自动重启服务的shell脚本代码

#!/bin/bash 
if [ ! -f /tmp/down_count ];then 
echo "0" > /tmp/down_count 
fi 
curl -I Tomcat-host -o "/tmp/status" >/dev/null 2>&1 
code=`awk 'NR==1 {print $2}' /tmp/status` 
if [ "$[code]" -ge 500 ];then 
down=`expr $(cat /tmp/down_count) + 1` 
echo "$down" > /tmp/down_count 
if [ "$down" -gt 3 ];then 
if [ ! -f "/tmp/restart_count" ];then 
echo "0" > /tmp/restart_count 
fi 
restart_count=`expr $(cat /tmp/restart_count) + 1` 
echo "$restart_count" > /tmp/restart_count 
if [ "$restart_count" -le 2 ];then 
echo "tomcat down at `date`" >> /tmp/down_info 
/etc/init.d/tomcat6 restart 
fi 
fi 
else 
echo "0" > /tmp/down_count 
echo "0" > /tmp/restart_count 
fi