simple_em_udp_client.rb

require 'eventmachine'
require 'pp'

$stdout.sync = true

class KeyboardHandler < EM::Connection
  include EM::Protocols::LineText2
  
  def post_init
    print "> "
  end
  
  def receive_line(line)
    line.chomp!
    line.gsub!(/^\s+/, '')
    
    case(line)
    when /^udp (.*)$/
      data = $1.chomp
      EventMachine::send_datagram UdpClient.signature, data, data.length, 'localhost', 8082
      
    when /^exit$/
      EM.stop
      return
    end
    
    print "> "
  end
end

class UdpClient < EM::Connection
  def self.new(sig, *args)
    @@signature = sig
    super
  end
  
  def self.signature
    @@signature
  end
  
  def receive_data(data)
    puts "Received: #{data.to_s}"
    print "> "
  end
end

EM::run {
  EM.open_keyboard(KeyboardHandler)
  EM.open_datagram_socket("0.0.0.0", 0, UdpClient)
}