Linux上使用shell腳本查看內存情況(超實用)

#!/bin/bash

# tomcat啟動程序(這里注意tomcat實際安裝的路徑) 
StartTomcat=/wls/jenkins/apache-tomcat-6.0.39/bin/startup.sh

export chknum=1
#shell攪拌存放目錄（輸出日志文件執行后也存於該目錄）
echo 3 > /wls/wls81/shell
sync
while [ $chknum -ge 0 ]
do
echo "-------------------------------------------------------" >> trace.log
mt=`free | tr [:blank:] \\\n | grep [0-9] | sed -n '1p'`
mu=`free | tr [:blank:] \\\n | grep [0-9] | sed -n '2p'`
mf=`free | tr [:blank:] \\\n | grep [0-9] | sed -n '3p'`
st=`free | tr [:blank:] \\\n | grep [0-9] | sed -n '9p'`
su=`free | tr [:blank:] \\\n | grep [0-9] | sed -n '10p'`
sf=`free | tr [:blank:] \\\n | grep [0-9] | sed -n '11p'`
t=`expr $mt + $st`
u=`expr $mu + $su`
echo "Total Mem: $t"
echo "Used Mem: $u"
R=`expr $mu \* 100 / $mt`
echo "當前內存使用率為: $R%" >>trace.log

echo "Used Mem(%): $R"
#開始釋放內存（只檢測不操作可把此段斃掉）
if [ $R -gt 10 ]
then
echo "the monitor is more,clean is begin.."
#執行內存>80%時清除，以下規則可自行修改
ps -ef|grep java |cut -c 9-15|xargs kill -9

sleep 3 
rm -rf $TomcatCache # 清理tomcat緩存 
echo "tomcat is restart..."
$StartTomcat 
fi
#釋放結束

echo "$R" >> memory.log
echo "記錄時間:" >> trace.log
echo `date` >> trace.log
echo "-------------------------------------------------------" >> trace.log

sleep 9h
done

#殺死sh腳本
#kill -9 ·ps -ef | grep shell.sh | awk '{ print $2 }'