Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

   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
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
@c Automatically generated from *.c and others (the comments before
@c each entry tell you which file and where in that file).  DO NOT EDIT!
@c Edit the *.c files, configure with --enable-maintainer-mode,
@c run 'make stamp-functions' and gather-docs will build a new copy.

@c alloca.c:26
@deftypefn Replacement void* alloca (size_t @var{size})

This function allocates memory which will be automatically reclaimed
after the procedure exits.  The @libib{} implementation does not free
the memory immediately but will do so eventually during subsequent
calls to this function.  Memory is allocated using @code{xmalloc} under
normal circumstances.

The header file @file{alloca-conf.h} can be used in conjunction with the
GNU Autoconf test @code{AC_FUNC_ALLOCA} to test for and properly make
available this function.  The @code{AC_FUNC_ALLOCA} test requires that
client code use a block of preprocessor code to be safe (see the Autoconf
manual for more); this header incorporates that logic and more, including
the possibility of a GCC built-in function.

@end deftypefn

@c asprintf.c:32
@deftypefn Extension int asprintf (char **@var{resptr}, const char *@var{format}, ...)

Like @code{sprintf}, but instead of passing a pointer to a buffer, you
pass a pointer to a pointer.  This function will compute the size of
the buffer needed, allocate memory with @code{malloc}, and store a
pointer to the allocated memory in @code{*@var{resptr}}.  The value
returned is the same as @code{sprintf} would return.  If memory could
not be allocated, minus one is returned and @code{NULL} is stored in
@code{*@var{resptr}}.

@end deftypefn

@c atexit.c:6
@deftypefn Supplemental int atexit (void (*@var{f})())

Causes function @var{f} to be called at exit.  Returns 0.

@end deftypefn

@c basename.c:6
@deftypefn Supplemental char* basename (const char *@var{name})

Returns a pointer to the last component of pathname @var{name}.
Behavior is undefined if the pathname ends in a directory separator.

@end deftypefn

@c bcmp.c:6
@deftypefn Supplemental int bcmp (char *@var{x}, char *@var{y}, int @var{count})

Compares the first @var{count} bytes of two areas of memory.  Returns
zero if they are the same, nonzero otherwise.  Returns zero if
@var{count} is zero.  A nonzero result only indicates a difference,
it does not indicate any sorting order (say, by having a positive
result mean @var{x} sorts before @var{y}).

@end deftypefn

@c bcopy.c:3
@deftypefn Supplemental void bcopy (char *@var{in}, char *@var{out}, int @var{length})

Copies @var{length} bytes from memory region @var{in} to region
@var{out}.  The use of @code{bcopy} is deprecated in new programs.

@end deftypefn

@c bsearch.c:33
@deftypefn Supplemental void* bsearch (const void *@var{key}, @
  const void *@var{base}, size_t @var{nmemb}, size_t @var{size}, @
  int (*@var{compar})(const void *, const void *))

Performs a search over an array of @var{nmemb} elements pointed to by
@var{base} for a member that matches the object pointed to by @var{key}.
The size of each member is specified by @var{size}.  The array contents
should be sorted in ascending order according to the @var{compar}
comparison function.  This routine should take two arguments pointing to
the @var{key} and to an array member, in that order, and should return an
integer less than, equal to, or greater than zero if the @var{key} object
is respectively less than, matching, or greater than the array member.

@end deftypefn

@c bsearch_r.c:33
@deftypefn Supplemental void* bsearch_r (const void *@var{key}, @
  const void *@var{base}, size_t @var{nmemb}, size_t @var{size}, @
  int (*@var{compar})(const void *, const void *, void *), void *@var{arg})

Performs a search over an array of @var{nmemb} elements pointed to by
@var{base} for a member that matches the object pointed to by @var{key}.
The size of each member is specified by @var{size}.  The array contents
should be sorted in ascending order according to the @var{compar}
comparison function.  This routine should take three arguments: the first
two point to the @var{key} and to an array member, and the last is passed
down unchanged from @code{bsearch_r}'s last argument.  It should return an
integer less than, equal to, or greater than zero if the @var{key} object
is respectively less than, matching, or greater than the array member.

@end deftypefn

@c argv.c:138
@deftypefn Extension char** buildargv (char *@var{sp})

Given a pointer to a string, parse the string extracting fields
separated by whitespace and optionally enclosed within either single
or double quotes (which are stripped off), and build a vector of
pointers to copies of the string for each field.  The input string
remains unchanged.  The last element of the vector is followed by a
@code{NULL} element.

All of the memory for the pointer array and copies of the string
is obtained from @code{xmalloc}.  All of the memory can be returned to the
system with the single function call @code{freeargv}, which takes the
returned result of @code{buildargv}, as it's argument.

Returns a pointer to the argument vector if successful.  Returns
@code{NULL} if @var{sp} is @code{NULL} or if there is insufficient
memory to complete building the argument vector.

If the input is a null string (as opposed to a @code{NULL} pointer),
then buildarg returns an argument vector that has one arg, a null
string.

@end deftypefn

@c bzero.c:6
@deftypefn Supplemental void bzero (char *@var{mem}, int @var{count})

Zeros @var{count} bytes starting at @var{mem}.  Use of this function
is deprecated in favor of @code{memset}.

@end deftypefn

@c calloc.c:6
@deftypefn Supplemental void* calloc (size_t @var{nelem}, size_t @var{elsize})

Uses @code{malloc} to allocate storage for @var{nelem} objects of
@var{elsize} bytes each, then zeros the memory.

@end deftypefn

@c filename_cmp.c:201
@deftypefn Extension int canonical_filename_eq (const char *@var{a}, const char *@var{b})

Return non-zero if file names @var{a} and @var{b} are equivalent.
This function compares the canonical versions of the filenames as returned by
@code{lrealpath()}, so that so that different file names pointing to the same
underlying file are treated as being identical.

@end deftypefn

@c choose-temp.c:45
@deftypefn Extension char* choose_temp_base (void)

Return a prefix for temporary file names or @code{NULL} if unable to
find one.  The current directory is chosen if all else fails so the
program is exited if a temporary directory can't be found (@code{mktemp}
fails).  The buffer for the result is obtained with @code{xmalloc}.

This function is provided for backwards compatibility only.  Its use is
not recommended.

@end deftypefn

@c make-temp-file.c:95
@deftypefn Replacement const char* choose_tmpdir ()

Returns a pointer to a directory path suitable for creating temporary
files in.

@end deftypefn

@c clock.c:27
@deftypefn Supplemental long clock (void)

Returns an approximation of the CPU time used by the process as a
@code{clock_t}; divide this number by @samp{CLOCKS_PER_SEC} to get the
number of seconds used.

@end deftypefn

@c concat.c:24
@deftypefn Extension char* concat (const char *@var{s1}, const char *@var{s2}, @
  @dots{}, @code{NULL})

Concatenate zero or more of strings and return the result in freshly
@code{xmalloc}ed memory.  The argument list is terminated by the first
@code{NULL} pointer encountered.  Pointers to empty strings are ignored.

@end deftypefn

@c argv.c:495
@deftypefn Extension int countargv (char * const *@var{argv})

Return the number of elements in @var{argv}.
Returns zero if @var{argv} is NULL.

@end deftypefn

@c crc32.c:140
@deftypefn Extension {unsigned int} crc32 (const unsigned char *@var{buf}, @
  int @var{len}, unsigned int @var{init})

Compute the 32-bit CRC of @var{buf} which has length @var{len}.  The
starting value is @var{init}; this may be used to compute the CRC of
data split across multiple buffers by passing the return value of each
call as the @var{init} parameter of the next.

This is used by the @command{gdb} remote protocol for the @samp{qCRC}
command.  In order to get the same results as gdb for a block of data,
you must pass the first CRC parameter as @code{0xffffffff}.

This CRC can be specified as:

  Width  : 32
  Poly   : 0x04c11db7
  Init   : parameter, typically 0xffffffff
  RefIn  : false
  RefOut : false
  XorOut : 0

This differs from the "standard" CRC-32 algorithm in that the values
are not reflected, and there is no final XOR value.  These differences
make it easy to compose the values of multiple blocks.

@end deftypefn

@c argv.c:59
@deftypefn Extension char** dupargv (char * const *@var{vector})

Duplicate an argument vector.  Simply scans through @var{vector},
duplicating each argument until the terminating @code{NULL} is found.
Returns a pointer to the argument vector if successful.  Returns
@code{NULL} if there is insufficient memory to complete building the
argument vector.

@end deftypefn

@c strerror.c:572
@deftypefn Extension int errno_max (void)

Returns the maximum @code{errno} value for which a corresponding
symbolic name or message is available.  Note that in the case where we
use the @code{sys_errlist} supplied by the system, it is possible for
there to be more symbolic names than messages, or vice versa.  In
fact, the manual page for @code{perror(3C)} explicitly warns that one
should check the size of the table (@code{sys_nerr}) before indexing
it, since new error codes may be added to the system before they are
added to the table.  Thus @code{sys_nerr} might be smaller than value
implied by the largest @code{errno} value defined in @code{<errno.h>}.

We return the maximum value that can be used to obtain a meaningful
symbolic name or message.

@end deftypefn

@c argv.c:352
@deftypefn Extension void expandargv (int *@var{argcp}, char ***@var{argvp})

The @var{argcp} and @code{argvp} arguments are pointers to the usual
@code{argc} and @code{argv} arguments to @code{main}.  This function
looks for arguments that begin with the character @samp{@@}.  Any such
arguments are interpreted as ``response files''.  The contents of the
response file are interpreted as additional command line options.  In
particular, the file is separated into whitespace-separated strings;
each such string is taken as a command-line option.  The new options
are inserted in place of the option naming the response file, and
@code{*argcp} and @code{*argvp} will be updated.  If the value of
@code{*argvp} is modified by this function, then the new value has
been dynamically allocated and can be deallocated by the caller with
@code{freeargv}.  However, most callers will simply call
@code{expandargv} near the beginning of @code{main} and allow the
operating system to free the memory when the program exits.

@end deftypefn

@c fdmatch.c:23
@deftypefn Extension int fdmatch (int @var{fd1}, int @var{fd2})

Check to see if two open file descriptors refer to the same file.
This is useful, for example, when we have an open file descriptor for
an unnamed file, and the name of a file that we believe to correspond
to that fd.  This can happen when we are exec'd with an already open
file (@code{stdout} for example) or from the SVR4 @file{/proc} calls
that return open file descriptors for mapped address spaces.  All we
have to do is open the file by name and check the two file descriptors
for a match, which is done by comparing major and minor device numbers
and inode numbers.

@end deftypefn

@c fopen_unlocked.c:49
@deftypefn Extension {FILE *} fdopen_unlocked (int @var{fildes}, @
  const char * @var{mode})

Opens and returns a @code{FILE} pointer via @code{fdopen}.  If the
operating system supports it, ensure that the stream is setup to avoid
any multi-threaded locking.  Otherwise return the @code{FILE} pointer
unchanged.

@end deftypefn

@c ffs.c:3
@deftypefn Supplemental int ffs (int @var{valu})

Find the first (least significant) bit set in @var{valu}.  Bits are
numbered from right to left, starting with bit 1 (corresponding to the
value 1).  If @var{valu} is zero, zero is returned.

@end deftypefn

@c filename_cmp.c:37
@deftypefn Extension int filename_cmp (const char *@var{s1}, const char *@var{s2})

Return zero if the two file names @var{s1} and @var{s2} are equivalent.
If not equivalent, the returned value is similar to what @code{strcmp}
would return.  In other words, it returns a negative value if @var{s1}
is less than @var{s2}, or a positive value if @var{s2} is greater than
@var{s2}.

This function does not normalize file names.  As a result, this function
will treat filenames that are spelled differently as different even in
the case when the two filenames point to the same underlying file.
However, it does handle the fact that on DOS-like file systems, forward
and backward slashes are equal.

@end deftypefn

@c filename_cmp.c:183
@deftypefn Extension int filename_eq (const void *@var{s1}, const void *@var{s2})

Return non-zero if file names @var{s1} and @var{s2} are equivalent.
This function is for use with hashtab.c hash tables.

@end deftypefn

@c filename_cmp.c:152
@deftypefn Extension hashval_t filename_hash (const void *@var{s})

Return the hash value for file name @var{s} that will be compared
using filename_cmp.
This function is for use with hashtab.c hash tables.

@end deftypefn

@c filename_cmp.c:94
@deftypefn Extension int filename_ncmp (const char *@var{s1}, const char *@var{s2}, size_t @var{n})

Return zero if the two file names @var{s1} and @var{s2} are equivalent
in range @var{n}.
If not equivalent, the returned value is similar to what @code{strncmp}
would return.  In other words, it returns a negative value if @var{s1}
is less than @var{s2}, or a positive value if @var{s2} is greater than
@var{s2}.

This function does not normalize file names.  As a result, this function
will treat filenames that are spelled differently as different even in
the case when the two filenames point to the same underlying file.
However, it does handle the fact that on DOS-like file systems, forward
and backward slashes are equal.

@end deftypefn

@c fnmatch.txh:1
@deftypefn Replacement int fnmatch (const char *@var{pattern}, @
  const char *@var{string}, int @var{flags})

Matches @var{string} against @var{pattern}, returning zero if it
matches, @code{FNM_NOMATCH} if not.  @var{pattern} may contain the
wildcards @code{?} to match any one character, @code{*} to match any
zero or more characters, or a set of alternate characters in square
brackets, like @samp{[a-gt8]}, which match one character (@code{a}
through @code{g}, or @code{t}, or @code{8}, in this example) if that one
character is in the set.  A set may be inverted (i.e., match anything
except what's in the set) by giving @code{^} or @code{!} as the first
character in the set.  To include those characters in the set, list them
as anything other than the first character of the set.  To include a
dash in the set, list it last in the set.  A backslash character makes
the following character not special, so for example you could match
against a literal asterisk with @samp{\*}.  To match a literal
backslash, use @samp{\\}.

@code{flags} controls various aspects of the matching process, and is a
boolean OR of zero or more of the following values (defined in
@code{<fnmatch.h>}):

@table @code

@item FNM_PATHNAME
@itemx FNM_FILE_NAME
@var{string} is assumed to be a path name.  No wildcard will ever match
@code{/}.

@item FNM_NOESCAPE
Do not interpret backslashes as quoting the following special character.

@item FNM_PERIOD
A leading period (at the beginning of @var{string}, or if
@code{FNM_PATHNAME} after a slash) is not matched by @code{*} or
@code{?} but must be matched explicitly.

@item FNM_LEADING_DIR
Means that @var{string} also matches @var{pattern} if some initial part
of @var{string} matches, and is followed by @code{/} and zero or more
characters.  For example, @samp{foo*} would match either @samp{foobar}
or @samp{foobar/grill}.

@item FNM_CASEFOLD
Ignores case when performing the comparison.

@end table

@end deftypefn

@c fopen_unlocked.c:39
@deftypefn Extension {FILE *} fopen_unlocked (const char *@var{path}, @
  const char * @var{mode})

Opens and returns a @code{FILE} pointer via @code{fopen}.  If the
operating system supports it, ensure that the stream is setup to avoid
any multi-threaded locking.  Otherwise return the @code{FILE} pointer
unchanged.

@end deftypefn

@c argv.c:93
@deftypefn Extension void freeargv (char **@var{vector})

Free an argument vector that was built using @code{buildargv}.  Simply
scans through @var{vector}, freeing the memory for each argument until
the terminating @code{NULL} is found, and then frees @var{vector}
itself.

@end deftypefn

@c fopen_unlocked.c:59
@deftypefn Extension {FILE *} freopen_unlocked (const char * @var{path}, @
  const char * @var{mode}, FILE * @var{stream})

Opens and returns a @code{FILE} pointer via @code{freopen}.  If the
operating system supports it, ensure that the stream is setup to avoid
any multi-threaded locking.  Otherwise return the @code{FILE} pointer
unchanged.

@end deftypefn

@c getruntime.c:86
@deftypefn Replacement long get_run_time (void)

Returns the time used so far, in microseconds.  If possible, this is
the time used by this process, else it is the elapsed time since the
process started.

@end deftypefn

@c getcwd.c:6
@deftypefn Supplemental char* getcwd (char *@var{pathname}, int @var{len})

Copy the absolute pathname for the current working directory into
@var{pathname}, which is assumed to point to a buffer of at least
@var{len} bytes, and return a pointer to the buffer.  If the current
directory's path doesn't fit in @var{len} characters, the result is
@code{NULL} and @code{errno} is set.  If @var{pathname} is a null pointer,
@code{getcwd} will obtain @var{len} bytes of space using
@code{malloc}.

@end deftypefn

@c getpagesize.c:5
@deftypefn Supplemental int getpagesize (void)

Returns the number of bytes in a page of memory.  This is the
granularity of many of the system memory management routines.  No
guarantee is made as to whether or not it is the same as the basic
memory management hardware page size.

@end deftypefn

@c getpwd.c:5
@deftypefn Supplemental char* getpwd (void)

Returns the current working directory.  This implementation caches the
result on the assumption that the process will not call @code{chdir}
between calls to @code{getpwd}.

@end deftypefn

@c gettimeofday.c:12
@deftypefn Supplemental int gettimeofday (struct timeval *@var{tp}, void *@var{tz})

Writes the current time to @var{tp}.  This implementation requires
that @var{tz} be NULL.  Returns 0 on success, -1 on failure.

@end deftypefn

@c hex.c:33
@deftypefn Extension void hex_init (void)

Initializes the array mapping the current character set to
corresponding hex values.  This function must be called before any
call to @code{hex_p} or @code{hex_value}.  If you fail to call it, a
default ASCII-based table will normally be used on ASCII systems.

@end deftypefn

@c hex.c:42
@deftypefn Extension int hex_p (int @var{c})

Evaluates to non-zero if the given character is a valid hex character,
or zero if it is not.  Note that the value you pass will be cast to
@code{unsigned char} within the macro.

@end deftypefn

@c hex.c:50
@deftypefn Extension {unsigned int} hex_value (int @var{c})

Returns the numeric equivalent of the given character when interpreted
as a hexadecimal digit.  The result is undefined if you pass an
invalid hex digit.  Note that the value you pass will be cast to
@code{unsigned char} within the macro.

The @code{hex_value} macro returns @code{unsigned int}, rather than
signed @code{int}, to make it easier to use in parsing addresses from
hex dump files: a signed @code{int} would be sign-extended when
converted to a wider unsigned type --- like @code{bfd_vma}, on some
systems.

@end deftypefn

@c safe-ctype.c:24
@defvr Extension HOST_CHARSET
This macro indicates the basic character set and encoding used by the
host: more precisely, the encoding used for character constants in
preprocessor @samp{#if} statements (the C "execution character set").
It is defined by @file{safe-ctype.h}, and will be an integer constant
with one of the following values:

@ftable @code
@item HOST_CHARSET_UNKNOWN
The host character set is unknown - that is, not one of the next two
possibilities.

@item HOST_CHARSET_ASCII
The host character set is ASCII.

@item HOST_CHARSET_EBCDIC
The host character set is some variant of EBCDIC.  (Only one of the
nineteen EBCDIC varying characters is tested; exercise caution.)
@end ftable
@end defvr

@c hashtab.c:327
@deftypefn Supplemental htab_t htab_create_typed_alloc (size_t @var{size}, @
htab_hash @var{hash_f}, htab_eq @var{eq_f}, htab_del @var{del_f}, @
htab_alloc @var{alloc_tab_f}, htab_alloc @var{alloc_f}, @
htab_free @var{free_f})

This function creates a hash table that uses two different allocators
@var{alloc_tab_f} and @var{alloc_f} to use for allocating the table itself
and its entries respectively.  This is useful when variables of different
types need to be allocated with different allocators.

The created hash table is slightly larger than @var{size} and it is
initially empty (all the hash table entries are @code{HTAB_EMPTY_ENTRY}).
The function returns the created hash table, or @code{NULL} if memory
allocation fails.

@end deftypefn

@c index.c:5
@deftypefn Supplemental char* index (char *@var{s}, int @var{c})

Returns a pointer to the first occurrence of the character @var{c} in
the string @var{s}, or @code{NULL} if not found.  The use of @code{index} is
deprecated in new programs in favor of @code{strchr}.

@end deftypefn

@c insque.c:6
@deftypefn Supplemental void insque (struct qelem *@var{elem}, @
  struct qelem *@var{pred})
@deftypefnx Supplemental void remque (struct qelem *@var{elem})

Routines to manipulate queues built from doubly linked lists.  The
@code{insque} routine inserts @var{elem} in the queue immediately
after @var{pred}.  The @code{remque} routine removes @var{elem} from
its containing queue.  These routines expect to be passed pointers to
structures which have as their first members a forward pointer and a
back pointer, like this prototype (although no prototype is provided):

@example
struct qelem @{
  struct qelem *q_forw;
  struct qelem *q_back;
  char q_data[];
@};
@end example

@end deftypefn

@c safe-ctype.c:45
@deffn  Extension ISALPHA  (@var{c})
@deffnx Extension ISALNUM  (@var{c})
@deffnx Extension ISBLANK  (@var{c})
@deffnx Extension ISCNTRL  (@var{c})
@deffnx Extension ISDIGIT  (@var{c})
@deffnx Extension ISGRAPH  (@var{c})
@deffnx Extension ISLOWER  (@var{c})
@deffnx Extension ISPRINT  (@var{c})
@deffnx Extension ISPUNCT  (@var{c})
@deffnx Extension ISSPACE  (@var{c})
@deffnx Extension ISUPPER  (@var{c})
@deffnx Extension ISXDIGIT (@var{c})

These twelve macros are defined by @file{safe-ctype.h}.  Each has the
same meaning as the corresponding macro (with name in lowercase)
defined by the standard header @file{ctype.h}.  For example,
@code{ISALPHA} returns true for alphabetic characters and false for
others.  However, there are two differences between these macros and
those provided by @file{ctype.h}:

@itemize @bullet
@item These macros are guaranteed to have well-defined behavior for all 
values representable by @code{signed char} and @code{unsigned char}, and
for @code{EOF}.

@item These macros ignore the current locale; they are true for these
fixed sets of characters:
@multitable {@code{XDIGIT}} {yada yada yada yada yada yada yada yada}
@item @code{ALPHA}  @tab @kbd{A-Za-z}
@item @code{ALNUM}  @tab @kbd{A-Za-z0-9}
@item @code{BLANK}  @tab @kbd{space tab}
@item @code{CNTRL}  @tab @code{!PRINT}
@item @code{DIGIT}  @tab @kbd{0-9}
@item @code{GRAPH}  @tab @code{ALNUM || PUNCT}
@item @code{LOWER}  @tab @kbd{a-z}
@item @code{PRINT}  @tab @code{GRAPH ||} @kbd{space}
@item @code{PUNCT}  @tab @kbd{`~!@@#$%^&*()_-=+[@{]@}\|;:'",<.>/?}
@item @code{SPACE}  @tab @kbd{space tab \n \r \f \v}
@item @code{UPPER}  @tab @kbd{A-Z}
@item @code{XDIGIT} @tab @kbd{0-9A-Fa-f}
@end multitable

Note that, if the host character set is ASCII or a superset thereof,
all these macros will return false for all values of @code{char} outside
the range of 7-bit ASCII.  In particular, both ISPRINT and ISCNTRL return
false for characters with numeric values from 128 to 255.
@end itemize
@end deffn

@c safe-ctype.c:94
@deffn  Extension ISIDNUM         (@var{c})
@deffnx Extension ISIDST          (@var{c})
@deffnx Extension IS_VSPACE       (@var{c})
@deffnx Extension IS_NVSPACE      (@var{c})
@deffnx Extension IS_SPACE_OR_NUL (@var{c})
@deffnx Extension IS_ISOBASIC     (@var{c})
These six macros are defined by @file{safe-ctype.h} and provide
additional character classes which are useful when doing lexical
analysis of C or similar languages.  They are true for the following
sets of characters:

@multitable {@code{SPACE_OR_NUL}} {yada yada yada yada yada yada yada yada}
@item @code{IDNUM}        @tab @kbd{A-Za-z0-9_}
@item @code{IDST}         @tab @kbd{A-Za-z_}
@item @code{VSPACE}       @tab @kbd{\r \n}
@item @code{NVSPACE}      @tab @kbd{space tab \f \v \0}
@item @code{SPACE_OR_NUL} @tab @code{VSPACE || NVSPACE}
@item @code{ISOBASIC}     @tab @code{VSPACE || NVSPACE || PRINT}
@end multitable
@end deffn

@c lbasename.c:23
@deftypefn Replacement {const char*} lbasename (const char *@var{name})

Given a pointer to a string containing a typical pathname
(@samp{/usr/src/cmd/ls/ls.c} for example), returns a pointer to the
last component of the pathname (@samp{ls.c} in this case).  The
returned pointer is guaranteed to lie within the original
string.  This latter fact is not true of many vendor C
libraries, which return special strings or modify the passed
strings for particular input.

In particular, the empty string returns the same empty string,
and a path ending in @code{/} returns the empty string after it.

@end deftypefn

@c lrealpath.c:25
@deftypefn Replacement {const char*} lrealpath (const char *@var{name})

Given a pointer to a string containing a pathname, returns a canonical
version of the filename.  Symlinks will be resolved, and ``.'' and ``..''
components will be simplified.  The returned value will be allocated using
@code{malloc}, or @code{NULL} will be returned on a memory allocation error.

@end deftypefn

@c make-relative-prefix.c:23
@deftypefn Extension {const char*} make_relative_prefix (const char *@var{progname}, @
  const char *@var{bin_prefix}, const char *@var{prefix})

Given three paths @var{progname}, @var{bin_prefix}, @var{prefix},
return the path that is in the same position relative to
@var{progname}'s directory as @var{prefix} is relative to
@var{bin_prefix}.  That is, a string starting with the directory
portion of @var{progname}, followed by a relative pathname of the
difference between @var{bin_prefix} and @var{prefix}.

If @var{progname} does not contain any directory separators,
@code{make_relative_prefix} will search @env{PATH} to find a program
named @var{progname}.  Also, if @var{progname} is a symbolic link,
the symbolic link will be resolved.

For example, if @var{bin_prefix} is @code{/alpha/beta/gamma/gcc/delta},
@var{prefix} is @code{/alpha/beta/gamma/omega/}, and @var{progname} is
@code{/red/green/blue/gcc}, then this function will return
@code{/red/green/blue/../../omega/}.

The return value is normally allocated via @code{malloc}.  If no
relative prefix can be found, return @code{NULL}.

@end deftypefn

@c make-temp-file.c:173
@deftypefn Replacement char* make_temp_file (const char *@var{suffix})

Return a temporary file name (as a string) or @code{NULL} if unable to
create one.  @var{suffix} is a suffix to append to the file name.  The
string is @code{malloc}ed, and the temporary file has been created.

@end deftypefn

@c memchr.c:3
@deftypefn Supplemental void* memchr (const void *@var{s}, int @var{c}, @
  size_t @var{n})

This function searches memory starting at @code{*@var{s}} for the
character @var{c}.  The search only ends with the first occurrence of
@var{c}, or after @var{length} characters; in particular, a null
character does not terminate the search.  If the character @var{c} is
found within @var{length} characters of @code{*@var{s}}, a pointer
to the character is returned.  If @var{c} is not found, then @code{NULL} is
returned.

@end deftypefn

@c memcmp.c:6
@deftypefn Supplemental int memcmp (const void *@var{x}, const void *@var{y}, @
  size_t @var{count})

Compares the first @var{count} bytes of two areas of memory.  Returns
zero if they are the same, a value less than zero if @var{x} is
lexically less than @var{y}, or a value greater than zero if @var{x}
is lexically greater than @var{y}.  Note that lexical order is determined
as if comparing unsigned char arrays.

@end deftypefn

@c memcpy.c:6
@deftypefn Supplemental void* memcpy (void *@var{out}, const void *@var{in}, @
  size_t @var{length})

Copies @var{length} bytes from memory region @var{in} to region
@var{out}.  Returns a pointer to @var{out}.

@end deftypefn

@c memmem.c:20
@deftypefn Supplemental void* memmem (const void *@var{haystack}, @
  size_t @var{haystack_len} const void *@var{needle}, size_t @var{needle_len})

Returns a pointer to the first occurrence of @var{needle} (length
@var{needle_len}) in @var{haystack} (length @var{haystack_len}).
Returns @code{NULL} if not found.

@end deftypefn

@c memmove.c:6
@deftypefn Supplemental void* memmove (void *@var{from}, const void *@var{to}, @
  size_t @var{count})

Copies @var{count} bytes from memory area @var{from} to memory area
@var{to}, returning a pointer to @var{to}.

@end deftypefn

@c mempcpy.c:23
@deftypefn Supplemental void* mempcpy (void *@var{out}, const void *@var{in}, @
  size_t @var{length})

Copies @var{length} bytes from memory region @var{in} to region
@var{out}.  Returns a pointer to @var{out} + @var{length}.

@end deftypefn

@c memset.c:6
@deftypefn Supplemental void* memset (void *@var{s}, int @var{c}, @
  size_t @var{count})

Sets the first @var{count} bytes of @var{s} to the constant byte
@var{c}, returning a pointer to @var{s}.

@end deftypefn

@c mkstemps.c:60
@deftypefn Replacement int mkstemps (char *@var{pattern}, int @var{suffix_len})

Generate a unique temporary file name from @var{pattern}.
@var{pattern} has the form:

@example
   @var{path}/ccXXXXXX@var{suffix}
@end example

@var{suffix_len} tells us how long @var{suffix} is (it can be zero
length).  The last six characters of @var{pattern} before @var{suffix}
must be @samp{XXXXXX}; they are replaced with a string that makes the
filename unique.  Returns a file descriptor open on the file for
reading and writing.

@end deftypefn

@c pexecute.txh:278
@deftypefn Extension void pex_free (struct pex_obj @var{obj})

Clean up and free all data associated with @var{obj}.  If you have not
yet called @code{pex_get_times} or @code{pex_get_status}, this will
try to kill the subprocesses.

@end deftypefn

@c pexecute.txh:251
@deftypefn Extension int pex_get_status (struct pex_obj *@var{obj}, @
  int @var{count}, int *@var{vector})

Returns the exit status of all programs run using @var{obj}.
@var{count} is the number of results expected.  The results will be
placed into @var{vector}.  The results are in the order of the calls
to @code{pex_run}.  Returns 0 on error, 1 on success.

@end deftypefn

@c pexecute.txh:261
@deftypefn Extension int pex_get_times (struct pex_obj *@var{obj}, @
  int @var{count}, struct pex_time *@var{vector})

Returns the process execution times of all programs run using
@var{obj}.  @var{count} is the number of results expected.  The
results will be placed into @var{vector}.  The results are in the
order of the calls to @code{pex_run}.  Returns 0 on error, 1 on
success.

@code{struct pex_time} has the following fields of the type
@code{unsigned long}: @code{user_seconds},
@code{user_microseconds}, @code{system_seconds},
@code{system_microseconds}.  On systems which do not support reporting
process times, all the fields will be set to @code{0}.

@end deftypefn

@c pexecute.txh:2
@deftypefn Extension {struct pex_obj *} pex_init (int @var{flags}, @
  const char *@var{pname}, const char *@var{tempbase})

Prepare to execute one or more programs, with standard output of each
program fed to standard input of the next.  This is a system
independent interface to execute a pipeline.

@var{flags} is a bitwise combination of the following:

@table @code

@vindex PEX_RECORD_TIMES
@item PEX_RECORD_TIMES
Record subprocess times if possible.

@vindex PEX_USE_PIPES
@item PEX_USE_PIPES
Use pipes for communication between processes, if possible.

@vindex PEX_SAVE_TEMPS
@item PEX_SAVE_TEMPS
Don't delete temporary files used for communication between
processes.

@end table

@var{pname} is the name of program to be executed, used in error
messages.  @var{tempbase} is a base name to use for any required
temporary files; it may be @code{NULL} to use a randomly chosen name.

@end deftypefn

@c pexecute.txh:161
@deftypefn Extension {FILE *} pex_input_file (struct pex_obj *@var{obj}, @
  int @var{flags}, const char *@var{in_name})

Return a stream for a temporary file to pass to the first program in
the pipeline as input.

The name of the input file is chosen according to the same rules
@code{pex_run} uses to choose output file names, based on
@var{in_name}, @var{obj} and the @code{PEX_SUFFIX} bit in @var{flags}.

Don't call @code{fclose} on the returned stream; the first call to
@code{pex_run} closes it automatically.

If @var{flags} includes @code{PEX_BINARY_OUTPUT}, open the stream in
binary mode; otherwise, open it in the default mode.  Including
@code{PEX_BINARY_OUTPUT} in @var{flags} has no effect on Unix.
@end deftypefn

@c pexecute.txh:179
@deftypefn Extension {FILE *} pex_input_pipe (struct pex_obj *@var{obj}, @
  int @var{binary})

Return a stream @var{fp} for a pipe connected to the standard input of
the first program in the pipeline; @var{fp} is opened for writing.
You must have passed @code{PEX_USE_PIPES} to the @code{pex_init} call
that returned @var{obj}.

You must close @var{fp} using @code{fclose} yourself when you have
finished writing data to the pipeline.

The file descriptor underlying @var{fp} is marked not to be inherited
by child processes.

On systems that do not support pipes, this function returns
@code{NULL}, and sets @code{errno} to @code{EINVAL}.  If you would
like to write code that is portable to all systems the @code{pex}
functions support, consider using @code{pex_input_file} instead.

There are two opportunities for deadlock using
@code{pex_input_pipe}:

@itemize @bullet
@item
Most systems' pipes can buffer only a fixed amount of data; a process
that writes to a full pipe blocks.  Thus, if you write to @file{fp}
before starting the first process, you run the risk of blocking when
there is no child process yet to read the data and allow you to
continue.  @code{pex_input_pipe} makes no promises about the
size of the pipe's buffer, so if you need to write any data at all
before starting the first process in the pipeline, consider using
@code{pex_input_file} instead.

@item
Using @code{pex_input_pipe} and @code{pex_read_output} together
may also cause deadlock.  If the output pipe fills up, so that each
program in the pipeline is waiting for the next to read more data, and
you fill the input pipe by writing more data to @var{fp}, then there
is no way to make progress: the only process that could read data from
the output pipe is you, but you are blocked on the input pipe.

@end itemize

@end deftypefn

@c pexecute.txh:286
@deftypefn Extension {const char *} pex_one (int @var{flags}, @
  const char *@var{executable}, char * const *@var{argv}, @
  const char *@var{pname}, const char *@var{outname}, const char *@var{errname}, @
  int *@var{status}, int *@var{err})

An interface to permit the easy execution of a
single program.  The return value and most of the parameters are as
for a call to @code{pex_run}.  @var{flags} is restricted to a
combination of @code{PEX_SEARCH}, @code{PEX_STDERR_TO_STDOUT}, and
@code{PEX_BINARY_OUTPUT}.  @var{outname} is interpreted as if
@code{PEX_LAST} were set.  On a successful return, @code{*@var{status}} will
be set to the exit status of the program.

@end deftypefn

@c pexecute.txh:237
@deftypefn Extension {FILE *} pex_read_err (struct pex_obj *@var{obj}, @
  int @var{binary})

Returns a @code{FILE} pointer which may be used to read the standard
error of the last program in the pipeline.  When this is used,
@code{PEX_LAST} should not be used in a call to @code{pex_run}.  After
this is called, @code{pex_run} may no longer be called with the same
@var{obj}.  @var{binary} should be non-zero if the file should be
opened in binary mode.  Don't call @code{fclose} on the returned file;
it will be closed by @code{pex_free}.

@end deftypefn

@c pexecute.txh:224
@deftypefn Extension {FILE *} pex_read_output (struct pex_obj *@var{obj}, @
  int @var{binary})

Returns a @code{FILE} pointer which may be used to read the standard
output of the last program in the pipeline.  When this is used,
@code{PEX_LAST} should not be used in a call to @code{pex_run}.  After
this is called, @code{pex_run} may no longer be called with the same
@var{obj}.  @var{binary} should be non-zero if the file should be
opened in binary mode.  Don't call @code{fclose} on the returned file;
it will be closed by @code{pex_free}.

@end deftypefn

@c pexecute.txh:34
@deftypefn Extension {const char *} pex_run (struct pex_obj *@var{obj}, @
  int @var{flags}, const char *@var{executable}, char * const *@var{argv}, @
  const char *@var{outname}, const char *@var{errname}, int *@var{err})

Execute one program in a pipeline.  On success this returns
@code{NULL}.  On failure it returns an error message, a statically
allocated string.

@var{obj} is returned by a previous call to @code{pex_init}.

@var{flags} is a bitwise combination of the following:

@table @code

@vindex PEX_LAST
@item PEX_LAST
This must be set on the last program in the pipeline.  In particular,
it should be set when executing a single program.  The standard output
of the program will be sent to @var{outname}, or, if @var{outname} is
@code{NULL}, to the standard output of the calling program.  Do @emph{not}
set this bit if you want to call @code{pex_read_output}
(described below).  After a call to @code{pex_run} with this bit set,
@var{pex_run} may no longer be called with the same @var{obj}.

@vindex PEX_SEARCH
@item PEX_SEARCH
Search for the program using the user's executable search path.

@vindex PEX_SUFFIX
@item PEX_SUFFIX
@var{outname} is a suffix.  See the description of @var{outname},
below.

@vindex PEX_STDERR_TO_STDOUT
@item PEX_STDERR_TO_STDOUT
Send the program's standard error to standard output, if possible.

@vindex PEX_BINARY_INPUT
@vindex PEX_BINARY_OUTPUT
@vindex PEX_BINARY_ERROR
@item PEX_BINARY_INPUT
@itemx PEX_BINARY_OUTPUT
@itemx PEX_BINARY_ERROR
The standard input (output or error) of the program should be read (written) in
binary mode rather than text mode.  These flags are ignored on systems
which do not distinguish binary mode and text mode, such as Unix.  For
proper behavior these flags should match appropriately---a call to
@code{pex_run} using @code{PEX_BINARY_OUTPUT} should be followed by a
call using @code{PEX_BINARY_INPUT}.

@vindex PEX_STDERR_TO_PIPE
@item PEX_STDERR_TO_PIPE
Send the program's standard error to a pipe, if possible.  This flag
cannot be specified together with @code{PEX_STDERR_TO_STDOUT}.  This
flag can be specified only on the last program in pipeline.

@end table

@var{executable} is the program to execute.  @var{argv} is the set of
arguments to pass to the program; normally @code{@var{argv}[0]} will
be a copy of @var{executable}.

@var{outname} is used to set the name of the file to use for standard
output.  There are two cases in which no output file will be used:

@enumerate
@item
if @code{PEX_LAST} is not set in @var{flags}, and @code{PEX_USE_PIPES}
was set in the call to @code{pex_init}, and the system supports pipes

@item
if @code{PEX_LAST} is set in @var{flags}, and @var{outname} is
@code{NULL}
@end enumerate

@noindent
Otherwise the code will use a file to hold standard
output.  If @code{PEX_LAST} is not set, this file is considered to be
a temporary file, and it will be removed when no longer needed, unless
@code{PEX_SAVE_TEMPS} was set in the call to @code{pex_init}.

There are two cases to consider when setting the name of the file to
hold standard output.

@enumerate
@item
@code{PEX_SUFFIX} is set in @var{flags}.  In this case
@var{outname} may not be @code{NULL}.  If the @var{tempbase} parameter
to @code{pex_init} was not @code{NULL}, then the output file name is
the concatenation of @var{tempbase} and @var{outname}.  If
@var{tempbase} was @code{NULL}, then the output file name is a random
file name ending in @var{outname}.

@item
@code{PEX_SUFFIX} was not set in @var{flags}.  In this
case, if @var{outname} is not @code{NULL}, it is used as the output
file name.  If @var{outname} is @code{NULL}, and @var{tempbase} was
not NULL, the output file name is randomly chosen using
@var{tempbase}.  Otherwise the output file name is chosen completely
at random.
@end enumerate

@var{errname} is the file name to use for standard error output.  If
it is @code{NULL}, standard error is the same as the caller's.
Otherwise, standard error is written to the named file.

On an error return, the code sets @code{*@var{err}} to an @code{errno}
value, or to 0 if there is no relevant @code{errno}.

@end deftypefn

@c pexecute.txh:145
@deftypefn Extension {const char *} pex_run_in_environment (struct pex_obj *@var{obj}, @
  int @var{flags}, const char *@var{executable}, char * const *@var{argv}, @
  char * const *@var{env}, int @var{env_size}, const char *@var{outname}, @
  const char *@var{errname}, int *@var{err})

Execute one program in a pipeline, permitting the environment for the
program to be specified.  Behaviour and parameters not listed below are
as for @code{pex_run}.

@var{env} is the environment for the child process, specified as an array of
character pointers.  Each element of the array should point to a string of the
form @code{VAR=VALUE}, with the exception of the last element that must be
@code{NULL}.

@end deftypefn

@c pexecute.txh:301
@deftypefn Extension int pexecute (const char *@var{program}, @
  char * const *@var{argv}, const char *@var{this_pname}, @
  const char *@var{temp_base}, char **@var{errmsg_fmt}, @
  char **@var{errmsg_arg}, int @var{flags})

This is the old interface to execute one or more programs.  It is
still supported for compatibility purposes, but is no longer
documented.

@end deftypefn

@c strsignal.c:541
@deftypefn Supplemental void psignal (int @var{signo}, char *@var{message})

Print @var{message} to the standard error, followed by a colon,
followed by the description of the signal specified by @var{signo},
followed by a newline.

@end deftypefn

@c putenv.c:21
@deftypefn Supplemental int putenv (const char *@var{string})

Uses @code{setenv} or @code{unsetenv} to put @var{string} into
the environment or remove it.  If @var{string} is of the form
@samp{name=value} the string is added; if no @samp{=} is present the
name is unset/removed.

@end deftypefn

@c pexecute.txh:312
@deftypefn Extension int pwait (int @var{pid}, int *@var{status}, int @var{flags})

Another part of the old execution interface.

@end deftypefn

@c random.c:39
@deftypefn Supplement {long int} random (void)
@deftypefnx Supplement void srandom (unsigned int @var{seed})
@deftypefnx Supplement void* initstate (unsigned int @var{seed}, @
  void *@var{arg_state}, unsigned long @var{n})
@deftypefnx Supplement void* setstate (void *@var{arg_state})

Random number functions.  @code{random} returns a random number in the
range 0 to @code{LONG_MAX}.  @code{srandom} initializes the random
number generator to some starting point determined by @var{seed}
(else, the values returned by @code{random} are always the same for each
run of the program).  @code{initstate} and @code{setstate} allow fine-grained
control over the state of the random number generator.

@end deftypefn

@c concat.c:160
@deftypefn Extension char* reconcat (char *@var{optr}, const char *@var{s1}, @
  @dots{}, @code{NULL})

Same as @code{concat}, except that if @var{optr} is not @code{NULL} it
is freed after the string is created.  This is intended to be useful
when you're extending an existing string or building up a string in a
loop:

@example
  str = reconcat (str, "pre-", str, NULL);
@end example

@end deftypefn

@c rename.c:6
@deftypefn Supplemental int rename (const char *@var{old}, const char *@var{new})

Renames a file from @var{old} to @var{new}.  If @var{new} already
exists, it is removed.

@end deftypefn

@c rindex.c:5
@deftypefn Supplemental char* rindex (const char *@var{s}, int @var{c})

Returns a pointer to the last occurrence of the character @var{c} in
the string @var{s}, or @code{NULL} if not found.  The use of @code{rindex} is
deprecated in new programs in favor of @code{strrchr}.

@end deftypefn

@c setenv.c:22
@deftypefn Supplemental int setenv (const char *@var{name}, @
  const char *@var{value}, int @var{overwrite})
@deftypefnx Supplemental void unsetenv (const char *@var{name})

@code{setenv} adds @var{name} to the environment with value
@var{value}.  If the name was already present in the environment,
the new value will be stored only if @var{overwrite} is nonzero.
The companion @code{unsetenv} function removes @var{name} from the
environment.  This implementation is not safe for multithreaded code.

@end deftypefn

@c setproctitle.c:31
@deftypefn Supplemental void setproctitle (const char *@var{fmt}, ...)

Set the title of a process to @var{fmt}. va args not supported for now,
but defined for compatibility with BSD. 

@end deftypefn

@c strsignal.c:348
@deftypefn Extension int signo_max (void)

Returns the maximum signal value for which a corresponding symbolic
name or message is available.  Note that in the case where we use the
@code{sys_siglist} supplied by the system, it is possible for there to
be more symbolic names than messages, or vice versa.  In fact, the
manual page for @code{psignal(3b)} explicitly warns that one should
check the size of the table (@code{NSIG}) before indexing it, since
new signal codes may be added to the system before they are added to
the table.  Thus @code{NSIG} might be smaller than value implied by
the largest signo value defined in @code{<signal.h>}.

We return the maximum value that can be used to obtain a meaningful
symbolic name or message.

@end deftypefn

@c sigsetmask.c:8
@deftypefn Supplemental int sigsetmask (int @var{set})

Sets the signal mask to the one provided in @var{set} and returns
the old mask (which, for libiberty's implementation, will always
be the value @code{1}).

@end deftypefn

@c simple-object.txh:96
@deftypefn Extension {const char *} simple_object_attributes_compare @
  (simple_object_attributes *@var{attrs1}, simple_object_attributes *@var{attrs2}, @
   int *@var{err})

Compare @var{attrs1} and @var{attrs2}.  If they could be linked
together without error, return @code{NULL}.  Otherwise, return an
error message and set @code{*@var{err}} to an errno value or @code{0}
if there is no relevant errno.

@end deftypefn

@c simple-object.txh:81
@deftypefn Extension {simple_object_attributes *} simple_object_fetch_attributes @
  (simple_object_read *@var{simple_object}, const char **@var{errmsg}, int *@var{err})

Fetch the attributes of @var{simple_object}.  The attributes are
internal information such as the format of the object file, or the
architecture it was compiled for.  This information will persist until
@code{simple_object_attributes_release} is called, even if
@var{simple_object} itself is released.

On error this returns @code{NULL}, sets @code{*@var{errmsg}} to an
error message, and sets @code{*@var{err}} to an errno value or
@code{0} if there is no relevant errno.

@end deftypefn

@c simple-object.txh:49
@deftypefn Extension {int} simple_object_find_section @
  (simple_object_read *@var{simple_object} off_t *@var{offset}, @
  off_t *@var{length}, const char **@var{errmsg}, int *@var{err})

Look for the section @var{name} in @var{simple_object}.  This returns
information for the first section with that name.

If found, return 1 and set @code{*@var{offset}} to the offset in the
file of the section contents and set @code{*@var{length}} to the
length of the section contents.  The value in @code{*@var{offset}}
will be relative to the offset passed to
@code{simple_object_open_read}.

If the section is not found, and no error occurs,
@code{simple_object_find_section} returns @code{0} and set
@code{*@var{errmsg}} to @code{NULL}.

If an error occurs, @code{simple_object_find_section} returns
@code{0}, sets @code{*@var{errmsg}} to an error message, and sets
@code{*@var{err}} to an errno value or @code{0} if there is no
relevant errno.

@end deftypefn

@c simple-object.txh:27
@deftypefn Extension {const char *} simple_object_find_sections @
  (simple_object_read *@var{simple_object}, int (*@var{pfn}) (void *@var{data}, @
  const char *@var{name}, off_t @var{offset}, off_t @var{length}), @
  void *@var{data}, int *@var{err})

This function calls @var{pfn} for each section in @var{simple_object}.
It calls @var{pfn} with the section name, the offset within the file
of the section contents, and the length of the section contents.  The
offset within the file is relative to the offset passed to
@code{simple_object_open_read}.  The @var{data} argument to this
function is passed along to @var{pfn}.

If @var{pfn} returns @code{0}, the loop over the sections stops and
@code{simple_object_find_sections} returns.  If @var{pfn} returns some
other value, the loop continues.

On success @code{simple_object_find_sections} returns.  On error it
returns an error string, and sets @code{*@var{err}} to an errno value
or @code{0} if there is no relevant errno.

@end deftypefn

@c simple-object.txh:2
@deftypefn Extension {simple_object_read *} simple_object_open_read @
  (int @var{descriptor}, off_t @var{offset}, const char *{segment_name}, @
  const char **@var{errmsg}, int *@var{err})

Opens an object file for reading.  Creates and returns an
@code{simple_object_read} pointer which may be passed to other
functions to extract data from the object file.

@var{descriptor} holds a file descriptor which permits reading.

@var{offset} is the offset into the file; this will be @code{0} in the
normal case, but may be a different value when reading an object file
in an archive file.

@var{segment_name} is only used with the Mach-O file format used on
Darwin aka Mac OS X.  It is required on that platform, and means to
only look at sections within the segment with that name.  The
parameter is ignored on other systems.

If an error occurs, this functions returns @code{NULL} and sets
@code{*@var{errmsg}} to an error string and sets @code{*@var{err}} to
an errno value or @code{0} if there is no relevant errno.

@end deftypefn

@c simple-object.txh:107
@deftypefn Extension {void} simple_object_release_attributes @
  (simple_object_attributes *@var{attrs})

Release all resources associated with @var{attrs}.

@end deftypefn

@c simple-object.txh:73
@deftypefn Extension {void} simple_object_release_read @
  (simple_object_read *@var{simple_object})

Release all resources associated with @var{simple_object}.  This does
not close the file descriptor.

@end deftypefn

@c simple-object.txh:184
@deftypefn Extension {void} simple_object_release_write @
  (simple_object_write *@var{simple_object})

Release all resources associated with @var{simple_object}.

@end deftypefn

@c simple-object.txh:114
@deftypefn Extension {simple_object_write *} simple_object_start_write @
  (simple_object_attributes @var{attrs}, const char *@var{segment_name}, @
  const char **@var{errmsg}, int *@var{err})

Start creating a new object file using the object file format
described in @var{attrs}.  You must fetch attribute information from
an existing object file before you can create a new one.  There is
currently no support for creating an object file de novo.

@var{segment_name} is only used with Mach-O as found on Darwin aka Mac
OS X.  The parameter is required on that target.  It means that all
sections are created within the named segment.  It is ignored for
other object file formats.

On error @code{simple_object_start_write} returns @code{NULL}, sets
@code{*@var{ERRMSG}} to an error message, and sets @code{*@var{err}}
to an errno value or @code{0} if there is no relevant errno.

@end deftypefn

@c simple-object.txh:153
@deftypefn Extension {const char *} simple_object_write_add_data @
  (simple_object_write *@var{simple_object}, @
  simple_object_write_section *@var{section}, const void *@var{buffer}, @
  size_t @var{size}, int @var{copy}, int *@var{err})

Add data @var{buffer}/@var{size} to @var{section} in
@var{simple_object}.  If @var{copy} is non-zero, the data will be
copied into memory if necessary.  If @var{copy} is zero, @var{buffer}
must persist until @code{simple_object_write_to_file} is called.  is
released.

On success this returns @code{NULL}.  On error this returns an error
message, and sets @code{*@var{err}} to an errno value or 0 if there is
no relevant erro.

@end deftypefn

@c simple-object.txh:134
@deftypefn Extension {simple_object_write_section *} simple_object_write_create_section @
  (simple_object_write *@var{simple_object}, const char *@var{name}, @
  unsigned int @var{align}, const char **@var{errmsg}, int *@var{err})

Add a section to @var{simple_object}.  @var{name} is the name of the
new section.  @var{align} is the required alignment expressed as the
number of required low-order 0 bits (e.g., 2 for alignment to a 32-bit
boundary).

The section is created as containing data, readable, not writable, not
executable, not loaded at runtime.  The section is not written to the
file until @code{simple_object_write_to_file} is called.

On error this returns @code{NULL}, sets @code{*@var{errmsg}} to an
error message, and sets @code{*@var{err}} to an errno value or
@code{0} if there is no relevant errno.

@end deftypefn

@c simple-object.txh:170
@deftypefn Extension {const char *} simple_object_write_to_file @
  (simple_object_write *@var{simple_object}, int @var{descriptor}, int *@var{err})

Write the complete object file to @var{descriptor}, an open file
descriptor.  This writes out all the data accumulated by calls to
@code{simple_object_write_create_section} and
@var{simple_object_write_add_data}.

This returns @code{NULL} on success.  On error this returns an error
message and sets @code{*@var{err}} to an errno value or @code{0} if
there is no relevant errno.

@end deftypefn

@c snprintf.c:28
@deftypefn Supplemental int snprintf (char *@var{buf}, size_t @var{n}, @
  const char *@var{format}, ...)

This function is similar to @code{sprintf}, but it will write to
@var{buf} at most @code{@var{n}-1} bytes of text, followed by a
terminating null byte, for a total of @var{n} bytes.
On error the return value is -1, otherwise it returns the number of
bytes, not including the terminating null byte, that would have been
written had @var{n} been sufficiently large, regardless of the actual
value of @var{n}.  Note some pre-C99 system libraries do not implement
this correctly so users cannot generally rely on the return value if
the system version of this function is used.

@end deftypefn

@c spaces.c:22
@deftypefn Extension char* spaces (int @var{count})

Returns a pointer to a memory region filled with the specified
number of spaces and null terminated.  The returned pointer is
valid until at least the next call.

@end deftypefn

@c splay-tree.c:305
@deftypefn Supplemental splay_tree splay_tree_new_with_typed_alloc @
(splay_tree_compare_fn @var{compare_fn}, @
splay_tree_delete_key_fn @var{delete_key_fn}, @
splay_tree_delete_value_fn @var{delete_value_fn}, @
splay_tree_allocate_fn @var{tree_allocate_fn}, @
splay_tree_allocate_fn @var{node_allocate_fn}, @
splay_tree_deallocate_fn @var{deallocate_fn}, @
void * @var{allocate_data})

This function creates a splay tree that uses two different allocators
@var{tree_allocate_fn} and @var{node_allocate_fn} to use for allocating the
tree itself and its nodes respectively.  This is useful when variables of
different types need to be allocated with different allocators.

The splay tree will use @var{compare_fn} to compare nodes,
@var{delete_key_fn} to deallocate keys, and @var{delete_value_fn} to
deallocate values.  Keys and values will be deallocated when the
tree is deleted using splay_tree_delete or when a node is removed
using splay_tree_remove.  splay_tree_insert will release the previously
inserted key and value using @var{delete_key_fn} and @var{delete_value_fn}
if the inserted key is already found in the tree.

@end deftypefn

@c stack-limit.c:28
@deftypefn Extension void stack_limit_increase (unsigned long @var{pref})

Attempt to increase stack size limit to @var{pref} bytes if possible.

@end deftypefn

@c stpcpy.c:23
@deftypefn Supplemental char* stpcpy (char *@var{dst}, const char *@var{src})

Copies the string @var{src} into @var{dst}.  Returns a pointer to
@var{dst} + strlen(@var{src}).

@end deftypefn

@c stpncpy.c:23
@deftypefn Supplemental char* stpncpy (char *@var{dst}, const char *@var{src}, @
  size_t @var{len})

Copies the string @var{src} into @var{dst}, copying exactly @var{len}
and padding with zeros if necessary.  If @var{len} < strlen(@var{src})
then return @var{dst} + @var{len}, otherwise returns @var{dst} +
strlen(@var{src}).

@end deftypefn

@c strcasecmp.c:15
@deftypefn Supplemental int strcasecmp (const char *@var{s1}, const char *@var{s2})

A case-insensitive @code{strcmp}.

@end deftypefn

@c strchr.c:6
@deftypefn Supplemental char* strchr (const char *@var{s}, int @var{c})

Returns a pointer to the first occurrence of the character @var{c} in
the string @var{s}, or @code{NULL} if not found.  If @var{c} is itself the
null character, the results are undefined.

@end deftypefn

@c strdup.c:3
@deftypefn Supplemental char* strdup (const char *@var{s})

Returns a pointer to a copy of @var{s} in memory obtained from
@code{malloc}, or @code{NULL} if insufficient memory was available.

@end deftypefn

@c strerror.c:675
@deftypefn Replacement {const char*} strerrno (int @var{errnum})

Given an error number returned from a system call (typically returned
in @code{errno}), returns a pointer to a string containing the
symbolic name of that error number, as found in @code{<errno.h>}.

If the supplied error number is within the valid range of indices for
symbolic names, but no name is available for the particular error
number, then returns the string @samp{Error @var{num}}, where @var{num}
is the error number.

If the supplied error number is not within the range of valid
indices, then returns @code{NULL}.

The contents of the location pointed to are only guaranteed to be
valid until the next call to @code{strerrno}.

@end deftypefn

@c strerror.c:608
@deftypefn Supplemental char* strerror (int @var{errnoval})

Maps an @code{errno} number to an error message string, the contents
of which are implementation defined.  On systems which have the
external variables @code{sys_nerr} and @code{sys_errlist}, these
strings will be the same as the ones used by @code{perror}.

If the supplied error number is within the valid range of indices for
the @code{sys_errlist}, but no message is available for the particular
error number, then returns the string @samp{Error @var{num}}, where
@var{num} is the error number.

If the supplied error number is not a valid index into
@code{sys_errlist}, returns @code{NULL}.

The returned string is only guaranteed to be valid only until the
next call to @code{strerror}.

@end deftypefn

@c strncasecmp.c:15
@deftypefn Supplemental int strncasecmp (const char *@var{s1}, const char *@var{s2})

A case-insensitive @code{strncmp}.

@end deftypefn

@c strncmp.c:6
@deftypefn Supplemental int strncmp (const char *@var{s1}, @
  const char *@var{s2}, size_t @var{n})

Compares the first @var{n} bytes of two strings, returning a value as
@code{strcmp}.

@end deftypefn

@c strndup.c:23
@deftypefn Extension char* strndup (const char *@var{s}, size_t @var{n})

Returns a pointer to a copy of @var{s} with at most @var{n} characters
in memory obtained from @code{malloc}, or @code{NULL} if insufficient
memory was available.  The result is always NUL terminated.

@end deftypefn

@c strnlen.c:6
@deftypefn Supplemental size_t strnlen (const char *@var{s}, size_t @var{maxlen})

Returns the length of @var{s}, as with @code{strlen}, but never looks
past the first @var{maxlen} characters in the string.  If there is no
'\0' character in the first @var{maxlen} characters, returns
@var{maxlen}.

@end deftypefn

@c strrchr.c:6
@deftypefn Supplemental char* strrchr (const char *@var{s}, int @var{c})

Returns a pointer to the last occurrence of the character @var{c} in
the string @var{s}, or @code{NULL} if not found.  If @var{c} is itself the
null character, the results are undefined.

@end deftypefn

@c strsignal.c:383
@deftypefn Supplemental {const char *} strsignal (int @var{signo})

Maps an signal number to an signal message string, the contents of
which are implementation defined.  On systems which have the external
variable @code{sys_siglist}, these strings will be the same as the
ones used by @code{psignal()}.

If the supplied signal number is within the valid range of indices for
the @code{sys_siglist}, but no message is available for the particular
signal number, then returns the string @samp{Signal @var{num}}, where
@var{num} is the signal number.

If the supplied signal number is not a valid index into
@code{sys_siglist}, returns @code{NULL}.

The returned string is only guaranteed to be valid only until the next
call to @code{strsignal}.

@end deftypefn

@c strsignal.c:448
@deftypefn Extension {const char*} strsigno (int @var{signo})

Given an signal number, returns a pointer to a string containing the
symbolic name of that signal number, as found in @code{<signal.h>}.

If the supplied signal number is within the valid range of indices for
symbolic names, but no name is available for the particular signal
number, then returns the string @samp{Signal @var{num}}, where
@var{num} is the signal number.

If the supplied signal number is not within the range of valid
indices, then returns @code{NULL}.

The contents of the location pointed to are only guaranteed to be
valid until the next call to @code{strsigno}.

@end deftypefn

@c strstr.c:6
@deftypefn Supplemental char* strstr (const char *@var{string}, const char *@var{sub})

This function searches for the substring @var{sub} in the string
@var{string}, not including the terminating null characters.  A pointer
to the first occurrence of @var{sub} is returned, or @code{NULL} if the
substring is absent.  If @var{sub} points to a string with zero
length, the function returns @var{string}.

@end deftypefn

@c strtod.c:27
@deftypefn Supplemental double strtod (const char *@var{string}, @
  char **@var{endptr})

This ISO C function converts the initial portion of @var{string} to a
@code{double}.  If @var{endptr} is not @code{NULL}, a pointer to the
character after the last character used in the conversion is stored in
the location referenced by @var{endptr}.  If no conversion is
performed, zero is returned and the value of @var{string} is stored in
the location referenced by @var{endptr}.

@end deftypefn

@c strerror.c:734
@deftypefn Extension int strtoerrno (const char *@var{name})

Given the symbolic name of a error number (e.g., @code{EACCES}), map it
to an errno value.  If no translation is found, returns 0.

@end deftypefn

@c strtol.c:33
@deftypefn Supplemental {long int} strtol (const char *@var{string}, @
  char **@var{endptr}, int @var{base})
@deftypefnx Supplemental {unsigned long int} strtoul (const char *@var{string}, @
  char **@var{endptr}, int @var{base})

The @code{strtol} function converts the string in @var{string} to a
long integer value according to the given @var{base}, which must be
between 2 and 36 inclusive, or be the special value 0.  If @var{base}
is 0, @code{strtol} will look for the prefixes @code{0} and @code{0x}
to indicate bases 8 and 16, respectively, else default to base 10.
When the base is 16 (either explicitly or implicitly), a prefix of
@code{0x} is allowed.  The handling of @var{endptr} is as that of
@code{strtod} above.  The @code{strtoul} function is the same, except
that the converted value is unsigned.

@end deftypefn

@c strtoll.c:33
@deftypefn Supplemental {long long int} strtoll (const char *@var{string}, @
  char **@var{endptr}, int @var{base})
@deftypefnx Supplemental {unsigned long long int} strtoul (@
  const char *@var{string}, char **@var{endptr}, int @var{base})

The @code{strtoll} function converts the string in @var{string} to a
long long integer value according to the given @var{base}, which must be
between 2 and 36 inclusive, or be the special value 0.  If @var{base}
is 0, @code{strtoll} will look for the prefixes @code{0} and @code{0x}
to indicate bases 8 and 16, respectively, else default to base 10.
When the base is 16 (either explicitly or implicitly), a prefix of
@code{0x} is allowed.  The handling of @var{endptr} is as that of
@code{strtod} above.  The @code{strtoull} function is the same, except
that the converted value is unsigned.

@end deftypefn

@c strsignal.c:502
@deftypefn Extension int strtosigno (const char *@var{name})

Given the symbolic name of a signal, map it to a signal number.  If no
translation is found, returns 0.

@end deftypefn

@c strverscmp.c:25
@deftypefun int strverscmp (const char *@var{s1}, const char *@var{s2})
The @code{strverscmp} function compares the string @var{s1} against
@var{s2}, considering them as holding indices/version numbers.  Return
value follows the same conventions as found in the @code{strverscmp}
function.  In fact, if @var{s1} and @var{s2} contain no digits,
@code{strverscmp} behaves like @code{strcmp}.

Basically, we compare strings normally (character by character), until
we find a digit in each string - then we enter a special comparison
mode, where each sequence of digits is taken as a whole.  If we reach the
end of these two parts without noticing a difference, we return to the
standard comparison mode.  There are two types of numeric parts:
"integral" and "fractional" (those  begin with a '0'). The types
of the numeric parts affect the way we sort them:

@itemize @bullet
@item
integral/integral: we compare values as you would expect.

@item
fractional/integral: the fractional part is less than the integral one.
Again, no surprise.

@item
fractional/fractional: the things become a bit more complex.
If the common prefix contains only leading zeroes, the longest part is less
than the other one; else the comparison behaves normally.
@end itemize

@smallexample
strverscmp ("no digit", "no digit")
    @result{} 0    // @r{same behavior as strcmp.}
strverscmp ("item#99", "item#100")
    @result{} <0   // @r{same prefix, but 99 < 100.}
strverscmp ("alpha1", "alpha001")
    @result{} >0   // @r{fractional part inferior to integral one.}
strverscmp ("part1_f012", "part1_f01")
    @result{} >0   // @r{two fractional parts.}
strverscmp ("foo.009", "foo.0")
    @result{} <0   // @r{idem, but with leading zeroes only.}
@end smallexample

This function is especially useful when dealing with filename sorting,
because filenames frequently hold indices/version numbers.
@end deftypefun

@c timeval-utils.c:43
@deftypefn Extension void timeval_add (struct timeval *@var{a}, @
  struct timeval *@var{b}, struct timeval *@var{result})

Adds @var{a} to @var{b} and stores the result in @var{result}.

@end deftypefn

@c timeval-utils.c:67
@deftypefn Extension void timeval_sub (struct timeval *@var{a}, @
  struct timeval *@var{b}, struct timeval *@var{result})

Subtracts @var{b} from @var{a} and stores the result in @var{result}.

@end deftypefn

@c tmpnam.c:3
@deftypefn Supplemental char* tmpnam (char *@var{s})

This function attempts to create a name for a temporary file, which
will be a valid file name yet not exist when @code{tmpnam} checks for
it.  @var{s} must point to a buffer of at least @code{L_tmpnam} bytes,
or be @code{NULL}.  Use of this function creates a security risk, and it must
not be used in new projects.  Use @code{mkstemp} instead.

@end deftypefn

@c unlink-if-ordinary.c:27
@deftypefn Supplemental int unlink_if_ordinary (const char*)

Unlinks the named file, unless it is special (e.g. a device file).
Returns 0 when the file was unlinked, a negative value (and errno set) when
there was an error deleting the file, and a positive value if no attempt
was made to unlink the file because it is special.

@end deftypefn

@c fopen_unlocked.c:31
@deftypefn Extension void unlock_std_streams (void)

If the OS supports it, ensure that the standard I/O streams,
@code{stdin}, @code{stdout} and @code{stderr} are setup to avoid any
multi-threaded locking.  Otherwise do nothing.

@end deftypefn

@c fopen_unlocked.c:23
@deftypefn Extension void unlock_stream (FILE * @var{stream})

If the OS supports it, ensure that the supplied stream is setup to
avoid any multi-threaded locking.  Otherwise leave the @code{FILE}
pointer unchanged.  If the @var{stream} is @code{NULL} do nothing.

@end deftypefn

@c vasprintf.c:47
@deftypefn Extension int vasprintf (char **@var{resptr}, @
  const char *@var{format}, va_list @var{args})

Like @code{vsprintf}, but instead of passing a pointer to a buffer,
you pass a pointer to a pointer.  This function will compute the size
of the buffer needed, allocate memory with @code{malloc}, and store a
pointer to the allocated memory in @code{*@var{resptr}}.  The value
returned is the same as @code{vsprintf} would return.  If memory could
not be allocated, minus one is returned and @code{NULL} is stored in
@code{*@var{resptr}}.

@end deftypefn

@c vfork.c:6
@deftypefn Supplemental int vfork (void)

Emulates @code{vfork} by calling @code{fork} and returning its value.

@end deftypefn

@c vprintf.c:3
@deftypefn Supplemental int vprintf (const char *@var{format}, va_list @var{ap})
@deftypefnx Supplemental int vfprintf (FILE *@var{stream}, @
  const char *@var{format}, va_list @var{ap})
@deftypefnx Supplemental int vsprintf (char *@var{str}, @
  const char *@var{format}, va_list @var{ap})

These functions are the same as @code{printf}, @code{fprintf}, and
@code{sprintf}, respectively, except that they are called with a
@code{va_list} instead of a variable number of arguments.  Note that
they do not call @code{va_end}; this is the application's
responsibility.  In @libib{} they are implemented in terms of the
nonstandard but common function @code{_doprnt}.

@end deftypefn

@c vsnprintf.c:28
@deftypefn Supplemental int vsnprintf (char *@var{buf}, size_t @var{n}, @
  const char *@var{format}, va_list @var{ap})

This function is similar to @code{vsprintf}, but it will write to
@var{buf} at most @code{@var{n}-1} bytes of text, followed by a
terminating null byte, for a total of @var{n} bytes.  On error the
return value is -1, otherwise it returns the number of characters that
would have been printed had @var{n} been sufficiently large,
regardless of the actual value of @var{n}.  Note some pre-C99 system
libraries do not implement this correctly so users cannot generally
rely on the return value if the system version of this function is
used.

@end deftypefn

@c waitpid.c:3
@deftypefn Supplemental int waitpid (int @var{pid}, int *@var{status}, int)

This is a wrapper around the @code{wait} function.  Any ``special''
values of @var{pid} depend on your implementation of @code{wait}, as
does the return value.  The third argument is unused in @libib{}.

@end deftypefn

@c argv.c:289
@deftypefn Extension int writeargv (char * const *@var{argv}, FILE *@var{file})

Write each member of ARGV, handling all necessary quoting, to the file
named by FILE, separated by whitespace.  Return 0 on success, non-zero
if an error occurred while writing to FILE.

@end deftypefn

@c xasprintf.c:31
@deftypefn Replacement char* xasprintf (const char *@var{format}, ...)

Print to allocated string without fail.  If @code{xasprintf} fails,
this will print a message to @code{stderr} (using the name set by
@code{xmalloc_set_program_name}, if any) and then call @code{xexit}.

@end deftypefn

@c xatexit.c:11
@deftypefun int xatexit (void (*@var{fn}) (void))

Behaves as the standard @code{atexit} function, but with no limit on
the number of registered functions.  Returns 0 on success, or @minus{}1 on
failure.  If you use @code{xatexit} to register functions, you must use
@code{xexit} to terminate your program.

@end deftypefun

@c xmalloc.c:38
@deftypefn Replacement void* xcalloc (size_t @var{nelem}, size_t @var{elsize})

Allocate memory without fail, and set it to zero.  This routine functions
like @code{calloc}, but will behave the same as @code{xmalloc} if memory
cannot be found.

@end deftypefn

@c xexit.c:22
@deftypefn Replacement void xexit (int @var{code})

Terminates the program.  If any functions have been registered with
the @code{xatexit} replacement function, they will be called first.
Termination is handled via the system's normal @code{exit} call.

@end deftypefn

@c xmalloc.c:22
@deftypefn Replacement void* xmalloc (size_t)

Allocate memory without fail.  If @code{malloc} fails, this will print
a message to @code{stderr} (using the name set by
@code{xmalloc_set_program_name},
if any) and then call @code{xexit}.  Note that it is therefore safe for
a program to contain @code{#define malloc xmalloc} in its source.

@end deftypefn

@c xmalloc.c:53
@deftypefn Replacement void xmalloc_failed (size_t)

This function is not meant to be called by client code, and is listed
here for completeness only.  If any of the allocation routines fail, this
function will be called to print an error message and terminate execution.

@end deftypefn

@c xmalloc.c:46
@deftypefn Replacement void xmalloc_set_program_name (const char *@var{name})

You can use this to set the name of the program used by
@code{xmalloc_failed} when printing a failure message.

@end deftypefn

@c xmemdup.c:7
@deftypefn Replacement void* xmemdup (void *@var{input}, @
  size_t @var{copy_size}, size_t @var{alloc_size})

Duplicates a region of memory without fail.  First, @var{alloc_size} bytes
are allocated, then @var{copy_size} bytes from @var{input} are copied into
it, and the new memory is returned.  If fewer bytes are copied than were
allocated, the remaining memory is zeroed.

@end deftypefn

@c xmalloc.c:32
@deftypefn Replacement void* xrealloc (void *@var{ptr}, size_t @var{size})
Reallocate memory without fail.  This routine functions like @code{realloc},
but will behave the same as @code{xmalloc} if memory cannot be found.

@end deftypefn

@c xstrdup.c:7
@deftypefn Replacement char* xstrdup (const char *@var{s})

Duplicates a character string without fail, using @code{xmalloc} to
obtain memory.

@end deftypefn

@c xstrerror.c:7
@deftypefn Replacement char* xstrerror (int @var{errnum})

Behaves exactly like the standard @code{strerror} function, but
will never return a @code{NULL} pointer.

@end deftypefn

@c xstrndup.c:23
@deftypefn Replacement char* xstrndup (const char *@var{s}, size_t @var{n})

Returns a pointer to a copy of @var{s} with at most @var{n} characters
without fail, using @code{xmalloc} to obtain memory.  The result is
always NUL terminated.

@end deftypefn

@c xvasprintf.c:38
@deftypefn Replacement char* xvasprintf (const char *@var{format}, va_list @var{args})

Print to allocated string without fail.  If @code{xvasprintf} fails,
this will print a message to @code{stderr} (using the name set by
@code{xmalloc_set_program_name}, if any) and then call @code{xexit}.

@end deftypefn