test.sh

#!/bin/bash
echo "Please wait, your video is downloading"
var=$(youtube-dl $1 | grep "Destination")
var=$(echo $var | cut -d ':' -f2)
var=$(echo $var | xargs)
output=$(echo $var | sed 's/...$//')
output=$output"mp3"
avconv -i "$var" "$output"
echo "Video File Name : " $var
echo "Audio File Name : " $output