Shell Programming and Scripting

#!/bin/bash
a=20
CPUIDLE=$(top -d 0.1 -n 2 | grep '^Cpu(s):'| tail -1 |awk '{print $5}'|sed 's/%.*//')
echo $CPUIDLE
if [ $CPUIDLE -lt $a ]
then
     exit 1
else
     exit 0
fi

root@ubuntu:~# ./phan6.sh
88.5
./phan6.sh: line 5: [: 88.5: integer expression expected

if [ "$CPUIDLE" -lt "$a" ]

root@ubuntu:~# ./phan6.sh
88.5
./phan6.sh: line 5: [: 88.5: integer expression expected

mpstat | tail -1 | cut -d' ' -f35

#! /usr/bin/env perl

my $cpu = qx~mpstat | tail -1 | perl -ane 'print $F[10]'~;
exit 1 if ( 100 - $cpu > 20 );

#! /bin/bash

CPU=$(mpstat | tail -1 | awk '{print $11}' | cut -c1-2);
if [ $CPU -gt 20  ]
then
    exit 1
fi