#!/bin/bash

getvolume() {
        volume=$(pactl list sinks | grep Volume | awk 'NR==1{print $5}' | sed 's/%//')
        mute=$(pactl list sinks | grep Mute | awk 'NR==1{print $2}')
        if [[ $mute == "yes" ]]; then
                is_muted="true"
        else
                is_muted="false"
        fi
        echo "{\"value\": ${volume}, \"is_muted\": ${is_muted}}"
}

getvolume
pactl subscribe | while read -r line; do
        if [[ "${line}" =~ sink|source ]]; then
                echo 'it is'
                getvolume
        fi
done