Youtube download MP3

#!/bin/bash
###################################################################### 
#Copyright (C) 2020  Kris Occhipinti
#https://filmsbykris.com

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

#This program 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 General Public License for more details.

#You should have received a copy of the GNU General Public License
#along with this program.  If not, see .
###################################################################### 

#downloads and extracts mp3 music from youtube url
#checks for url given on command line
#or clipboard

cmd="youtube-dl -c --extract-audio --audio-format mp3"

function fail(){
  echo "$1"
  exit 1
}

echo "Trying to get URL."
[[ "$1" == *"youtu"* ]] && url="$1" || url="$(xclip -o)"
[[ "$url" == *"youtu"* ]] || fail "Bad URL"

echo "$url has been found."

#add command to zsh history
echo ": $(date +%s):0;$cmd '$url'" >> $HOME/.zsh_history
$cmd $url