linux 监视端口是否正常的shell脚本

代码如下：

#!/bin/bash 
port=”80″ 
restart=”/etc/init.d/httpd restart” 
EMAIL=”/bin/echo selboo | mutt -s "重新启动httpd" [email protected]” 

netstat -ln |awk ‘/^tcp/ {print $4}' |grep -q “:$port$” || { 
#reboot httpd 
eval $restart;$EMAIL 
exit $? 
} 
exit 0