my small last.fm script

it's a pity that lastfm is not going to be free anymore but still... here is my small script that i usually use to listen to last.fm:

#!/usr/bin/env bash
# shell-fm helper
#* lastfm://user/${user}/loved
#* lastfm://user/${user}/personal
#* lastfm://usertags/${user}/${usertag}
#* lastfm://artist/${artist}/similarartists
#* lastfm://artist/${artist}/fans
#* lastfm://globaltags/${globaltag}
killall -9 shell-fm

function usage() {
 printf "Usage: %s: [-u username] [[-p(ersonal)] [-l(oved)]] [-g globaltag] [-a artist]\n" $(basename $0) >&2
}

 command="lastfm:/"
 artflag=
 while getopts 'u:plg:a' OPTION

 do
   case $OPTION in
   u) command="$command/user/$OPTARG"
   ;;
   l)    command="$command/loved"
  break
   ;;
   p)  command="$command/personal"
  break
   ;;
   a) artflag=1
  command="$command/artist/$artist"
  break
   ;;
   ?)  usage
   exit 2
   ;;
   esac
 done
 

 #printf "Remaining arguments are: %s\n" "$*"

shift $(($OPTIND - 1))
rest=""
if [ $artflag ] 
then
     while [ $# -ge 1 ]; do
         if [ "$rest" != "" ]; then
             rest="$rest+"
         fi
        rest="$rest${1}"
        shift
     done
fi

shell-fm -d $command$rest

(In order to use you need to install also a small "shell-fm" application.)