sysdeps/posix/sysconf.c

   1 /* Copyright (C) 1991-2021 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    <https://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 <sys/uio.h>
  33 #include <regex.h>
  34 #include <signal.h>
  35 #include <sysconf-pthread_stack_min.h>
  36
  37 #define NEED_SPEC_ARRAY 0
  38 #include <posix-conf-vars.h>
  39
  40 #define NEED_CHECK_SPEC \
  41   (!defined _XBS5_ILP32_OFF32 || !defined _XBS5_ILP32_OFFBIG \
  42    || !defined _XBS5_LP64_OFF64 || !defined _XBS5_LPBIG_OFFBIG \
  43    || !defined _POSIX_V6_ILP32_OFF32 || !defined _POSIX_V6_ILP32_OFFBIG \
  44    || !defined _POSIX_V6_LP64_OFF64 || !defined _POSIX_V6_LPBIG_OFFBIG \
  45    || !defined _POSIX_V7_ILP32_OFF32 || !defined _POSIX_V7_ILP32_OFFBIG \
  46    || !defined _POSIX_V7_LP64_OFF64 || !defined _POSIX_V7_LPBIG_OFFBIG)
  47 #if NEED_CHECK_SPEC
  48 static long int __sysconf_check_spec (const char *spec);
  49 #endif
  50
  51
  52 /* Get the value of the system variable NAME.  */
  53 long int
  54 __sysconf (int name)
  55 {
  56   switch (name)
  57     {
  58       /* Also add obsolete or unnecessarily added constants here.  */
  59     case _SC_EQUIV_CLASS_MAX:
  60     default:
  61       __set_errno (EINVAL);
  62       return -1;
  63
  64     case _SC_ARG_MAX:
  65 #ifdef  ARG_MAX
  66       return ARG_MAX;
  67 #else
  68       return -1;
  69 #endif
  70
  71     case _SC_CHILD_MAX:
  72 #ifdef  CHILD_MAX
  73       return CHILD_MAX;
  74 #else
  75       return __get_child_max ();
  76 #endif
  77
  78     case _SC_CLK_TCK:
  79       return __getclktck ();
  80
  81     case _SC_NGROUPS_MAX:
  82 #ifdef  NGROUPS_MAX
  83       return NGROUPS_MAX;
  84 #else
  85       return -1;
  86 #endif
  87
  88     case _SC_OPEN_MAX:
  89       return __getdtablesize ();
  90
  91     case _SC_STREAM_MAX:
  92 #ifdef  STREAM_MAX
  93       return STREAM_MAX;
  94 #else
  95       return FOPEN_MAX;
  96 #endif
  97
  98     case _SC_TZNAME_MAX:
  99       return -1;
 100
 101     case _SC_JOB_CONTROL:
 102 #if CONF_IS_DEFINED_SET (_POSIX_JOB_CONTROL)
 103       return _POSIX_JOB_CONTROL;
 104 #else
 105       return -1;
 106 #endif
 107
 108     case _SC_SAVED_IDS:
 109 #if CONF_IS_DEFINED_SET (_POSIX_SAVED_IDS)
 110       return 1;
 111 #else
 112       return -1;
 113 #endif
 114
 115     case _SC_REALTIME_SIGNALS:
 116 #if CONF_IS_DEFINED_SET (_POSIX_REALTIME_SIGNALS)
 117       return _POSIX_REALTIME_SIGNALS;
 118 #else
 119       return -1;
 120 #endif
 121
 122     case _SC_PRIORITY_SCHEDULING:
 123 #if CONF_IS_DEFINED_SET (_POSIX_PRIORITY_SCHEDULING)
 124       return _POSIX_PRIORITY_SCHEDULING;
 125 #else
 126       return -1;
 127 #endif
 128
 129     case _SC_TIMERS:
 130 #if CONF_IS_DEFINED_SET (_POSIX_TIMERS)
 131       return _POSIX_TIMERS;
 132 #else
 133       return -1;
 134 #endif
 135
 136     case _SC_ASYNCHRONOUS_IO:
 137 #if CONF_IS_DEFINED_SET (_POSIX_ASYNCHRONOUS_IO)
 138       return _POSIX_ASYNCHRONOUS_IO;
 139 #else
 140       return -1;
 141 #endif
 142
 143     case _SC_PRIORITIZED_IO:
 144 #if CONF_IS_DEFINED_SET (_POSIX_PRIORITIZED_IO)
 145       return _POSIX_PRIORITIZED_IO;
 146 #else
 147       return -1;
 148 #endif
 149
 150     case _SC_SYNCHRONIZED_IO:
 151 #if CONF_IS_DEFINED_SET (_POSIX_SYNCHRONIZED_IO)
 152       return _POSIX_SYNCHRONIZED_IO;
 153 #else
 154       return -1;
 155 #endif
 156
 157     case _SC_FSYNC:
 158 #if CONF_IS_DEFINED_SET (_POSIX_FSYNC)
 159       return _POSIX_FSYNC;
 160 #else
 161       return -1;
 162 #endif
 163
 164     case _SC_MAPPED_FILES:
 165 #if CONF_IS_DEFINED_SET (_POSIX_MAPPED_FILES)
 166       return _POSIX_MAPPED_FILES;
 167 #else
 168       return -1;
 169 #endif
 170
 171     case _SC_MEMLOCK:
 172 #if CONF_IS_DEFINED_SET (_POSIX_MEMLOCK)
 173       return _POSIX_MEMLOCK;
 174 #else
 175       return -1;
 176 #endif
 177
 178     case _SC_MEMLOCK_RANGE:
 179 #if CONF_IS_DEFINED_SET (_POSIX_MEMLOCK_RANGE)
 180       return _POSIX_MEMLOCK_RANGE;
 181 #else
 182       return -1;
 183 #endif
 184
 185     case _SC_MEMORY_PROTECTION:
 186 #if CONF_IS_DEFINED_SET (_POSIX_MEMORY_PROTECTION)
 187       return _POSIX_MEMORY_PROTECTION;
 188 #else
 189       return -1;
 190 #endif
 191
 192     case _SC_MESSAGE_PASSING:
 193 #if CONF_IS_DEFINED_SET (_POSIX_MESSAGE_PASSING)
 194       return _POSIX_MESSAGE_PASSING;
 195 #else
 196       return -1;
 197 #endif
 198
 199     case _SC_SEMAPHORES:
 200 #if CONF_IS_DEFINED_SET (_POSIX_SEMAPHORES)
 201       return _POSIX_SEMAPHORES;
 202 #else
 203       return -1;
 204 #endif
 205
 206     case _SC_SHARED_MEMORY_OBJECTS:
 207 #if CONF_IS_DEFINED_SET (_POSIX_SHARED_MEMORY_OBJECTS)
 208       return _POSIX_SHARED_MEMORY_OBJECTS;
 209 #else
 210       return -1;
 211 #endif
 212
 213     case _SC_VERSION:
 214       return _POSIX_VERSION;
 215
 216     case _SC_PAGESIZE:
 217       return __getpagesize ();
 218
 219     case _SC_AIO_LISTIO_MAX:
 220 #ifdef  AIO_LISTIO_MAX
 221       return AIO_LISTIO_MAX;
 222 #else
 223       return -1;
 224 #endif
 225
 226     case _SC_AIO_MAX:
 227 #ifdef  AIO_MAX
 228       return AIO_MAX;
 229 #else
 230       return -1;
 231 #endif
 232
 233     case _SC_AIO_PRIO_DELTA_MAX:
 234 #ifdef  AIO_PRIO_DELTA_MAX
 235       return AIO_PRIO_DELTA_MAX;
 236 #else
 237       return -1;
 238 #endif
 239
 240     case _SC_DELAYTIMER_MAX:
 241 #ifdef  DELAYTIMER_MAX
 242       return DELAYTIMER_MAX;
 243 #else
 244       return -1;
 245 #endif
 246
 247     case _SC_MQ_OPEN_MAX:
 248 #ifdef  MQ_OPEN_MAX
 249       return MQ_OPEN_MAX;
 250 #else
 251       return -1;
 252 #endif
 253
 254     case _SC_MQ_PRIO_MAX:
 255 #ifdef  MQ_PRIO_MAX
 256       return MQ_PRIO_MAX;
 257 #else
 258       return -1;
 259 #endif
 260
 261     case _SC_RTSIG_MAX:
 262 #ifdef  RTSIG_MAX
 263       return RTSIG_MAX;
 264 #else
 265       return -1;
 266 #endif
 267
 268     case _SC_SEM_NSEMS_MAX:
 269 #ifdef  SEM_NSEMS_MAX
 270       return SEM_NSEMS_MAX;
 271 #else
 272       return -1;
 273 #endif
 274
 275     case _SC_SEM_VALUE_MAX:
 276 #ifdef  SEM_VALUE_MAX
 277       return SEM_VALUE_MAX;
 278 #else
 279       return -1;
 280 #endif
 281
 282     case _SC_SIGQUEUE_MAX:
 283 #ifdef  SIGQUEUE_MAX
 284       return SIGQUEUE_MAX;
 285 #else
 286       return -1;
 287 #endif
 288
 289     case _SC_TIMER_MAX:
 290 #ifdef  TIMER_MAX
 291       return TIMER_MAX;
 292 #else
 293       return -1;
 294 #endif
 295
 296     case _SC_BC_BASE_MAX:
 297 #ifdef  BC_BASE_MAX
 298       return BC_BASE_MAX;
 299 #else
 300       return -1;
 301 #endif
 302
 303     case _SC_BC_DIM_MAX:
 304 #ifdef  BC_DIM_MAX
 305       return BC_DIM_MAX;
 306 #else
 307       return -1;
 308 #endif
 309
 310     case _SC_BC_SCALE_MAX:
 311 #ifdef  BC_SCALE_MAX
 312       return BC_SCALE_MAX;
 313 #else
 314       return -1;
 315 #endif
 316
 317     case _SC_BC_STRING_MAX:
 318 #ifdef  BC_STRING_MAX
 319       return BC_STRING_MAX;
 320 #else
 321       return -1;
 322 #endif
 323
 324     case _SC_COLL_WEIGHTS_MAX:
 325 #ifdef  COLL_WEIGHTS_MAX
 326       return COLL_WEIGHTS_MAX;
 327 #else
 328       return -1;
 329 #endif
 330
 331     case _SC_EXPR_NEST_MAX:
 332 #ifdef  EXPR_NEST_MAX
 333       return EXPR_NEST_MAX;
 334 #else
 335       return -1;
 336 #endif
 337
 338     case _SC_LINE_MAX:
 339 #ifdef  LINE_MAX
 340       return LINE_MAX;
 341 #else
 342       return -1;
 343 #endif
 344
 345     case _SC_RE_DUP_MAX:
 346 #ifdef  RE_DUP_MAX
 347       return RE_DUP_MAX;
 348 #else
 349       return -1;
 350 #endif
 351
 352     case _SC_CHARCLASS_NAME_MAX:
 353 #ifdef  CHARCLASS_NAME_MAX
 354       return CHARCLASS_NAME_MAX;
 355 #else
 356       return -1;
 357 #endif
 358
 359     case _SC_PII:
 360 #if CONF_IS_DEFINED_SET (_POSIX_PII)
 361       return 1;
 362 #else
 363       return -1;
 364 #endif
 365
 366     case _SC_PII_XTI:
 367 #if CONF_IS_DEFINED_SET (_POSIX_PII_XTI)
 368       return 1;
 369 #else
 370       return -1;
 371 #endif
 372
 373     case _SC_PII_SOCKET:
 374 #if CONF_IS_DEFINED_SET (_POSIX_PII_SOCKET)
 375       return 1;
 376 #else
 377       return -1;
 378 #endif
 379
 380     case _SC_PII_INTERNET:
 381 #if CONF_IS_DEFINED_SET (_POSIX_PII_INTERNET)
 382       return 1;
 383 #else
 384       return -1;
 385 #endif
 386
 387     case _SC_PII_OSI:
 388 #if CONF_IS_DEFINED_SET (_POSIX_PII_OSI)
 389       return 1;
 390 #else
 391       return -1;
 392 #endif
 393
 394     case _SC_POLL:
 395 #if CONF_IS_DEFINED_SET (_POSIX_POLL)
 396       return 1;
 397 #else
 398       return -1;
 399 #endif
 400
 401     case _SC_SELECT:
 402 #if CONF_IS_DEFINED_SET (_POSIX_SELECT)
 403       return 1;
 404 #else
 405       return -1;
 406 #endif
 407
 408       /* The same as _SC_IOV_MAX.  */
 409     case _SC_UIO_MAXIOV:
 410 #ifdef  UIO_MAXIOV
 411       return UIO_MAXIOV;
 412 #else
 413       return -1;
 414 #endif
 415
 416     case _SC_PII_INTERNET_STREAM:
 417 #if CONF_IS_DEFINED_SET (_POSIX_PII_INTERNET_STREAM)
 418       return 1;
 419 #else
 420       return -1;
 421 #endif
 422
 423     case _SC_PII_INTERNET_DGRAM:
 424 #if CONF_IS_DEFINED_SET (_POSIX_PII_INTERNET_DGRAM)
 425       return 1;
 426 #else
 427       return -1;
 428 #endif
 429
 430     case _SC_PII_OSI_COTS:
 431 #if CONF_IS_DEFINED_SET (_POSIX_PII_OSI_COTS)
 432       return 1;
 433 #else
 434       return -1;
 435 #endif
 436
 437     case _SC_PII_OSI_CLTS:
 438 #if CONF_IS_DEFINED_SET (_POSIX_PII_OSI_CLTS)
 439       return 1;
 440 #else
 441       return -1;
 442 #endif
 443
 444     case _SC_PII_OSI_M:
 445 #if CONF_IS_DEFINED_SET (_POSIX_PII_OSI_M)
 446       return 1;
 447 #else
 448       return -1;
 449 #endif
 450
 451     case _SC_T_IOV_MAX:
 452 #ifdef  _T_IOV_MAX
 453       return _T_IOV_MAX;
 454 #else
 455       return -1;
 456 #endif
 457
 458     case _SC_2_VERSION:
 459       return _POSIX2_VERSION;
 460
 461     case _SC_2_C_BIND:
 462 #ifdef  _POSIX2_C_BIND
 463       return _POSIX2_C_BIND;
 464 #else
 465       return -1;
 466 #endif
 467
 468     case _SC_2_C_DEV:
 469 #ifdef  _POSIX2_C_DEV
 470       return _POSIX2_C_DEV;
 471 #else
 472       return -1;
 473 #endif
 474
 475     case _SC_2_C_VERSION:
 476 #ifdef  _POSIX2_C_VERSION
 477       return _POSIX2_C_VERSION;
 478 #else
 479       return -1;
 480 #endif
 481
 482     case _SC_2_FORT_DEV:
 483 #ifdef  _POSIX2_FORT_DEV
 484       return _POSIX2_FORT_DEV;
 485 #else
 486       return -1;
 487 #endif
 488
 489     case _SC_2_FORT_RUN:
 490 #ifdef  _POSIX2_FORT_RUN
 491       return _POSIX2_FORT_RUN;
 492 #else
 493       return -1;
 494 #endif
 495
 496     case _SC_2_LOCALEDEF:
 497 #ifdef  _POSIX2_LOCALEDEF
 498       return _POSIX2_LOCALEDEF;
 499 #else
 500       return -1;
 501 #endif
 502
 503     case _SC_2_SW_DEV:
 504 #ifdef  _POSIX2_SW_DEV
 505       return _POSIX2_SW_DEV;
 506 #else
 507       return -1;
 508 #endif
 509
 510     case _SC_2_CHAR_TERM:
 511 #ifdef  _POSIX2_CHAR_TERM
 512       return _POSIX2_CHAR_TERM;
 513 #else
 514       return -1;
 515 #endif
 516
 517     case _SC_2_UPE:
 518 #ifdef  _POSIX2_UPE
 519       return _POSIX2_UPE;
 520 #else
 521       return -1;
 522 #endif
 523
 524       /* POSIX 1003.1c (POSIX Threads).  */
 525     case _SC_THREADS:
 526 #if CONF_IS_DEFINED_SET (_POSIX_THREADS)
 527       return _POSIX_THREADS;
 528 #else
 529       return -1;
 530 #endif
 531
 532     case _SC_THREAD_SAFE_FUNCTIONS:
 533 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_SAFE_FUNCTIONS)
 534       return _POSIX_THREAD_SAFE_FUNCTIONS;
 535 #else
 536       return -1;
 537 #endif
 538
 539     case _SC_GETGR_R_SIZE_MAX:
 540       return NSS_BUFLEN_GROUP;
 541
 542     case _SC_GETPW_R_SIZE_MAX:
 543       return NSS_BUFLEN_PASSWD;
 544
 545     case _SC_LOGIN_NAME_MAX:
 546 #ifdef  LOGIN_NAME_MAX
 547       return LOGIN_NAME_MAX;
 548 #else
 549       return -1;
 550 #endif
 551
 552     case _SC_TTY_NAME_MAX:
 553 #ifdef  TTY_NAME_MAX
 554       return TTY_NAME_MAX;
 555 #else
 556       return -1;
 557 #endif
 558
 559     case _SC_THREAD_DESTRUCTOR_ITERATIONS:
 560 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_DESTRUCTOR_ITERATIONS)
 561       return _POSIX_THREAD_DESTRUCTOR_ITERATIONS;
 562 #else
 563       return -1;
 564 #endif
 565
 566     case _SC_THREAD_KEYS_MAX:
 567 #ifdef  PTHREAD_KEYS_MAX
 568       return PTHREAD_KEYS_MAX;
 569 #else
 570       return -1;
 571 #endif
 572
 573     case _SC_THREAD_STACK_MIN:
 574       return __get_pthread_stack_min ();
 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 CONF_IS_DEFINED_SET (_POSIX_THREAD_ATTR_STACKADDR)
 585       return _POSIX_THREAD_ATTR_STACKADDR;
 586 #else
 587       return -1;
 588 #endif
 589
 590     case _SC_THREAD_ATTR_STACKSIZE:
 591 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_ATTR_STACKSIZE)
 592       return _POSIX_THREAD_ATTR_STACKSIZE;
 593 #else
 594       return -1;
 595 #endif
 596
 597     case _SC_THREAD_PRIORITY_SCHEDULING:
 598 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_PRIORITY_SCHEDULING)
 599       return _POSIX_THREAD_PRIORITY_SCHEDULING;
 600 #else
 601       return -1;
 602 #endif
 603
 604     case _SC_THREAD_PRIO_INHERIT:
 605 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_PRIO_INHERIT)
 606       return _POSIX_THREAD_PRIO_INHERIT;
 607 #else
 608       return -1;
 609 #endif
 610
 611     case _SC_THREAD_PRIO_PROTECT:
 612 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_PRIO_PROTECT)
 613       return _POSIX_THREAD_PRIO_PROTECT;
 614 #else
 615       return -1;
 616 #endif
 617
 618     case _SC_THREAD_PROCESS_SHARED:
 619 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_PROCESS_SHARED)
 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 CONF_IS_DEFINED_SET (_POSIX_ADVISORY_INFO)
 837       return _POSIX_ADVISORY_INFO;
 838 #else
 839       return -1;
 840 #endif
 841
 842     case _SC_BARRIERS:
 843 #if CONF_IS_DEFINED_SET (_POSIX_BARRIERS)
 844       return _POSIX_BARRIERS;
 845 #else
 846       return -1;
 847 #endif
 848
 849     case _SC_BASE:
 850 #if CONF_IS_DEFINED_SET (_POSIX_BASE)
 851       return _POSIX_BASE;
 852 #else
 853       return -1;
 854 #endif
 855     case _SC_C_LANG_SUPPORT:
 856 #if CONF_IS_DEFINED_SET (_POSIX_C_LANG_SUPPORT)
 857       return _POSIX_C_LANG_SUPPORT;
 858 #else
 859       return -1;
 860 #endif
 861     case _SC_C_LANG_SUPPORT_R:
 862 #if CONF_IS_DEFINED_SET (_POSIX_C_LANG_SUPPORT_R)
 863       return _POSIX_C_LANG_SUPPORT_R;
 864 #else
 865       return -1;
 866 #endif
 867
 868     case _SC_CLOCK_SELECTION:
 869 #if CONF_IS_DEFINED_SET (_POSIX_CLOCK_SELECTION)
 870       return _POSIX_CLOCK_SELECTION;
 871 #else
 872       return -1;
 873 #endif
 874
 875     case _SC_CPUTIME:
 876 #if CONF_IS_DEFINED_SET (_POSIX_CPUTIME)
 877       return _POSIX_CPUTIME;
 878 #else
 879       return -1;
 880 #endif
 881
 882     case _SC_DEVICE_IO:
 883 #if CONF_IS_DEFINED_SET (_POSIX_DEVICE_IO)
 884       return _POSIX_DEVICE_IO;
 885 #else
 886       return -1;
 887 #endif
 888     case _SC_DEVICE_SPECIFIC:
 889 #if CONF_IS_DEFINED_SET (_POSIX_DEVICE_SPECIFIC)
 890       return _POSIX_DEVICE_SPECIFIC;
 891 #else
 892       return -1;
 893 #endif
 894     case _SC_DEVICE_SPECIFIC_R:
 895 #if CONF_IS_DEFINED_SET (_POSIX_DEVICE_SPECIFIC_R)
 896       return _POSIX_DEVICE_SPECIFIC_R;
 897 #else
 898       return -1;
 899 #endif
 900
 901     case _SC_FD_MGMT:
 902 #if CONF_IS_DEFINED_SET (_POSIX_FD_MGMT)
 903       return _POSIX_FD_MGMT;
 904 #else
 905       return -1;
 906 #endif
 907
 908     case _SC_FIFO:
 909 #if CONF_IS_DEFINED_SET (_POSIX_FIFO)
 910       return _POSIX_FIFO;
 911 #else
 912       return -1;
 913 #endif
 914     case _SC_PIPE:
 915 #if CONF_IS_DEFINED_SET (_POSIX_PIPE)
 916       return _POSIX_PIPE;
 917 #else
 918       return -1;
 919 #endif
 920
 921     case _SC_FILE_ATTRIBUTES:
 922 #if CONF_IS_DEFINED_SET (_POSIX_FILE_ATTRIBUTES)
 923       return _POSIX_FILE_ATTRIBUTES;
 924 #else
 925       return -1;
 926 #endif
 927     case _SC_FILE_LOCKING:
 928 #if CONF_IS_DEFINED_SET (_POSIX_FILE_LOCKING)
 929       return _POSIX_FILE_LOCKING;
 930 #else
 931       return -1;
 932 #endif
 933     case _SC_FILE_SYSTEM:
 934 #if CONF_IS_DEFINED_SET (_POSIX_FILE_SYSTEM)
 935       return _POSIX_FILE_SYSTEM;
 936 #else
 937       return -1;
 938 #endif
 939
 940     case _SC_MONOTONIC_CLOCK:
 941 #if CONF_IS_DEFINED_SET (_POSIX_MONOTONIC_CLOCK)
 942       return _POSIX_MONOTONIC_CLOCK;
 943 #else
 944       return -1;
 945 #endif
 946
 947     case _SC_MULTI_PROCESS:
 948 #if CONF_IS_DEFINED_SET (_POSIX_MULTI_PROCESS)
 949       return _POSIX_MULTI_PROCESS;
 950 #else
 951       return -1;
 952 #endif
 953     case _SC_SINGLE_PROCESS:
 954 #if CONF_IS_DEFINED_SET (_POSIX_SINGLE_PROCESS)
 955       return _POSIX_SINGLE_PROCESS;
 956 #else
 957       return -1;
 958 #endif
 959
 960     case _SC_NETWORKING:
 961 #if CONF_IS_DEFINED_SET (_POSIX_NETWORKING)
 962       return _POSIX_NETWORKING;
 963 #else
 964       return -1;
 965 #endif
 966
 967     case _SC_READER_WRITER_LOCKS:
 968 #if CONF_IS_DEFINED_SET (_POSIX_READER_WRITER_LOCKS)
 969       return _POSIX_READER_WRITER_LOCKS;
 970 #else
 971       return -1;
 972 #endif
 973     case _SC_SPIN_LOCKS:
 974 #if CONF_IS_DEFINED_SET (_POSIX_SPIN_LOCKS)
 975       return _POSIX_SPIN_LOCKS;
 976 #else
 977       return -1;
 978 #endif
 979
 980     case _SC_REGEXP:
 981 #if CONF_IS_DEFINED_SET (_POSIX_REGEXP)
 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 CONF_IS_DEFINED_SET (_POSIX_SHELL)
 993       return _POSIX_SHELL;
 994 #else
 995       return -1;
 996 #endif
 997
 998     case _SC_SIGNALS:
 999 #if CONF_IS_DEFINED (_POSIX_SIGNALS)
1000       return _POSIX_SIGNALS;
1001 #else
1002       return -1;
1003 #endif
1004
1005     case _SC_SPAWN:
1006 #if CONF_IS_DEFINED_SET (_POSIX_SPAWN)
1007       return _POSIX_SPAWN;
1008 #else
1009       return -1;
1010 #endif
1011
1012     case _SC_SPORADIC_SERVER:
1013 #if CONF_IS_DEFINED_SET (_POSIX_SPORADIC_SERVER)
1014       return _POSIX_SPORADIC_SERVER;
1015 #else
1016       return -1;
1017 #endif
1018     case _SC_THREAD_SPORADIC_SERVER:
1019 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_SPORADIC_SERVER)
1020       return _POSIX_THREAD_SPORADIC_SERVER;
1021 #else
1022       return -1;
1023 #endif
1024
1025     case _SC_SYSTEM_DATABASE:
1026 #if CONF_IS_DEFINED_SET (_POSIX_SYSTEM_DATABASE)
1027       return _POSIX_SYSTEM_DATABASE;
1028 #else
1029       return -1;
1030 #endif
1031     case _SC_SYSTEM_DATABASE_R:
1032 #if CONF_IS_DEFINED_SET (_POSIX_SYSTEM_DATABASE_R)
1033       return _POSIX_SYSTEM_DATABASE_R;
1034 #else
1035       return -1;
1036 #endif
1037
1038     case _SC_THREAD_CPUTIME:
1039 #if CONF_IS_DEFINED_SET (_POSIX_THREAD_CPUTIME)
1040       return _POSIX_THREAD_CPUTIME;
1041 #else
1042       return -1;
1043 #endif
1044
1045     case _SC_TIMEOUTS:
1046 #if CONF_IS_DEFINED_SET (_POSIX_TIMEOUTS)
1047       return _POSIX_TIMEOUTS;
1048 #else
1049       return -1;
1050 #endif
1051
1052     case _SC_TYPED_MEMORY_OBJECTS:
1053 #if CONF_IS_DEFINED_SET (_POSIX_TYPED_MEMORY_OBJECTS)
1054       return _POSIX_TYPED_MEMORY_OBJECTS;
1055 #else
1056       return -1;
1057 #endif
1058
1059     case _SC_USER_GROUPS:
1060 #if CONF_IS_DEFINED_SET (_POSIX_USER_GROUPS)
1061       return _POSIX_USER_GROUPS;
1062 #else
1063       return -1;
1064 #endif
1065     case _SC_USER_GROUPS_R:
1066 #if CONF_IS_DEFINED_SET (_POSIX_USER_GROUPS_R)
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       return -1;
1118
1119     case _SC_HOST_NAME_MAX:
1120 #ifdef HOST_NAME_MAX
1121       return HOST_NAME_MAX;
1122 #else
1123       return -1;
1124 #endif
1125
1126     case _SC_TRACE:
1127 #if CONF_IS_DEFINED_SET (_POSIX_TRACE)
1128       return _POSIX_TRACE;
1129 #else
1130       return -1;
1131 #endif
1132     case _SC_TRACE_EVENT_FILTER:
1133 #if CONF_IS_DEFINED_SET (_POSIX_TRACE_EVENT_FILTER)
1134       return _POSIX_TRACE_EVENT_FILTER;
1135 #else
1136       return -1;
1137 #endif
1138     case _SC_TRACE_INHERIT:
1139 #if CONF_IS_DEFINED_SET (_POSIX_TRACE_INHERIT)
1140       return _POSIX_TRACE_INHERIT;
1141 #else
1142       return -1;
1143 #endif
1144     case _SC_TRACE_LOG:
1145 #if CONF_IS_DEFINED_SET (_POSIX_TRACE_LOG)
1146       return _POSIX_TRACE_LOG;
1147 #else
1148       return -1;
1149 #endif
1150
1151     case _SC_TRACE_EVENT_NAME_MAX:
1152     case _SC_TRACE_NAME_MAX:
1153     case _SC_TRACE_SYS_MAX:
1154     case _SC_TRACE_USER_EVENT_MAX:
1155       /* No support for tracing.  */
1156
1157     case _SC_XOPEN_STREAMS:
1158       /* No support for STREAMS.  */
1159       return -1;
1160
1161     case _SC_LEVEL1_ICACHE_SIZE:
1162     case _SC_LEVEL1_ICACHE_ASSOC:
1163     case _SC_LEVEL1_ICACHE_LINESIZE:
1164     case _SC_LEVEL1_DCACHE_SIZE:
1165     case _SC_LEVEL1_DCACHE_ASSOC:
1166     case _SC_LEVEL1_DCACHE_LINESIZE:
1167     case _SC_LEVEL2_CACHE_SIZE:
1168     case _SC_LEVEL2_CACHE_ASSOC:
1169     case _SC_LEVEL2_CACHE_LINESIZE:
1170     case _SC_LEVEL3_CACHE_SIZE:
1171     case _SC_LEVEL3_CACHE_ASSOC:
1172     case _SC_LEVEL3_CACHE_LINESIZE:
1173     case _SC_LEVEL4_CACHE_SIZE:
1174     case _SC_LEVEL4_CACHE_ASSOC:
1175     case _SC_LEVEL4_CACHE_LINESIZE:
1176       /* In general we cannot determine these values.  Therefore we
1177          return zero which indicates that no information is
1178          available.  */
1179       return 0;
1180
1181     case _SC_IPV6:
1182 #if CONF_IS_DEFINED_SET (_POSIX_IPV6)
1183       return _POSIX_IPV6;
1184 #else
1185       return -1;
1186 #endif
1187
1188     case _SC_RAW_SOCKETS:
1189 #if CONF_IS_DEFINED_SET (_POSIX_RAW_SOCKETS)
1190       return _POSIX_RAW_SOCKETS;
1191 #else
1192       return -1;
1193 #endif
1194
1195     case _SC_SIGSTKSZ:
1196 #ifdef SIGSTKSZ
1197       return SIGSTKSZ;
1198 #else
1199       return -1;
1200 #endif
1201
1202     case _SC_MINSIGSTKSZ:
1203 #ifdef MINSIGSTKSZ
1204       return MINSIGSTKSZ;
1205 #else
1206       return -1;
1207 #endif
1208     }
1209 }
1210
1211 #undef __sysconf
1212 weak_alias (__sysconf, sysconf)
1213 libc_hidden_def (__sysconf)
1214
1215 #if NEED_CHECK_SPEC
1216 static long int
1217 __sysconf_check_spec (const char *spec)
1218 {
1219   int save_errno = errno;
1220
1221   const char *getconf_dir = __libc_secure_getenv ("GETCONF_DIR") ?: GETCONF_DIR;
1222   size_t getconf_dirlen = strlen (getconf_dir);
1223   size_t speclen = strlen (spec);
1224
1225   char name[getconf_dirlen + sizeof ("/POSIX_V6_") + speclen];
1226   memcpy (mempcpy (mempcpy (name, getconf_dir, getconf_dirlen),
1227                    "/POSIX_V6_", sizeof ("/POSIX_V6_") - 1),
1228           spec, speclen + 1);
1229
1230   struct __stat64_t64 st;
1231   long int ret = __stat64_time64 (name, &st) >= 0 ? 1 : -1;
1232
1233   __set_errno (save_errno);
1234   return ret;
1235 }
1236 #endif