random ruby irc bot

#!/usr/bin/env ruby

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
    end

    def send(s)
        # sends 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 "User blah blah blah :blah blah"
        send "NICK #{@nick}"
        send "JOIN #{@channel}"
    end

    def evaluate(s)
        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)
    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 #{$1} :\001VERSION Ruby-irc v0.042\001"
        when /^:(.+?)!(.+?)@(.+?)\sPRIVMSG\s(.+)\s:EVAL (.+)$/i
        puts "[ EVAL #{$5} from #{$1}!#{$2}@#{$3} ]"
        send "PRIVMSG #{(($4==@nick)?$1:$4)} :#{evaluate($5)}"
    else
        puts s
    end
end


def main_loop()
    #Just keep on truckin
    while true
        ready = select([@irc, $stdin], nil, nil, nil)
        next if !ready
        for s in ready[0]
            if s == $stdin then
                return if $stdin.eof
                s = $stdin.gets
                send s
            elsif s == @irc then
                return if @irc.eof
                s = @irc.gets
                handle_server_input(s)
            end
            end
        end
    end
end


# Main Program If we get an exception print and keep going
# WE DO NOT WANT TO DISCONNECT UNEXPECTEDLY!
irc = Irc.new('irc.paraphysics.net', 6667, 'addyracerb0t1', '#ironflag')
irc.connect()
begin
    irc.main_loop()
rescue Interrupt
rescue Exception => detail
    puts detail.message()
    print detail.backtrace.join("\n")
    retry
end