Toggle LED with a switch

toggle_led_w_switch.sh

#!/bin/sh

echo "25" > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio25/direction

echo "24" > /sys/class/gpio/export
echo "in" > /sys/class/gpio/gpio24/direction

OUTPUT="0"
INPUT="$(cat /sys/class/gpio/gpio24/value)"
while [ 1 ]; do
        if [ "$INPUT" -eq "1" ]; then
            echo "$OUTPUT" > /sys/class/gpio/gpio25/value
        
            if [ "$OUTPUT" -eq "0" ]; then
                let OUTPUT="1"
            else 
                let OUTPUT="0"
            fi
            sleep .5
        else
            echo "0" > /sys/class/gpio/gpio25/value
        fi
        let INPUT="$(cat /sys/class/gpio/gpio24/value)"
done