mpd-notify/libmpdclient.h

   1 /* libmpdclient
   2    (c)2003-2006 by Warren Dukes (warren.dukes@gmail.com)
   3    This project's homepage is: http://www.musicpd.org
   4
   5    Redistribution and use in source and binary forms, with or without
   6    modification, are permitted provided that the following conditions
   7    are met:
   8
   9    - Redistributions of source code must retain the above copyright
  10    notice, this list of conditions and the following disclaimer.
  11
  12    - Redistributions in binary form must reproduce the above copyright
  13    notice, this list of conditions and the following disclaimer in the
  14    documentation and/or other materials provided with the distribution.
  15
  16    - Neither the name of the Music Player Daemon nor the names of its
  17    contributors may be used to endorse or promote products derived from
  18    this software without specific prior written permission.
  19
  20    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  21    ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  22    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  23    A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
  24    CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  25    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  26    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  27    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  28    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  29    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  30    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31 */
  32
  33 #ifndef LIBMPDCLIENT_H
  34 #define LIBMPDCLIENT_H
  35
  36 #ifdef WIN32
  37 #  define __W32API_USE_DLLIMPORT__ 1
  38 #endif
  39
  40 #include <sys/time.h>
  41 #include <stdarg.h>
  42 #define MPD_BUFFER_MAX_LENGTH   50000
  43 #define MPD_ERRORSTR_MAX_LENGTH 1000
  44 #define MPD_WELCOME_MESSAGE     "OK MPD "
  45
  46 #define MPD_ERROR_TIMEOUT       10 /* timeout trying to talk to mpd */
  47 #define MPD_ERROR_SYSTEM        11 /* system error */
  48 #define MPD_ERROR_UNKHOST       12 /* unknown host */
  49 #define MPD_ERROR_CONNPORT      13 /* problems connecting to port on host */
  50 #define MPD_ERROR_NOTMPD        14 /* mpd not running on port at host */
  51 #define MPD_ERROR_NORESPONSE    15 /* no response on attempting to connect */
  52 #define MPD_ERROR_SENDING       16 /* error sending command */
  53 #define MPD_ERROR_CONNCLOSED    17 /* connection closed by mpd */
  54 #define MPD_ERROR_ACK           18 /* ACK returned! */
  55 #define MPD_ERROR_BUFFEROVERRUN 19 /* Buffer was overrun! */
  56
  57 #define MPD_ACK_ERROR_UNK       -1
  58 #define MPD_ERROR_AT_UNK        -1
  59
  60 #define MPD_ACK_ERROR_NOT_LIST                  1
  61 #define MPD_ACK_ERROR_ARG                       2
  62 #define MPD_ACK_ERROR_PASSWORD                  3
  63 #define MPD_ACK_ERROR_PERMISSION                4
  64 #define MPD_ACK_ERROR_UNKNOWN_CMD               5
  65
  66 #define MPD_ACK_ERROR_NO_EXIST                  50
  67 #define MPD_ACK_ERROR_PLAYLIST_MAX              51
  68 #define MPD_ACK_ERROR_SYSTEM                    52
  69 #define MPD_ACK_ERROR_PLAYLIST_LOAD             53
  70 #define MPD_ACK_ERROR_UPDATE_ALREADY            54
  71 #define MPD_ACK_ERROR_PLAYER_SYNC               55
  72 #define MPD_ACK_ERROR_EXIST                     56
  73
  74 #ifdef __cplusplus
  75 extern "C" {
  76 #endif
  77
  78 typedef enum mpd_TagItems
  79 {
  80         MPD_TAG_ITEM_ARTIST,
  81         MPD_TAG_ITEM_ALBUM,
  82         MPD_TAG_ITEM_TITLE,
  83         MPD_TAG_ITEM_TRACK,
  84         MPD_TAG_ITEM_NAME,
  85         MPD_TAG_ITEM_GENRE,
  86         MPD_TAG_ITEM_DATE,
  87         MPD_TAG_ITEM_COMPOSER,
  88         MPD_TAG_ITEM_PERFORMER,
  89         MPD_TAG_ITEM_COMMENT,
  90         MPD_TAG_ITEM_DISC,
  91         MPD_TAG_ITEM_FILENAME,
  92         MPD_TAG_ITEM_ANY,
  93         MPD_TAG_NUM_OF_ITEM_TYPES
  94 } mpd_TagItems;
  95
  96 extern char * mpdTagItemKeys[MPD_TAG_NUM_OF_ITEM_TYPES];
  97
  98 /* internal stuff don't touch this struct */
  99 typedef struct _mpd_ReturnElement {
 100         char * name;
 101         char * value;
 102 } mpd_ReturnElement;
 103
 104 /* mpd_Connection
 105  * holds info about connection to mpd
 106  * use error, and errorStr to detect errors
 107  */
 108 typedef struct _mpd_Connection {
 109         /* use this to check the version of mpd */
 110         int version[3];
 111         /* IMPORTANT, you want to get the error messages from here */
 112         char errorStr[MPD_ERRORSTR_MAX_LENGTH+1];
 113         int errorCode;
 114         int errorAt;
 115         /* this will be set to MPD_ERROR_* if there is an error, 0 if not */
 116         int error;
 117         /* DON'T TOUCH any of the rest of this stuff */
 118         int sock;
 119         char buffer[MPD_BUFFER_MAX_LENGTH+1];
 120         int buflen;
 121         int bufstart;
 122         int doneProcessing;
 123         int listOks;
 124         int doneListOk;
 125         int commandList;
 126         mpd_ReturnElement * returnElement;
 127         struct timeval timeout;
 128         char *request;
 129 } mpd_Connection;
 130
 131 /* mpd_newConnection
 132  * use this to open a new connection
 133  * you should use mpd_closeConnection, when your done with the connection,
 134  * even if an error has occurred
 135  * _timeout_ is the connection timeout period in seconds
 136  */
 137 mpd_Connection * mpd_newConnection(const char * host, int port, float timeout);
 138
 139 void mpd_setConnectionTimeout(mpd_Connection * connection, float timeout);
 140
 141 /* mpd_closeConnection
 142  * use this to close a connection and free'ing subsequent memory
 143  */
 144 void mpd_closeConnection(mpd_Connection * connection);
 145
 146 /* mpd_clearError
 147  * clears error
 148  */
 149 void mpd_clearError(mpd_Connection * connection);
 150
 151 /* STATUS STUFF */
 152
 153 /* use these with status.state to determine what state the player is in */
 154 #define MPD_STATUS_STATE_UNKNOWN        0
 155 #define MPD_STATUS_STATE_STOP           1
 156 #define MPD_STATUS_STATE_PLAY           2
 157 #define MPD_STATUS_STATE_PAUSE          3
 158
 159 /* us this with status.volume to determine if mpd has volume support */
 160 #define MPD_STATUS_NO_VOLUME            -1
 161
 162 /* mpd_Status
 163  * holds info return from status command
 164  */
 165 typedef struct mpd_Status {
 166         /* 0-100, or MPD_STATUS_NO_VOLUME when there is no volume support */
 167         int volume;
 168         /* 1 if repeat is on, 0 otherwise */
 169         int repeat;
 170         /* 1 if random is on, 0 otherwise */
 171         int random;
 172         /* playlist length */
 173         int playlistLength;
 174         /* playlist, use this to determine when the playlist has changed */
 175         long long playlist;
 176         /* use with MPD_STATUS_STATE_* to determine state of player */
 177         int state;
 178         /* crossfade setting in seconds */
 179         int crossfade;
 180         /* if a song is currently selected (always the case when state is
 181          * PLAY or PAUSE), this is the position of the currently
 182          * playing song in the playlist, beginning with 0
 183          */
 184         int song;
 185         /* Song ID of the currently selected song */
 186         int songid;
 187         /* time in seconds that have elapsed in the currently playing/paused
 188          * song
 189          */
 190         int elapsedTime;
 191         /* length in seconds of the currently playing/paused song */
 192         int totalTime;
 193         /* current bit rate in kbs */
 194         int bitRate;
 195         /* audio sample rate */
 196         unsigned int sampleRate;
 197         /* audio bits */
 198         int bits;
 199         /* audio channels */
 200         int channels;
 201         /* 1 if mpd is updating, 0 otherwise */
 202         int updatingDb;
 203         /* error */
 204         char * error;
 205 } mpd_Status;
 206
 207 void mpd_sendStatusCommand(mpd_Connection * connection);
 208
 209 /* mpd_getStatus
 210  * returns status info, be sure to free it with mpd_freeStatus()
 211  * call this after mpd_sendStatusCommand()
 212  */
 213 mpd_Status * mpd_getStatus(mpd_Connection * connection);
 214
 215 /* mpd_freeStatus
 216  * free's status info malloc'd and returned by mpd_getStatus
 217  */
 218 void mpd_freeStatus(mpd_Status * status);
 219
 220 typedef struct _mpd_Stats {
 221         int numberOfArtists;
 222         int numberOfAlbums;
 223         int numberOfSongs;
 224         unsigned long uptime;
 225         unsigned long dbUpdateTime;
 226         unsigned long playTime;
 227         unsigned long dbPlayTime;
 228 } mpd_Stats;
 229
 230 void mpd_sendStatsCommand(mpd_Connection * connection);
 231
 232 mpd_Stats * mpd_getStats(mpd_Connection * connection);
 233
 234 void mpd_freeStats(mpd_Stats * stats);
 235
 236 /* SONG STUFF */
 237
 238 #define MPD_SONG_NO_TIME        -1
 239 #define MPD_SONG_NO_NUM         -1
 240 #define MPD_SONG_NO_ID          -1
 241
 242 /* mpd_Song
 243  * for storing song info returned by mpd
 244  */
 245 typedef struct _mpd_Song {
 246         /* filename of song */
 247         char * file;
 248         /* artist, maybe NULL if there is no tag */
 249         char * artist;
 250         /* title, maybe NULL if there is no tag */
 251         char * title;
 252         /* album, maybe NULL if there is no tag */
 253         char * album;
 254         /* track, maybe NULL if there is no tag */
 255         char * track;
 256         /* name, maybe NULL if there is no tag; it's the name of the current
 257          * song, f.e. the icyName of the stream */
 258         char * name;
 259         /* date */
 260         char *date;
 261
 262         /* added by qball */
 263         /* Genre */
 264         char *genre;
 265         /* Composer */
 266         char *composer;
 267         /* Disc */
 268         char *disc;
 269         /* Comment */
 270         char *comment;
 271
 272         /* length of song in seconds, check that it is not MPD_SONG_NO_TIME  */
 273         int time;
 274         /* if plchanges/playlistinfo/playlistid used, is the position of the
 275          * song in the playlist */
 276         int pos;
 277         /* song id for a song in the playlist */
 278         int id;
 279 } mpd_Song;
 280
 281 /* mpd_newSong
 282  * use to allocate memory for a new mpd_Song
 283  * file, artist, etc all initialized to NULL
 284  * if your going to assign values to file, artist, etc
 285  * be sure to malloc or strdup the memory
 286  * use mpd_freeSong to free the memory for the mpd_Song, it will also
 287  * free memory for file, artist, etc, so don't do it yourself
 288  */
 289 mpd_Song * mpd_newSong(void);
 290
 291 /* mpd_freeSong
 292  * use to free memory allocated by mpd_newSong
 293  * also it will free memory pointed to by file, artist, etc, so be careful
 294  */
 295 void mpd_freeSong(mpd_Song * song);
 296
 297 /* mpd_songDup
 298  * works like strDup, but for a mpd_Song
 299  */
 300 mpd_Song * mpd_songDup(mpd_Song * song);
 301
 302 /* DIRECTORY STUFF */
 303
 304 /* mpd_Directory
 305  * used to store info fro directory (right now that just the path)
 306  */
 307 typedef struct _mpd_Directory {
 308         char * path;
 309 } mpd_Directory;
 310
 311 /* mpd_newDirectory
 312  * allocates memory for a new directory
 313  * use mpd_freeDirectory to free this memory
 314  */
 315 mpd_Directory * mpd_newDirectory(void);
 316
 317 /* mpd_freeDirectory
 318  * used to free memory allocated with mpd_newDirectory, and it frees
 319  * path of mpd_Directory, so be careful
 320  */
 321 void mpd_freeDirectory(mpd_Directory * directory);
 322
 323 /* mpd_directoryDup
 324  * works like strdup, but for mpd_Directory
 325  */
 326 mpd_Directory * mpd_directoryDup(mpd_Directory * directory);
 327
 328 /* PLAYLISTFILE STUFF */
 329
 330 /* mpd_PlaylistFile
 331  * stores info about playlist file returned by lsinfo
 332  */
 333 typedef struct _mpd_PlaylistFile {
 334         char * path;
 335 } mpd_PlaylistFile;
 336
 337 /* mpd_newPlaylistFile
 338  * allocates memory for new mpd_PlaylistFile, path is set to NULL
 339  * free this memory with mpd_freePlaylistFile
 340  */
 341 mpd_PlaylistFile * mpd_newPlaylistFile(void);
 342
 343 /* mpd_freePlaylist
 344  * free memory allocated for freePlaylistFile, will also free
 345  * path, so be careful
 346  */
 347 void mpd_freePlaylistFile(mpd_PlaylistFile * playlist);
 348
 349 /* mpd_playlistFileDup
 350  * works like strdup, but for mpd_PlaylistFile
 351  */
 352 mpd_PlaylistFile * mpd_playlistFileDup(mpd_PlaylistFile * playlist);
 353
 354 /* INFO ENTITY STUFF */
 355
 356 /* the type of entity returned from one of the commands that generates info
 357  * use in conjunction with mpd_InfoEntity.type
 358  */
 359 #define MPD_INFO_ENTITY_TYPE_DIRECTORY          0
 360 #define MPD_INFO_ENTITY_TYPE_SONG               1
 361 #define MPD_INFO_ENTITY_TYPE_PLAYLISTFILE       2
 362
 363 /* mpd_InfoEntity
 364  * stores info on stuff returned info commands
 365  */
 366 typedef struct mpd_InfoEntity {
 367         /* the type of entity, use with MPD_INFO_ENTITY_TYPE_* to determine
 368          * what this entity is (song, directory, etc...)
 369          */
 370         int type;
 371         /* the actual data you want, mpd_Song, mpd_Directory, etc */
 372         union {
 373                 mpd_Directory * directory;
 374                 mpd_Song * song;
 375                 mpd_PlaylistFile * playlistFile;
 376         } info;
 377 } mpd_InfoEntity;
 378
 379 mpd_InfoEntity * mpd_newInfoEntity(void);
 380
 381 void mpd_freeInfoEntity(mpd_InfoEntity * entity);
 382
 383 /* INFO COMMANDS AND STUFF */
 384
 385 /* use this function to loop over after calling Info/Listall functions */
 386 mpd_InfoEntity * mpd_getNextInfoEntity(mpd_Connection * connection);
 387
 388 /* fetches the currently seeletect song (the song referenced by status->song
 389  * and status->songid*/
 390 void mpd_sendCurrentSongCommand(mpd_Connection * connection);
 391
 392 /* songNum of -1, means to display the whole list */
 393 void mpd_sendPlaylistInfoCommand(mpd_Connection * connection, int songNum);
 394
 395 /* songId of -1, means to display the whole list */
 396 void mpd_sendPlaylistIdCommand(mpd_Connection * connection, int songId);
 397
 398 /* use this to get the changes in the playlist since version _playlist_ */
 399 void mpd_sendPlChangesCommand(mpd_Connection * connection, long long playlist);
 400
 401 /**
 402  * @param connection: A valid and connected mpd_Connection.
 403  * @param playlist: The playlist version you want the diff with.
 404  * A more bandwidth efficient version of the mpd_sendPlChangesCommand.
 405  * It only returns the pos+id of the changes song.
 406  */
 407 void mpd_sendPlChangesPosIdCommand(mpd_Connection * connection, long long playlist);
 408
 409 /* recursivel fetches all songs/dir/playlists in "dir* (no metadata is
 410  * returned) */
 411 void mpd_sendListallCommand(mpd_Connection * connection, const char * dir);
 412
 413 /* same as sendListallCommand, but also metadata is returned */
 414 void mpd_sendListallInfoCommand(mpd_Connection * connection, const char * dir);
 415
 416 /* non-recursive version of ListallInfo */
 417 void mpd_sendLsInfoCommand(mpd_Connection * connection, const char * dir);
 418
 419 #define MPD_TABLE_ARTIST        0
 420 #define MPD_TABLE_ALBUM         1
 421 #define MPD_TABLE_TITLE         2
 422 #define MPD_TABLE_FILENAME      3
 423
 424 void mpd_sendSearchCommand(mpd_Connection * connection, int table,
 425                 const char * str);
 426
 427 void mpd_sendFindCommand(mpd_Connection * connection, int table,
 428                 const char * str);
 429
 430 /* LIST TAG COMMANDS */
 431
 432 /* use this function fetch next artist entry, be sure to free the returned
 433  * string.  NULL means there are no more.  Best used with sendListArtists
 434  */
 435 char * mpd_getNextArtist(mpd_Connection * connection);
 436
 437 char * mpd_getNextAlbum(mpd_Connection * connection);
 438
 439 char * mpd_getNextTag(mpd_Connection *connection, int type);
 440
 441 /* list artist or albums by artist, arg1 should be set to the artist if
 442  * listing albums by a artist, otherwise NULL for listing all artists or albums
 443  */
 444 void mpd_sendListCommand(mpd_Connection * connection, int table,
 445                 const char * arg1);
 446
 447 /* SIMPLE COMMANDS */
 448
 449 void mpd_sendAddCommand(mpd_Connection * connection, const char * file);
 450
 451 int mpd_sendAddIdCommand(mpd_Connection *connection, const char *file);
 452
 453 void mpd_sendDeleteCommand(mpd_Connection * connection, int songNum);
 454
 455 void mpd_sendDeleteIdCommand(mpd_Connection * connection, int songNum);
 456
 457 void mpd_sendSaveCommand(mpd_Connection * connection, const char * name);
 458
 459 void mpd_sendLoadCommand(mpd_Connection * connection, const char * name);
 460
 461 void mpd_sendRmCommand(mpd_Connection * connection, const char * name);
 462
 463 void mpd_sendShuffleCommand(mpd_Connection * connection);
 464
 465 void mpd_sendClearCommand(mpd_Connection * connection);
 466
 467 /* use this to start playing at the beginning, useful when in random mode */
 468 #define MPD_PLAY_AT_BEGINNING   -1
 469
 470 void mpd_sendPlayCommand(mpd_Connection * connection, int songNum);
 471
 472 void mpd_sendPlayIdCommand(mpd_Connection * connection, int songNum);
 473
 474 void mpd_sendStopCommand(mpd_Connection * connection);
 475
 476 void mpd_sendPauseCommand(mpd_Connection * connection, int pauseMode);
 477
 478 void mpd_sendNextCommand(mpd_Connection * connection);
 479
 480 void mpd_sendPrevCommand(mpd_Connection * connection);
 481
 482 void mpd_sendMoveCommand(mpd_Connection * connection, int from, int to);
 483
 484 void mpd_sendMoveIdCommand(mpd_Connection * connection, int from, int to);
 485
 486 void mpd_sendSwapCommand(mpd_Connection * connection, int song1, int song2);
 487
 488 void mpd_sendSwapIdCommand(mpd_Connection * connection, int song1, int song2);
 489
 490 void mpd_sendSeekCommand(mpd_Connection * connection, int song, int time);
 491
 492 void mpd_sendSeekIdCommand(mpd_Connection * connection, int song, int time);
 493
 494 void mpd_sendRepeatCommand(mpd_Connection * connection, int repeatMode);
 495
 496 void mpd_sendRandomCommand(mpd_Connection * connection, int randomMode);
 497
 498 void mpd_sendSetvolCommand(mpd_Connection * connection, int volumeChange);
 499
 500 /* WARNING: don't use volume command, its depreacted */
 501 void mpd_sendVolumeCommand(mpd_Connection * connection, int volumeChange);
 502
 503 void mpd_sendCrossfadeCommand(mpd_Connection * connection, int seconds);
 504
 505 void mpd_sendUpdateCommand(mpd_Connection * connection, char * path);
 506
 507 /* returns the update job id, call this after a update command*/
 508 int mpd_getUpdateId(mpd_Connection * connection);
 509
 510 void mpd_sendPasswordCommand(mpd_Connection * connection, const char * pass);
 511
 512 /* after executing a command, when your done with it to get its status
 513  * (you want to check connection->error for an error)
 514  */
 515 void mpd_finishCommand(mpd_Connection * connection);
 516
 517 /* command list stuff, use this to do things like add files very quickly */
 518 void mpd_sendCommandListBegin(mpd_Connection * connection);
 519
 520 void mpd_sendCommandListOkBegin(mpd_Connection * connection);
 521
 522 void mpd_sendCommandListEnd(mpd_Connection * connection);
 523
 524 /* advance to the next listOk
 525  * returns 0 if advanced to the next list_OK,
 526  * returns -1 if it advanced to an OK or ACK */
 527 int mpd_nextListOkCommand(mpd_Connection * connection);
 528
 529 typedef struct _mpd_OutputEntity {
 530         int id;
 531         char * name;
 532         int enabled;
 533 } mpd_OutputEntity;
 534
 535 void mpd_sendOutputsCommand(mpd_Connection * connection);
 536
 537 mpd_OutputEntity * mpd_getNextOutput(mpd_Connection * connection);
 538
 539 void mpd_sendEnableOutputCommand(mpd_Connection * connection, int outputId);
 540
 541 void mpd_sendDisableOutputCommand(mpd_Connection * connection, int outputId);
 542
 543 void mpd_freeOutputElement(mpd_OutputEntity * output);
 544
 545 /**
 546  * @param connection a #mpd_Connection
 547  *
 548  * Queries mpd for the allowed commands
 549  */
 550 void mpd_sendCommandsCommand(mpd_Connection * connection);
 551
 552 /**
 553  * @param connection a #mpd_Connection
 554  *
 555  * Queries mpd for the not allowed commands
 556  */
 557 void mpd_sendNotCommandsCommand(mpd_Connection * connection);
 558
 559 /**
 560  * @param connection a #mpd_Connection
 561  *
 562  * returns the next supported command.
 563  *
 564  * @returns a string, needs to be free'ed
 565  */
 566 char *mpd_getNextCommand(mpd_Connection *connection);
 567
 568 /**
 569  * @param connection a MpdConnection
 570  * @param path  the path to the playlist.
 571  *
 572  * List the content, with full metadata, of a stored playlist.
 573  *
 574  */
 575 void mpd_sendListPlaylistInfoCommand(mpd_Connection *connection, char *path);
 576
 577 /**
 578  * @param connection a MpdConnection
 579  * @param path  the path to the playlist.
 580  *
 581  * List the content of a stored playlist.
 582  *
 583  */
 584 void mpd_sendListPlaylistCommand(mpd_Connection *connection, char *path);
 585
 586 /**
 587  * @param connection a #mpd_Connection
 588  * @param exact if to match exact
 589  *
 590  * starts a search, use mpd_addConstraintSearch to add
 591  * a constraint to the search, and mpd_commitSearch to do the actual search
 592  */
 593 void mpd_startSearch(mpd_Connection *connection, int exact);
 594
 595 /**
 596  * @param connection a #mpd_Connection
 597  * @param type
 598  * @param name
 599  */
 600 void mpd_addConstraintSearch(mpd_Connection *connection, int type, char *name);
 601
 602 /**
 603  * @param connection a #mpd_Connection
 604  */
 605 void mpd_commitSearch(mpd_Connection *connection);
 606
 607 /**
 608  * @param connection a #mpd_Connection
 609  * @param type The type to search for
 610  *
 611  * starts a search for fields... f.e. get a list of artists would be:
 612  * @code
 613  * mpd_startFieldSearch(connection, MPD_TAG_ITEM_ARTIST);
 614  * mpd_commitSearch(connection);
 615  * @endcode
 616  *
 617  * or get a list of artist in genre "jazz" would be:
 618  * @code
 619  * mpd_startFieldSearch(connection, MPD_TAG_ITEM_ARTIST);
 620  * mpd_addConstraintSearch(connection, MPD_TAG_ITEM_GENRE, "jazz")
 621  * mpd_commitSearch(connection);
 622  * @endcode
 623  *
 624  * mpd_startSearch will return  a list of songs (and you need mpd_getNextInfoEntity)
 625  * this one will return a list of only one field (the one specified with type) and you need
 626  * mpd_getNextTag to get the results
 627  */
 628 void mpd_startFieldSearch(mpd_Connection *connection, int type);
 629 #ifdef __cplusplus
 630 }
 631 #endif
 632
 633 #endif