#!/bin/bash

 

# check command line arguments first

if [ $# != 1 ]; then

        echo "Usage ${0} up|down|mute"

        exit 1

fi

 

if [ $1 != "up" -a $1 != "down" -a $1 != "mute" ]; then

        echo "Usage ${0} up|down|mute"

        exit 1

fi

 

# go through each line of the sink-inputs output

pactl list sink-inputs | while read line; do

        # Update current sink input id 

        [[ $line =~ ^Sink\ Input\ \#([[:digit:]]+) ]] && this_input=${BASH_REMATCH[1]}

        # check if it is spotify

        if [[ $line =~ "application.name = \"spotify\"" ]]; then

                echo "Spotify is sink-input ${this_input}"

                case $1 in

                        up) 

                                pactl set-sink-input-volume ${this_input} +5%

                                ;;

                        down)

                                pactl set-sink-input-volume ${this_input} -5%

                                ;;

                        mute)

                                pactl set-sink-input-mute ${this_input} toggle

                                ;;

                        *)

                                echo "Error"

                                ;;

                esac

        fi

 

done