!/bin/bash

user=root
port=3306
CmdPath=/opt/mysql/bin
password=xxxxxxxxxx

base_dir=/opt/mysql
inst_dir=/data/3306
alive="00"
sMysqld=0
sMysqldSafe=0
fSock=0
fPID=0

check_alive()
{
echo "running check_alive..."
if [ ps -ef | grep $port | grep -v grep | grep 'mysqld ' |awk '{print $2}' ];then
echo "Process mysqld is running!"
sMysqld=1
else
echo "Process mysqld is not running!"
sMysqld=0
fi

     if [  `ps -ef | grep 3306 | grep -v grep | grep 'mysqld_safe' |awk '{print $2}'` ];then 
        echo "Process mysqld_safe is running!"
        sMysqldSafe=1
 else 
    echo "Process mysqld_safe is not running!"
    sMysqldSafe=0
     fi

     if [ -e  ${inst_dir}/mysql.sock ];then
        echo "socked file exists!"
        fSock=1
 else 
    echo "socked file not exists!"
    fSock=0
     fi

     if [ -e  ${inst_dir}/mysql.pid ];then
        echo "pid file exists!"
        fPID=1
 else 
    echo "pid file  not exists!"
    fPID=0
     fi

     if [ $sMysqld -eq 1 ];then
        if [ $fPID -eq 0 ];then
            echo "PID is missing, tring to recreate..."
            ps -ef | grep $port | grep -v grep | grep 'mysqld ' |awk '{print $2}' > ${inst_dir}/mysql.pid
            if [ -e ${inst_dir}/mysql.pid ]; then
                echo "pid file is created!"
            else
                echo "can not create PID file, please have a check!"
            fi
        fi
        if [ $sMysqldSafe -eq 0 ];then
            echo "Process mysqld_safe is missing, please have a check! May cause mysqld crash!"
        fi
        if [ $fSock -eq 1 ];then
            echo "MySQL running fine!!!"
            alive="11"
        else
            echo "socket file is missing, you may have to login without socket!"
            alive="10"          
        fi                          
     else
        echo "process mysqld is missing, mysql is stopped!"
        if [ $fSock -eq 1 ] | [ $fPID -eq 1 ];then
            echo "mysql was stopped abnormality!"
            echo "cleaning socket file and pid file"
            alive="01"
        else
            alive="00"
    fi

     fi

}

start_mysql()
{
check_alive
printf "MySQL is starting ... \n"
if [ $alive == "00" ]; then
${CmdPath}/mysqld_safe --defaults-file=${inst_dir}/my.cnf --user=${user} 2>&1 >/dev/null &
else
if [ $alive == "11" ]; then
echo "MySQL is runnig!"
else
if [ $alive == "01" ]; then
echo "MySQL was stopped but pid or sock file still exits!"
echo "Cleanning pid or sock files!"
if [ $fSock -eq 1 ];then
rm -f ${inst_dir}/mysql.sock
fi
if [ $fPID -eq 1 ];then
rm -f ${inst_dir}/mysql.pid
fi
echo "Tring to start MySQL again!!!"
${CmdPath}/mysqld_safe --defaults-file=${inst_dir}/my.cnf --user=${user} 2>&1 >/dev/null &
fi
fi
fi
}

stop_mysql()
{
check_alive
printf "MySQL is Stopping...\n"
if [ $alive == "11" ]; then
${CmdPath}/mysqladmin -u root -p${password} -S ${inst_dir}/mysql.sock shutdown 2>&1 >/dev/null &
else
if [ $alive == "10" ]; then
${CmdPath}/mysqladmin -u root -p${password} -h $HOSTNAME -P $port --protocol tcp shutdown 2>&1 >/dev/null &
else
echo "MySQL is not running, no need stop!"
fi
fi
}

restart_mysql()
{
stop_mysql
sleep 5
if [ $? == 0 ];then
start_mysql
else
echo "stop mysql failed!"
fi
}

case $1 in

start)
start_mysql
;;
stop)
stop_mysql
;;
restart)
restart_mysql
;;
status)
status_mysql
;;
alive)
check_alive
;;
*)
printf "Please in put start|stop|restart|status as input"
;;
esac