A bash script to mute/unmute as GPIO button command of moOde Audio Player

mute_unmute.sh

#!/bin/bash
if [ ! -f /var/log/mute_unmute.lock ]; then # avoid running twice in the debounce time
  touch /var/log/mute_unmute.lock
else
  exit 0
fi
volume=$(mpc status | grep volume | awk '{print $2}')
vol=${volume::-1}
if [ "$vol" != "0" ]; then
  echo $vol > /tmp/last_vol
  mpc volume 0
else
  last_vol=$(cat /tmp/last_vol 2>/dev/null | echo 50)
  mpc volume $last_vol
fi
sleep 1.5  # great than the debounce time (which is 1000ms by default)
rm /var/log/mute_unmute.lock