Code to check RPi GPIO Inputs via bash

##note pin 4 has to be set as an input

#!/bin/bash

while true

do
        sleep .01
        #echo "Checking Button; hit [CTRL+C] to stop!"
        trigger=$(sudo cat /sys/class/gpio/gpio4/value)


        if [ $trigger = "0" ]; then
               echo "button pressed"
            fi


done