Linux上使用shell脚本查看内存情况(超实用)

#!/bin/bash

# tomcat启动程序(这里注意tomcat实际安装的路径) 
StartTomcat=/wls/jenkins/apache-tomcat-6.0.39/bin/startup.sh

export chknum=1
#shell搅拌存放目录（输出日志文件执行后也存于该目录）
echo 3 > /wls/wls81/shell
sync
while [ $chknum -ge 0 ]
do
echo "-------------------------------------------------------" >> trace.log
mt=`free | tr [:blank:] \
 | grep [0-9] | sed -n '1p'`
mu=`free | tr [:blank:] \
 | grep [0-9] | sed -n '2p'`
mf=`free | tr [:blank:] \
 | grep [0-9] | sed -n '3p'`
st=`free | tr [:blank:] \
 | grep [0-9] | sed -n '9p'`
su=`free | tr [:blank:] \
 | grep [0-9] | sed -n '10p'`
sf=`free | tr [:blank:] \
 | 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 "当前内存使用率为: $R%" >>trace.log

echo "Used Mem(%): $R"
#开始释放内存（只检测不操作可把此段毙掉）
if [ $R -gt 10 ]
then
echo "the monitor is more,clean is begin.."
#执行内存>80%时清除，以下规则可自行修改
ps -ef|grep java |cut -c 9-15|xargs kill -9

sleep 3 
rm -rf $TomcatCache # 清理tomcat缓存 
echo "tomcat is restart..."
$StartTomcat 
fi
#释放结束

echo "$R" >> memory.log
echo "记录时间:" >> trace.log
echo `date` >> trace.log
echo "-------------------------------------------------------" >> trace.log

sleep 9h
done

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