sockets.rb

require 'socket'
child_socket, parent_socket = Socket.pair(:UNIX, :DGRAM, 0)
maxlen = 1000
fork do 
  parent_socket.close
  4.times do
    instruction = child_socket.recv(maxlen) 
    child_socket.send("#{instruction} accomplished!", 0)
  end 
end

child_socket.close
2.times do
  parent_socket.send("Heavy lifting", 0)
end 

2.times do
  parent_socket.send("Feather lifting", 0) 
end

4.times do
  $stdout.puts parent_socket.recv(maxlen)
end

输出：

Heavy lifting accomplished!
Heavy lifting accomplished!
Feather lifting accomplished!
Feather lifting accomplished!