Unprivileged standalone instance of MySQL

Small script to run a instance of mysql in my home directory using the binary provided by the OS. Maybe some day I will make it more usable but for the time being it suits my needs.

#!/bin/bash

MYSQL_HOME=$HOME
MYSQL_USER=$USER
MYSQL_PORT=13306

ACTION=$1
if [ $ACTION == 'init' ]; then
    echo "initalising new mysql installation at $MYSQL_HOME/var/lib/mysql"
    rm -rf $MYSQL_HOME/var/lib/mysql
    mkdir -p $MYSQL_HOME/var/lib/mysql $MYSQL_HOME/mysql/data $HOME/var/lib/mysql/tmp
    mysql_install_db --user=$MYSQL_USER  --datadir=$MYSQL_HOME/var/lib/mysql/data/

    cat < $HOME/.my.cnf
[mysqld]
user=$MYSQL_USER
datadir=$MYSQL_HOME/var/lib/mysql/data
log-error=mysqld.log
pid-file=mysqld.pid
socket=$MYSQL_HOME/var/lib/mysql/tmp/mysql.sock
port=$MYSQL_PORT

[client]
user=$MYSQL_USER
socket=$MYSQL_HOME/var/lib/mysql/tmp/mysql.sock
port=$MYSQL_PORT

[safe_mysqld]
log-error=mysqld.log
pid-file=mysqld.pid
port=$MYSQL_PORT
EOT
    echo "   Done"

elif [ $ACTION == 'start' ];then
    echo -n "Starting mysqld as $MYSQL_USER on $MYSQL_PORT"
    nohup mysqld_safe &>/dev/null &
    echo "   Done"
elif [ $ACTION == 'stop' ];then
    PID=$(cat $MYSQL_HOME/var/lib/mysql/data/mysqld.pid)
    echo -n "Stopping mysql instance [$PID]"
    kill `cat $MYSQL_HOME/var/lib/mysql/data/mysqld.pid`
    echo "   Done"
else
    echo "Unknown command '$1'"

fi

UPDATED SCRIPT:

I decided to update the script and make it less hacky

#!/bin/bash

MYSQL_HOME=$HOME
MYSQL_USER=$USER
MYSQL_PORT=13306

function init {

    echo "initalising new mysql installation at $MYSQL_HOME/var/lib/mysql"
    rm -rf $MYSQL_HOME/var/lib/mysql
    mkdir -p $MYSQL_HOME/var/lib/mysql $MYSQL_HOME/mysql/data $HOME/var/lib/mysql/tmp
    mysql_install_db --user=$MYSQL_USER  --datadir=$MYSQL_HOME/var/lib/mysql/data/

    cat < $HOME/.my.cnf
[mysqld]
user=$MYSQL_USER
datadir=$MYSQL_HOME/var/lib/mysql/data
log-error=mysqld.log
pid-file=mysqld.pid
socket=$MYSQL_HOME/var/lib/mysql/tmp/mysql.sock
port=$MYSQL_PORT
innodb_file_per_table

[client]
user=$MYSQL_USER
socket=$MYSQL_HOME/var/lib/mysql/tmp/mysql.sock
port=$MYSQL_PORT

[safe_mysqld]
log-error=mysqld.log
pid-file=mysqld.pid
port=$MYSQL_PORT
EOT
    echo "   Done"
}

function start {
    echo -n "Starting mysqld as $MYSQL_USER on $MYSQL_PORT"
    nohup mysqld_safe &>/dev/null &
    echo "   Done"
}

function stop {
    if [ -e $MYSQL_HOME/var/lib/mysql/data/mysqld.pid ]; then
        PID=$(cat $MYSQL_HOME/var/lib/mysql/data/mysqld.pid)
        echo -n "Stopping mysql instance [$PID]"
        kill $PID
        echo "   Done"
    else
        echo "mysqld.pid file doesnt exist"
    fi
}

function usage {
    echo "Unknown command '$1'"
}

function status {
    if [ -e $MYSQL_HOME/var/lib/mysql/data/mysqld.pid ]; then
        PID=$(cat $MYSQL_HOME/var/lib/mysql/data/mysqld.pid)
        ps -p $PID &>/dev/null
        RTN=$?
    else
        RTN=-1
    fi
    if [ $RTN -eq 0 ]; then
        echo "Mysql Running, pid:$PID"
    elif [ $RTN -eq 1 ]; then
        echo "mysql stopped but pidfile exists"
    elif [ $RTN -eq -1 ]; then
        echo "Stopped"
    fi
}

case "$1" in
        start)
            start
            ;;
        stop)
            stop
            ;;
        status)
            status
            ;;
        restart)
            stop
            start
            ;;
        init)
            init
            ;;
        *)
            echo $"Usage: $0 {start|stop|status|restart|init}"
            exit 1
esac