Linux CPU & Memory monitoring

#!/bin/bash

cpu=$(grep -c '^processor' /proc/cpuinfo)

cpuuse=0

while [ $cpuuse -le 20 ]

do

#cpuuse=$(top -bn1 | grep load | awk '{printf "2f%%", $(NF-2)}')

cpuused=$(top -bn1 | grep load | awk '{printf "%.2f%%\t\t\n", $(NF-2)}')

memKB=$(cat /proc/meminfo | grep MemTotal|awk -F ":" '{print $2}'|awk -F "kB" '{print $1}')

memGB=`expr $memKB / 1024 / 1024`"GB"

#freemem=$(free -m | awk 'NR==2{printf "%.2f%%\t\t", $3*100/$2 }')

usedmem=$(free -m | awk 'NR==2{printf "%.1fGB", $3/1024 }')

freemem=$(free -m | awk 'NR==2{printf "%.1fGB", $4/1024 }')

echo "Total# of CPUs :  $cpu"

echo "CPU ussage                :  $cpuused"

echo "Total memory :  $memGB"

echo "Used memory :  $usedmem"

echo "Free memory :  $freemem"

echo "**********************************************************"

echo " CTRL + c to exit"

sleep 2

done