zmq_client_test.rb

require 'zmq'

socket = ZMQ::Context.new.socket(ZMQ::REQ)
socket.connect("ipc://sm")

trap(:INT) { socket.close; exit }

socket.send(ARGV[0])
puts socket.recv
socket.close

zmq_test.rb

require 'zmq'

socket = ZMQ::Context.new.socket(ZMQ::REP)
socket.bind("ipc://sm")
trap(:INT) { socket.close; exit }

loop do
  msg = socket.recv(ZMQ::NOBLOCK)

  if msg
    socket.send("well hello there!")
  end

  sleep 1
end