ruby udp

client.rb

require 'socket'
socket = UDPSocket.new
socket.send("I am ok.", 0, 'localhost', 1234)
text, sender = socket.recvfrom(16)
socket.close

server.rb

# encoding: utf-8
require 'socket'
server = UDPSocket.new
host, port = "127.0.0.1", 1234
server.bind(host, port)

while true
  text, sender = server.recvfrom(16)
  remote_host = sender[3]
  STDOUT.puts "#{remote_host}:" + text
  server.send("received.", 0, host, port)
end