mqtt_test_pub.rb

#!/bin/ruby
# -*- encoding: utf-8 -*-
#
#  $ gem install mqtt
#

require 'rubygems'
require 'mqtt'
require 'uri'

uri = URI.parse 'mqtt://localhost:1883'

conn_opts = {
	remote_host: uri.host,
	remote_port: uri.port,
	username: uri.user,
	password: uri.password,
}

MQTT::Client.connect(conn_opts) do |c|
  c.publish('topic/message', 'こんにちは')
end

mqtt_test_sub.rb

#!/bin/ruby
# -*- encoding: utf-8 -*-
#
#  $ gem install mqtt
#
require 'rubygems'
require 'mqtt'
require 'uri'

uri = URI.parse 'mqtt://localhost:1883'

conn_opts = {
	remote_host: uri.host,
	remote_port: uri.port,
	username: uri.user,
	password: uri.password,
}

MQTT::Client.connect(conn_opts) do |c|
	puts "connect..."
	c.get('#') do |topic, message|
		puts "#{topic}: #{message}"
	end
end