control iTunes from command line

itunes.sh

#!/bin/sh
#
#########################################
# iTunes Command Line Control v1.1
# written by David Schlosnagle
# created 2001.11.08
# edit    2010.06.01 rahul kumar
# edit    2012.12.08 Michael F. Weinberg
#########################################

showHelp () {
    echo "-----------------------------";
    echo "iTunes Command Line Interface";
    echo "-----------------------------";
    echo "Usage: `basename $0` <option>";
    echo;
    echo "Options:";
    echo " status   = Shows iTunes' status, current artist and track.";
    echo " play     = Start playing iTunes.";
    echo " pause    = Pause iTunes.";
    echo " next     = Go to the next track.";
    echo " prev     = Go to the previous track.";
    echo " mute     = Mute iTunes' volume.";
    echo " unmute   = Unmute iTunes' volume.";
    echo " vol up   = Increase iTunes' volume by 10%";
    echo " vol down = Increase iTunes' volume by 10%";
    echo " vol #    = Set iTunes' volume to # [0-100]";
    echo " stop     = Stop iTunes.";
    echo " quit     = Quit iTunes.";
    echo " rate     = Set rating for current track to # [0-5]";
    echo " playlist = Show playlists saved in iTunes.";
    echo " tracks   = Show tracks for current or given playlist.";
}

if [ $# = 0 ]; then
    showHelp;
fi

while [ $# -gt 0 ]; do
    arg=$1;
    case $arg in
        "status" ) state=`osascript -e 'tell application "iTunes" to player state as string'`;
            echo "iTunes is currently $state.";
            if [ $state = "playing" ]; then
                artist=`osascript -e 'tell application "iTunes" to artist of current track as string'`;
                track=`osascript -e 'tell application "iTunes" to name of current track as string'`;
		rating=`osascript -e 'tell application "iTunes" to get rating of current track'`;
		stars=$(( $rating/20 ))
                echo "Current track $artist: $track - $stars stars.";
            fi
            break ;;

        "play"    ) echo "Playing iTunes.";
            osascript -e 'tell application "iTunes" to play';
            break ;;

        "pause"    ) echo "Pausing iTunes.";
            osascript -e 'tell application "iTunes" to pause';
            break ;;

        "next"    ) echo "Going to next track." ;
            osascript -e 'tell application "iTunes" to next track';
            break ;;

        "prev"    ) echo "Going to previous track.";
            osascript -e 'tell application "iTunes" to previous track';
            break ;;

        "mute"    ) echo "Muting iTunes volume level.";
            osascript -e 'tell application "iTunes" to set mute to true';
            break ;;

        "unmute" ) echo "Unmuting iTunes volume level.";
            osascript -e 'tell application "iTunes" to set mute to false';
            break ;;

        "vol"    ) echo "Changing iTunes volume level.";
            vol=`osascript -e 'tell application "iTunes" to sound volume as integer'`;
            if [ $2 = "up" ]; then
                newvol=$(( vol+10 ));
            fi

            if [ $2 = "down" ]; then
                newvol=$(( vol-10 ));
            fi

            if [ $2 -gt 0 ]; then
                newvol=$2;
            fi
            osascript -e "tell application \"iTunes\" to set sound volume to $newvol";
            break ;;

	"rate"    ) echo "Setting track rating to $2 stars.";
	    if [ $2 -ge 0 ] && [ $2 -le 5 ]; then
		rating=$(( $2*20))
	    osascript -e "tell application \"iTunes\" to set rating of current track to $rating";
	    else
	    echo "Rating must be 0-5.";
	    fi
	    break;;

        "stop"    ) echo "Stopping iTunes.";
            osascript -e 'tell application "iTunes" to stop';
            break ;;
            
        "quit"    ) echo "Quitting iTunes.";
            osascript -e 'tell application "iTunes" to quit';
            exit 1 ;;

       ## addition playlist of choice
       "playlist" )
          if [ -n "$2" ]; then
             echo "Changing iTunes playlists to '$2'.";
             osascript -e 'tell application "iTunes"' -e "set new_playlist to \"$2\" as string" -e "play playlist new_playlist" -e "end tell"; 
            break ;
          else
            # Show available iTunes playlists.
            echo "Playlists:";
            playlists=`osascript -e 'tell application "iTunes"' -e "set allPlaylists to (get name of every playlist)" -e "end tell"`;
	    echo $playlists| tr ',' '\n';
            break;
         fi
         break;;

       "tracks" )
          if [ -n "$2" ]; then
             tracks=`osascript -e 'tell application "iTunes"' -e "set new_playlist to \"$2\" as string" -e " get name of every track in playlist new_playlist" -e "end tell"`; 
	     echo $tracks | tr ',' '\n'

             break;
         fi
             tracks=`osascript -e 'tell application "iTunes" to get name of every track in current playlist'`;
	     echo $tracks | tr ',' '\n'
             break ;; 

        "help" | * ) echo "help:";
            showHelp;
            break ;;
    esac
done