shell 服务状态监控

#!/bin/sh
DBSTAT=`ps -ef|grep 'postmaster'|grep -v 'grep'`

if [ "$DBSTAT" == "" ];
then
    echo "DB down" 
    DBstus=`ps -ef|grep 'postmaster'|grep -v 'grep'`
    while [ "$DBstus" == "" ];
    do
    if ["$DBstus" == ""];
    then
    echo "DB starting ..."
    /etc/init.d/postgresql start
    DBstus=`ps -ef|grep 'postmaster'|grep -v 'grep'`
    else
    echo "PostgreSQL already running! "
    fi
    done
else
    echo "DB running"
fi