monitor cpu and memory usage for long time

processMonitoring.sh

#!/bin/bash

DATE=$(date "+%Y-%m-%dT%H:%M:%S")
echo "total CPU, total Memory Usage, highest CPU process, Highest mem process " > stats-$DATE.csv
while :
do
	cpu=`grep 'cpu ' /proc/stat | awk '{usage=($2+$4)*100/($2+$4+$5)} END {print usage "%"}'`;
	memory=`free | grep Mem | awk '{print $3/$2 * 100.0}'`
	top_cpu=`ps --sort=-pcpu -aux | sed -n 2p | awk '{print $3"|"$11}'`
	top_mem=`ps --sort=-pcpu -aux | sed -n 2p | awk '{print $4"|"$11}'`
	echo "$cpu,$memory,$top_cpu,$top_mem" >> stats-$DATE.csv
	sleep 10
done