Linux之监控服务器内存、CPU、磁盘使用率shell脚本

#Memory
totalMemory=$(free -m | awk -F '[ :]+' NR==2{print $2}')
usedMemory=$(free -m | awk -F NR==2{print $3})
freeMemory=$(free -m|awk  {print $4}'|sed -n 3p)
usedPerMemory=$(awk BEGIN{printf "%.0f",('$usedMemory/'$totalMemory)*100})
freePerMemory=$(awk '$freeMemory)
logFile=/tmp/monitor.log
#alerm date
now_time=`date +%Y-%m%d %H:%M:%S`
#Disk
diskusAge=$(df -h | grep /dev/mapper/centos-root | awk -F [ %]+{print $5})

#CPU
cpuusAge=$(top -b -n 1 |grep Cpu|awk {print $8}'|cut -f 1 -d.)

echo $cpuusAge


# send mail
function send_mail(){
        mail -s "test alerm" test@163.com < /tmp/monitor.log
}


if [[ $usedPerMemory" > 90 ]] || [[ $diskusAge$cpuusAge95 ]];then

                echo 报警时间：${now_time}" > $logFile
                echo CPU usage:${cpuusAge}%" >>Memory usage:${usedPerMemory}%Disk usage:${diskusAge}% $logFile
                send_mail
fi