This file is indexed.

/usr/include/ini_config.h is in libini-config-dev 0.1.3-2.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

   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
/*
    INI LIBRARY

    Header file for reading configuration from INI file
    and storing as a collection.

    Copyright (C) Dmitri Pal <dpal@redhat.com> 2009

    INI Library is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    INI Library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

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

#ifndef INI_CONFIG_H
#define INI_CONFIG_H

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <limits.h>
#include <stdio.h>
#include "collection.h"

/** @mainpage The INI configuration interface
 *
 * The goal of the this interface is to allow applications
 * to read configuration from the INI file.
 *
 * So why yet another library to read data from INI file?
 * As we started the SSSD project we looked around for a
 * open source library that would meet the following
 * requirements:
 * - Is written in C (not C++)
 * - Is lightweight.
 * - Has an live community.
 * - Supported on multiple platforms .
 * - Can evolve as we build SSSD solution.
 * - Can deal with different types of values including arrays.
 * - Can deal with sections that are related to each other
 *   and can form a hierarchy of sections.
 * - Has a compatible license we can use.
 *
 * We have seen several solutions but none was able to address our
 * requirements fully. As a result we started developing our own
 * INI parsing library. It is currently stable, however there is
 * a list of the enhancements that we eventually plan to implement.
 * One of the most interesting future features is the grammar
 * validation utility. It is targeted at helping to diagnose
 * a misconfiguration.
 *
 * Currently INI parser allows reading and merging INI files
 * and getting a resulting configuration in one object.
 *
 * One of the main differences of this interface is that
 * the library is created with the idea of reading the configuration
 * data not managing it. Thus currently you will not find
 * any function that alters the configuration data read from the files.
 * There is a set of proposed enhancements to be able to manipulate
 * the configuration data and save it back but there have been no real
 * driver for it. This API is focused on letting applications read data
 * from a file (or files) and interpret it, not to generate configuration
 * files. There are all sorts of different tools that already do that.
 *
 * The INI configuration interface uses COLLECTION (see libcollection
 * interface) to store data internally.
 *
 * Concepts:
 * - The INI file consists of the key value pairs.
 * - The keys and values are separated by the equal sign.
 *   The spaces around equal sign are trimmed. Everything before the equal
 *   sign is the key, everything after is the value.
 * - Comments are the lines that start with ";" or "#" in the first
 *   position of the line.
 * - Library currently does not support multi-line values.
 * - The keys and values are read and stored in the internal
 *   collection.
 * - More than one file can constitute the configuration for the application.
 *   For example there can be a generic file in the /etc that
 *   contains configuration for all the applications of this class running
 *   on the box and then there might be a special file
 *   with parameters specific for the application in the
 *   /etc/whatever.d directory. Interface allows reading
 *   both files in one call. The specific configuration for application
 *   will overwrite the generic one.
 * - If there is no section in the file or there are key value pairs
 *   declared before the first section those pairs will be placed into
 *   the default section.
 * - The values are treated as strings. Spaces are trimmed at the beginning
 *   and the end of the value. The value ends at the end of the line.
 *   If values is too long an error will be returned.
 * - Parsing of the values happens when the caller tries to interpret
 *   the value. The caller can use different functions to do this.
 *   The value can be treated as numeric, logical, string, binary,
 *   array of strings or array of numbers. In case of arrays the functions
 *   accept separators that will be used to slice the value into the array
 *   elements.
 * - If there is any error parsing the section and key values it can be
 *   intercepted by the caller. There are different modes that the library
 *   supports regarding error handling. See details in the description
 *   of the individual functions.
 */

/**
 * @defgroup ini_config INI configuration interface
 * @{
 */

/**
 * @defgroup constants Constants
 * @{
 */

/**
 * @brief Name of the default section.
 *
 * This is the name of the implied section where orphan key-value
 * pairs will be put.
 */
#define INI_DEFAULT_SECTION "default"

/**
 * @defgroup classes Collection classes
 *
 * INI uses COLLECTION library to store data.
 * It creates different objects with implied internal structure.
 * To be able to validate the objects
 * it is a good practice to define a class for each type of
 * the object.
 *
 * This section contains constants that define
 * internal collection classes used by INI interface.
 * They are exposed so that if you use collection for
 * other purposes you can make sure that the object classes
 * do not overlap. It is a good practice to avoid
 * them overlapping. Non-overlapping class space
 * would make internal type checking more effective
 * so that if an object of the wrong class is passed to
 * some interface the interface would be able to
 * check and detect an error.
 *
 * @{
 */
/** @brief Base for the class definitions. */
#define COL_CLASS_INI_BASE        20000
/**
 * @brief Class for the configuration object.
 *
 * The configuration object consists of the collection
 * of collections where each sub collection is a section.
 * Application however should not assume that this always
 * be the case. Use only INI interface functions
 * get data from the configuration object.
 * Do not use the raw collection interface to get
 * data.
 */
#define COL_CLASS_INI_CONFIG      COL_CLASS_INI_BASE + 0
/**
 * @brief A one level collection of key value pairs
 * where values are always strings.
 */
#define COL_CLASS_INI_SECTION     COL_CLASS_INI_BASE + 1
/**
 * @brief A one level collection of parse errors.
 *
 * Collection stores \ref parse_error structures.
 */
#define COL_CLASS_INI_PERROR      COL_CLASS_INI_BASE + 2
/**
 * @brief Collection of error collections.
 *
 * When multiple files are read during one call
 * each file has its own set of parsing errors
 * and warnings. This is the collection
 * of such sets.
 */
#define COL_CLASS_INI_PESET       COL_CLASS_INI_BASE + 3

/**
 * @brief Collection of metadata.
 *
 * Collection that stores metadata.
 */
#define COL_CLASS_INI_META        COL_CLASS_INI_BASE + 4
/**
 * @}
 */

/**
 * @defgroup errorlevel Error tolerance constants
 *
 * Constants in this section define what to do if
 * error or warning encountered while parsing the INI file.
 *
 * @{
 */
/** @brief Fail if any problem is detected. */
#define INI_STOP_ON_ANY     0
/** @brief Best effort - do not fail. */
#define INI_STOP_ON_NONE    1
/** @brief Fail on errors only. */
#define INI_STOP_ON_ERROR   2

/**
 * @}
 */

/**
 * @defgroup parseerr Parsing errors and warnings
 *
 * @{
 */
/** @brief Line is too long (Error). */
#define ERR_LONGDATA        1
/** @brief No closing bracket in section definition (Error). */
#define ERR_NOCLOSESEC      2
/** @brief Section name is missing (Error). */
#define ERR_NOSECTION       3
/** @brief Section name too long (Error). */
#define ERR_SECTIONLONG     4
/** @brief No equal sign (Warning). */
#define ERR_NOEQUAL         5
/** @brief No key before equal sign (Warning). */
#define ERR_NOKEY           6
/** @brief Key is too long (Warning). */
#define ERR_LONGKEY         7

/** @brief Size of the error array. */
#define ERR_MAXPARSE        ERR_LONGKEY

/**
 * @}
 */

/**
 * @defgroup gramerr Grammar errors and warnings
 *
 * Placeholder for now. Reserved for future use.
 *
 * @{
 */
#define ERR_MAXGRAMMAR      0
/**
 * @}
 */

/**
 * @defgroup valerr Validation errors and warnings
 *
 * Placeholder for now. Reserved for future use.
 *
 * @{
 */
#define ERR_MAXVALID        0


/**
 * @}
 */

/**
 * @defgroup accesscheck Access control check flags
 *
 * @{
 */

/**
 * @brief Validate access mode
 *
 * If this flag is specified the mode parameter
 * will be matched against the permissions set on the file
 * using the provided mask.
 */
#define INI_ACCESS_CHECK_MODE   0x00000001

/**
 * @brief Validate uid
 *
 * Provided uid will be checked against uid
 * of the file.
 */
#define INI_ACCESS_CHECK_UID   0x00000002

/**
 * @brief Validate gid
 *
 * Provided gid will be checked against gid
 * of the file.
 */
#define INI_ACCESS_CHECK_GID   0x00000004

/**
 * @}
 */


/**
 * @}
 */

/**
 * @defgroup structures Structures
 * @{
 */

/** @brief Structure that holds error number and
 *  line number for the encountered error.
 */
struct parse_error {
    unsigned line;
    int error;
};


/**
 * @}
 */

/**
 * @defgroup metadata Meta data
 *
 * Metadata is a collection of a similar structure as any ini file.
 * The difference is that there are some predefined sections
 * and attributes inside these sections.
 * Using meta flags one can specify what section he is interested
 * in including into the meta data. If a flag for a corresponding
 * meta data section is specified the data for this section will
 * be included into the meta data collection. The caller can then
 * use meta data collection to get items from it and then get
 * a specific value using a corresponding conversion function.
 *
 * Think about the meta data as an INI file that looks like this:
 *
 * <b>
 * [ACCESS]
 * - uid = <i>\<ini file owner uid\></i>
 * - gid = <i>\<ini file group gid\></i>
 * - perm = <i>\<permissions word\></i>
 * - name = <i>\<file name\></i>
 * - created = <i>\<time stamp\></i>
 * - modified = <i>\<time stamp\></i>
 * - ...
 *
 * [ERROR]
 * - read_error = <i><file open error if any\></i>
 * - ...
 *
 * [<i>TBD</i>]
 * - ...
 *
 * </b>
 *
 * The names of the keys and sections provide an example
 * of how the meta data is structured. Look information
 * about specific sections and available keys in this manual
 * to get the exact set of currently supported sections
 * and keys.
 *
 * @{
 */

/**
 * @brief Collect only meta data.
 *
 * Special flag that indicates that only meta data
 * needs to be collected. No parsing should be performed.
 *
 */
#define INI_META_ACTION_NOPARSE     0x10000000

/**
 * @defgroup metasection Meta data section names
 *
 * @{
 */

/**
 * @brief Meta data section that stores file access information
 * and ownership.
 */
#define INI_META_SEC_ACCESS     "ACCESS"

/**
 * @brief Meta data "access" section flag to include access section
 * into the output.
 */
#define INI_META_SEC_ACCESS_FLAG     0x00000001


/**
 * @defgroup metaaccesskeys Key names available in the "ACCESS" section
 *
 * @{
 *
 */

/**
 * @brief The value for this key will store user ID of the INI file owner.
 *
 */
#define INI_META_KEY_UID     "uid"

/**
 * @brief The value for this key will store group ID of the INI file owner.
 *
 */
#define INI_META_KEY_GID     "gid"

/**
 * @brief The value for this key will store INI file access permissions.
 *
 */
#define INI_META_KEY_PERM     "perm"

/**
 * @brief The value for this key will store INI file device ID.
 *
 */
#define INI_META_KEY_DEV     "dev"

/**
 * @brief The value for this key will store INI file inode number.
 *
 */
#define INI_META_KEY_INODE     "inode"

/**
 * @brief The value for this key will store INI file modification time stamp.
 *
 */
#define INI_META_KEY_MODIFIED     "modified"

/**
 * @brief The value for this key will store INI file full name.
 *
 */
#define INI_META_KEY_NAME     "name"

/**
 * @}
 */

/**
 * @brief Meta data section that stores error related information.
 */
#define INI_META_SEC_ERROR     "ERROR"

/**
 * @brief Meta data "error" section flag to include access section
 * into the output.
 */
#define INI_META_SEC_ERROR_FLAG     0x00000002


/**
 * @defgroup metaerrorkeys Key names available in the "ERROR" section
 *
 * @{
 *
 */

/**
 * @brief The value for this key will store read error when file was opened.
 *
 * If file was opened by caller first but this section was requested
 * the value will be zero.
 */
#define INI_META_KEY_READ_ERROR     "read_error"


/**
 * @}
 */

/**
 * @}
 */

/**
 * @}
 */


/**
 * @defgroup functions Functions
 * @{
 */

/** @brief Function to return a parsing error as a string.
 *
 * @param[in] parsing_error    Error code for the parsing error.
 *
 * @return Error string.
 */
const char *parsing_error_str(int parsing_error);


/**
 * @brief Read configuration information from a file.
 *
 * @param[in]  application         Name of the application,
 *                                 will be used as name of
 *                                 the collection.
 * @param[in]  config_filename     Name of the config file,
 *                                 if NULL the configuration
 *                                 collection will be empty.
 * @param[out] ini_config          If *ini_config is NULL
 *                                 a new ini object will be
 *                                 allocated, otherwise
 *                                 the one that is pointed to
 *                                 will be updated.
 * @param[in]  error_level         Break for errors, warnings
 *                                 or best effort (don't break).
 * @param[out] error_list          List of errors for the file
 *                                 detected during parsing.
 *
 * @return 0 - Success.
 * @return EINVAL - Invalid parameter.
 * @return EMOMEM - No memory.
 * @return Any error returned by fopen().
 *
 */
int config_from_file(const char *application,
                     const char *config_filename,
                     struct collection_item **ini_config,
                     int error_level,
                     struct collection_item **error_list);

/**
 * @brief Read configuration information from a file descriptor.
 *
 * @param[in]  application         Name of the application,
 *                                 will be used as name of
 *                                 the collection.
 * @param[in]  fd                  Previously opened file
 *                                 descriptor for the config file.
 * @param[in]  config_source       Name of the file being parsed,
 *                                 for use when printing the error
 *                                 list.
 * @param[out] ini_config          If *ini_config is NULL
 *                                 a new ini object will be
 *                                 allocated, otherwise
 *                                 the one that is pointed to
 *                                 will be updated.
 * @param[in]  error_level         Break for errors, warnings
 *                                 or best effort (don't break).
 * @param[out] error_list          List of errors for the file
 *                                 detected during parsing.
 *
 * @return 0 - Success.
 * @return EMOMEM - No memory.
 * @return EINVAL - Invalid parameter.
 *
 */
int config_from_fd(const char *application,
                   int fd,
                   const char *config_source,
                   struct collection_item **ini_config,
                   int error_level,
                   struct collection_item **error_list);



/**
 * @brief Read configuration information from a file with
 * additional meta data.
 *
 * Meta data consists of addition information about
 * the file for example when it was created
 * or who is the owner. For the detailed description
 * of the meta data content and structure see
 * \ref metadata "meta data" section.
 *
 * If the metadata argument is not NULL
 * the calling function MUST always free meta data since it can
 * be allocated even if the function returned error.
 *
 * @param[in]  application         Name of the application,
 *                                 will be used as name of
 *                                 the collection.
 * @param[in]  config_filename     Name of the config file,
 *                                 if NULL the configuration
 *                                 collection will be empty.
 * @param[out] ini_config          If *ini_config is NULL
 *                                 a new ini object will be
 *                                 allocated, otherwise
 *                                 the one that is pointed to
 *                                 will be updated.
 * @param[in]  error_level         Break for errors, warnings
 *                                 or best effort (don't break).
 * @param[out] error_list          List of errors for the file
 *                                 detected during parsing.
 * @param[in]  metaflags           A bit mask of flags that define
 *                                 what kind of metadata should
 *                                 be collected.
 * @param[out] metadata            Collection of metadata
 *                                 values. See \ref metadata "meta data"
 *                                 section for more details.
 *                                 Can be NULL.
 *
 * @return 0 - Success.
 * @return EINVAL - Invalid parameter.
 * @return EMOMEM - No memory.
 * @return Any error returned by fopen().
 *
 *
 */
int config_from_file_with_metadata(
                     const char *application,
                     const char *config_filename,
                     struct collection_item **ini_config,
                     int error_level,
                     struct collection_item **error_list,
                     uint32_t metaflags,
                     struct collection_item **metadata);


/**
 * @brief Read configuration information from a file descriptor
 * with additional meta data.
 *
 * Meta data consists of addition information about
 * the file for example when it was created
 * or who is the owner. For the detailed description
 * of the meta data content and structure see
 * \ref metadata "meta data" section.
 *
 * If the metadata argument is not NULL
 * the calling function MUST always free meta data since it can
 * be allocated even if the function returned error.
 *
 * @param[in]  application         Name of the application,
 *                                 will be used as name of
 *                                 the collection.
 * @param[in]  fd                  Previously opened file
 *                                 descriptor for the config file.
 * @param[in]  config_source       Name of the file being parsed,
 *                                 for use when printing the error
 *                                 list.
 * @param[out] ini_config          If *ini_config is NULL
 *                                 a new ini object will be
 *                                 allocated, otherwise
 *                                 the one that is pointed to
 *                                 will be updated.
 * @param[in]  error_level         Break for errors, warnings
 *                                 or best effort (don't break).
 * @param[out] error_list          List of errors for the file
 *                                 detected during parsing.
 * @param[in]  metaflags           A bit mask of flags that define
 *                                 what kind of metadata should
 *                                 be collected.
 * @param[out] metadata            Collection of metadata
 *                                 values. See \ref metadata "meta data"
 *                                 section for more details.
 *                                 Can be NULL.
 *
 * @return 0 - Success.
 * @return EINVAL - Invalid parameter.
 * @return EMOMEM - No memory.
 *
 */
int config_from_fd_with_metadata(
                   const char *application,
                   int fd,
                   const char *config_source,
                   struct collection_item **ini_config,
                   int error_level,
                   struct collection_item **error_list,
                   uint32_t metaflags,
                   struct collection_item **metadata);


/**
 * @brief Read default configuration file and then
 * overwrite it with a specific one from the directory.
 *
 * @param[in]  application         Name of the application,
 *                                 will be used as name of
 *                                 the collection.
 * @param[in]  config_file         Name of the configuration file,
 *                                 with default settings for all
 *                                 appplications.
 * @param[in]  config_dir          Name of the directory where
 *                                 the configuration files for
 *                                 different applications reside.
 *                                 Function will look for file
 *                                 with the name constructed by
 *                                 appending ".ini" to the end of
 *                                 the "application" argument.
 * @param[out] ini_config          A new configuration object.
 * @param[in]  error_level         Break for errors, warnings
 *                                 or best effort (don't break).
 * @param[out] error_set           Collection of error lists.
 *                                 One list per file.
 *
 * @return 0 - Success.
 * @return EINVAL - Invalid parameter.
 * @return EMOMEM - No memory.
 * @return Any error returned by fopen().
 */
int config_for_app(const char *application,
                   const char *config_file,
                   const char *config_dir,
                   struct collection_item **ini_config,
                   int error_level,
                   struct collection_item **error_set);

/**
 * @brief Read default configuration file and then
 * overwrite it with a specific one from the directory.
 *
 * If requested collect meta data for both.
 *
 * If the metadata argument is not NULL
 * the calling function MUST always free meta data since it can
 * be allocated even if the function returned error.
 *
 * @param[in]  application         Name of the application,
 *                                 will be used as name of
 *                                 the collection.
 * @param[in]  config_file         Name of the configuration file,
 *                                 with default settings for all
 *                                 appplications.
 * @param[in]  config_dir          Name of the directory where
 *                                 the configuration files for
 *                                 different applications reside.
 *                                 Function will look for file
 *                                 with the name constructed by
 *                                 appending ".ini" to the end of
 *                                 the "application" argument.
 * @param[out] ini_config          A new configuration object.
 * @param[in]  error_level         Break for errors, warnings
 *                                 or best effort (don't break).
 * @param[out] error_set           Collection of error lists.
 *                                 One list per file.
 * @param[in]  metaflags           A bit mask of flags that define
 *                                 what kind of metadata should
 *                                 be collected.
 * @param[out] meta_default        Collection of metadata
 *                                 values for the default common
 *                                 config file for all applications.
 *                                 See \ref metadata "meta data"
 *                                 section for more details.
 *                                 Can be NULL.
 * @param[out] meta_appini         Collection of metadata
 *                                 values for the application
 *                                 specific config file.
 *                                 See \ref metadata "meta data"
 *                                 section for more details.
 *                                 Can be NULL.
 *
 * @return 0 - Success.
 * @return EINVAL - Invalid parameter.
 * @return EMOMEM - No memory.
 * @return Any error returned by fopen().
 */
int config_for_app_with_metadata(
                   const char *application,
                   const char *config_file,
                   const char *config_dir,
                   struct collection_item **ini_config,
                   int error_level,
                   struct collection_item **error_set,
                   uint32_t metaflags,
                   struct collection_item **meta_default,
                   struct collection_item **meta_appini);


/**
 *
 * @brief Function to check ownership and permissions
 *
 * The function allow caller to make decision
 * if the configuration file is from a trusted source
 * or not.
 *
 * The flags control how to perform check.
 * See \ref accesscheck "Access control check flags"
 * section for more information.
 *
 * @param[in] metadata     Meta data object.
 *                         Can't be NULL.
 * @param[in] flags        How and what to check.
 *                         Must be nonzero.
 * @param[in] uid          UID to check.
 * @param[in] gid          GID to check.
 * @param[in] mode         Mode to check.
 *                         Only permission bits
 *                         are used.
 * @param[in] mask         Which mode bits to check.
 *                         If 0 all permision bits
 *                         are checked.
 *
 * @return 0 - Success.
 * @return EINVAL  - Invalid parameter.
 * @return EACCESS - File properties do not match provided
 *                   access parameters.
 */
int config_access_check(struct collection_item *metadata,
                        uint32_t flags,
                        uid_t uid,
                        gid_t gid,
                        mode_t mode,
                        mode_t mask);


/**
 * @brief Function compares two meta data objects
 *
 * Function compares two meta data objects
 * to determine whether the configuration
 * has changed since last time the meta data
 * was collected.
 * The function checks three things about the
 * file:
 * - time stamp
 * - device ID
 * - i-node
 * If any of those changes function will indicate
 * that configuration changed.
 *
 * @param[in] metadata        Recent meta data object.
 * @param[in] saved_metadata  Previously saved meta
 *                            data object.
 * @param[out] changed        Will be set to a nonzero value
 *                            if the configuration has changed.
 *
 * @return 0 - No internal error
 * @return EINVAL - Invalid argument
 * @return ENOENT - Expected value is missing
 * @return ENOMEM - No memory
 */
int config_changed(struct collection_item *metadata,
                   struct collection_item *saved_metadata,
                   int *changed);

/**
 * @brief Function to free configuration object.
 *
 * @param[in] ini_config       Configuration object.
 *
 */
void free_ini_config(struct collection_item *ini_config);

/**
 * @brief Function to free configuration errors.
 *
 * @param[in] error_set       Configuration error set object.
 *
 */
void free_ini_config_errors(struct collection_item *error_set);


/**
 * @brief Function to free metadata.
 *
 * @param[in] metadata       Configuration meta data object.
 *
 */
void free_ini_config_metadata(struct collection_item *metadata);


/**
 * @brief Print errors and warnings that were detected while parsing one file.
 *
 * @param[in] file           File descriptor.
 * @param[in] error_list     List of the parsing errors.
 *
 */
void print_file_parsing_errors(FILE *file,
                               struct collection_item *error_list);


/**
 * @brief Print errors and warnings that were detected
 * parsing configuration as a whole.
 *
 * Use this function to print results of the config_for_app() call.
 *
 * @param[in] file           File descriptor.
 * @param[in] error_set      List of lists of the parsing errors.
 *
 */
void print_config_parsing_errors(FILE *file,
                                 struct collection_item *error_set);

/**
 * @brief Get list of sections.
 *
 * Get list of sections from the configuration object
 * as an array of strings.
 * Function allocates memory for the array of the sections.
 * Use \ref free_section_list() to free allocated memory.
 *
 * @param[in]  ini_config       Configuration object.
 * @param[out] size             If not NULL parameter will
 *                              receive number of sections
 *                              in the configuration.
 * @param[out] error            If not NULL parameter will
 *                              receive the error code.
 *                              0 - Success.
 *                              EINVAL - Invalid parameter.
 *                              ENOMEM - No memory.
 *
 * @return Array of strings.
 */
char **get_section_list(struct collection_item *ini_config,
                        int *size,
                        int *error);

/**
 * @brief Free list of sections.
 *
 * The section array created by \ref get_section_list()
 * should be freed using this function.
 *
 * @param[in] section_list       Array of strings returned by
 *                               \ref get_section_list() function.
 */
void free_section_list(char **section_list);

/**
 * @brief Get list of attributes.
 *
 * Get list of attributes in a section as an array of strings.
 * Function allocates memory for the array of attributes.
 * Use \ref free_attribute_list() to free allocated memory.
 *
 * @param[in]  ini_config       Configuration object.
 * @param[in]  section          Section name.
 * @param[out] size             If not NULL parameter will
 *                              receive number of attributes
 *                              in the section.
 * @param[out] error            If not NULL parameter will
 *                              receive the error code.
 *                              0 - Success.
 *                              EINVAL - Invalid parameter.
 *                              ENOMEM - No memory.
 *
 * @return Array of strings.
 */
char **get_attribute_list(struct collection_item *ini_config,
                          const char *section,
                          int *size,
                          int *error);

/**
 * @brief Free list of attributes.
 *
 * The attribute array created by \ref get_attribute_list()
 * should be freed using this function.
 *
 * @param[in] attr_list          Array of strings returned by
 *                               \ref get_attribute_list() function.
 */
void free_attribute_list(char **attr_list);

/**
 * @brief Get a configuration item form the configuration.
 *
 * Check return error code first. If the function returns
 * an error there is a serious problem.
 * Then check if item is found. Function will set
 * item parameter to NULL if no attribute with
 * provided name is found in the collection.
 *
 * @param[in]  section          Section name.
 *                              If NULL assumed default.
 * @param[in]  name             Attribute name to find.
 * @param[in]  ini_config       Configuration object to search.
 * @param[out] item             Element of configuration
 *                              collection.
 *                              Will be set to NULL if
 *                              element with the given name
 *                              is not found.
 * @return 0 - Success.
 * @return EINVAL - Invalid parameter.
 * @return ENOMEM - No memory.
 *
 */
int get_config_item(const char *section,
                    const char *name,
                    struct collection_item *ini_config,
                    struct collection_item **item);

/**
 * @brief Convert item value to integer number.
 *
 * This is a conversion function.
 * It converts the value read from the INI file
 * and stored in the configuration item
 * into an integer number. Any of the conversion
 * functions can be used to try to convert the value
 * stored as a string inside the item.
 * The results can be different depending upon
 * how the caller tries to interpret the value.
 * If "strict" parameter is non zero the function will fail
 * if there are more characters after the last digit.
 * The value range is from INT_MIN to INT_MAX.
 *
 * @param[in]  item             Item to interpret.
 *                              It must be retrieved using
 *                              \ref get_config_item().
 * @param[in]  strict           Fail the function if
 *                              the symbol after last digit
 *                              is not valid.
 * @param[in]  def              Default value to use if
 *                              conversion failed.
 * @param[out] error            Variable will get the value
 *                              of the error code if
 *                              error happened.
 *                              Can be NULL. In this case
 *                              function does not set
 *                              the code.
 *                              Codes:
 *                              - 0 - Success.
 *                              - EINVAL - Argument is invalid.
 *                              - EIO - Conversion failed due
 *                                invalid characters.
 *                              - ERANGE - Value is out of range.
 *
 * @return Converted value.
 * In case of failure the function returns default value and
 * sets error code into the provided variable.
 */
int get_int_config_value(struct collection_item *item,
                         int strict,
                         int def,
                         int *error);

/**
 * @brief Convert item value to long number.
 *
 * This is a conversion function.
 * It converts the value read from the INI file
 * and stored in the configuration item
 * into a long number. Any of the conversion
 * functions can be used to try to convert the value
 * stored as a string inside the item.
 * The results can be different depending upon
 * how the caller tries to interpret the value.
 * If "strict" parameter is non zero the function will fail
 * if there are more characters after the last digit.
 * The value range is from LONG_MIN to LONG_MAX.
 *
 * @param[in]  item             Item to interpret.
 *                              It must be retrieved using
 *                              \ref get_config_item().
 * @param[in]  strict           Fail the function if
 *                              the symbol after last digit
 *                              is not valid.
 * @param[in]  def              Default value to use if
 *                              conversion failed.
 * @param[out] error            Variable will get the value
 *                              of the error code if
 *                              error happened.
 *                              Can be NULL. In this case
 *                              function does not set
 *                              the code.
 *                              Codes:
 *                              - 0 - Success.
 *                              - EINVAL - Argument is invalid.
 *                              - EIO - Conversion failed due
 *                                invalid characters.
 *                              - ERANGE - Value is out of range.
 *
 * @return Converted value.
 * In case of failure the function returns default value and
 * sets error code into the provided variable.
 */
long get_long_config_value(struct collection_item *item,
                           int strict,
                           long def,
                           int *error);

/**
 * @brief Convert item value to unsigned integer number.
 *
 * This is a conversion function.
 * It converts the value read from the INI file
 * and stored in the configuration item
 * into an unsigned integer number. Any of the conversion
 * functions can be used to try to convert the value
 * stored as a string inside the item.
 * The results can be different depending upon
 * how the caller tries to interpret the value.
 * If "strict" parameter is non zero the function will fail
 * if there are more characters after the last digit.
 * The value range is from 0 to UINT_MAX.
 *
 * @param[in]  item             Item to interpret.
 *                              It must be retrieved using
 *                              \ref get_config_item().
 * @param[in]  strict           Fail the function if
 *                              the symbol after last digit
 *                              is not valid.
 * @param[in]  def              Default value to use if
 *                              conversion failed.
 * @param[out] error            Variable will get the value
 *                              of the error code if
 *                              error happened.
 *                              Can be NULL. In this case
 *                              function does not set
 *                              the code.
 *                              Codes:
 *                              - 0 - Success.
 *                              - EINVAL - Argument is invalid.
 *                              - EIO - Conversion failed due
 *                                invalid characters.
 *                              - ERANGE - Value is out of range.
 *
 * @return Converted value.
 * In case of failure the function returns default value and
 * sets error code into the provided variable.
 */
unsigned get_unsigned_config_value(struct collection_item *item,
                                   int strict,
                                   unsigned def,
                                   int *error);

/**
 * @brief Convert item value to unsigned long number.
 *
 * This is a conversion function.
 * It converts the value read from the INI file
 * and stored in the configuration item
 * into an unsigned long number. Any of the conversion
 * functions can be used to try to convert the value
 * stored as a string inside the item.
 * The results can be different depending upon
 * how the caller tries to interpret the value.
 * If "strict" parameter is non zero the function will fail
 * if there are more characters after the last digit.
 * The value range is from 0 to ULONG_MAX.
 *
 * @param[in]  item             Item to interpret.
 *                              It must be retrieved using
 *                              \ref get_config_item().
 * @param[in]  strict           Fail the function if
 *                              the symbol after last digit
 *                              is not valid.
 * @param[in]  def              Default value to use if
 *                              conversion failed.
 * @param[out] error            Variable will get the value
 *                              of the error code if
 *                              error happened.
 *                              Can be NULL. In this case
 *                              function does not set
 *                              the code.
 *                              Codes:
 *                              - 0 - Success.
 *                              - EINVAL - Argument is invalid.
 *                              - EIO - Conversion failed due
 *                                invalid characters.
 *                              - ERANGE - Value is out of range.
 *
 * @return Converted value.
 * In case of failure the function returns default value and
 * sets error code into the provided variable.
 */
unsigned long get_ulong_config_value(struct collection_item *item,
                                     int strict,
                                     unsigned long def,
                                     int *error);

/**
 * @brief Convert item value to integer number.
 *
 * This is a conversion function.
 * It converts the value read from the INI file
 * and stored in the configuration item
 * into an int32_t number. Any of the conversion
 * functions can be used to try to convert the value
 * stored as a string inside the item.
 * The results can be different depending upon
 * how the caller tries to interpret the value.
 * If "strict" parameter is non zero the function will fail
 * if there are more characters after the last digit.
 * The value range is from INT_MIN to INT_MAX.
 *
 * @param[in]  item             Item to interpret.
 *                              It must be retrieved using
 *                              \ref get_config_item().
 * @param[in]  strict           Fail the function if
 *                              the symbol after last digit
 *                              is not valid.
 * @param[in]  def              Default value to use if
 *                              conversion failed.
 * @param[out] error            Variable will get the value
 *                              of the error code if
 *                              error happened.
 *                              Can be NULL. In this case
 *                              function does not set
 *                              the code.
 *                              Codes:
 *                              - 0 - Success.
 *                              - EINVAL - Argument is invalid.
 *                              - EIO - Conversion failed due
 *                                invalid characters.
 *                              - ERANGE - Value is out of range.
 *
 * @return Converted value.
 * In case of failure the function returns default value and
 * sets error code into the provided variable.
 */
int32_t get_int32_config_value(struct collection_item *item,
                               int strict,
                               int32_t def,
                               int *error);

/**
 * @brief Convert item value to integer number.
 *
 * This is a conversion function.
 * It converts the value read from the INI file
 * and stored in the configuration item
 * into an uint32_t number. Any of the conversion
 * functions can be used to try to convert the value
 * stored as a string inside the item.
 * The results can be different depending upon
 * how the caller tries to interpret the value.
 * If "strict" parameter is non zero the function will fail
 * if there are more characters after the last digit.
 * The value range is from 0 to ULONG_MAX.
 *
 * @param[in]  item             Item to interpret.
 *                              It must be retrieved using
 *                              \ref get_config_item().
 * @param[in]  strict           Fail the function if
 *                              the symbol after last digit
 *                              is not valid.
 * @param[in]  def              Default value to use if
 *                              conversion failed.
 * @param[out] error            Variable will get the value
 *                              of the error code if
 *                              error happened.
 *                              Can be NULL. In this case
 *                              function does not set
 *                              the code.
 *                              Codes:
 *                              - 0 - Success.
 *                              - EINVAL - Argument is invalid.
 *                              - EIO - Conversion failed due
 *                                invalid characters.
 *                              - ERANGE - Value is out of range.
 *
 * @return Converted value.
 * In case of failure the function returns default value and
 * sets error code into the provided variable.
 */
uint32_t get_uint32_config_value(struct collection_item *item,
                                 int strict,
                                 uint32_t def,
                                 int *error);

/**
 * @brief Convert item value to integer number.
 *
 * This is a conversion function.
 * It converts the value read from the INI file
 * and stored in the configuration item
 * into an int64_t number. Any of the conversion
 * functions can be used to try to convert the value
 * stored as a string inside the item.
 * The results can be different depending upon
 * how the caller tries to interpret the value.
 * If "strict" parameter is non zero the function will fail
 * if there are more characters after the last digit.
 * The value range is from LLONG_MIN to LLONG_MAX.
 *
 * @param[in]  item             Item to interpret.
 *                              It must be retrieved using
 *                              \ref get_config_item().
 * @param[in]  strict           Fail the function if
 *                              the symbol after last digit
 *                              is not valid.
 * @param[in]  def              Default value to use if
 *                              conversion failed.
 * @param[out] error            Variable will get the value
 *                              of the error code if
 *                              error happened.
 *                              Can be NULL. In this case
 *                              function does not set
 *                              the code.
 *                              Codes:
 *                              - 0 - Success.
 *                              - EINVAL - Argument is invalid.
 *                              - EIO - Conversion failed due
 *                                invalid characters.
 *                              - ERANGE - Value is out of range.
 *
 * @return Converted value.
 * In case of failure the function returns default value and
 * sets error code into the provided variable.
 */
int64_t get_int64_config_value(struct collection_item *item,
                               int strict,
                               int64_t def,
                               int *error);

/**
 * @brief Convert item value to integer number.
 *
 * This is a conversion function.
 * It converts the value read from the INI file
 * and stored in the configuration item
 * into an uint64_t number. Any of the conversion
 * functions can be used to try to convert the value
 * stored as a string inside the item.
 * The results can be different depending upon
 * how the caller tries to interpret the value.
 * If "strict" parameter is non zero the function will fail
 * if there are more characters after the last digit.
 * The value range is from 0 to ULLONG_MAX.
 *
 * @param[in]  item             Item to interpret.
 *                              It must be retrieved using
 *                              \ref get_config_item().
 * @param[in]  strict           Fail the function if
 *                              the symbol after last digit
 *                              is not valid.
 * @param[in]  def              Default value to use if
 *                              conversion failed.
 * @param[out] error            Variable will get the value
 *                              of the error code if
 *                              error happened.
 *                              Can be NULL. In this case
 *                              function does not set
 *                              the code.
 *                              Codes:
 *                              - 0 - Success.
 *                              - EINVAL - Argument is invalid.
 *                              - EIO - Conversion failed due
 *                                invalid characters.
 *                              - ERANGE - Value is out of range.
 *
 * @return Converted value.
 * In case of failure the function returns default value and
 * sets error code into the provided variable.
 */
uint64_t get_uint64_config_value(struct collection_item *item,
                                 int strict,
                                 uint64_t def,
                                 int *error);

/**
 * @brief Convert item value to floating point number.
 *
 * This is a conversion function.
 * It converts the value read from the INI file
 * and stored in the configuration item
 * into a floating point number. Any of the conversion
 * functions can be used to try to convert the value
 * stored as a string inside the item.
 * The results can be different depending upon
 * how the caller tries to interpret the value.
 * If "strict" parameter is non zero the function will fail
 * if there are more characters after the last digit.
 *
 * @param[in]  item             Item to interpret.
 *                              It must be retrieved using
 *                              \ref get_config_item().
 * @param[in]  strict           Fail the function if
 *                              the symbol after last digit
 *                              is not valid.
 * @param[in]  def              Default value to use if
 *                              conversion failed.
 * @param[out] error            Variable will get the value
 *                              of the error code if
 *                              error happened.
 *                              Can be NULL. In this case
 *                              function does not set
 *                              the code.
 *                              Codes:
 *                              - 0 - Success.
 *                              - EINVAL - Argument is invalid.
 *                              - EIO - Conversion failed due
 *                                invalid characters.
 *
 * @return Converted value.
 * In case of failure the function returns default value and
 * sets error code into the provided variable.
 */
double get_double_config_value(struct collection_item *item,
                               int strict,
                               double def,
                               int *error);

/**
 * @brief Convert item value into a logical value.
 *
 * This is a conversion function.
 * It converts the value read from the INI file
 * and stored in the configuration item
 * into a Boolean. Any of the conversion
 * functions can be used to try to convert the value
 * stored as a string inside the item.
 * The results can be different depending upon
 * how the caller tries to interpret the value.
 *
 * @param[in]  item             Item to interpret.
 *                              It must be retrieved using
 *                              \ref get_config_item().
 * @param[in]  def              Default value to use if
 *                              conversion failed.
 * @param[out] error            Variable will get the value
 *                              of the error code if
 *                              error happened.
 *                              Can be NULL. In this case
 *                              function does not set
 *                              the code.
 *                              Codes:
 *                              - 0 - Success.
 *                              - EINVAL - Argument is invalid.
 *                              - EIO - Conversion failed due
 *                                invalid characters.
 *
 * @return Converted value.
 * In case of failure the function returns default value and
 * sets error code into the provided variable.
 */
unsigned char get_bool_config_value(struct collection_item *item,
                                    unsigned char def,
                                    int *error);

/**
 * @brief Get string configuration value
 *
 * Function creates a copy of the string value stored in the item.
 * Returned value needs to be freed after use.
 * If error occurred the returned value will be NULL.
 *
 * @param[in]  item             Item to use.
 *                              It must be retrieved using
 *                              \ref get_config_item().
 * @param[out] error            Variable will get the value
 *                              of the error code if
 *                              error happened.
 *                              Can be NULL. In this case
 *                              function does not set
 *                              the code.
 *                              Codes:
 *                              - 0 - Success.
 *                              - EINVAL - Argument is invalid.
 *                              - ENOMEM - No memory.
 *
 * @return Copy of the string or NULL.
 */
char *get_string_config_value(struct collection_item *item,
                              int *error);
/**
 * @brief Function returns the string stored in the item.
 *
 * Function returns a reference to the string value
 * stored inside the item. This string can't be altered.
 * The string will go out of scope if the item is deleted.
 *
 * @param[in]  item             Item to use.
 *                              It must be retrieved using
 *                              \ref get_config_item().
 * @param[out] error            Variable will get the value
 *                              of the error code if
 *                              error happened.
 *                              Can be NULL. In this case
 *                              function does not set
 *                              the code.
 *                              Codes:
 *                              - 0 - Success.
 *                              - EINVAL - Argument is invalid.
 *
 * @return String from the item.
 */
const char *get_const_string_config_value(struct collection_item *item,
                                          int *error);

/**
 * @brief Convert item value into a binary sequence.
 *
 * This is a conversion function.
 * It converts the value read from the INI file
 * and stored in the configuration item
 * into a sequence of bytes.
 * Any of the conversion functions
 * can be used to try to convert the value
 * stored as a string inside the item.
 * The results can be different depending upon
 * how the caller tries to interpret the value.
 *
 * The function allocates memory.
 * It is the responsibility of the caller to free it after use.
 * Use \ref free_bin_config_value() for this purpose.
 * Functions will return NULL if conversion failed.
 *
 * Function assumes that the value being interpreted
 * has a special format.
 * The string should be taken in single quotes
 * and consist of hex encoded value represented by
 * two hex digits per byte.
 * Case does not matter.
 *
 * Example: '0a2BFeCc'
 *
 * @param[in]  item             Item to interpret.
 *                              It must be retrieved using
 *                              \ref get_config_item().
 * @param[out] length           Variable that optionally receives
 *                              the length of the binary
 *                              sequence.
 * @param[out] error            Variable will get the value
 *                              of the error code if
 *                              error happened.
 *                              Can be NULL. In this case
 *                              function does not set
 *                              the code.
 *                              Codes:
 *                              - 0 - Success.
 *                              - EINVAL - Argument is invalid.
 *                              - EIO - Conversion failed due
 *                                invalid characters.
 *                              - ENOMEM - No memory.
 *
 * @return Converted value.
 * In case of failure the function returns NULL.
 */
char *get_bin_config_value(struct collection_item *item,
                           int *length,
                           int *error);

/**
 * @brief Free binary buffer
 *
 * Free binary value returned by \ref get_bin_config_value().
 *
 * @param[in] bin              Binary buffer to free.
 *
 */
void free_bin_config_value(char *bin);

/**
 * @brief Convert value to an array of strings.
 *
 * This is a conversion function.
 * It converts the value read from the INI file
 * and stored in the configuration item
 * into an array of strings. Any of the conversion
 * functions can be used to try to convert the value
 * stored as a string inside the item.
 * The results can be different depending upon
 * how the caller tries to interpret the value.
 *
 * Separator string includes up to three different separators.
 * If separator NULL, comma is assumed.
 * The spaces are trimmed automatically around separators
 * in the string.
 * The function drops empty tokens from the list.
 * This means that the string like this: "apple, ,banana, ,orange ,"
 * will be translated into the list of three items:
 * "apple","banana" and "orange".
 *
 * The length of the allocated array is returned in "size".
 * Size and error parameters can be NULL.
 * Use \ref free_string_config_array() to free the array after use.
 *
 * The array is always NULL terminated so
 * it is safe not to get size and just loop until
 * array element is NULL.
 *
 * @param[in]  item             Item to interpret.
 *                              It must be retrieved using
 *                              \ref get_config_item().
 * @param[in]  sep              String cosisting of separator
 *                              symbols. For example: ",.;" would mean
 *                              that comma, dot and semicolon
 *                              should be treated as separators
 *                              in the value.
 * @param[out] size             Variable that optionally receives
 *                              the size of the array.
 * @param[out] error            Variable will get the value
 *                              of the error code if
 *                              error happened.
 *                              Can be NULL. In this case
 *                              function does not set
 *                              the code.
 *                              Codes:
 *                              - 0 - Success.
 *                              - EINVAL - Argument is invalid.
 *                              - EIO - Conversion failed.
 *                              - ENOMEM - No memory.
 *
 * @return Array of strings.
 * In case of failure the function returns NULL.
 */
char **get_string_config_array(struct collection_item *item,
                               const char *sep,
                               int *size,
                               int *error);

/**
 * @brief Convert value to an array of strings.
 *
 * This is a conversion function.
 * It converts the value read from the INI file
 * and stored in the configuration item
 * into an array of strings. Any of the conversion
 * functions can be used to try to convert the value
 * stored as a string inside the item.
 * The results can be different depending upon
 * how the caller tries to interpret the value.
 *
 * Separator string includes up to three different separators.
 * If separator NULL, comma is assumed.
 * The spaces are trimmed automatically around separators
 * in the string.
 * The function does not drop empty tokens from the list.
 * This means that the string like this: "apple, ,banana, ,orange ,"
 * will be translated into the list of five items:
 * "apple", "", "banana", "" and "orange".
 *
 * The length of the allocated array is returned in "size".
 * Size and error parameters can be NULL.
 * Use \ref free_string_config_array() to free the array after use.
 *
 * The array is always NULL terminated so
 * it is safe not to get size and just loop until
 * array element is NULL.
 *
 * @param[in]  item             Item to interpret.
 *                              It must be retrieved using
 *                              \ref get_config_item().
 * @param[in]  sep              String cosisting of separator
 *                              symbols. For example: ",.;" would mean
 *                              that comma, dot and semicolon
 *                              should be treated as separators
 *                              in the value.
 * @param[out] size             Variable that optionally receives
 *                              the size of the array.
 * @param[out] error            Variable will get the value
 *                              of the error code if
 *                              error happened.
 *                              Can be NULL. In this case
 *                              function does not set
 *                              the code.
 *                              Codes:
 *                              - 0 - Success.
 *                              - EINVAL - Argument is invalid.
 *                              - EIO - Conversion failed.
 *                              - ENOMEM - No memory.
 *
 * @return Array of strings.
 * In case of failure the function returns NULL.
 */
char **get_raw_string_config_array(struct collection_item *item,
                                   const char *sep,
                                   int *size,
                                   int *error);

/**
 * @brief Convert value to an array of long values.
 *
 * This is a conversion function.
 * It converts the value read from the INI file
 * and stored in the configuration item
 * into an array of long values. Any of the conversion
 * functions can be used to try to convert the value
 * stored as a string inside the item.
 * The results can be different depending upon
 * how the caller tries to interpret the value.
 *
 * Separators inside the string are detected automatically.
 * The spaces are trimmed automatically around separators
 * in the string.
 *
 * The length of the allocated array is returned in "size".
 * Size parameter can't be NULL.
 *
 * Use \ref free_long_config_array() to free the array after use.
 *
 * @param[in]  item             Item to interpret.
 *                              It must be retrieved using
 *                              \ref get_config_item().
 * @param[out] size             Variable that receives
 *                              the size of the array.
 * @param[out] error            Variable will get the value
 *                              of the error code if
 *                              error happened.
 *                              Can be NULL. In this case
 *                              function does not set
 *                              the code.
 *                              Codes:
 *                              - 0 - Success.
 *                              - EINVAL - Argument is invalid.
 *                              - EIO - Conversion failed.
 *                              - ERANGE - Value is out of range.
 *                              - ENOMEM - No memory.
 *
 * @return Array of long values.
 * In case of failure the function returns NULL.
 */
long *get_long_config_array(struct collection_item *item,
                            int *size,
                            int *error);

/**
 * @brief Convert value to an array of floating point values.
 *
 * This is a conversion function.
 * It converts the value read from the INI file
 * and stored in the configuration item
 * into an array of floating point values. Any of the conversion
 * functions can be used to try to convert the value
 * stored as a string inside the item.
 * The results can be different depending upon
 * how the caller tries to interpret the value.
 *
 * Separators inside the string are detected automatically.
 * The spaces are trimmed automatically around separators
 * in the string.
 *
 * The length of the allocated array is returned in "size".
 * Size parameter can't be NULL.
 *
 * Use \ref free_double_config_array() to free the array after use.
 *
 * @param[in]  item             Item to interpret.
 *                              It must be retrieved using
 *                              \ref get_config_item().
 * @param[out] size             Variable that receives
 *                              the size of the array.
 * @param[out] error            Variable will get the value
 *                              of the error code if
 *                              error happened.
 *                              Can be NULL. In this case
 *                              function does not set
 *                              the code.
 *                              Codes:
 *                              - 0 - Success.
 *                              - EINVAL - Argument is invalid.
 *                              - EIO - Conversion failed.
 *                              - ENOMEM - No memory.
 *
 * @return Array of floating point values.
 * In case of failure the function returns NULL.
 */
double *get_double_config_array(struct collection_item *item,
                                int *size,
                                int *error);

/**
 * @brief Free array of string values.
 *
 * Use this function to free the array returned by
 * \ref get_string_config_array() or by
 * \ref get_raw_string_config_array().
 *
 * @param[in] str_config        Array of string values.
 */
void free_string_config_array(char **str_config);

/**
 * @brief Free array of long values.
 *
 * Use this function to free the array returned by
 * \ref get_long_config_array().
 *
 * @param[in] array         Array of long values.
 */
void free_long_config_array(long *array);
/**
 * @brief Free array of floating pointer values.
 *
 * Use this function to free the array returned by
 * \ref get_double_config_array().
 *
 * @param[in] array         Array of floating pointer values.
 */
void free_double_config_array(double *array);


/**
 * @}
 */

#endif