #endif
 463
 464     case _SC_2_C_DEV:
 465 #ifdef  _POSIX2_C_DEV
 466       return _POSIX2_C_DEV;
 467 #else
 468       return -1;
 469 #endif
 470
 471     case _SC_2_C_VERSION:
 472 #ifdef  _POSIX2_C_VERSION
 473       return _POSIX2_C_VERSION;
 474 #else
 475       return -1;
 476 #endif
 477
 478     case _SC_2_FORT_DEV:
 479 #ifdef  _POSIX2_FORT_DEV
 480       return _POSIX2_FORT_DEV;
 481 #else
 482       return -1;
 483 #endif
 484
 485     case _SC_2_FORT_RUN:
 486 #ifdef  _POSIX2_FORT_RUN
 487       return _POSIX2_FORT_RUN;
 488 #else
 489       return -1;
 490 #endif
 491
 492     case _SC_2_LOCALEDEF:
 493 #ifdef  _POSIX2_LOCALEDEF
 494       return _POSIX2_LOCALEDEF;
 495 #else
 496       return -1;
 497 #endif
 498
 499     case _SC_2_SW_DEV:
 500 #ifdef  _POSIX2_SW_DEV
 501       return _POSIX2_SW_DEV;
 502 #else
 503       return -1;
 504 #endif
 505
 506     case _SC_2_CHAR_TERM:
 507 #ifdef  _POSIX2_CHAR_TERM
 508       return _POSIX2_CHAR_TERM;
 509 #else
 510       return -1;
 511 #endif
 512
 513     case _SC_2_UPE:
 514 #ifdef  _POSIX2_UPE
 515       return _POSIX2_UPE;
 516 #else
 517       return -1;
 518 #endif
 519
 520       /* POSIX 1003.1c (POSIX Threads).  */
 521     case _SC_THREADS:
 522 #if _POSIX_THREADS > 0
 523       return _POSIX_THREADS;
 524 #else
 525       return -1;
 526 #endif
 527
 528     case _SC_THREAD_SAFE_FUNCTIONS:
 529 #if _POSIX_THREAD_SAFE_FUNCTIONS > 0
 530       return _POSIX_THREAD_SAFE_FUNCTIONS;
 531 #else
 532       return -1;
 533 #endif
 534
 535     case _SC_GETGR_R_SIZE_MAX:
 536       return NSS_BUFLEN_GROUP;
 537
 538     case _SC_GETPW_R_SIZE_MAX:
 539       return NSS_BUFLEN_PASSWD;
 540
 541     case _SC_LOGIN_NAME_MAX:
 542 #ifdef  LOGIN_NAME_MAX
 543       return LOGIN_NAME_MAX;
 544 #else
 545       return -1;
 546 #endif
 547
 548     case _SC_TTY_NAME_MAX:
 549 #ifdef  TTY_NAME_MAX
 550       return TTY_NAME_MAX;
 551 #else
 552       return -1;
 553 #endif
 554
 555     case _SC_THREAD_DESTRUCTOR_ITERATIONS:
 556 #if _POSIX_THREAD_DESTRUCTOR_ITERATIONS > 0
 557       return _POSIX_THREAD_DESTRUCTOR_ITERATIONS;
 558 #else
 559       return -1;
 560 #endif
 561
 562     case _SC_THREAD_KEYS_MAX:
 563 #ifdef  PTHREAD_KEYS_MAX
 564       return PTHREAD_KEYS_MAX;
 565 #else
 566       return -1;
 567 #endif
 568
 569     case _SC_THREAD_STACK_MIN:
 570 #ifdef  PTHREAD_STACK_MIN
 571       return PTHREAD_STACK_MIN;
 572 #else
 573       return -1;
 574 #endif
 575
 576     case _SC_THREAD_THREADS_MAX:
 577 #ifdef  PTHREAD_THREADS_MAX
 578       return PTHREAD_THREADS_MAX;
 579 #else
 580       return -1;
 581 #endif
 582
 583     case _SC_THREAD_ATTR_STACKADDR:
 584 #if _POSIX_THREAD_ATTR_STACKADDR > 0
 585       return _POSIX_THREAD_ATTR_STACKADDR;
 586 #else
 587       return -1;
 588 #endif
 589
 590     case _SC_THREAD_ATTR_STACKSIZE:
 591 #if _POSIX_THREAD_ATTR_STACKSIZE > 0
 592       return _POSIX_THREAD_ATTR_STACKSIZE;
 593 #else
 594       return -1;
 595 #endif
 596
 597     case _SC_THREAD_PRIORITY_SCHEDULING:
 598 #if _POSIX_THREAD_PRIORITY_SCHEDULING > 0
 599       return _POSIX_THREAD_PRIORITY_SCHEDULING;
 600 #else
 601       return -1;
 602 #endif
 603
 604     case _SC_THREAD_PRIO_INHERIT:
 605 #if _POSIX_THREAD_PRIO_INHERIT > 0
 606       return _POSIX_THREAD_PRIO_INHERIT;
 607 #else
 608       return -1;
 609 #endif
 610
 611     case _SC_THREAD_PRIO_PROTECT:
 612 #if _POSIX_THREAD_PRIO_PROTECT > 0
 613       return _POSIX_THREAD_PRIO_PROTECT;
 614 #else
 615       return -1;
 616 #endif
 617
 618     case _SC_THREAD_PROCESS_SHARED:
 619 #if _POSIX_THREAD_PROCESS_SHARED > 0
 620       return _POSIX_THREAD_PROCESS_SHARED;
 621 #else
 622       return -1;
 623 #endif
 624
 625     case _SC_NPROCESSORS_CONF:
 626       return __get_nprocs_conf ();
 627
 628     case _SC_NPROCESSORS_ONLN:
 629       return __get_nprocs ();
 630
 631     case _SC_PHYS_PAGES:
 632       return __get_phys_pages ();
 633
 634     case _SC_AVPHYS_PAGES:
 635       return __get_avphys_pages ();
 636
 637     case _SC_ATEXIT_MAX:
 638       /* We have no limit since we use lists.  */
 639       return INT_MAX;
 640
 641     case _SC_PASS_MAX:
 642       /* We have no limit but since the return value might be used to
 643          allocate a buffer we restrict the value.  */
 644       return BUFSIZ;
 645
 646     case _SC_XOPEN_VERSION:
 647       return _XOPEN_VERSION;
 648
 649     case _SC_XOPEN_XCU_VERSION:
 650       return _XOPEN_XCU_VERSION;
 651
 652     case _SC_XOPEN_UNIX:
 653       return _XOPEN_UNIX;
 654
 655     case _SC_XOPEN_CRYPT:
 656 #ifdef  _XOPEN_CRYPT
 657       return _XOPEN_CRYPT;
 658 #else
 659       return -1;
 660 #endif
 661
 662     case _SC_XOPEN_ENH_I18N:
 663 #ifdef  _XOPEN_ENH_I18N
 664       return _XOPEN_ENH_I18N;
 665 #else
 666       return -1;
 667 #endif
 668
 669     case _SC_XOPEN_SHM:
 670 #ifdef  _XOPEN_SHM
 671       return _XOPEN_SHM;
 672 #else
 673       return -1;
 674 #endif
 675
 676     case _SC_XOPEN_XPG2:
 677 #ifdef  _XOPEN_XPG2
 678       return _XOPEN_XPG2;
 679 #else
 680       return -1;
 681 #endif
 682
 683     case _SC_XOPEN_XPG3:
 684 #ifdef  _XOPEN_XPG3
 685       return _XOPEN_XPG3;
 686 #else
 687       return -1;
 688 #endif
 689
 690     case _SC_XOPEN_XPG4:
 691 #ifdef  _XOPEN_XPG4
 692       return _XOPEN_XPG4;
 693 #else
 694       return -1;
 695 #endif
 696
 697     case _SC_CHAR_BIT:
 698       return CHAR_BIT;
 699
 700     case _SC_CHAR_MAX:
 701       return CHAR_MAX;
 702
 703     case _SC_CHAR_MIN:
 704       return CHAR_MIN;
 705
 706     case _SC_INT_MAX:
 707       return INT_MAX;
 708
 709     case _SC_INT_MIN:
 710       return INT_MIN;
 711
 712     case _SC_LONG_BIT:
 713       return sizeof (long int) * CHAR_BIT;
 714
 715     case _SC_WORD_BIT:
 716       return sizeof (int) * CHAR_BIT;
 717
 718     case _SC_MB_LEN_MAX:
 719       return MB_LEN_MAX;
 720
 721     case _SC_NZERO:
 722       return NZERO;
 723
 724     case _SC_SSIZE_MAX:
 725       return _POSIX_SSIZE_MAX;
 726
 727     case _SC_SCHAR_MAX:
 728       return SCHAR_MAX;
 729
 730     case _SC_SCHAR_MIN:
 731       return SCHAR_MIN;
 732
 733     case _SC_SHRT_MAX:
 734       return SHRT_MAX;
 735
 736     case _SC_SHRT_MIN:
 737       return SHRT_MIN;
 738
 739     case _SC_UCHAR_MAX:
 740       return UCHAR_MAX;
 741
 742     case _SC_UINT_MAX:
 743       return UINT_MAX;
 744
 745     case _SC_ULONG_MAX:
 746       return ULONG_MAX;
 747
 748     case _SC_USHRT_MAX:
 749       return USHRT_MAX;
 750
 751     case _SC_NL_ARGMAX:
 752 #ifdef  NL_ARGMAX
 753       return NL_ARGMAX;
 754 #else
 755       return -1;
 756 #endif
 757
 758     case _SC_NL_LANGMAX:
 759 #ifdef  NL_LANGMAX
 760       return NL_LANGMAX;
 761 #else
 762       return -1;
 763 #endif
 764
 765     case _SC_NL_MSGMAX:
 766 #ifdef  NL_MSGMAX
 767       return NL_MSGMAX;
 768 #else
 769       return -1;
 770 #endif
 771
 772     case _SC_NL_NMAX:
 773 #ifdef  NL_NMAX
 774       return NL_NMAX;
 775 #else
 776       return -1;
 777 #endif
 778
 779     case _SC_NL_SETMAX:
 780 #ifdef  NL_SETMAX
 781       return NL_SETMAX;
 782 #else
 783       return -1;
 784 #endif
 785
 786     case _SC_NL_TEXTMAX:
 787 #ifdef  NL_TEXTMAX
 788       return NL_TEXTMAX;
 789 #else
 790       return -1;
 791 #endif
 792
 793 #define START_ENV_GROUP(VERSION)                \
 794       /* Empty.  */
 795
 796 #define END_ENV_GROUP(VERSION)                  \
 797       /* Empty.  */
 798
 799 #define KNOWN_ABSENT_ENVIRONMENT(SC_PREFIX, ENV_PREFIX, SUFFIX) \
 800     case _SC_##SC_PREFIX##_##SUFFIX:                            \
 801       return _##ENV_PREFIX##_##SUFFIX;
 802
 803 #define KNOWN_PRESENT_ENVIRONMENT(SC_PREFIX, ENV_PREFIX, SUFFIX)        \
 804     case _SC_##SC_PREFIX##_##SUFFIX:                                    \
 805       return _##ENV_PREFIX##_##SUFFIX;
 806
 807 #define UNKNOWN_ENVIRONMENT(SC_PREFIX, ENV_PREFIX, SUFFIX)      \
 808     case _SC_##SC_PREFIX##_##SUFFIX:                            \
 809       return __sysconf_check_spec (#SUFFIX);
 810
 811 #include <posix/posix-envs.def>
 812
 813 #undef START_ENV_GROUP
 814 #undef END_ENV_GROUP
 815 #undef KNOWN_ABSENT_ENVIRONMENT
 816 #undef KNOWN_PRESENT_ENVIRONMENT
 817 #undef UNKNOWN_ENVIRONMENT
 818
 819     case _SC_XOPEN_LEGACY:
 820       return _XOPEN_LEGACY;
 821
 822     case _SC_XOPEN_REALTIME:
 823 #ifdef _XOPEN_REALTIME
 824       return _XOPEN_REALTIME;
 825 #else
 826       return -1;
 827 #endif
 828     case _SC_XOPEN_REALTIME_THREADS:
 829 #ifdef _XOPEN_REALTIME_THREADS
 830       return _XOPEN_REALTIME_THREADS;
 831 #else
 832       return -1;
 833 #endif
 834
 835     case _SC_ADVISORY_INFO:
 836 #if _POSIX_ADVISORY_INFO > 0
 837       return _POSIX_ADVISORY_INFO;
 838 #else
 839       return -1;
 840 #endif
 841
 842     case _SC_BARRIERS:
 843 #if _POSIX_BARRIERS > 0
 844       return _POSIX_BARRIERS;
 845 #else
 846       return -1;
 847 #endif
 848
 849     case _SC_BASE:
 850 #if _POSIX_BASE > 0
 851       return _POSIX_BASE;
 852 #else
 853       return -1;
 854 #endif
 855     case _SC_C_LANG_SUPPORT:
 856 #if _POSIX_C_LANG_SUPPORT > 0
 857       return _POSIX_C_LANG_SUPPORT;
 858 #else
 859       return -1;
 860 #endif
 861     case _SC_C_LANG_SUPPORT_R:
 862 #if _POSIX_C_LANG_SUPPORT_R > 0
 863       return _POSIX_C_LANG_SUPPORT_R;
 864 #else
 865       return -1;
 866 #endif
 867
 868     case _SC_CLOCK_SELECTION:
 869 #if _POSIX_CLOCK_SELECTION > 0
 870       return _POSIX_CLOCK_SELECTION;
 871 #else
 872       return -1;
 873 #endif
 874
 875     case _SC_CPUTIME:
 876 #if _POSIX_CPUTIME > 0
 877       return _POSIX_CPUTIME;
 878 #else
 879       return -1;
 880 #endif
 881
 882     case _SC_DEVICE_IO:
 883 #if _POSIX_DEVICE_IO > 0
 884       return _POSIX_DEVICE_IO;
 885 #else
 886       return -1;
 887 #endif
 888     case _SC_DEVICE_SPECIFIC:
 889 #if _POSIX_DEVICE_SPECIFIC > 0
 890       return _POSIX_DEVICE_SPECIFIC;
 891 #else
 892       return -1;
 893 #endif
 894     case _SC_DEVICE_SPECIFIC_R:
 895 #if _POSIX_DEVICE_SPECIFIC_R > 0
 896       return _POSIX_DEVICE_SPECIFIC_R;
 897 #else
 898       return -1;
 899 #endif
 900
 901     case _SC_FD_MGMT:
 902 #if _POSIX_FD_MGMT > 0
 903       return _POSIX_FD_MGMT;
 904 #else
 905       return -1;
 906 #endif
 907
 908     case _SC_FIFO:
 909 #if _POSIX_FIFO > 0
 910       return _POSIX_FIFO;
 911 #else
 912       return -1;
 913 #endif
 914     case _SC_PIPE:
 915 #if _POSIX_PIPE > 0
 916       return _POSIX_PIPE;
 917 #else
 918       return -1;
 919 #endif
 920
 921     case _SC_FILE_ATTRIBUTES:
 922 #if _POSIX_FILE_ATTRIBUTES > 0
 923       return _POSIX_FILE_ATTRIBUTES;
 924 #else
 925       return -1;
 926 #endif
 927     case _SC_FILE_LOCKING:
 928 #if _POSIX_FILE_LOCKING > 0
 929       return _POSIX_FILE_LOCKING;
 930 #else
 931       return -1;
 932 #endif
 933     case _SC_FILE_SYSTEM:
 934 #if _POSIX_FILE_SYSTEM > 0
 935       return _POSIX_FILE_SYSTEM;
 936 #else
 937       return -1;
 938 #endif
 939
 940     case _SC_MONOTONIC_CLOCK:
 941 #if _POSIX_MONOTONIC_CLOCK
 942       return _POSIX_MONOTONIC_CLOCK;
 943 #else
 944       return -1;
 945 #endif
 946
 947     case _SC_MULTI_PROCESS:
 948 #if _POSIX_MULTI_PROCESS > 0
 949       return _POSIX_MULTI_PROCESS;
 950 #else
 951       return -1;
 952 #endif
 953     case _SC_SINGLE_PROCESS:
 954 #if _POSIX_SINGLE_PROCESS > 0
 955       return _POSIX_SINGLE_PROCESS;
 956 #else
 957       return -1;
 958 #endif
 959
 960     case _SC_NETWORKING:
 961 #if _POSIX_NETWORKING > 0
 962       return _POSIX_NETWORKING;
 963 #else
 964       return -1;
 965 #endif
 966
 967     case _SC_READER_WRITER_LOCKS:
 968 #if _POSIX_READER_WRITER_LOCKS > 0
 969       return _POSIX_READER_WRITER_LOCKS;
 970 #else
 971       return -1;
 972 #endif
 973     case _SC_SPIN_LOCKS:
 974 #if _POSIX_SPIN_LOCKS > 0
 975       return _POSIX_SPIN_LOCKS;
 976 #else
 977       return -1;
 978 #endif
 979
 980     case _SC_REGEXP:
 981 #if _POSIX_REGEXP > 0
 982       return _POSIX_REGEXP;
 983 #else
 984       return -1;
 985 #endif
 986     /* _REGEX_VERSION has been removed with IEEE Std 1003.1-2001/Cor 2-2004,
 987        item XSH/TC2/D6/137.  */
 988     case _SC_REGEX_VERSION:
 989       return -1;
 990
 991     case _SC_SHELL:
 992 #if _POSIX_SHELL > 0
 993       return _POSIX_SHELL;
 994 #else
 995       return -1;
 996 #endif
 997
 998     case _SC_SIGNALS:
 999 #ifdef _POSIX_SIGNALS
1000       return _POSIX_SIGNALS;
1001 #else
1002       return -1;
1003 #endif
1004
1005     case _SC_SPAWN:
1006 #if _POSIX_SPAWN > 0
1007       return _POSIX_SPAWN;
1008 #else
1009       return -1;
1010 #endif
1011
1012     case _SC_SPORADIC_SERVER:
1013 #if _POSIX_SPORADIC_SERVER > 0
1014       return _POSIX_SPORADIC_SERVER;
1015 #else
1016       return -1;
1017 #endif
1018     case _SC_THREAD_SPORADIC_SERVER:
1019 #if _POSIX_THREAD_SPORADIC_SERVER > 0
1020       return _POSIX_THREAD_SPORADIC_SERVER;
1021 #else
1022       return -1;
1023 #endif
1024
1025     case _SC_SYSTEM_DATABASE:
1026 #if _POSIX_SYSTEM_DATABASE > 0
1027       return _POSIX_SYSTEM_DATABASE;
1028 #else
1029       return -1;
1030 #endif
1031     case _SC_SYSTEM_DATABASE_R:
1032 #if _POSIX_SYSTEM_DATABASE_R > 0
1033       return _POSIX_SYSTEM_DATABASE_R;
1034 #else
1035       return -1;
1036 #endif
1037
1038     case _SC_THREAD_CPUTIME:
1039 #if _POSIX_THREAD_CPUTIME > 0
1040       return _POSIX_THREAD_CPUTIME;
1041 #else
1042       return -1;
1043 #endif
1044
1045     case _SC_TIMEOUTS:
1046 #if _POSIX_TIMEOUTS > 0
1047       return _POSIX_TIMEOUTS;
1048 #else
1049       return -1;
1050 #endif
1051
1052     case _SC_TYPED_MEMORY_OBJECTS:
1053 #if _POSIX_TYPED_MEMORY_OBJECTS > 0
1054       return _POSIX_TYPED_MEMORY_OBJECTS;
1055 #else
1056       return -1;
1057 #endif
1058
1059     case _SC_USER_GROUPS:
1060 #if _POSIX_USER_GROUPS > 0
1061       return _POSIX_USER_GROUPS;
1062 #else
1063       return -1;
1064 #endif
1065     case _SC_USER_GROUPS_R:
1066 #if _POSIX_USER_GROUPS_R > 0
1067       return _POSIX_USER_GROUPS_R;
1068 #else
1069       return -1;
1070 #endif
1071
1072     case _SC_2_PBS:
1073 #ifdef _POSIX2_PBS
1074       return _POSIX2_PBS;
1075 #else
1076       return -1;
1077 #endif
1078     case _SC_2_PBS_ACCOUNTING:
1079 #ifdef _POSIX2_PBS_ACCOUNTING
1080       return _POSIX2_PBS_ACCOUNTING;
1081 #else
1082       return -1;
1083 #endif
1084     case _SC_2_PBS_CHECKPOINT:
1085 #ifdef _POSIX2_PBS_CHECKPOINT
1086       return _POSIX2_PBS_CHECKPOINT;
1087 #else
1088       return -1;
1089 #endif
1090     case _SC_2_PBS_LOCATE:
1091 #ifdef _POSIX2_PBS_LOCATE
1092       return _POSIX2_PBS_LOCATE;
1093 #else
1094       return -1;
1095 #endif
1096     case _SC_2_PBS_MESSAGE:
1097 #ifdef _POSIX2_PBS_MESSAGE
1098       return _POSIX2_PBS_MESSAGE;
1099 #else
1100       return -1;
1101 #endif
1102     case _SC_2_PBS_TRACK:
1103 #ifdef _POSIX2_PBS_TRACK
1104       return _POSIX2_PBS_TRACK;
1105 #else
1106       return -1;
1107 #endif
1108
1109     case _SC_SYMLOOP_MAX:
1110 #ifdef SYMLOOP_MAX
1111       return SYMLOOP_MAX;
1112 #else
1113       return -1;
1114 #endif
1115
1116     case _SC_STREAMS:
1117 #ifdef _XOPEN_STREAMS
1118       return _XOPEN_STREAMS;
1119 #else
1120       return -1;
1121 #endif
1122
1123     case _SC_HOST_NAME_MAX:
1124 #ifdef HOST_NAME_MAX
1125       return HOST_NAME_MAX;
1126 #else
1127       return -1;
1128 #endif
1129
1130     case _SC_TRACE:
1131 #if _POSIX_TRACE > 0
1132       return _POSIX_TRACE;
1133 #else
1134       return -1;
1135 #endif
1136     case _SC_TRACE_EVENT_FILTER:
1137 #if _POSIX_TRACE_EVENT_FILTER > 0
1138       return _POSIX_TRACE_EVENT_FILTER;
1139 #else
1140       return -1;
1141 #endif
1142     case _SC_TRACE_INHERIT:
1143 #if _POSIX_TRACE_INHERIT > 0
1144       return _POSIX_TRACE_INHERIT;
1145 #else
1146       return -1;
1147 #endif
1148     case _SC_TRACE_LOG:
1149 #if _POSIX_TRACE_LOG > 0
1150       return _POSIX_TRACE_LOG;
1151 #else
1152       return -1;
1153 #endif
1154
1155     case _SC_TRACE_EVENT_NAME_MAX:
1156     case _SC_TRACE_NAME_MAX:
1157     case _SC_TRACE_SYS_MAX:
1158     case _SC_TRACE_USER_EVENT_MAX:
1159       /* No support for tracing.  */
1160
1161     case _SC_XOPEN_STREAMS:
1162       /* No support for STREAMS.  */
1163       return -1;
1164
1165     case _SC_LEVEL1_ICACHE_SIZE:
1166     case _SC_LEVEL1_ICACHE_ASSOC:
1167     case _SC_LEVEL1_ICACHE_LINESIZE:
1168     case _SC_LEVEL1_DCACHE_SIZE:
1169     case _SC_LEVEL1_DCACHE_ASSOC:
1170     case _SC_LEVEL1_DCACHE_LINESIZE:
1171     case _SC_LEVEL2_CACHE_SIZE:
1172     case _SC_LEVEL2_CACHE_ASSOC:
1173     case _SC_LEVEL2_CACHE_LINESIZE:
1174     case _SC_LEVEL3_CACHE_SIZE:
1175     case _SC_LEVEL3_CACHE_ASSOC:
1176     case _SC_LEVEL3_CACHE_LINESIZE:
1177     case _SC_LEVEL4_CACHE_SIZE:
1178     case _SC_LEVEL4_CACHE_ASSOC:
1179     case _SC_LEVEL4_CACHE_LINESIZE:
1180       /* In general we cannot determine these values.  Therefore we
1181          return zero which indicates that no information is
1182          available.  */
1183       return 0;
1184
1185     case _SC_IPV6:
1186 #if _POSIX_IPV6 > 0
1187       return _POSIX_IPV6;
1188 #else
1189       return -1;
1190 #endif
1191
1192     case _SC_RAW_SOCKETS:
1193 #if _POSIX_RAW_SOCKETS > 0
1194       return _POSIX_RAW_SOCKETS;
1195 #else
1196       return -1;
1197 #endif
1198     }
1199 }
1200
1201 #undef __sysconf
1202 weak_alias (__sysconf, sysconf)
1203 libc_hidden_def (__sysconf)
1204
1205 #if NEED_CHECK_SPEC
1206 static long int
1207 __sysconf_check_spec (const char *spec)
1208 {
1209   int save_errno = errno;
1210
1211   const char *getconf_dir = __libc_secure_getenv ("GETCONF_DIR") ?: GETCONF_DIR;
1212   size_t getconf_dirlen = strlen (getconf_dir);
1213   size_t speclen = strlen (spec);
1214
1215   char name[getconf_dirlen + sizeof ("/POSIX_V6_") + speclen];
1216   memcpy (mempcpy (mempcpy (name, getconf_dir, getconf_dirlen),
1217                    "/POSIX_V6_", sizeof ("/POSIX_V6_") - 1),
1218           spec, speclen + 1);
1219
1220   struct stat64 st;
1221   long int ret = __xstat64 (_STAT_VER, name, &st) >= 0 ? 1 : -1;
1222
1223   __set_errno (save_errno);
1224   return ret;
1225 }
1226 #endif