#!/bin/bash

open="0"
closed="1"

previousState="0"
timeOfChange=`date +%s`

while true
do
  sleep 1
  #state=$(gpio read 7)
  state=$(cat doorstate)
  if [ $state != $previousState  ]; then
    now=`date +%s`
    duration=$((now-timeOfChange))
    previousState=$state
    timeOfChange=$now
    if [ $state = $open ]; then
      echo "The door just opened after $duration seconds"
    else
      echo "The door just closed after $duration seconds"
    fi
  fi
done