#!/bin/sh

test -c /dev/ttyS0 || exit

stty -F /dev/ttyS0 9600

Mac=`ifconfig | grep -Eiwoh '[a-z0-9:]{17}' | tr '\n' ';'`

Status=`wget -q -O - http://the.displays.cpsc.ucalgary.ca/presentation/begin/$Mac \
        | grep -Eoh "room_status[^\"]*" \
        | tail -n 1 \
        | awk '{print $2}'`

if [[ "$Status" == "available" ]] ; then
        # turn light green
        echo -e "\xFE\x00" > /dev/ttyS0
else
        # turn light red
        echo -e "\xFE\x01" > /dev/ttyS0
fi