#!/bin/sh
# The script to extract information about battery level.
# Michael Pozhidaev 2008 <msp@altlinux.org>

BATTERY_DIR='/etc/battery'
BATTERY_INFO_FILE="$BATTERY_DIR/info"
BATTERY_STATE_FILE="$BATTERY_DIR/state"

if ! [ -d $BATTERY_DIR ]; then
    echo "$BATTERY_DIR does not exist"
    exit 1
fi

set -e

battery_remaining()
{
    l="$(grep 'remaining capacity:' $BATTERY_STATE_FILE)"
    l="${l/remaining capacity:}"
    l="${l/ mAh}"
    echo $l
}

battery_capacity()
{
    l="$(grep 'design capacity:' $BATTERY_INFO_FILE)"
    l="${l/design capacity:}"
    l="${l/ mAh}"
    echo $l
}

battery_level()
{
    c=$(battery_capacity)
    r=$(battery_remaining)
    let l=$r*100/$c
    echo $l
}

battery_level