mysql.sh (start, stop, restart, force-quit and status)

mysql.sh

#!/bin/bash

PREFIX=/usr/local/mysql

MYSQL_CONFIG=${PREFIX}/my.cnf
MYSQL_PORT=3306
MYSQL_USERNAME="root"
MYSQL_PASSWORD="password"

MYSQLD_SAFE=${PREFIX}/bin/mysqld_safe
MYSQLADMIN=${PREFIX}/bin/mysqladmin

MYSQLD_PID_FILE_PATH=${PREFIX}/data/mysql.pid
SERVICE_STARTUP_TIMEOUT=900

# Message control
lsb_functions="/lib/lsb/init-functions"

if test -f $lsb_functions ; then
    . $lsb_functions
else
    log_success_msg() {
        echo " SUCCESS! $@"
    }
    
    log_failure_msg() {
        echo " ERROR! $@"
    }
fi

function wait_for_pid() {
    verb="$1"           # created | removed
    pid="$2"            # process ID of the program operating on the pid-file
    pid_file_path="$3" # path to the PID file.

    i=0
    avoid_race_condition="by checking again"

    while test $i -ne $SERVICE_STARTUP_TIMEOUT ; do

        case "$verb" in
            'created')
                # wait for a PID-file to pop into existence.
                test -s "$pid_file_path" && i='' && break
                ;;

            'removed')
                # wait for this PID-file to disappear
                test ! -s "$pid_file_path" && i='' && break
                ;;
            
            *)
                echo "wait_for_pid () usage: wait_for_pid created|removed pid pid_file_path"
                exit 1
                ;;
        esac

        # if server isn't running, then pid-file will never be updated
        if test -n "$pid"; then
            if kill -0 "$pid" 2>/dev/null; then
                :  # the server still runs
            else
                # The server may have exited between the last pid-file check and now.
                if test -n "$avoid_race_condition"; then
                    avoid_race_condition=""
                    continue  # Check again.
                fi

                # there's nothing that will affect the file.
                log_failure_msg "The server quit without updating PID file ($pid_file_path)."
                return 1  # not waiting any more.
            fi
        fi

        i=`expr $i + 1`
        sleep 1

    done

    if test -z "$i" ; then
        log_success_msg
        return 0
    else
        log_failure_msg
        return 1
    fi
}

function is_running() {
    status=$(ps -ef | grep 'bin/mysqld_safe' | wc -l)

    if [ $status -gt 1 ]; then
        return 0 # have process
    else
        return 1 # not have process
    fi
}

function start() {
    echo -n "Starting MySQL"

    if is_running ; then
        echo " failed, MySQL is running"
        exit 1
    else
        $MYSQLD_SAFE --defaults-file=$MYSQL_CONFIG 2>&1 > /dev/null &

        echo " done"
    fi
}

function stop() {
    if test -s $MYSQLD_PID_FILE_PATH
    then
        mysqld_pid=`cat $MYSQLD_PID_FILE_PATH`

        if (kill -0 $mysqld_pid 2>/dev/null)
        then
            echo "Shutting down MySQL"

            kill $mysqld_pid

            wait_for_pid removed "$mysqld_pid" "$MYSQLD_PID_FILE_PATH"; return_value=$?
        else
            log_failure_msg "MySQL server process #$mysqld_pid is not running!"
            
            rm "$mysqld_pid_file_path"
        fi

        exit $return_value
    else
        log_failure_msg "MySQL server PID file could not be found!"
    fi
}

case "$1" in
    start)
        start
    ;;

    stop)
        stop
    ;;

    restart)
        echo -n "Restarting MySQL"
        start
        stop
    ;;

    force-quit)
        kill -9 $(ps -ef | grep 'bin/mysqld_safe' | awk '{printf $2}')
    ;;

    status)
        if is_running ; then
            echo "MySQL is running"
        else
            echo "MySQL is not running"
        fi
    ;;

    *)
        echo "Usage: $0 {start|stop|restart|force-quit|status}"
        exit 1
    ;;
esac