notify.rb

#!/usr/bin/env ruby

CHANNEL = "#shrug_bots"
SERVER = 'irc.freenode.net'
PORT = 6667
NICK = 'notify'
PASS = ''

require "socket"

# Don't allow use of "tainted" data by potentially dangerous operations
$SAFE=1

# The irc class, which talks to the server and holds the main event loop
class IRC
    def initialize(server, port, nick, channel)
        @server = server
        @port = port
        @nick = nick
        @channel = channel
        @@instance = self
    end

    def self.send_message(s)
      @@instance.send "PRIVMSG #{CHANNEL} :#{s}"
    end
        
    def send(s)
      # Send a message to the irc server and print it to the screen
      puts "--> #{s}"
      @irc.send "#{s}\n", 0 
    end
    
    def connect
        # Connect to the IRC server
        @irc = TCPSocket.open(@server, @port)
        send "PASS #{PASS}" if PASS
        send "USER bot bot bot :bot bot"
        send "NICK #{@nick}"
    end
    
    def evaluate(s)
        # Make sure we have a valid expression (for security reasons), and
        # evaluate it if we do, otherwise return an error message
        if s =~ /^[-+*\/\d\s\eE.()]*$/ then
            begin
                s.untaint
                return eval(s).to_s
            rescue Exception => detail
                puts detail.message()
            end
        end
        return "Error"
    end
    
    def handle_server_input(s)
        # This isn't at all efficient, but it shows what we can do with Ruby
        # (Dave Thomas calls this construct "a multiway if on steroids")
        case s.strip
            when /^PING :(.+)$/i
                puts "[ Server ping ]"
                send "PONG :#{$1}"
            when /^:(.+?)!(.+?)@(.+?)\sPRIVMSG\s.+\s:[\001]PING (.+)[\001]$/i
                puts "[ CTCP PING from #{$1}!#{$2}@#{$3} ]"
                send "NOTICE #{$1} :\001PING #{$4}\001"
            when /^:(.+?)!(.+?)@(.+?)\sPRIVMSG\s.+\s:[\001]VERSION[\001]$/i
                puts "[ CTCP VERSION from #{$1}!#{$2}@#{$3} ]"
                send "NOTICE #{$1} :\001VERSION Ruby-irc v0.042\001"
            when /^:(.+?)!(.+?)@(.+?)\sPRIVMSG\s(.+)\s:EVAL (.+)$/i
                puts "[ EVAL #{$5} from #{$1}!#{$2}@#{$3} ]"
                send "PRIVMSG #{(($4==@nick)?$1:$4)} :#{evaluate($5)}"
            when /376/i
                send "JOIN #{@channel}"
            else
                puts s
        end
    end
    
    def main_loop
      # Just keep on truckin' until we disconnect
      while true
          ready = select([@irc], nil, nil, nil)
          if ready
              return if @irc.eof
              s = @irc.gets
              handle_server_input(s)
          end
      end
    end
end


Thread.new do
  irc = IRC.new(SERVER, PORT, NICK, CHANNEL)
  while true
    irc.connect
    begin
        irc.main_loop
    rescue Interrupt
    rescue Exception => detail
        puts detail.message()
        print detail.backtrace.join("\n")
        retry
    end
    sleep 2
  end
end

require 'rubygems'
require 'sinatra'

get '/irc' do
  IRC.send_message params["m"]
end