sockets.rb

require 'socket'

server1 = TCPServer.new('0.0.0.0', 1337)
server2 = TCPServer.new('0.0.0.0', 1338)

servers = [server1, server2]
clients = []

loop do
  readables, * = IO.select(servers+clients)
  readables.each do |sock|
    if sock.is_a?(TCPServer)
      puts 'Connection'
      clients << sock.accept
    else
      puts 'Client'
      sock.puts(sock.gets)
    end
  end
end