核心代码：
#/bin/bash
set -x
HOSTS="nginx mysql php-cgi"
for myhost in $HOSTS
do
count=(`ps aux |grep $myhost |grep -v grep |wc -l`)
echo "$myhost"
echo "$count"
if [ $count -eq 0 ]; then
case $myhost in
nginx)
cd /usr/local/webserver/nginx/sbin/
./nginx
echo "nginx has be down"
sleep 5
mysql)
/etc/init.d/mysqld start
echo "mysql has be down"
*)
echo "what‘s the hell?"
esac
fi
done
set +x
