restart Firefox instead of shutting down when power button is pressed

powerbtn.sh

#!/bin/bash
seconds=5
targetuser="bytecommander"
killprocess="firefox"
startprocess="firefox"

mytempfile="/tmp/powerbtn-touched"

if [ -e /tmp/powerbtn-touched ] && 
   [ $(date +%s --date="$seconds seconds ago") -lt $(date +%s -r "$mytempfile") ]
then
    # run the original powerbtn.sh script
    /etc/acpi/powerbtn-default.sh
    # shut down in case the script does not trigegr that itself
    shutdown now
else
    # set tempfile's modification timestamp to be able to check when it ran the last time
    touch -m "$mytempfile"
    
    # try to softly close all windows of "$killprocess" and give them 5 seconds time
    sudo -u "$targetuser" wmctrl -ic "$(wmctrl -lp | grep "$(pgrep $killprocess)" | tail -1 | awk '{ print $1 }')"
    sleep 5
    
    # force-kill all remaining processes 
    killall -u "$targetuser" "$killprocess"
    # restart the process
    sudo -u "$targetuser" "$startprocess"
fi