volume notification script

#!/bin/bash

#DESKTOP=:0 # need for notifications run 'over' display
mixer_state=$(amixer get Master | awk '$1=="Mono:" {print $6}')
x=$(amixer get Master | sed -rn "/[^[]+\[/{s///;s/%.+//p;q}")
z=$[x/10];  y='◼◼◼◼◼◼◼◼◼◼'
zz=$[10-z];yy='◻◻◻◻◻◻◻◻◻◻'

# get current screen resoultion
curres=$(xdpyinfo | grep dimensions | awk '{print $2}')
# calculate current max x
curmx=$(echo $curres | sed 's/x.*$//')
# calculate current max y
curmy=$(echo $curres | sed 's/^.*x//')

poffset=0

notify_title="Volume"

case $x in
    0*|?|1?)  notify_icon="notification-audio-volume-off";;
    2?|3?|4?)  notify_icon="notification-audio-volume-low";;
    5?|6?|7?)  notify_icon="notification-audio-volume-medium";;
    8?|9?|100)  notify_icon="notification-audio-volume-high";;
esac

if [ $mixer_state == "[off]" ];then
    notify_icon="notification-audio-volume-muted"
    notify_title="$notify_title muted"
fi

notify-send -i $notify_icon -t 1500 -u low -h int:x:$[$curmx-$poffset] -h \
    int:y:$[$curmy-$poffset] "$notify_title" "${y::z}${yy::zz} $x%"