Twitter-to-IRC bridge
A hacky Ruby script to route Twitter status updates into IRC.

Copyright © Tom Morris 2009-2010.
<tom@tommorris.org>

This program is free software: you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later
version.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with
this program. If not, see <http://www.gnu.org/licenses/>.

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I created this for the LeWeb conference and also used it at the Dev8D 
conference, the Science Hack Day and Music Hack Days in London.

It has the following dependencies:
- Ruby 1.8.6 (MRI) or higher
- JRuby 1.4.x or higher
- pircbot.jar 1.5.0 or higher
- tweetstream gem
- GNU Screen or equivalent

To run:
0. Start a screen session. If you don't know about GNU screen, teach yourself 
how to use it. You won't regret it. (BSD types can use tmux instead.)

1. First start server.rb - this is a DRb server. Be careful to run this behind 
a firewall: it is not secured in any way, and a malicious user could inject
stuff into the DRb queue.

2. Start chat_j.rb with JRuby (the "_j" gives it away!). Be sure to customise
it with an IRC nick and channel.

3. Start grabber.rb with RubyMRI. Be sure to insert your own Twitter 
credentials and choose some keywords for it to track.

grabber.rb does just what it says - it connects to Twitter's firehose (or 
rather, Twitter's tracking firehose). This is a long-polling HTTP connection 
that sits and waits for bundles of XML or JSON. The tweetstream uses JSON. 
grabber.rb attempts to connect to the DRb server and puts a formatted string 
into the shared queue object. chat_j.rb also connects to the DRb server and 
posts to IRC - importantly, with a delay.

If you want to add rules - to filter out specific tweets - do it in line 7 of 
grabber.rb. I've included two: one to filter out retweets (any tweet starting 
with 'RT') and another to filter out tweets containing the string 'live on 
uStream'. These are due to a significant amount of spam during LeWeb. We also 
filtered out bit.ly links for a while. I'm tempted to filter out ow.ly links, 
which are forged in Satan's very own cgi-bin.

The three scripts can be restarted individually - the one you may need to 
restart most often is grabber.rb, if the connection to Twitter gets silently 
dropped or whatever. The nice thing about this is if you kill the grabber 
process, the queue and chat bot processes are left unharmed. Remember: Ruby 
(as opposed to JRuby) doesn't handle long-life processes well. During LeWeb, I 
had this running on my MacBook for two days - I may have restarted the grabber 
process in the middle of the night. During dev8d, I had this running on my 
desktop Linux machine for four days with a nightly restart.

Beware: it is a total hack.