#!/bin/sh

VER=1.0

TMPFILE=/tmp/.battcheck

if [ -f $TMPFILE ]; then
	echo "Already in progress?"
	exit
fi

LOGGER=/usr/bin/logger
BAT_INFO=/proc/acpi/battery/BAT0/info
BAT_STATE=/proc/acpi/battery/BAT0/state
REMAINING=`grep "remaining capacity:" $BAT_STATE | sed -e 's/ //g' | cut -f 2 -d ':' | cut -f 1 -d 'm'`
LOW=`grep "design capacity low:" $BAT_INFO | sed -e 's/ //g' | cut -f 2 -d ':' | cut -f 1 -d 'm'`

if grep -q discharging $BAT_STATE >/dev/null 2>&1
then
	touch $TMPFILE
	if [ $REMAINING -lt $LOW ]; then
		$LOGGER Battery is extremely low, shutting down in 5 minutes
# Alert here
		sleep 5m
		if grep -q discharging $BAT_STATE >/dev/null 2>&1
		then
			rm -f $TMPFILE
			shutdown -hP now Battery is extremely low, shutting down
# If you prefer, comment/delete the shutdown line and use my suspend script
#			/usr/local/bin/suspend hibernate
		else
			rm -f $TMPFILE
			$LOGGER Shutdown avoided, AC has been restored.
		fi
	else
		rm -f $TMPFILE
	fi
fi