Minecraft script

#!/bin/bash
# chkconfig: 2345 20 80
# description: A basic minecraft startup script created by Piffey \
#              and modified by Robert Pendell to support users.

# Simple bukkit startup script by Piffey
# This is by no means a clean script, but it will get the job done.
# Suggestions? Improvements? Let me know at Piffey.com

# All of the screen stuff was adapted from ragon's <frederik.engels24 AT gmail DOT com> script for his Arch Linux package.
# Reason: I don't use screen, but it's likely the best option for anyone looking for a simple script they can run and ignore.
# His script worked perfect for my first server too. Thanks ragon.

# Some modifications by Robert Pendell
# * Added sudo string and set user to run server as (security)
# * Added save state option (for crons)
# * Added friendly restart option (for crons)
# * Modified backups to be more verbose in console and game
# * Modified backup function to create backup dir if it doesn't exist
# * Added more string variables

# Set these values to match your server's settings.

backupdir=/minecraft/backups/
bukkitdir=/minecraft/
bukkitfilename=craftbukkit.jar
bukkitupdate=craftbukkit-updater.jar
username=minecraft

backupmsg="Starting multiworld backup..."
backupdone="Multiworld backup completed!"
backupworldmsg="Backing up world"
readonlymsg="Server is now in Read-Only Mode."
readwritemsg="Server now in Read-Write Mode."
savestatemsg="Saving state..."

dateformat=$(date '+%Y%m%dh%Hm%M')

# Make sure you change this to the name of your world folder! Add additional worlds by separating them with a white space. If you only have one world, change
# this to have only one value like "world" or "creative".
declare -a worlds=(world world_nether skyrealm creative)
numworlds=${#worlds[@]}

# Set these for the amount of RAM you want to allocate. Good practice is to have the numbers match.
# This is the Java heap max and initial size.
# The second line is an attempt at agressive garbage collection

javaparams="-client -Xmx1024M"
#javaparams="-server -Xmx1024M -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:+CMSIncrementalPacing -XX:ParallelGCThreads=2 -XX:+AggressiveOpts"

# You can find this location with "whereis java". Make sure this points to the binary.

javaloc=/usr/bin/java

# This currently points to the "preferred" release for bukkit which is kind of like a stable version.
# Change this value if you want to use the snapshot release.
bukkiturl=http://ci.bukkit.org/job/dev-CraftBukkit/promotion/latest/Recommended/artifact/target/craftbukkit-0.0.1-SNAPSHOT.jar

startbukkit()
{
    if [ "$(screen -ls | grep bukkit)" == "" ] ; then
        cd $bukkitdir
        screen -S bukkit -dmS sudo -u $username $javaloc $javaparams -jar $bukkitdir$bukkitfilename nogui
    echo $!
        echo "Starting bukkit server."
    else
        echo "Bukkit is already running."
        exit 0
    fi
}

stopbukkit()
{
    if [ "$(screen -ls | grep bukkit)" == "" ] ; then
        echo "Bukkit is not running."
        exit 0
    else
        screen -S bukkit -p 0 -X stuff "stop$(echo -ne '\r')"
        sleep 5
    fi
}

updatebukkit()
{
    if [ "$(screen -ls | grep bukkit)" == "" ] ; then
        sleep 0
    else
        screen -S bukkit -p 0 -X stuff "say Going down for an update in 60 seconds.$(echo -ne '\r')"
        sleep 55
        screen -S bukkit -p 0 -X stuff "say Going down for an update in 5 seconds.$(echo -ne '\r')"
        sleep 5
        stopbukkit
    fi

    wget -O $bukkitdir$bukkitupdate $bukkiturl
    sleep 5
    mv $bukkitdir$bukkitupdate $bukkitdir$bukkitfilename
    sleep 5
}

backupbukkit()
{
    echo "Starting multiworld backup..."
    if [ "$(screen -ls | grep bukkit)" == "" ] ; then
        sleep 0
    else
        screen -S bukkit -p 0 -X stuff "say $backupmsg $(echo -ne '\r')"
        screen -S bukkit -p 0 -X stuff "save-all$(echo -ne '\r')"
        sleep 5
        screen -S bukkit -p 0 -X stuff "save-off$(echo -ne '\r')"
        screen -S bukkit -p 0 -X stuff "say $readonlymsg $(echo -ne '\r')"
    fi
    if [ -d $backupdir ] ; then
        sleep 0
    else
        mkdir -p $backupdir
    fi
    mkdir $backupdir$dateformat
    for ((i=0;i<$numworlds;i++)); do
        screen -S bukkit -p 0 -X stuff "say $backupworldmsg ${worlds[$i]}. $(echo -ne '\r')"
        cp -R $bukkitdir${worlds[$i]} $backupdir$dateformat
        echo "Saving '${worlds[$i]}' to '$backupdir$dateformat'"
    done

    if [ "$(screen -ls | grep bukkit)" == "" ] ; then
        sleep 0
    else
        sleep 5
        screen -S bukkit -p 0 -X stuff "save-on$(echo -ne '\r')"
        screen -S bukkit -p 0 -X stuff "say $readwritemsg $(echo -ne '\r')"
        screen -S bukkit -p 0 -X stuff "say $backupdone $(echo -ne '\r')"
    fi
    echo "Backup complete."
}

savestatebukkit()
{
    if [ "$(screen -ls | grep bukkit)" == "" ] ; then
        sleep 0
    else
        screen -S bukkit -p 0 -X stuff "say $savestatemsg $(echo -ne '\r')"
        screen -S bukkit -p 0 -X stuff "save-all$(echo -ne '\r')"
    fi
}

case $1 in
    start)
        startbukkit
        ;;
    stop)
        stopbukkit
        ;;
    restart)
        stopbukkit
        sleep 5
        startbukkit
        ;;
    update)
        updatebukkit
        ;;
    backup)
        backupbukkit
        ;;
    savestate)
        savestatebukkit
        ;;
    friendlyrestart)
        if [ "$(screen -ls | grep bukkit)" == "" ] ; then
            sleep 0
        else
            screen -S bukkit -p 0 -X stuff "say Restarting in 60 seconds.$(echo -ne '\r')"
        sleep 55
        screen -S bukkit -p 0 -X stuff "say Restarting in 5 seconds.$(echo -ne '\r')"
        sleep 5
            stopbukkit
            sleep 5
            startbukkit
        fi
        ;;
    friendlystop)
        screen -S bukkit -p 0 -X stuff "say Going down in 5 minutes.$(echo -ne '\r')"
        sleep 240
        screen -S bukkit -p 0 -X stuff "say Going down in 60 seconds.$(echo -ne '\r')"
        sleep 55
        screen -S bukkit -p 0 -X stuff "say Going down in 5 seconds.$(echo -ne '\r')"
        sleep 5
        stopbukkit
        ;;
    *)
        echo "Usage: $0 {start|stop|restart|update|backup|savestate|friendlyrestart|friendlystop}"
esac

exit 0