#!/bin/bash

# Simple utility script for turning the LEDs on and off.
# Spares the user having to flip the GPIO lines constantly.
#
# Version 1.0.0

print_usage_and_die()
{
	echo "Usage:  led-a [red | green | amber | off]"
        exit 1
}

if [ ! "$UID" -eq 0 ] ; then
        echo "LEDs must be controlled as root or sudo."
        exit -1
fi

RED_GPIO=22
GREEN_GPIO=23

if [ "$#" -eq 0 ] ; then
	print_usage_and_die
elif [ "$1" == "red" ] ; then
        echo 1 > /sys/class/gpio/gpio$RED_GPIO/value
        echo 0 > /sys/class/gpio/gpio$GREEN_GPIO/value
elif [ "$1" == "green" ] ; then
        echo 1 > /sys/class/gpio/gpio$GREEN_GPIO/value
        echo 0 > /sys/class/gpio/gpio$RED_GPIO/value
elif [ "$1" == "amber" ] ; then
        echo 1 > /sys/class/gpio/gpio$RED_GPIO/value
        echo 1 > /sys/class/gpio/gpio$GREEN_GPIO/value
elif [ "$1" == "off" ] ; then
        echo 0 > /sys/class/gpio/gpio$RED_GPIO/value
        echo 0 > /sys/class/gpio/gpio$GREEN_GPIO/value
else
	print_usage_and_die
fi

exit 0

