sysdeps/posix/sysconf.c

   1 /* Copyright (C) 1991-2016 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 #define NEED_SPEC_ARRAY 0
  35 #include <posix-conf-vars.h>
  36
  37 #define NEED_CHECK_SPEC \
  38   (!defined _XBS5_ILP32_OFF32 || !defined _XBS5_ILP32_OFFBIG \
  39    || !defined _XBS5_LP64_OFF64 || !defined _XBS5_LPBIG_OFFBIG \
  40    || !defined _POSIX_V6_ILP32_OFF32 || !defined _POSIX_V6_ILP32_OFFBIG \
  41    || !defined _POSIX_V6_LP64_OFF64 || !defined _POSIX_V6_LPBIG_OFFBIG \
  42    || !defined _POSIX_V7_ILP32_OFF32 || !defined _POSIX_V7_ILP32_OFFBIG \
  43    || !defined _POSIX_V7_LP64_OFF64 || !defined _POSIX_V7_LPBIG_OFFBIG)
  44 #if NEED_CHECK_SPEC
  45 static long int __sysconf_check_spec (const char *spec);
  46 #endif
  47
  48
  49 /* Get the value of the system variable NAME.  */
  50 long int
  51 __sysconf (int name)
  52 {
  53   switch (name)
  54     {
  55       /* Also add obsolete or unnecessarily added constants here.  */
  56     case _SC_EQUIV_CLASS_MAX:
  57     default:
  58       __set_errno (EINVAL);
  59       return -1;
  60
  61     case _SC_ARG_MAX:
  62 #ifdef  ARG_MAX
  63       return ARG_MAX;
  64 #else
  65       return -1;
  66 #endif
  67
  68     case _SC_CHILD_MAX:
  69 #ifdef  CHILD_MAX
  70       return CHILD_MAX;
  71 #else
  72       return __get_child_max ();
  73 #endif
  74
  75     case _SC_CLK_TCK:
  76       return __getclktck ();
  77
  78     case _SC_NGROUPS_MAX:
  79 #ifdef  NGROUPS_MAX
  80       return NGROUPS_MAX;
  81 #else
  82       return -1;
  83 #endif
  84
  85     case _SC_OPEN_MAX:
  86       return __getdtablesize ();
  87
  88     case _SC_STREAM_MAX:
  89 #ifdef  STREAM_MAX
  90       return STREAM_MAX;
  91 #else
  92       return FOPEN_MAX;
  93 #endif
  94
  95     case _SC_TZNAME_MAX:
  96       return MAX (__tzname_max (), _POSIX_TZNAME_MAX);
  97
  98     case _SC_JOB_CONTROL:
  99 #if CONF_IS_DEFINED_SET (_POSIX_JOB_CONTROL)
 100       return _POSIX_JOB_CONTROL;
 101 #else
 102       return -1;
 103 #endif
 104
 105     case _SC_SAVED_IDS:
 106 #if CONF_IS_DEFINED_SET (_POSIX_SAVED_IDS)
 107       return 1;
 108 #else
 109       return -1;
 110 #endif
 111
 112     case _SC_REALTIME_SIGNALS:
 113 #if CONF_IS_DEFINED_SET (_POSIX_REALTIME_SIGNALS)
 114       return _POSIX_REALTIME_SIGNALS;
 115 #else
 116       return -1;
 117 #endif
 118
 119     case _SC_PRIORITY_SCHEDULING:
 120 #if CONF_IS_DEFINED_SET (_POSIX_PRIORITY_SCHEDULING)
 121       return _POSIX_PRIORITY_SCHEDULING;
 122 #else
 123       return -1;
 124 #endif
 125
 126     case _SC_TIMERS:
 127 #if CONF_IS_DEFINED_SET (_POSIX_TIMERS)
 128       return _POSIX_TIMERS;
 129 #else
 130       return -1;
 131 #endif
 132
 133     case _SC_ASYNCHRONOUS_IO:
 134 #if CONF_IS_DEFINED_SET (_POSIX_ASYNCHRONOUS_IO)
 135       return _POSIX_ASYNCHRONOUS_IO;
 136 #else
 137       return -1;
 138 #endif
 139
 140     case _SC_PRIORITIZED_IO:
 141 #if CONF_IS_DEFINED_SET (_POSIX_PRIORITIZED_IO)
 142       return _POSIX_PRIORITIZED_IO;
 143 #else
 144       return -1;
 145 #endif
 146
 147     case _SC_SYNCHRONIZED_IO:
 148 #if CONF_IS_DEFINED_SET (_POSIX_SYNCHRONIZED_IO)
 149       return _POSIX_SYNCHRONIZED_IO;
 150 #else
 151       return -1;
 152 #endif
 153
 154     case _SC_FSYNC:
 155 #if CONF_IS_DEFINED_SET (_POSIX_FSYNC)
 156       return _POSIX_FSYNC;
 157 #else
 158       return -1;
 159 #endif
 160
 161     case _SC_MAPPED_FILES:
 162 #if CONF_IS_DEFINED_SET (_POSIX_MAPPED_FILES)
 163       return _POSIX_MAPPED_FILES;
 164 #else
 165       return -1;
 166 #endif
 167
 168     case _SC_MEMLOCK:
 169 #if CONF_IS_DEFINED_SET (_POSIX_MEMLOCK)
 170       return _POSIX_MEMLOCK;
 171 #else
 172       return -1;
 173 #endif
 174
 175     case _SC_MEMLOCK_RANGE:
 176 #if CONF_IS_DEFINED_SET (_POSIX_MEMLOCK_RANGE)
 177       return _POSIX_MEMLOCK_RANGE;
 178 #else
 179       return -1;
 180 #endif
 181
 182     case _SC_MEMORY_PROTECTION:
 183 #if CONF_IS_DEFINED_SET (_POSIX_MEMORY_PROTECTION)
 184       return _POSIX_MEMORY_PROTECTION;
 185 #else
 186       return -1;
 187 #endif
 188
 189     case _SC_MESSAGE_PASSING:
 190 #if CONF_IS_DEFINED_SET (_POSIX_MESSAGE_PASSING)
 191       return _POSIX_MESSAGE_PASSING;
 192 #else
 193       return -1;
 194 #endif
 195
 196     case _SC_SEMAPHORES:
 197 #if CONF_IS_DEFINED_SET (_POSIX_SEMAPHORES)
 198       return _POSIX_SEMAPHORES;
 199 #else
 200       return -1;
 201 #endif
 202
 203     case _SC_SHARED_MEMORY_OBJECTS:
 204 #if CONF_IS_DEFINED_SET (_POSIX_SHARED_MEMORY_OBJECTS)
 205       return _POSIX_SHARED_MEMORY_OBJECTS;
 206 #else
 207       return -1;
 208 #endif
 209
 210     case _SC_VERSION:
 211       return _POSIX_VERSION;
 212
 213     case _SC_PAGESIZE:
 214       return __getpagesize ();
 215
 216     case _SC_AIO_LISTIO_MAX:
 217 #ifdef  AIO_LISTIO_MAX
 218       return AIO_LISTIO_MAX;
 219 #else
 220       return -1;
 221 #endif
 222
 223     case _SC_AIO_MAX:
 224 #ifdef  AIO_MAX
 225       return AIO_MAX;
 226 #else
 227       return -1;
 228 #endif
 229
 230     case _SC_AIO_PRIO_DELTA_MAX:
 231 #ifdef  AIO_PRIO_DELTA_MAX
 232       return AIO_PRIO_DELTA_MAX;
 233 #else
 234       return -1;
 235 #endif
 236
 237     case _SC_DELAYTIMER_MAX:
 238 #ifdef  DELAYTIMER_MAX
 239       return DELAYTIMER_MAX;
 240 #else
 241       return -1;
 242 #endif
 243
 244     case _SC_MQ_OPEN_MAX:
 245 #ifdef  MQ_OPEN_MAX
 246       return MQ_OPEN_MAX;
 247 #else
 248       return -1;
 249 #endif
 250
 251     case _SC_MQ_PRIO_MAX:
 252 #ifdef  MQ_PRIO_MAX
 253       return MQ_PRIO_MAX;
 254 #else
 255       return -1;
 256 #endif
 257
 258     case _SC_RTSIG_MAX:
 259 #ifdef  RTSIG_MAX
 260       return RTSIG_MAX;
 261 #else
 262       return -1;
 263 #endif
 264
 265     case _SC_SEM_NSEMS_MAX:
 266 #ifdef  SEM_NSEMS_MAX
 267       return SEM_NSEMS_MAX;
 268 #else
 269       return -1;
 270 #endif
 271
 272     case _SC_SEM_VALUE_MAX:
 273 #ifdef  SEM_VALUE_MAX
 274       return SEM_VALUE_MAX;
 275 #else
 276       return -1;
 277 #endif
 278
 279     case _SC_SIGQUEUE_MAX:
 280 #ifdef  SIGQUEUE_MAX
 281       return SIGQUEUE_MAX;
 282 #else
 283       return -1;
 284 #endif
 285
 286     case _SC_TIMER_MAX:
 287 #ifdef  TIMER_MAX
 288       return TIMER_MAX;
 289 #else
 290       return -1;
 291 #endif
 292
 293     case _SC_BC_BASE_MAX:
 294 #ifdef  BC_BASE_MAX
 295       return BC_BASE_MAX;
 296 #else
 297       return -1;
 298 #endif
 299
 300     case _SC_BC_DIM_MAX:
 301 #ifdef  BC_DIM_MAX
 302       return BC_DIM_MAX;
 303 #else
 304       return -1;
 305 #endif
 306
 307     case _SC_BC_SCALE_MAX:
 308 #ifdef  BC_SCALE_MAX
 309       return BC_SCALE_MAX;
 310 #else
 311       return -1;
 312 #endif
 313
 314     case _SC_BC_STRING_MAX:
 315 #ifdef  BC_STRING_MAX
 316       return BC_STRING_MAX;
 317 #else
 318       return -1;
 319 #endif
 320
 321     case _SC_COLL_WEIGHTS_MAX:
 322 #ifdef  COLL_WEIGHTS_MAX
 323       return COLL_WEIGHTS_MAX;
 324 #else
 325       return -1;
 326 #endif
 327
 328     case _SC_EXPR_NEST_MAX:
 329 #ifdef  EXPR_NEST_MAX
 330       return EXPR_NEST_MAX;
 331 #else
 332       return -1;
 333 #endif
 334
 335     case _SC_LINE_MAX:
 336 #ifdef  LINE_MAX
 337       return LINE_MAX;
 338 #else
 339       return -1;
 340 #endif
 341
 342     case _SC_RE_DUP_MAX:
 343 #ifdef  RE_DUP_MAX
 344       return RE_DUP_MAX;
 345 #else
 346       return -1;
 347 #endif
 348
 349     case _SC_CHARCLASS_NAME_MAX:
 350 #ifdef  CHARCLASS_NAME_MAX
 351       return CHARCLASS_NAME_MAX;
 352 #else
 353       return -1;
 354 #endif
 355
 356     case _SC_PII:
 357 #if CONF_IS_DEFINED_SET (_POSIX_PII)
 358       return 1;
 359 #else
 360       return -1;
 361 #endif
 362
 363     case _SC_PII_XTI:
 364 #if CONF_IS_DEFINED_SET (_POSIX_PII_XTI)
 365       return 1;
 366 #else
 367       return -1;
 368 #endif
 369
 370     case _SC_PII_SOCKET:
 371 #if CONF_IS_DEFINED_SET (_POSIX_PII_SOCKET)
 372       return 1;
 373 #else
 374       return -1;
 375 #endif
 376
 377     case _SC_PII_INTERNET:
 378 #if CONF_IS_DEFINED_SET (_POSIX_PII_INTERNET)
 379       return 1;
 380 #else
 381       return -1;
 382 #endif
 383
 384     case _SC_PII_OSI:
 385 #if CONF_IS_DEFINED_SET (_POSIX_PII_OSI)
 386       return 1;
 387 #else
 388       return -1;
 389 #endif
 390
 391     case _SC_POLL:
 392 #if CONF_IS_DEFINED_SET (_POSIX_POLL)
 393       return 1;
 394 #else
 395       return -1;
 396 #endif
 397
 398     case _SC_SELECT:
 399 #if CONF_IS_DEFINED_SET (_POSIX_SELECT)
 400       return 1;
 401 #else
 402       return -1;
 403 #endif
 404
 405       /* The same as _SC_IOV_MAX.  */
 406     case _SC_UIO_MAXIOV:
 407 #ifdef  UIO_MAXIOV
 408       return UIO_MAXIOV;
 409 #else
 410       return -1;
 411 #endif
 412
 413     case _SC_PII_INTERNET_STREAM:
 414 #if CONF_IS_DEFINED_SET (_POSIX_PII_INTERNET_STREAM)
 415       return 1;
 416 #else
 417       return -1;
 418 #endif
 419
 420     case _SC_PII_INTERNET_DGRAM:
 421 #if CONF_IS_DEFINED_SET (_POSIX_PII_INTERNET_DGRAM)
 422       return 1;
 423 #else
 424       return -1;
 425 #endif
 426
 427     case _SC_PII_OSI_COTS:
 428 #if CONF_IS_DEFINED_SET (_POSIX_PII_OSI_COTS)
 429       return 1;
 430 #else
 431       return -1;
 432 #endif
 433
 434     case _SC_PII_OSI_CLTS:
 435 #if CONF_IS_DEFINED_SET (_POSIX_PII_OSI_CLTS)
 436       return 1;
 437 #else
 438       return -1;
 439 #endif
 440
 441     case _SC_PII_OSI_M:
 442 #if CONF_IS_DEFINED_SET (_POSIX_PII_OSI_M)
 443       return 1;
 444 #else
 445       return -1;
 446 #endif
 447
 448     case _SC_T_IOV_MAX:
 449 #ifdef  _T_IOV_MAX
 450       return _T_IOV_MAX;
 451 #else
 452       return -1;
 453 #endif
 454
 455     case _SC_2_VERSION:
 456       return _POSIX2_VERSION;
 457
 458     case _SC_2_C_BIND:
 459 #ifdef  _POSIX2_C_BIND
 460       return _POSIX2_C_BIND;
 461 #else
 462       return -1;
 463 #endif
 464
 465     case _SC_2_C_DEV:
 466 #ifdef  _POSIX2_C_DEV
 467       return _POSIX2_C_DEV;
 468 #else
 469       return -1;
 470 #endif
 471
 472     case _SC_2_C_VERSION:
 473 #ifdef  _POSIX2_C_VERSION
 474       return _POSIX2_C_VERSION;
 475 #else
 476       return -1;
 477 #endif
 478
 479     case _SC_2_FORT_DEV:
 480 #ifdef  _POSIX2_FORT_DEV
 481       return _POSIX2_FORT_DEV;
 482 #else
 483       return -1;
 484 #endif
 485
 486     case _SC_2_FORT_RUN:
 487 #ifdef  _POSIX2_FORT_RUN
 488       return _POSIX2_FORT_RUN;
 489 #else
 490       return -1;
 491 #endif
 492
 493     case _SC_2_LOCALEDEF:
 494 #ifdef  _POSIX2_LOCALEDEF
 495       return _POSIX2_LOCALEDEF;
 496 #else
 497       return -1;
 498 #endif
 499
 500     case _SC_2_SW_DEV:
 501 #ifdef  _POSIX2_SW_DEV
 502       return _POSIX2_SW_DEV;
 503 #else
 504       return -1;
 505 #endif
 506
 507     case _SC_2_CHAR_TERM:
 508 #ifdef  _POSIX2_CHAR_TERM
 509       return _POSIX2_CHAR_TERM;
 510 #else
 511       return -1;
 512 #endif
 513
 514     case _SC_2_UPE:
 515 #ifdef  _POSIX2_UPE
 516       return _POSIX2_UPE;
 517 #else
 518       return -1;
 519 #endif
 520
 521       /* POSIX 1003.1c (POSIX Threads).  */
 522     case _SC_THREADS:
 523 #if CONF_IS_DEFINED_SET (_POSIX_THREADS)
 524       return _POSIX_THREADS;
 525 #else
 526       return -1;
 527 #endif
 528
 529     case _SC_THREAD_SAFE_FUNCTIONS:
 530 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_SAFE_FUNCTIONS)
 531       return _POSIX_THREAD_SAFE_FUNCTIONS;
 532 #else
 533       return -1;
 534 #endif
 535
 536     case _SC_GETGR_R_SIZE_MAX:
 537       return NSS_BUFLEN_GROUP;
 538
 539     case _SC_GETPW_R_SIZE_MAX:
 540       return NSS_BUFLEN_PASSWD;
 541
 542     case _SC_LOGIN_NAME_MAX:
 543 #ifdef  LOGIN_NAME_MAX
 544       return LOGIN_NAME_MAX;
 545 #else
 546       return -1;
 547 #endif
 548
 549     case _SC_TTY_NAME_MAX:
 550 #ifdef  TTY_NAME_MAX
 551       return TTY_NAME_MAX;
 552 #else
 553       return -1;
 554 #endif
 555
 556     case _SC_THREAD_DESTRUCTOR_ITERATIONS:
 557 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_DESTRUCTOR_ITERATIONS)
 558       return _POSIX_THREAD_DESTRUCTOR_ITERATIONS;
 559 #else
 560       return -1;
 561 #endif
 562
 563     case _SC_THREAD_KEYS_MAX:
 564 #ifdef  PTHREAD_KEYS_MAX
 565       return PTHREAD_KEYS_MAX;
 566 #else
 567       return -1;
 568 #endif
 569
 570     case _SC_THREAD_STACK_MIN:
 571 #ifdef  PTHREAD_STACK_MIN
 572       return PTHREAD_STACK_MIN;
 573 #else
 574       return -1;
 575 #endif
 576
 577     case _SC_THREAD_THREADS_MAX:
 578 #ifdef  PTHREAD_THREADS_MAX
 579       return PTHREAD_THREADS_MAX;
 580 #else
 581       return -1;
 582 #endif
 583
 584     case _SC_THREAD_ATTR_STACKADDR:
 585 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_ATTR_STACKADDR)
 586       return _POSIX_THREAD_ATTR_STACKADDR;
 587 #else
 588       return -1;
 589 #endif
 590
 591     case _SC_THREAD_ATTR_STACKSIZE:
 592 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_ATTR_STACKSIZE)
 593       return _POSIX_THREAD_ATTR_STACKSIZE;
 594 #else
 595       return -1;
 596 #endif
 597
 598     case _SC_THREAD_PRIORITY_SCHEDULING:
 599 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_PRIORITY_SCHEDULING)
 600       return _POSIX_THREAD_PRIORITY_SCHEDULING;
 601 #else
 602       return -1;
 603 #endif
 604
 605     case _SC_THREAD_PRIO_INHERIT:
 606 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_PRIO_INHERIT)
 607       return _POSIX_THREAD_PRIO_INHERIT;
 608 #else
 609       return -1;
 610 #endif
 611
 612     case _SC_THREAD_PRIO_PROTECT:
 613 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_PRIO_PROTECT)
 614       return _POSIX_THREAD_PRIO_PROTECT;
 615 #else
 616       return -1;
 617 #endif
 618
 619     case _SC_THREAD_PROCESS_SHARED:
 620 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_PROCESS_SHARED)
 621       return _POSIX_THREAD_PROCESS_SHARED;
 622 #else
 623       return -1;
 624 #endif
 625
 626     case _SC_NPROCESSORS_CONF:
 627       return __get_nprocs_conf ();
 628
 629     case _SC_NPROCESSORS_ONLN:
 630       return __get_nprocs ();
 631
 632     case _SC_PHYS_PAGES:
 633       return __get_phys_pages ();
 634
 635     case _SC_AVPHYS_PAGES:
 636       return __get_avphys_pages ();
 637
 638     case _SC_ATEXIT_MAX:
 639       /* We have no limit since we use lists.  */
 640       return INT_MAX;
 641
 642     case _SC_PASS_MAX:
 643       /* We have no limit but since the return value might be used to
 644          allocate a buffer we restrict the value.  */
 645       return BUFSIZ;
 646
 647     case _SC_XOPEN_VERSION:
 648       return _XOPEN_VERSION;
 649
 650     case _SC_XOPEN_XCU_VERSION:
 651       return _XOPEN_XCU_VERSION;
 652
 653     case _SC_XOPEN_UNIX:
 654       return _XOPEN_UNIX;
 655
 656     case _SC_XOPEN_CRYPT:
 657 #ifdef  _XOPEN_CRYPT
 658       return _XOPEN_CRYPT;
 659 #else
 660       return -1;
 661 #endif
 662
 663     case _SC_XOPEN_ENH_I18N:
 664 #ifdef  _XOPEN_ENH_I18N
 665       return _XOPEN_ENH_I18N;
 666 #else
 667       return -1;
 668 #endif
 669
 670     case _SC_XOPEN_SHM:
 671 #ifdef  _XOPEN_SHM
 672       return _XOPEN_SHM;
 673 #else
 674       return -1;
 675 #endif
 676
 677     case _SC_XOPEN_XPG2:
 678 #ifdef  _XOPEN_XPG2
 679       return _XOPEN_XPG2;
 680 #else
 681       return -1;
 682 #endif
 683
 684     case _SC_XOPEN_XPG3:
 685 #ifdef  _XOPEN_XPG3
 686       return _XOPEN_XPG3;
 687 #else
 688       return -1;
 689 #endif
 690
 691     case _SC_XOPEN_XPG4:
 692 #ifdef  _XOPEN_XPG4
 693       return _XOPEN_XPG4;
 694 #else
 695       return -1;
 696 #endif
 697
 698     case _SC_CHAR_BIT:
 699       return CHAR_BIT;
 700
 701     case _SC_CHAR_MAX:
 702       return CHAR_MAX;
 703
 704     case _SC_CHAR_MIN:
 705       return CHAR_MIN;
 706
 707     case _SC_INT_MAX:
 708       return INT_MAX;
 709
 710     case _SC_INT_MIN:
 711       return INT_MIN;
 712
 713     case _SC_LONG_BIT:
 714       return sizeof (long int) * CHAR_BIT;
 715
 716     case _SC_WORD_BIT:
 717       return sizeof (int) * CHAR_BIT;
 718
 719     case _SC_MB_LEN_MAX:
 720       return MB_LEN_MAX;
 721
 722     case _SC_NZERO:
 723       return NZERO;
 724
 725     case _SC_SSIZE_MAX:
 726       return _POSIX_SSIZE_MAX;
 727
 728     case _SC_SCHAR_MAX:
 729       return SCHAR_MAX;
 730
 731     case _SC_SCHAR_MIN:
 732       return SCHAR_MIN;
 733
 734     case _SC_SHRT_MAX:
 735       return SHRT_MAX;
 736
 737     case _SC_SHRT_MIN:
 738       return SHRT_MIN;
 739
 740     case _SC_UCHAR_MAX:
 741       return UCHAR_MAX;
 742
 743     case _SC_UINT_MAX:
 744       return UINT_MAX;
 745
 746     case _SC_ULONG_MAX:
 747       return ULONG_MAX;
 748
 749     case _SC_USHRT_MAX:
 750       return USHRT_MAX;
 751
 752     case _SC_NL_ARGMAX:
 753 #ifdef  NL_ARGMAX
 754       return NL_ARGMAX;
 755 #else
 756       return -1;
 757 #endif
 758
 759     case _SC_NL_LANGMAX:
 760 #ifdef  NL_LANGMAX
 761       return NL_LANGMAX;
 762 #else
 763       return -1;
 764 #endif
 765
 766     case _SC_NL_MSGMAX:
 767 #ifdef  NL_MSGMAX
 768       return NL_MSGMAX;
 769 #else
 770       return -1;
 771 #endif
 772
 773     case _SC_NL_NMAX:
 774 #ifdef  NL_NMAX
 775       return NL_NMAX;
 776 #else
 777       return -1;
 778 #endif
 779
 780     case _SC_NL_SETMAX:
 781 #ifdef  NL_SETMAX
 782       return NL_SETMAX;
 783 #else
 784       return -1;
 785 #endif
 786
 787     case _SC_NL_TEXTMAX:
 788 #ifdef  NL_TEXTMAX
 789       return NL_TEXTMAX;
 790 #else
 791       return -1;
 792 #endif
 793
 794 #define START_ENV_GROUP(VERSION)                \
 795       /* Empty.  */
 796
 797 #define END_ENV_GROUP(VERSION)                  \
 798       /* Empty.  */
 799
 800 #define KNOWN_ABSENT_ENVIRONMENT(SC_PREFIX, ENV_PREFIX, SUFFIX) \
 801     case _SC_##SC_PREFIX##_##SUFFIX:                            \
 802       return _##ENV_PREFIX##_##SUFFIX;
 803
 804 #define KNOWN_PRESENT_ENVIRONMENT(SC_PREFIX, ENV_PREFIX, SUFFIX)        \
 805     case _SC_##SC_PREFIX##_##SUFFIX:                                    \
 806       return _##ENV_PREFIX##_##SUFFIX;
 807
 808 #define UNKNOWN_ENVIRONMENT(SC_PREFIX, ENV_PREFIX, SUFFIX)      \
 809     case _SC_##SC_PREFIX##_##SUFFIX:                            \
 810       return __sysconf_check_spec (#SUFFIX);
 811
 812 #include <posix/posix-envs.def>
 813
 814 #undef START_ENV_GROUP
 815 #undef END_ENV_GROUP
 816 #undef KNOWN_ABSENT_ENVIRONMENT
 817 #undef KNOWN_PRESENT_ENVIRONMENT
 818 #undef UNKNOWN_ENVIRONMENT
 819
 820     case _SC_XOPEN_LEGACY:
 821       return _XOPEN_LEGACY;
 822
 823     case _SC_XOPEN_REALTIME:
 824 #ifdef _XOPEN_REALTIME
 825       return _XOPEN_REALTIME;
 826 #else
 827       return -1;
 828 #endif
 829     case _SC_XOPEN_REALTIME_THREADS:
 830 #ifdef _XOPEN_REALTIME_THREADS
 831       return _XOPEN_REALTIME_THREADS;
 832 #else
 833       return -1;
 834 #endif
 835
 836     case _SC_ADVISORY_INFO:
 837 #if CONF_IS_DEFINED_SET (_POSIX_ADVISORY_INFO)
 838       return _POSIX_ADVISORY_INFO;
 839 #else
 840       return -1;
 841 #endif
 842
 843     case _SC_BARRIERS:
 844 #if CONF_IS_DEFINED_SET (_POSIX_BARRIERS)
 845       return _POSIX_BARRIERS;
 846 #else
 847       return -1;
 848 #endif
 849
 850     case _SC_BASE:
 851 #if CONF_IS_DEFINED_SET (_POSIX_BASE)
 852       return _POSIX_BASE;
 853 #else
 854       return -1;
 855 #endif
 856     case _SC_C_LANG_SUPPORT:
 857 #if CONF_IS_DEFINED_SET (_POSIX_C_LANG_SUPPORT)
 858       return _POSIX_C_LANG_SUPPORT;
 859 #else
 860       return -1;
 861 #endif
 862     case _SC_C_LANG_SUPPORT_R:
 863 #if CONF_IS_DEFINED_SET (_POSIX_C_LANG_SUPPORT_R)
 864       return _POSIX_C_LANG_SUPPORT_R;
 865 #else
 866       return -1;
 867 #endif
 868
 869     case _SC_CLOCK_SELECTION:
 870 #if CONF_IS_DEFINED_SET (_POSIX_CLOCK_SELECTION)
 871       return _POSIX_CLOCK_SELECTION;
 872 #else
 873       return -1;
 874 #endif
 875
 876     case _SC_CPUTIME:
 877 #if CONF_IS_DEFINED_SET (_POSIX_CPUTIME)
 878       return _POSIX_CPUTIME;
 879 #else
 880       return -1;
 881 #endif
 882
 883     case _SC_DEVICE_IO:
 884 #if CONF_IS_DEFINED_SET (_POSIX_DEVICE_IO)
 885       return _POSIX_DEVICE_IO;
 886 #else
 887       return -1;
 888 #endif
 889     case _SC_DEVICE_SPECIFIC:
 890 #if CONF_IS_DEFINED_SET (_POSIX_DEVICE_SPECIFIC)
 891       return _POSIX_DEVICE_SPECIFIC;
 892 #else
 893       return -1;
 894 #endif
 895     case _SC_DEVICE_SPECIFIC_R:
 896 #if CONF_IS_DEFINED_SET (_POSIX_DEVICE_SPECIFIC_R)
 897       return _POSIX_DEVICE_SPECIFIC_R;
 898 #else
 899       return -1;
 900 #endif
 901
 902     case _SC_FD_MGMT:
 903 #if CONF_IS_DEFINED_SET (_POSIX_FD_MGMT)
 904       return _POSIX_FD_MGMT;
 905 #else
 906       return -1;
 907 #endif
 908
 909     case _SC_FIFO:
 910 #if CONF_IS_DEFINED_SET (_POSIX_FIFO)
 911       return _POSIX_FIFO;
 912 #else
 913       return -1;
 914 #endif
 915     case _SC_PIPE:
 916 #if CONF_IS_DEFINED_SET (_POSIX_PIPE)
 917       return _POSIX_PIPE;
 918 #else
 919       return -1;
 920 #endif
 921
 922     case _SC_FILE_ATTRIBUTES:
 923 #if CONF_IS_DEFINED_SET (_POSIX_FILE_ATTRIBUTES)
 924       return _POSIX_FILE_ATTRIBUTES;
 925 #else
 926       return -1;
 927 #endif
 928     case _SC_FILE_LOCKING:
 929 #if CONF_IS_DEFINED_SET (_POSIX_FILE_LOCKING)
 930       return _POSIX_FILE_LOCKING;
 931 #else
 932       return -1;
 933 #endif
 934     case _SC_FILE_SYSTEM:
 935 #if CONF_IS_DEFINED_SET (_POSIX_FILE_SYSTEM)
 936       return _POSIX_FILE_SYSTEM;
 937 #else
 938       return -1;
 939 #endif
 940
 941     case _SC_MONOTONIC_CLOCK:
 942 #if CONF_IS_DEFINED_SET (_POSIX_MONOTONIC_CLOCK)
 943       return _POSIX_MONOTONIC_CLOCK;
 944 #else
 945       return -1;
 946 #endif
 947
 948     case _SC_MULTI_PROCESS:
 949 #if CONF_IS_DEFINED_SET (_POSIX_MULTI_PROCESS)
 950       return _POSIX_MULTI_PROCESS;
 951 #else
 952       return -1;
 953 #endif
 954     case _SC_SINGLE_PROCESS:
 955 #if CONF_IS_DEFINED_SET (_POSIX_SINGLE_PROCESS)
 956       return _POSIX_SINGLE_PROCESS;
 957 #else
 958       return -1;
 959 #endif
 960
 961     case _SC_NETWORKING:
 962 #if CONF_IS_DEFINED_SET (_POSIX_NETWORKING)
 963       return _POSIX_NETWORKING;
 964 #else
 965       return -1;
 966 #endif
 967
 968     case _SC_READER_WRITER_LOCKS:
 969 #if CONF_IS_DEFINED_SET (_POSIX_READER_WRITER_LOCKS)
 970       return _POSIX_READER_WRITER_LOCKS;
 971 #else
 972       return -1;
 973 #endif
 974     case _SC_SPIN_LOCKS:
 975 #if CONF_IS_DEFINED_SET (_POSIX_SPIN_LOCKS)
 976       return _POSIX_SPIN_LOCKS;
 977 #else
 978       return -1;
 979 #endif
 980
 981     case _SC_REGEXP:
 982 #if CONF_IS_DEFINED_SET (_POSIX_REGEXP)
 983       return _POSIX_REGEXP;
 984 #else
 985       return -1;
 986 #endif
 987     /* _REGEX_VERSION has been removed with IEEE Std 1003.1-2001/Cor 2-2004,
 988        item XSH/TC2/D6/137.  */
 989     case _SC_REGEX_VERSION:
 990       return -1;
 991
 992     case _SC_SHELL:
 993 #if CONF_IS_DEFINED_SET (_POSIX_SHELL)
 994       return _POSIX_SHELL;
 995 #else
 996       return -1;
 997 #endif
 998
 999     case _SC_SIGNALS:
1000 #if CONF_IS_DEFINED (_POSIX_SIGNALS)
1001       return _POSIX_SIGNALS;
1002 #else
1003       return -1;
1004 #endif
1005
1006     case _SC_SPAWN:
1007 #if CONF_IS_DEFINED_SET (_POSIX_SPAWN)
1008       return _POSIX_SPAWN;
1009 #else
1010       return -1;
1011 #endif
1012
1013     case _SC_SPORADIC_SERVER:
1014 #if CONF_IS_DEFINED_SET (_POSIX_SPORADIC_SERVER)
1015       return _POSIX_SPORADIC_SERVER;
1016 #else
1017       return -1;
1018 #endif
1019     case _SC_THREAD_SPORADIC_SERVER:
1020 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_SPORADIC_SERVER)
1021       return _POSIX_THREAD_SPORADIC_SERVER;
1022 #else
1023       return -1;
1024 #endif
1025
1026     case _SC_SYSTEM_DATABASE:
1027 #if CONF_IS_DEFINED_SET (_POSIX_SYSTEM_DATABASE)
1028       return _POSIX_SYSTEM_DATABASE;
1029 #else
1030       return -1;
1031 #endif
1032     case _SC_SYSTEM_DATABASE_R:
1033 #if CONF_IS_DEFINED_SET (_POSIX_SYSTEM_DATABASE_R)
1034       return _POSIX_SYSTEM_DATABASE_R;
1035 #else
1036       return -1;
1037 #endif
1038
1039     case _SC_THREAD_CPUTIME:
1040 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_CPUTIME)
1041       return _POSIX_THREAD_CPUTIME;
1042 #else
1043       return -1;
1044 #endif
1045
1046     case _SC_TIMEOUTS:
1047 #if CONF_IS_DEFINED_SET (_POSIX_TIMEOUTS)
1048       return _POSIX_TIMEOUTS;
1049 #else
1050       return -1;
1051 #endif
1052
1053     case _SC_TYPED_MEMORY_OBJECTS:
1054 #if CONF_IS_DEFINED_SET (_POSIX_TYPED_MEMORY_OBJECTS)
1055       return _POSIX_TYPED_MEMORY_OBJECTS;
1056 #else
1057       return -1;
1058 #endif
1059
1060     case _SC_USER_GROUPS:
1061 #if CONF_IS_DEFINED_SET (_POSIX_USER_GROUPS)
1062       return _POSIX_USER_GROUPS;
1063 #else
1064       return -1;
1065 #endif
1066     case _SC_USER_GROUPS_R:
1067 #if CONF_IS_DEFINED_SET (_POSIX_USER_GROUPS_R)
1068       return _POSIX_USER_GROUPS_R;
1069 #else
1070       return -1;
1071 #endif
1072
1073     case _SC_2_PBS:
1074 #ifdef _POSIX2_PBS
1075       return _POSIX2_PBS;
1076 #else
1077       return -1;
1078 #endif
1079     case _SC_2_PBS_ACCOUNTING:
1080 #ifdef _POSIX2_PBS_ACCOUNTING
1081       return _POSIX2_PBS_ACCOUNTING;
1082 #else
1083       return -1;
1084 #endif
1085     case _SC_2_PBS_CHECKPOINT:
1086 #ifdef _POSIX2_PBS_CHECKPOINT
1087       return _POSIX2_PBS_CHECKPOINT;
1088 #else
1089       return -1;
1090 #endif
1091     case _SC_2_PBS_LOCATE:
1092 #ifdef _POSIX2_PBS_LOCATE
1093       return _POSIX2_PBS_LOCATE;
1094 #else
1095       return -1;
1096 #endif
1097     case _SC_2_PBS_MESSAGE:
1098 #ifdef _POSIX2_PBS_MESSAGE
1099       return _POSIX2_PBS_MESSAGE;
1100 #else
1101       return -1;
1102 #endif
1103     case _SC_2_PBS_TRACK:
1104 #ifdef _POSIX2_PBS_TRACK
1105       return _POSIX2_PBS_TRACK;
1106 #else
1107       return -1;
1108 #endif
1109
1110     case _SC_SYMLOOP_MAX:
1111 #ifdef SYMLOOP_MAX
1112       return SYMLOOP_MAX;
1113 #else
1114       return -1;
1115 #endif
1116
1117     case _SC_STREAMS:
1118 #ifdef _XOPEN_STREAMS
1119       return _XOPEN_STREAMS;
1120 #else
1121       return -1;
1122 #endif
1123
1124     case _SC_HOST_NAME_MAX:
1125 #ifdef HOST_NAME_MAX
1126       return HOST_NAME_MAX;
1127 #else
1128       return -1;
1129 #endif
1130
1131     case _SC_TRACE:
1132 #if CONF_IS_DEFINED_SET (_POSIX_TRACE)
1133       return _POSIX_TRACE;
1134 #else
1135       return -1;
1136 #endif
1137     case _SC_TRACE_EVENT_FILTER:
1138 #if CONF_IS_DEFINED_SET (_POSIX_TRACE_EVENT_FILTER)
1139       return _POSIX_TRACE_EVENT_FILTER;
1140 #else
1141       return -1;
1142 #endif
1143     case _SC_TRACE_INHERIT:
1144 #if CONF_IS_DEFINED_SET (_POSIX_TRACE_INHERIT)
1145       return _POSIX_TRACE_INHERIT;
1146 #else
1147       return -1;
1148 #endif
1149     case _SC_TRACE_LOG:
1150 #if CONF_IS_DEFINED_SET (_POSIX_TRACE_LOG)
1151       return _POSIX_TRACE_LOG;
1152 #else
1153       return -1;
1154 #endif
1155
1156     case _SC_TRACE_EVENT_NAME_MAX:
1157     case _SC_TRACE_NAME_MAX:
1158     case _SC_TRACE_SYS_MAX:
1159     case _SC_TRACE_USER_EVENT_MAX:
1160       /* No support for tracing.  */
1161
1162     case _SC_XOPEN_STREAMS:
1163       /* No support for STREAMS.  */
1164       return -1;
1165
1166     case _SC_LEVEL1_ICACHE_SIZE:
1167     case _SC_LEVEL1_ICACHE_ASSOC:
1168     case _SC_LEVEL1_ICACHE_LINESIZE:
1169     case _SC_LEVEL1_DCACHE_SIZE:
1170     case _SC_LEVEL1_DCACHE_ASSOC:
1171     case _SC_LEVEL1_DCACHE_LINESIZE:
1172     case _SC_LEVEL2_CACHE_SIZE:
1173     case _SC_LEVEL2_CACHE_ASSOC:
1174     case _SC_LEVEL2_CACHE_LINESIZE:
1175     case _SC_LEVEL3_CACHE_SIZE:
1176     case _SC_LEVEL3_CACHE_ASSOC:
1177     case _SC_LEVEL3_CACHE_LINESIZE:
1178     case _SC_LEVEL4_CACHE_SIZE:
1179     case _SC_LEVEL4_CACHE_ASSOC:
1180     case _SC_LEVEL4_CACHE_LINESIZE:
1181       /* In general we cannot determine these values.  Therefore we
1182          return zero which indicates that no information is
1183          available.  */
1184       return 0;
1185
1186     case _SC_IPV6:
1187 #if CONF_IS_DEFINED_SET (_POSIX_IPV6)
1188       return _POSIX_IPV6;
1189 #else
1190       return -1;
1191 #endif
1192
1193     case _SC_RAW_SOCKETS:
1194 #if CONF_IS_DEFINED_SET (_POSIX_RAW_SOCKETS)
1195       return _POSIX_RAW_SOCKETS;
1196 #else
1197       return -1;
1198 #endif
1199     }
1200 }
1201
1202 #undef __sysconf
1203 weak_alias (__sysconf, sysconf)
1204 libc_hidden_def (__sysconf)
1205
1206 #if NEED_CHECK_SPEC
1207 static long int
1208 __sysconf_check_spec (const char *spec)
1209 {
1210   int save_errno = errno;
1211
1212   const char *getconf_dir = __libc_secure_getenv ("GETCONF_DIR") ?: GETCONF_DIR;
1213   size_t getconf_dirlen = strlen (getconf_dir);
1214   size_t speclen = strlen (spec);
1215
1216   char name[getconf_dirlen + sizeof ("/POSIX_V6_") + speclen];
1217   memcpy (mempcpy (mempcpy (name, getconf_dir, getconf_dirlen),
1218                    "/POSIX_V6_", sizeof ("/POSIX_V6_") - 1),
1219           spec, speclen + 1);
1220
1221   struct stat64 st;
1222   long int ret = __xstat64 (_STAT_VER, name, &st) >= 0 ? 1 : -1;
1223
1224   __set_errno (save_errno);
1225   return ret;
1226 }
1227 #endif