This file is indexed.

/usr/include/asterisk/pbx.h is in asterisk-dev 1:1.8.10.1~dfsg-1ubuntu1.

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
/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2006, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 * \brief Core PBX routines and definitions.
 */

#ifndef _ASTERISK_PBX_H
#define _ASTERISK_PBX_H

#include "asterisk/channel.h"
#include "asterisk/sched.h"
#include "asterisk/devicestate.h"
#include "asterisk/chanvars.h"
#include "asterisk/hashtab.h"
#include "asterisk/stringfields.h"
#include "asterisk/xmldoc.h"
#include "asterisk/frame_defs.h"

#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif

#define AST_MAX_APP	32	/*!< Max length of an application */

#define AST_PBX_GOTO_FAILED -3
#define AST_PBX_KEEP    0
#define AST_PBX_REPLACE 1

/*! \brief Special return values from applications to the PBX
 * @{ */
#define AST_PBX_HANGUP                -1    /*!< Jump to the 'h' exten */
#define AST_PBX_OK                     0    /*!< No errors */
#define AST_PBX_ERROR                  1    /*!< Jump to the 'e' exten */
#define AST_PBX_INCOMPLETE             12   /*!< Return to PBX matching, allowing more digits for the extension */
/*! @} */

#define PRIORITY_HINT	-1	/*!< Special Priority for a hint */

/*!
 * \brief Extension states
 * \note States can be combined
 * \ref AstExtState
 */
enum ast_extension_states {
	AST_EXTENSION_REMOVED = -2,	/*!< Extension removed */
	AST_EXTENSION_DEACTIVATED = -1,	/*!< Extension hint removed */
	AST_EXTENSION_NOT_INUSE = 0,	/*!< No device INUSE or BUSY  */
	AST_EXTENSION_INUSE = 1 << 0,	/*!< One or more devices INUSE */
	AST_EXTENSION_BUSY = 1 << 1,	/*!< All devices BUSY */
	AST_EXTENSION_UNAVAILABLE = 1 << 2, /*!< All devices UNAVAILABLE/UNREGISTERED */
	AST_EXTENSION_RINGING = 1 << 3,	/*!< All devices RINGING */
	AST_EXTENSION_ONHOLD = 1 << 4,	/*!< All devices ONHOLD */
};


struct ast_context;
struct ast_exten;
struct ast_include;
struct ast_ignorepat;
struct ast_sw;

/*! \brief Typedef for devicestate and hint callbacks */
typedef int (*ast_state_cb_type)(char *context, char *id, enum ast_extension_states state, void *data);

/*! \brief Typedef for devicestate and hint callback removal indication callback */
typedef void (*ast_state_cb_destroy_type)(int id, void *data);

/*! \brief Data structure associated with a custom dialplan function */
struct ast_custom_function {
	const char *name;			/*!< Name */
	AST_DECLARE_STRING_FIELDS(
		AST_STRING_FIELD(synopsis);     /*!< Synopsis text for 'show functions' */
		AST_STRING_FIELD(desc);		/*!< Description (help text) for 'show functions &lt;name&gt;' */
		AST_STRING_FIELD(syntax);       /*!< Syntax text for 'core show functions' */
		AST_STRING_FIELD(arguments);    /*!< Arguments description */
		AST_STRING_FIELD(seealso);      /*!< See also */
	);
	enum ast_doc_src docsrc;		/*!< Where the documentation come from */
	/*! Read function, if read is supported */
	ast_acf_read_fn_t read;		/*!< Read function, if read is supported */
	/*! Read function, if read is supported.  Note: only one of read or read2
	 * needs to be implemented.  In new code, read2 should be implemented as
	 * the way forward, but they should return identical results, within the
	 * constraints of buffer size, if both are implemented.  That is, if the
	 * read function is handed a 16-byte buffer, and the result is 17 bytes
	 * long, then the first 15 bytes (remember NULL terminator) should be
	 * the same for both the read and the read2 methods. */
	ast_acf_read2_fn_t read2;
	/*! If no read2 function is provided, what maximum size? */
	size_t read_max;
	/*! Write function, if write is supported */
	ast_acf_write_fn_t write;	/*!< Write function, if write is supported */
	struct ast_module *mod;         /*!< Module this custom function belongs to */
	AST_RWLIST_ENTRY(ast_custom_function) acflist;
};

/*! \brief All switch functions have the same interface, so define a type for them */
typedef int (ast_switch_f)(struct ast_channel *chan, const char *context,
	const char *exten, int priority, const char *callerid, const char *data);

/*!< Data structure associated with an Asterisk switch */
struct ast_switch {
	AST_LIST_ENTRY(ast_switch) list;
	const char *name;			/*!< Name of the switch */
	const char *description;		/*!< Description of the switch */

	ast_switch_f *exists;
	ast_switch_f *canmatch;
	ast_switch_f *exec;
	ast_switch_f *matchmore;
};

struct ast_timing {
	int hastime;                    /*!< If time construct exists */
	unsigned int monthmask;         /*!< Mask for month */
	unsigned int daymask;           /*!< Mask for date */
	unsigned int dowmask;           /*!< Mask for day of week (sun-sat) */
	unsigned int minmask[48];       /*!< Mask for minute */
	char *timezone;                 /*!< NULL, or zoneinfo style timezone */
};

/*!
 * \brief Construct a timing bitmap, for use in time-based conditionals.
 * \param i Pointer to an ast_timing structure.
 * \param info Standard string containing a timerange, weekday range, monthday range, and month range, as well as an optional timezone.
 * \retval Returns 1 on success or 0 on failure.
 */
int ast_build_timing(struct ast_timing *i, const char *info);

/*!
 * \brief Evaluate a pre-constructed bitmap as to whether the current time falls within the range specified.
 * \param i Pointer to an ast_timing structure.
 * \retval Returns 1, if the time matches or 0, if the current time falls outside of the specified range.
 */
int ast_check_timing(const struct ast_timing *i);

/*!
 * \brief Evaluate a pre-constructed bitmap as to whether a particular time falls within the range specified.
 * \param i Pointer to an ast_timing structure.
 * \param tv Specified time
 * \retval Returns 1, if the time matches or 0, if the time falls outside of the specified range.
 */
int ast_check_timing2(const struct ast_timing *i, const struct timeval tv);

/*!
 * \brief Deallocates memory structures associated with a timing bitmap.
 * \param i Pointer to an ast_timing structure.
 * \retval 0 success
 * \retval non-zero failure (number suitable to pass to \see strerror)
 */
int ast_destroy_timing(struct ast_timing *i);

struct ast_pbx {
	int dtimeoutms;				/*!< Timeout between digits (milliseconds) */
	int rtimeoutms;				/*!< Timeout for response (milliseconds) */
};


/*!
 * \brief Register an alternative dialplan switch
 *
 * \param sw switch to register
 *
 * This function registers a populated ast_switch structure with the
 * asterisk switching architecture.
 *
 * \retval 0 success
 * \retval non-zero failure
 */
int ast_register_switch(struct ast_switch *sw);

/*!
 * \brief Unregister an alternative switch
 *
 * \param sw switch to unregister
 *
 * Unregisters a switch from asterisk.
 *
 * \return nothing
 */
void ast_unregister_switch(struct ast_switch *sw);

/*!
 * \brief Look up an application
 *
 * \param app name of the app
 *
 * This function searches for the ast_app structure within
 * the apps that are registered for the one with the name
 * you passed in.
 *
 * \return the ast_app structure that matches on success, or NULL on failure
 */
struct ast_app *pbx_findapp(const char *app);

/*!
 * \brief Execute an application
 *
 * \param c channel to execute on
 * \param app which app to execute
 * \param data the data passed into the app
 *
 * This application executes an application on a given channel.  It
 * saves the stack and executes the given application passing in
 * the given data.
 *
 * \retval 0 success
 * \retval -1 failure
 */
int pbx_exec(struct ast_channel *c, struct ast_app *app, const char *data);

/*!
 * \brief Register a new context or find an existing one
 *
 * \param extcontexts pointer to the ast_context structure pointer
 * \param exttable pointer to the hashtable that contains all the elements in extcontexts
 * \param name name of the new context
 * \param registrar registrar of the context
 *
 * This function allows you to play in two environments: the global contexts (active dialplan)
 * or an external context set of your choosing. To act on the external set, make sure extcontexts
 * and exttable are set; for the globals, make sure both extcontexts and exttable are NULL.
 *
 * This will first search for a context with your name.  If it exists already, it will not
 * create a new one.  If it does not exist, it will create a new one with the given name
 * and registrar.
 *
 * \return NULL on failure, and an ast_context structure on success
 */
struct ast_context *ast_context_find_or_create(struct ast_context **extcontexts, struct ast_hashtab *exttable, const char *name, const char *registrar);

/*!
 * \brief Merge the temporary contexts into a global contexts list and delete from the
 *        global list the ones that are being added
 *
 * \param extcontexts pointer to the ast_context structure
 * \param exttable pointer to the ast_hashtab structure that contains all the elements in extcontexts
 * \param registrar of the context; if it's set the routine will delete all contexts
 *        that belong to that registrar; if NULL only the contexts that are specified
 *        in extcontexts
 */
void ast_merge_contexts_and_delete(struct ast_context **extcontexts, struct ast_hashtab *exttable, const char *registrar);

/*!
 * \brief Destroy a context (matches the specified context (or ANY context if NULL)
 *
 * \param con context to destroy
 * \param registrar who registered it
 *
 * You can optionally leave out either parameter.  It will find it
 * based on either the ast_context or the registrar name.
 *
 * \return nothing
 */
void ast_context_destroy(struct ast_context *con, const char *registrar);

/*!
 * \brief Find a context
 *
 * \param name name of the context to find
 *
 * Will search for the context with the given name.
 *
 * \return the ast_context on success, NULL on failure.
 */
struct ast_context *ast_context_find(const char *name);

/*!
 * \brief The result codes when starting the PBX on a channel with ast_pbx_start.
 * \note AST_PBX_CALL_LIMIT refers to the maxcalls call limit in asterisk.conf
 * \see ast_pbx_start
 */
enum ast_pbx_result {
	AST_PBX_SUCCESS = 0,
	AST_PBX_FAILED = -1,
	AST_PBX_CALL_LIMIT = -2,
};

/*!
 * \brief Create a new thread and start the PBX
 *
 * \param c channel to start the pbx on
 *
 * \see ast_pbx_run for a synchronous function to run the PBX in the
 * current thread, as opposed to starting a new one.
 *
 * \retval Zero on success
 * \retval non-zero on failure
 */
enum ast_pbx_result ast_pbx_start(struct ast_channel *c);

/*!
 * \brief Execute the PBX in the current thread
 *
 * \param c channel to run the pbx on
 *
 * This executes the PBX on a given channel. It allocates a new
 * PBX structure for the channel, and provides all PBX functionality.
 * See ast_pbx_start for an asynchronous function to run the PBX in a
 * new thread as opposed to the current one.
 *
 * \retval Zero on success
 * \retval non-zero on failure
 */
enum ast_pbx_result ast_pbx_run(struct ast_channel *c);

/*!
 * \brief Options for ast_pbx_run()
 */
struct ast_pbx_args {
	union {
		/*! Pad this out so that we have plenty of room to add options
		 *  but still maintain ABI compatibility over time. */
		uint64_t __padding;
		struct {
			/*! Do not hangup the channel when the PBX is complete. */
			unsigned int no_hangup_chan:1;
		};
	};
};

/*!
 * \brief Execute the PBX in the current thread
 *
 * \param c channel to run the pbx on
 * \param args options for the pbx
 *
 * This executes the PBX on a given channel. It allocates a new
 * PBX structure for the channel, and provides all PBX functionality.
 * See ast_pbx_start for an asynchronous function to run the PBX in a
 * new thread as opposed to the current one.
 *
 * \retval Zero on success
 * \retval non-zero on failure
 */
enum ast_pbx_result ast_pbx_run_args(struct ast_channel *c, struct ast_pbx_args *args);

/*!
 * \brief Add and extension to an extension context.
 *
 * \param context context to add the extension to
 * \param replace
 * \param extension extension to add
 * \param priority priority level of extension addition
 * \param label extension label
 * \param callerid pattern to match CallerID, or NULL to match any CallerID
 * \param application application to run on the extension with that priority level
 * \param data data to pass to the application
 * \param datad
 * \param registrar who registered the extension
 *
 * \retval 0 success
 * \retval -1 failure
 */
int ast_add_extension(const char *context, int replace, const char *extension,
	int priority, const char *label, const char *callerid,
	const char *application, void *data, void (*datad)(void *), const char *registrar);

/*!
 * \brief Add an extension to an extension context, this time with an ast_context *.
 *
 * \note For details about the arguments, check ast_add_extension()
 */
int ast_add_extension2(struct ast_context *con, int replace, const char *extension,
	int priority, const char *label, const char *callerid,
	const char *application, void *data, void (*datad)(void *), const char *registrar);

/*!
 * \brief Map devstate to an extension state.
 *
 * \param[in] devstate device state
 *
 * \return the extension state mapping.
 */
enum ast_extension_states ast_devstate_to_extenstate(enum ast_device_state devstate);

/*!
 * \brief Uses hint and devicestate callback to get the state of an extension
 *
 * \param c this is not important
 * \param context which context to look in
 * \param exten which extension to get state
 *
 * \return extension state as defined in the ast_extension_states enum
 */
int ast_extension_state(struct ast_channel *c, const char *context, const char *exten);

/*!
 * \brief Return string representation of the state of an extension
 *
 * \param extension_state is the numerical state delivered by ast_extension_state
 *
 * \return the state of an extension as string
 */
const char *ast_extension_state2str(int extension_state);

/*!
 * \brief Registers a state change callback with destructor.
 * \since 1.8.9
 * \since 10.1.0
 *
 * \param context which context to look in
 * \param exten which extension to get state
 * \param change_cb callback to call if state changed
 * \param destroy_cb callback to call when registration destroyed.
 * \param data to pass to callback
 *
 * \note The change_cb is called if the state of an extension is changed.
 *
 * \note The destroy_cb is called when the registration is
 * deleted so the registerer can release any associated
 * resources.
 *
 * \retval -1 on failure
 * \retval ID on success
 */
int ast_extension_state_add_destroy(const char *context, const char *exten,
	ast_state_cb_type change_cb, ast_state_cb_destroy_type destroy_cb, void *data);

/*!
 * \brief Registers a state change callback
 *
 * \param context which context to look in
 * \param exten which extension to get state
 * \param change_cb callback to call if state changed
 * \param data to pass to callback
 *
 * \note The change_cb is called if the state of an extension is changed.
 *
 * \retval -1 on failure
 * \retval ID on success
 */
int ast_extension_state_add(const char *context, const char *exten,
	ast_state_cb_type change_cb, void *data);

/*!
 * \brief Deletes a registered state change callback by ID
 *
 * \param id of the registered state callback to delete
 * \param change_cb callback to call if state changed (Used if id == 0 (global))
 *
 * \retval 0 success
 * \retval -1 failure
 */
int ast_extension_state_del(int id, ast_state_cb_type change_cb);

/*!
 * \brief If an extension hint exists, return non-zero
 *
 * \param hint buffer for hint
 * \param hintsize size of hint buffer, in bytes
 * \param name buffer for name portion of hint
 * \param namesize size of name buffer
 * \param c Channel from which to return the hint.  This is only important when the hint or name contains an expression to be expanded.
 * \param context which context to look in
 * \param exten which extension to search for
 *
 * \return If an extension within the given context with the priority PRIORITY_HINT
 * is found, a non zero value will be returned.
 * Otherwise, 0 is returned.
 */
int ast_get_hint(char *hint, int hintsize, char *name, int namesize,
	struct ast_channel *c, const char *context, const char *exten);

/*!
 * \brief If an extension hint exists, return non-zero
 *
 * \param hint buffer for hint
 * \param hintsize Maximum size of hint buffer (<0 to prevent growth, >0 to limit growth to that number of bytes, or 0 for unlimited growth)
 * \param name buffer for name portion of hint
 * \param namesize Maximum size of name buffer (<0 to prevent growth, >0 to limit growth to that number of bytes, or 0 for unlimited growth)
 * \param c Channel from which to return the hint.  This is only important when the hint or name contains an expression to be expanded.
 * \param context which context to look in
 * \param exten which extension to search for
 *
 * \return If an extension within the given context with the priority PRIORITY_HINT
 * is found, a non zero value will be returned.
 * Otherwise, 0 is returned.
 */
int ast_str_get_hint(struct ast_str **hint, ssize_t hintsize, struct ast_str **name, ssize_t namesize,
	struct ast_channel *c, const char *context, const char *exten);

/*!
 * \brief Determine whether an extension exists
 *
 * \param c this is not important
 * \param context which context to look in
 * \param exten which extension to search for
 * \param priority priority of the action within the extension
 * \param callerid callerid to search for
 *
 * \note It is possible for autoservice to be started and stopped on c during this
 * function call, it is important that c is not locked prior to calling this. Otherwise
 * a deadlock may occur
 *
 * \return If an extension within the given context(or callerid) with the given priority
 *         is found a non zero value will be returned. Otherwise, 0 is returned.
 */
int ast_exists_extension(struct ast_channel *c, const char *context, const char *exten,
	int priority, const char *callerid);

/*!
 * \brief Find the priority of an extension that has the specified label
 *
 * \param c this is not important
 * \param context which context to look in
 * \param exten which extension to search for
 * \param label label of the action within the extension to match to priority
 * \param callerid callerid to search for
 *
 * \note It is possible for autoservice to be started and stopped on c during this
 * function call, it is important that c is not locked prior to calling this. Otherwise
 * a deadlock may occur
 *
 * \retval the priority which matches the given label in the extension
 * \retval -1 if not found.
 */
int ast_findlabel_extension(struct ast_channel *c, const char *context,
	const char *exten, const char *label, const char *callerid);

/*!
 * \brief Find the priority of an extension that has the specified label
 *
 * \note It is possible for autoservice to be started and stopped on c during this
 * function call, it is important that c is not locked prior to calling this. Otherwise
 * a deadlock may occur
 *
 * \note This function is the same as ast_findlabel_extension, except that it accepts
 * a pointer to an ast_context structure to specify the context instead of the
 * name of the context. Otherwise, the functions behave the same.
 */
int ast_findlabel_extension2(struct ast_channel *c, struct ast_context *con,
	const char *exten, const char *label, const char *callerid);

/*!
 * \brief Looks for a valid matching extension
 *
 * \param c not really important
 * \param context context to serach within
 * \param exten extension to check
 * \param priority priority of extension path
 * \param callerid callerid of extension being searched for
 *
 * \note It is possible for autoservice to be started and stopped on c during this
 * function call, it is important that c is not locked prior to calling this. Otherwise
 * a deadlock may occur
 *
 * \return If "exten" *could be* a valid extension in this context with or without
 * some more digits, return non-zero.  Basically, when this returns 0, no matter
 * what you add to exten, it's not going to be a valid extension anymore
 */
int ast_canmatch_extension(struct ast_channel *c, const char *context,
	const char *exten, int priority, const char *callerid);

/*!
 * \brief Looks to see if adding anything to this extension might match something. (exists ^ canmatch)
 *
 * \param c not really important XXX
 * \param context context to serach within
 * \param exten extension to check
 * \param priority priority of extension path
 * \param callerid callerid of extension being searched for
 *
 * \note It is possible for autoservice to be started and stopped on c during this
 * function call, it is important that c is not locked prior to calling this. Otherwise
 * a deadlock may occur
 *
 * \return If "exten" *could match* a valid extension in this context with
 * some more digits, return non-zero.  Does NOT return non-zero if this is
 * an exact-match only.  Basically, when this returns 0, no matter
 * what you add to exten, it's not going to be a valid extension anymore
 */
int ast_matchmore_extension(struct ast_channel *c, const char *context,
	const char *exten, int priority, const char *callerid);

/*!
 * \brief Determine if a given extension matches a given pattern (in NXX format)
 *
 * \param pattern pattern to match
 * \param extension extension to check against the pattern.
 *
 * Checks whether or not the given extension matches the given pattern.
 *
 * \retval 1 on match
 * \retval 0 on failure
 */
int ast_extension_match(const char *pattern, const char *extension);

int ast_extension_close(const char *pattern, const char *data, int needmore);

/*!
 * \brief Determine if one extension should match before another
 *
 * \param a extension to compare with b
 * \param b extension to compare with a
 *
 * Checks whether or extension a should match before extension b
 *
 * \retval 0 if the two extensions have equal matching priority
 * \retval 1 on a > b
 * \retval -1 on a < b
 */
int ast_extension_cmp(const char *a, const char *b);

/*!
 * \brief Launch a new extension (i.e. new stack)
 *
 * \param c not important
 * \param context which context to generate the extension within
 * \param exten new extension to add
 * \param priority priority of new extension
 * \param callerid callerid of extension
 * \param found
 * \param combined_find_spawn
 *
 * This adds a new extension to the asterisk extension list.
 *
 * \note It is possible for autoservice to be started and stopped on c during this
 * function call, it is important that c is not locked prior to calling this. Otherwise
 * a deadlock may occur
 *
 * \retval 0 on success
 * \retval -1 on failure.
 */
int ast_spawn_extension(struct ast_channel *c, const char *context,
      const char *exten, int priority, const char *callerid, int *found, int combined_find_spawn);

/*!
 * \brief Add a context include
 *
 * \param context context to add include to
 * \param include new include to add
 * \param registrar who's registering it
 *
 * Adds an include taking a char * string as the context parameter
 *
 * \retval 0 on success
 * \retval -1 on error
*/
int ast_context_add_include(const char *context, const char *include,
	const char *registrar);

/*!
 * \brief Add a context include
 *
 * \param con context to add the include to
 * \param include include to add
 * \param registrar who registered the context
 *
 * Adds an include taking a struct ast_context as the first parameter
 *
 * \retval 0 on success
 * \retval -1 on failure
 */
int ast_context_add_include2(struct ast_context *con, const char *include,
	const char *registrar);

/*!
 * \brief Remove a context include
 *
 * \note See ast_context_add_include for information on arguments
 *
 * \retval 0 on success
 * \retval -1 on failure
 */
int ast_context_remove_include(const char *context, const char *include,
	const char *registrar);

/*!
 * \brief Removes an include by an ast_context structure
 *
 * \note See ast_context_add_include2 for information on arguments
 *
 * \retval 0 on success
 * \retval -1 on success
 */
int ast_context_remove_include2(struct ast_context *con, const char *include,
	const char *registrar);

/*!
 * \brief Verifies includes in an ast_contect structure
 *
 * \param con context in which to verify the includes
 *
 * \retval 0 if no problems found
 * \retval -1 if there were any missing context
 */
int ast_context_verify_includes(struct ast_context *con);

/*!
 * \brief Add a switch
 *
 * \param context context to which to add the switch
 * \param sw switch to add
 * \param data data to pass to switch
 * \param eval whether to evaluate variables when running switch
 * \param registrar whoever registered the switch
 *
 * This function registers a switch with the asterisk switch architecture
 *
 * \retval 0 on success
 * \retval -1 on failure
 */
int ast_context_add_switch(const char *context, const char *sw, const char *data,
	int eval, const char *registrar);

/*!
 * \brief Adds a switch (first param is a ast_context)
 *
 * \note See ast_context_add_switch() for argument information, with the exception of
 *       the first argument. In this case, it's a pointer to an ast_context structure
 *       as opposed to the name.
 */
int ast_context_add_switch2(struct ast_context *con, const char *sw, const char *data,
	int eval, const char *registrar);

/*!
 * \brief Remove a switch
 *
 * Removes a switch with the given parameters
 *
 * \retval 0 on success
 * \retval -1 on failure
 */
int ast_context_remove_switch(const char *context, const char *sw,
	const char *data, const char *registrar);

int ast_context_remove_switch2(struct ast_context *con, const char *sw,
	const char *data, const char *registrar);

/*!
 * \brief Simply remove extension from context
 *
 * \param context context to remove extension from
 * \param extension which extension to remove
 * \param priority priority of extension to remove (0 to remove all)
 * \param registrar registrar of the extension
 *
 * This function removes an extension from a given context.
 *
 * \retval 0 on success
 * \retval -1 on failure
 *
 * @{
 */
int ast_context_remove_extension(const char *context, const char *extension, int priority,
	const char *registrar);

int ast_context_remove_extension2(struct ast_context *con, const char *extension,
	int priority, const char *registrar, int already_locked);

int ast_context_remove_extension_callerid(const char *context, const char *extension,
	int priority, const char *callerid, int matchcid, const char *registrar);

int ast_context_remove_extension_callerid2(struct ast_context *con, const char *extension,
	int priority, const char *callerid, int matchcid, const char *registrar,
	int already_locked);
/*! @} */

/*!
 * \brief Add an ignorepat
 *
 * \param context which context to add the ignorpattern to
 * \param ignorepat ignorepattern to set up for the extension
 * \param registrar registrar of the ignore pattern
 *
 * Adds an ignore pattern to a particular context.
 *
 * \retval 0 on success
 * \retval -1 on failure
 */
int ast_context_add_ignorepat(const char *context, const char *ignorepat, const char *registrar);

int ast_context_add_ignorepat2(struct ast_context *con, const char *ignorepat, const char *registrar);

/*
 * \brief Remove an ignorepat
 *
 * \param context context from which to remove the pattern
 * \param ignorepat the pattern to remove
 * \param registrar the registrar of the ignore pattern
 *
 * This removes the given ignorepattern
 *
 * \retval 0 on success
 * \retval -1 on failure
 */
int ast_context_remove_ignorepat(const char *context, const char *ignorepat, const char *registrar);

int ast_context_remove_ignorepat2(struct ast_context *con, const char *ignorepat, const char *registrar);

/*!
 * \brief Checks to see if a number should be ignored
 *
 * \param context context to search within
 * \param pattern to check whether it should be ignored or not
 *
 * Check if a number should be ignored with respect to dialtone cancellation.
 *
 * \retval 0 if the pattern should not be ignored
 * \retval non-zero if the pattern should be ignored
 */
int ast_ignore_pattern(const char *context, const char *pattern);

/* Locking functions for outer modules, especially for completion functions */

/*!
 * \brief Write locks the context list
 *
 * \retval 0 on success
 * \retval -1 on error
 */
int ast_wrlock_contexts(void);

/*!
 * \brief Read locks the context list
 *
 * \retval 0 on success
 * \retval -1 on error
 */
int ast_rdlock_contexts(void);

/*!
 * \brief Unlocks contexts
 *
 * \retval 0 on success
 * \retval -1 on failure
 */
int ast_unlock_contexts(void);

/*!
 * \brief Write locks a given context
 *
 * \param con context to lock
 *
 * \retval 0 on success
 * \retval -1 on failure
 */
int ast_wrlock_context(struct ast_context *con);

/*!
 * \brief Read locks a given context
 *
 * \param con context to lock
 *
 * \retval 0 on success
 * \retval -1 on failure
 */
int ast_rdlock_context(struct ast_context *con);

/*!
 * \retval Unlocks the given context
 *
 * \param con context to unlock
 *
 * \retval 0 on success
 * \retval -1 on failure
 */
int ast_unlock_context(struct ast_context *con);

/*!
 * \brief locks the macrolock in the given given context
 *
 * \param macrocontext name of the macro-context to lock
 *
 * Locks the given macro-context to ensure only one thread (call) can execute it at a time
 *
 * \retval 0 on success
 * \retval -1 on failure
 */
int ast_context_lockmacro(const char *macrocontext);

/*!
 * \brief Unlocks the macrolock in the given context
 *
 * \param macrocontext name of the macro-context to unlock
 *
 * Unlocks the given macro-context so that another thread (call) can execute it
 *
 * \retval 0 on success
 * \retval -1 on failure
 */
int ast_context_unlockmacro(const char *macrocontext);

/*!
 * \brief Set the channel to next execute the specified dialplan location.
 * \see ast_async_parseable_goto, ast_async_goto_if_exists
 *
 * \note Do _NOT_ hold any channel locks when calling this function.
 */
int ast_async_goto(struct ast_channel *chan, const char *context, const char *exten, int priority);

/*!
 * \brief Set the channel to next execute the specified dialplan location.
 */
int ast_async_goto_by_name(const char *chan, const char *context, const char *exten, int priority);

/*! Synchronously or asynchronously make an outbound call and send it to a
   particular extension */
int ast_pbx_outgoing_exten(const char *type, format_t format, void *data, int timeout, const char *context, const char *exten, int priority, int *reason, int sync, const char *cid_num, const char *cid_name, struct ast_variable *vars, const char *account, struct ast_channel **locked_channel);

/*! Synchronously or asynchronously make an outbound call and send it to a
   particular application with given extension */
int ast_pbx_outgoing_app(const char *type, format_t format, void *data, int timeout, const char *app, const char *appdata, int *reason, int sync, const char *cid_num, const char *cid_name, struct ast_variable *vars, const char *account, struct ast_channel **locked_channel);

/*!
 * \brief Evaluate a condition
 *
 * \retval 0 if the condition is NULL or of zero length
 * \retval int If the string is an integer, the integer representation of
 *             the integer is returned
 * \retval 1 Any other non-empty string
 */
int pbx_checkcondition(const char *condition);

/*! @name
 * Functions for returning values from structures */
/*! @{ */
const char *ast_get_context_name(struct ast_context *con);
const char *ast_get_extension_name(struct ast_exten *exten);
struct ast_context *ast_get_extension_context(struct ast_exten *exten);
const char *ast_get_include_name(struct ast_include *include);
const char *ast_get_ignorepat_name(struct ast_ignorepat *ip);
const char *ast_get_switch_name(struct ast_sw *sw);
const char *ast_get_switch_data(struct ast_sw *sw);
int ast_get_switch_eval(struct ast_sw *sw);

/*! @} */

/*! @name Other Extension stuff */
/*! @{ */
int ast_get_extension_priority(struct ast_exten *exten);
int ast_get_extension_matchcid(struct ast_exten *e);
const char *ast_get_extension_cidmatch(struct ast_exten *e);
const char *ast_get_extension_app(struct ast_exten *e);
const char *ast_get_extension_label(struct ast_exten *e);
void *ast_get_extension_app_data(struct ast_exten *e);
/*! @} */

/*! @name Registrar info functions ... */
/*! @{ */
const char *ast_get_context_registrar(struct ast_context *c);
const char *ast_get_extension_registrar(struct ast_exten *e);
const char *ast_get_include_registrar(struct ast_include *i);
const char *ast_get_ignorepat_registrar(struct ast_ignorepat *ip);
const char *ast_get_switch_registrar(struct ast_sw *sw);
/*! @} */

/*! @name Walking functions ... */
/*! @{ */
struct ast_context *ast_walk_contexts(struct ast_context *con);
struct ast_exten *ast_walk_context_extensions(struct ast_context *con,
	struct ast_exten *priority);
struct ast_exten *ast_walk_extension_priorities(struct ast_exten *exten,
	struct ast_exten *priority);
struct ast_include *ast_walk_context_includes(struct ast_context *con,
	struct ast_include *inc);
struct ast_ignorepat *ast_walk_context_ignorepats(struct ast_context *con,
	struct ast_ignorepat *ip);
struct ast_sw *ast_walk_context_switches(struct ast_context *con, struct ast_sw *sw);
/*! @} */

/*!
 * \brief Create a human-readable string, specifying all variables and their corresponding values.
 * \param chan Channel from which to read variables
 * \param buf Dynamic string in which to place the result (should be allocated with ast_str_create).
 * \see ast_str_create
 * \note Will lock the channel.
 */
int pbx_builtin_serialize_variables(struct ast_channel *chan, struct ast_str **buf);

/*!
 * \brief Return a pointer to the value of the corresponding channel variable.
 * \note Will lock the channel.
 *
 * \note This function will return a pointer to the buffer inside the channel
 * variable.  This value should only be accessed with the channel locked.  If
 * the value needs to be kept around, it should be done by using the following
 * thread-safe code:
 * \code
 *		const char *var;
 *
 *		ast_channel_lock(chan);
 *		if ((var = pbx_builtin_getvar_helper(chan, "MYVAR"))) {
 *			var = ast_strdupa(var);
 *		}
 *		ast_channel_unlock(chan);
 * \endcode
 */
const char *pbx_builtin_getvar_helper(struct ast_channel *chan, const char *name);

/*!
 * \brief Add a variable to the channel variable stack, without removing any previously set value.
 * \note Will lock the channel.
 */
void pbx_builtin_pushvar_helper(struct ast_channel *chan, const char *name, const char *value);

/*!
 * \brief Add a variable to the channel variable stack, removing the most recently set value for the same name.
 * \note Will lock the channel.  May also be used to set a channel dialplan function to a particular value.
 * \see ast_func_write
 * \return -1 if the dialplan function fails to be set
 * \version 1.8 changed the function to return an error code
 */
int pbx_builtin_setvar_helper(struct ast_channel *chan, const char *name, const char *value);

/*!
 * \brief Retrieve the value of a builtin variable or variable from the channel variable stack.
 * \note Will lock the channel.
 */
void pbx_retrieve_variable(struct ast_channel *c, const char *var, char **ret, char *workspace, int workspacelen, struct varshead *headp);
void pbx_builtin_clear_globals(void);

/*!
 * \brief Parse and set a single channel variable, where the name and value are separated with an '=' character.
 * \note Will lock the channel.
 */
int pbx_builtin_setvar(struct ast_channel *chan, const char *data);

/*!
 * \brief Parse and set multiple channel variables, where the pairs are separated by the ',' character, and name and value are separated with an '=' character.
 * \note Will lock the channel.
 */
int pbx_builtin_setvar_multiple(struct ast_channel *chan, const char *data);

int pbx_builtin_raise_exception(struct ast_channel *chan, const char *data);

/*! @name Substitution routines, using static string buffers
 * @{ */
void pbx_substitute_variables_helper(struct ast_channel *c, const char *cp1, char *cp2, int count);
void pbx_substitute_variables_varshead(struct varshead *headp, const char *cp1, char *cp2, int count);
void pbx_substitute_variables_helper_full(struct ast_channel *c, struct varshead *headp, const char *cp1, char *cp2, int cp2_size, size_t *used);
/*! @} */
/*! @} */

/*! @name Substitution routines, using dynamic string buffers */

/*!
 * \param buf Result will be placed in this buffer.
 * \param maxlen -1 if the buffer should not grow, 0 if the buffer may grow to any size, and >0 if the buffer should grow only to that number of bytes.
 * \param chan Channel variables from which to extract values, and channel to pass to any dialplan functions.
 * \param headp If no channel is specified, a channel list from which to extract variable values
 * \param var Variable name to retrieve.
 */
const char *ast_str_retrieve_variable(struct ast_str **buf, ssize_t maxlen, struct ast_channel *chan, struct varshead *headp, const char *var);

/*!
 * \param buf Result will be placed in this buffer.
 * \param maxlen -1 if the buffer should not grow, 0 if the buffer may grow to any size, and >0 if the buffer should grow only to that number of bytes.
 * \param chan Channel variables from which to extract values, and channel to pass to any dialplan functions.
 * \param templ Variable template to expand.
 */
void ast_str_substitute_variables(struct ast_str **buf, ssize_t maxlen, struct ast_channel *chan, const char *templ);

/*!
 * \param buf Result will be placed in this buffer.
 * \param maxlen -1 if the buffer should not grow, 0 if the buffer may grow to any size, and >0 if the buffer should grow only to that number of bytes.
 * \param headp If no channel is specified, a channel list from which to extract variable values
 * \param templ Variable template to expand.
 */
void ast_str_substitute_variables_varshead(struct ast_str **buf, ssize_t maxlen, struct varshead *headp, const char *templ);

/*!
 * \param buf Result will be placed in this buffer.
 * \param maxlen -1 if the buffer should not grow, 0 if the buffer may grow to any size, and >0 if the buffer should grow only to that number of bytes.
 * \param c Channel variables from which to extract values, and channel to pass to any dialplan functions.
 * \param headp If no channel is specified, a channel list from which to extract variable values
 * \param templ Variable template to expand.
 * \param used Number of bytes read from the template.
 */
void ast_str_substitute_variables_full(struct ast_str **buf, ssize_t maxlen, struct ast_channel *c, struct varshead *headp, const char *templ, size_t *used);
/*! @} */

int ast_extension_patmatch(const char *pattern, const char *data);

/*! Set "autofallthrough" flag, if newval is <0, does not actually set.  If
  set to 1, sets to auto fall through.  If newval set to 0, sets to no auto
  fall through (reads extension instead).  Returns previous value. */
int pbx_set_autofallthrough(int newval);

/*! Set "extenpatternmatchnew" flag, if newval is <0, does not actually set.  If
  set to 1, sets to use the new Trie-based pattern matcher.  If newval set to 0, sets to use
  the old linear-search algorithm.  Returns previous value. */
int pbx_set_extenpatternmatchnew(int newval);

/*! Set "overrideswitch" field.  If set and of nonzero length, all contexts
 * will be tried directly through the named switch prior to any other
 * matching within that context.
 * \since 1.6.1
 */
void pbx_set_overrideswitch(const char *newval);

/*!
 * \note This function will handle locking the channel as needed.
 */
int ast_goto_if_exists(struct ast_channel *chan, const char *context, const char *exten, int priority);

/*!
 * \note This function will handle locking the channel as needed.
 */
int ast_parseable_goto(struct ast_channel *chan, const char *goto_string);

/*!
 * \note This function will handle locking the channel as needed.
 */
int ast_async_parseable_goto(struct ast_channel *chan, const char *goto_string);

/*!
 * \note This function will handle locking the channel as needed.
 */
int ast_explicit_goto(struct ast_channel *chan, const char *context, const char *exten, int priority);

/*!
 * \note This function will handle locking the channel as needed.
 */
int ast_async_goto_if_exists(struct ast_channel *chan, const char *context, const char *exten, int priority);

struct ast_custom_function* ast_custom_function_find(const char *name);

/*!
 * \brief Unregister a custom function
 */
int ast_custom_function_unregister(struct ast_custom_function *acf);

/*!
 * \brief Register a custom function
 */
#define ast_custom_function_register(acf) __ast_custom_function_register(acf, ast_module_info->self)

/*!
 * \brief Register a custom function
 */
int __ast_custom_function_register(struct ast_custom_function *acf, struct ast_module *mod);

/*!
 * \brief Retrieve the number of active calls
 */
int ast_active_calls(void);

/*!
 * \brief Retrieve the total number of calls processed through the PBX since last restart
 */
int ast_processed_calls(void);

/*!
 * \brief executes a read operation on a function
 *
 * \param chan Channel to execute on
 * \param function Data containing the function call string (will be modified)
 * \param workspace A pointer to safe memory to use for a return value
 * \param len the number of bytes in workspace
 *
 * This application executes a function in read mode on a given channel.
 *
 * \retval 0 success
 * \retval non-zero failure
 */
int ast_func_read(struct ast_channel *chan, const char *function, char *workspace, size_t len);

/*!
 * \brief executes a read operation on a function
 *
 * \param chan Channel to execute on
 * \param function Data containing the function call string (will be modified)
 * \param str A dynamic string buffer into which to place the result.
 * \param maxlen <0 if the dynamic buffer should not grow; >0 if the dynamic buffer should be limited to that number of bytes; 0 if the dynamic buffer has no upper limit
 *
 * This application executes a function in read mode on a given channel.
 *
 * \retval 0 success
 * \retval non-zero failure
 */
int ast_func_read2(struct ast_channel *chan, const char *function, struct ast_str **str, ssize_t maxlen);

/*!
 * \brief executes a write operation on a function
 *
 * \param chan Channel to execute on
 * \param function Data containing the function call string (will be modified)
 * \param value A value parameter to pass for writing
 *
 * This application executes a function in write mode on a given channel.
 *
 * \retval 0 success
 * \retval non-zero failure
 */
int ast_func_write(struct ast_channel *chan, const char *function, const char *value);

/*!
 * \details
 * When looking up extensions, we can have different requests
 * identified by the 'action' argument, as follows.
 *
 * \note that the coding is such that the low 4 bits are the
 * third argument to extension_match_core.
 */
enum ext_match_t {
	E_MATCHMORE = 	0x00,	/* extension can match but only with more 'digits' */
	E_CANMATCH =	0x01,	/* extension can match with or without more 'digits' */
	E_MATCH =	0x02,	/* extension is an exact match */
	E_MATCH_MASK =	0x03,	/* mask for the argument to extension_match_core() */
	E_SPAWN =	0x12,	/* want to spawn an extension. Requires exact match */
	E_FINDLABEL =	0x22	/* returns the priority for a given label. Requires exact match */
};

#define STATUS_NO_CONTEXT	1
#define STATUS_NO_EXTENSION	2
#define STATUS_NO_PRIORITY	3
#define STATUS_NO_LABEL		4
#define STATUS_SUCCESS		5
#define AST_PBX_MAX_STACK  128

/* request and result for pbx_find_extension */
struct pbx_find_info {
#if 0
	const char *context;
	const char *exten;
	int priority;
#endif

	char *incstack[AST_PBX_MAX_STACK];      /* filled during the search */
	int stacklen;                   /* modified during the search */
	int status;                     /* set on return */
	struct ast_switch *swo;         /* set on return */
	const char *data;               /* set on return */
	const char *foundcontext;       /* set on return */
};

struct ast_exten *pbx_find_extension(struct ast_channel *chan,
									 struct ast_context *bypass, struct pbx_find_info *q,
									 const char *context, const char *exten, int priority,
									 const char *label, const char *callerid, enum ext_match_t action);

/*! \brief hashtable functions for contexts */
/*! @{ */
int ast_hashtab_compare_contexts(const void *ah_a, const void *ah_b);
unsigned int ast_hashtab_hash_contexts(const void *obj);
/*! @} */

/*!
 * \brief Command completion for the list of installed applications.
 *
 * This can be called from a CLI command completion function that wants to
 * complete from the list of available applications.
 */
char *ast_complete_applications(const char *line, const char *word, int state);

#if defined(__cplusplus) || defined(c_plusplus)
}
#endif

#endif /* _ASTERISK_PBX_H */