Restart node server where changes are made to server file

node restarter

#! /bin/bash

if [[ -f ./$1 ]]; then
	while true; do 
		time=$(stat -c %Y server.js | cut -d ' ' -f1);
		oldtime=$(cat log);
		if [[ "$oldtime" -lt "$time" ]]
			then
				if [[ $pid -gt 0 ]]; then
					node server &
				else	
					echo "kill former node instance"
					kill -9 $pid
					node $1 &
					echo "restarted"
				fi
		fi
		echo $time > log;
		pid=$(ps | grep node | cut -d ' ' -f1)
		sleep 2;
	done
else
	echo "Usage: ./server.sh [server_file.js]"
fi