Quick bash script to check battery status from acpi command and alert using using zenity.

check_battery.sh

#!/bin/bash

warn_on=20
debug=0

discharging=`acpi | grep Discharging | wc -l` # will be 1 if discharging and 0 if chargin

if [ $discharging -eq 1 ]; then # if discharging, check percentage
    percentage_remaining=`acpi | grep -o [0-9]*% | sed s/%//g`
    echo "Remaining ${percentage_remaining}"
    if [ $percentage_remaining -lt $warn_on ]; then
        DISPLAY=:0  zenity --notification --text "Warning, battery is discharging and at ${percentage_remaining}%!"
    elif [ $debug -eq 1 ]; then
        DISPLAY=:0  zenity --notification --text "Battery is discharging, but at ${percentage_remaining}% so it's grand!"
    fi
fi