Some helper functions to work with the GPIO ports of the RPi

gpio_functions.sh

function export() {
  echo "$1" | sudo tee /sys/class/gpio/export
  sudo chgrp -RH --dereference users /sys/class/gpio/*
  sudo chmod -R g+w+r /sys/class/gpio/*/*
}

function unexport() {
  echo "$1" | sudo tee /sys/class/gpio/unexport
}

function output() {
  export $1
  echo "out" > /sys/class/gpio/gpio$1/direction 
}

function input() {
  export $1
  echo "in" > /sys/class/gpio/gpio$1/direction
}

function enable() {
  echo "1" > /sys/class/gpio/gpio$1/value
}

function disable() {
  echo "0" > /sys/class/gpio/gpio$1/value
}


function display() {
  cat /sys/class/gpio/gpio$1/value
}