Cute little IRC bot

cakla.rb

require 'socket'
server, port, name, channels = ARGV

bot = Hash.new { |hash, key| -> _ { 'Unknown command: ' + key } }

bot['sum']   = -> args { args.map(&:to_i).reduce(0, :+) }
bot['dice']  = -> args { args.map{|n| rand(n.to_i) + 1}.join(' ') }
bot['emoji'] = -> args { (1..5).map{rand(300) + 0x1f300}.pack('U*') }

TCPSocket.open(server, port) do |irc|
  irc.puts "NICK #{name}", "USER #{name} 0 * :#{name}"

  while irc.gets.chomp do
    puts $_
    irc.puts "JOIN #{channels}" if ~/^:\S+ 004/  # registered!
    irc.puts $_.sub('I', 'O')   if ~/^PING :/    # answer pings

    irc.puts "PRIVMSG #{$3?$2:$1} :#{bot[$4][$5.split]}" \
        if ~/^:(\S+)!\S+ PRIVMSG ((#)?\S+) :#{name}: (\w+) ?(.*)/
  end
end