#!/bin/sh

if [ "$1" == "" ]
then
    V=" "
else
    V="$1"
fi

awk '{u=$2+$4; t=$2+$4+$5; if (NR==1){u1=u; t1=t;} else print ($2+$4-u1) * 100 / (t-t1) ; }' <(grep "cpu${V}" /proc/stat) <(sleep 0.5;grep "cpu${V}" /proc/stat)


#awk '{u=$2+$4; t=$2+$4+$5; if (NR==1){u1=u; t1=t;} else print ($2+$4-u1) * 100 / (t-t1) "%"; }' <(grep "cpu${V}" /proc/stat) <(sleep 1;grep "cpu${V}" /proc/stat)