Simple Minecraft jabber bot

jabber_bot.rb

###
# Simple jabber bot to let me talk to users of my minecraft server from gtalk

require 'xmpp4r-simple'

BOT_USERNAME = '...'
BOT_PASSWORD = '...'

ADMIN_USERNAME = '...'

SCREEN_NAME = 'minecraft'

# The idea for this method came from here but I blockified it:
#   http://stackoverflow.com/questions/1293695/watch-read-a-growing-log-file-with-ruby
def watch_file(file, &block)
  timeout = 1
  f = File.open(file, "r")
  f.seek(0, IO::SEEK_END)

  while true do
    select [f]
    yield f.gets
    sleep timeout
  end
end

def say(message)
  %x{screen -S #{SCREEN_NAME} -p 0 -X stuff "`printf "say #{message}\r"`"}
end

jabber = Jabber::Simple.new(BOT_USERNAME, BOT_PASSWORD, nil, 'Minecraft Bot')

admin_online = false

# Trap CTRL-C to logoff cleanly.
trap("INT") do
  jabber.disconnect
  puts "\nLogging off."
  exit
end

watch_file('server.log') do |line|
  case line
  when /\[INFO\] (.*?) \[[0-9\/\.:]+\] logged in/
    jabber.deliver(ADMIN_USERNAME, "#{$1} logged in")
  when /\[INFO\] (.*?) lost connection: (.*)/
    jabber.deliver(ADMIN_USERNAME, "#{$1} lost connection: #{$2}")
  when /\[INFO\] (?:\[.*?\] )?(.*?): (.*)/
    jabber.deliver(ADMIN_USERNAME, "#{$1}: #{$2}")
  end

  # Crudely determine if the admin is online
  jabber.presence_updates do |update|
    admin_online = true if update[0] == ADMIN_USERNAME && update[1] == :online
    admin_online = false if update[0] == ADMIN_USERNAME && update[1] == :unavailable
  end

  jabber.received_messages {|msg| say msg.body if admin_online }
end

The exact echo in the server.log is formatted such as this:

timestamp - [INFO] - [Groupname] Username: Message
21:33:40 [INFO] [Developer] Xanza: test

Also yes, I did screen -S WonderLand and then did my java command to start the server.

IMAGE: http://i.imgur.com/nrbYX.png

On the left you can see the screen window in which the server is currently running, to the right is my Jabber client (PSI) which as you can see the script is running correctly because I receive no error form "ruby jabber.rb" and the bot successfully logs on. I sent the message "test" to the bot, and as you can see, it's not reflected in the client, or in the server.log. Also just to be sure, I chmodded both the ruby script and the server.log to 0777.

I really appreciate the help! I've been looking for this exact script for what seems like forever! haha.

Hey, I don't mind helping at all. I wish it was easier to use but I only used it for a few months and didn't know it would be useful for anyone else. :) I think I see 2 problems you're having:

Set the admin username to the jabber user (full email address) who will receive the chat messages. This is also the only person who can chat to the server through jabber. It's not your minecraft username.

Another problem is that the regular expression isn't matching the messages anymore. I updated the gist so that it will use the new format for chats.

Let me know if you still have problems.

It's almost totally functioning now! WooHoo!

The only problem I have is that it keeps logging off jabber. :(

IMAGE: http://i.imgur.com/Mk5Ss.png

As you can see, it notifies me of used commands, and I'm able to communicate as [Server], but after about 30 seconds it logs off (even when running in it's own screen!) and any additional messages are sent via a new chat window. Any ideas?

This script is so cash by the way!

I don't think I'll be able to help you with this one. Are you getting any errors from the ruby script when that happens? I can't reproduce it. I remember it staying connected for hours when I used it. Are you running it twice or something? One version might kick another one off.

Yup! That was it. :P For whatever reason a single 'ruby jabber.rb' command was running it twice! I restarted my server and it's working 100% now! Thank you so much for taking the time to help, and to create this little gem!

No problem at all, I'm glad it's useful!