John Hawthorn

Minecraft to IRC bridge

Like almost 2.5 million others, my recent productivity has taken a hit due to the game Minecraft. I have a home server set up to play with roommates and friends. Funnily enough, Minecraft turned into a frequent medium of communication for us. To take part in this when not logged into minecraft, and to get notifications to when friends were playing, I set out to make a bridge between minecraft and IRC.

The result is mcirc, a simple minecraft to irc gateway. It tails the minecraft log looking for player joins quits and messages, and relays them to the IRC server. This script requires that there is a FIFO for input to the server.

It is worth noting that this probably not the best minecraft <-> irc bridge which exists, but perhaps the simplest, and runs on a vanilla minecraft server. There are several which function as bukkit plugins: 1 2 3 .

Usage is

ruby irc.rb -s -c balmoralmc -f minecraft/console.pipe -l minecraft/server.log

The script itself is very small and largely command line parsing

#!/usr/bin/env ruby require 'socket' require 'uri' class MinecraftIrcBot def initialize(options) uri = URI.parse("irc://#{options[:server]}") @channel = options[:channel] @socket =, uri.port || 6667) @mclog = IO.popen("tail -f -n0 '#{options[:log]}'", "r") @name = options[:name] @pipe = options[:pipe] say "NICK #{@name}" say "USER #{@name} 0 * #{@name}" say "JOIN ##{@channel}" end def say(msg) puts msg @socket.puts msg end def say_to_chan(msg) say "PRIVMSG ##{@channel} :#{msg}" end def say_to_minecraft(msg) msg = "say #{msg}" puts msg, "w") do |console| console.puts msg end end def run loop do read, write, error =[@socket, @mclog]) if read.include? @socket msg = @socket.gets # connection lost return unless msg case msg.strip when /^PING :(.+)$/i say "PONG #{$1}" when /^:(.+?)!.+?@.+?\sPRIVMSG\s.+?\s:(.+)$/i say_to_minecraft("<#{$1}> #{$2}") end end if read.include? @mclog msg = @mclog.gets msg.gsub!(/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2} /, '') case msg.strip when /^\[INFO\] ([a-z0-9]*) lost connection/i say_to_chan("#{$1} has left") when /^\[INFO\] ([a-z0-9]*) \[[^\]]*\] logged in/i say_to_chan("#{$1} has joined") when /^\[INFO\] <([a-z0-9]*)> (.*)$/i say_to_chan("<#{$1}> #{$2}") end end end end def quit say "PART ##{@channel} :bye bye" say 'QUIT' end end def parse require 'optparse' options = {} optparse = do |opts| opts.banner = "Usage: #{$0} options" opts.on("-s", "--server SERVER", "IRC server") do |v| options[:server] = v end opts.on("-c", "--channel CHAN", "IRC channel") do |v| options[:channel] = v end opts.on("-f", "--fifo FIFO", "named pipe into minecraft server's console") do |v| options[:pipe] = v end opts.on("-l", "--log LOG", "minecraft servers's log file for reading") do |v| options[:log] = v end options[:name] = "mcirc" opts.on("-n", "--name NAME", "name of the irc user") do |v| options[:name] = v end end begin optparse.parse! required = [:server, :channel, :pipe, :log] required.each do |arg| raise OptionParser::MissingArgument, arg if options[arg].nil? end rescue OptionParser::InvalidOption, OptionParser::MissingArgument puts $!.to_s puts optparse exit 1 end options end def run options = parse bot = trap("INT"){ bot.quit } end run