paho_mqtt_pub.rb

require 'paho-mqtt'

### Create a simple client with default attributes
client = PahoMqtt::Client.new

### Register a callback for puback event when the Broker acknowledges a publication
waiting_puback = true # A flag so we can wait for the acknowledgement
client.on_puback do
  waiting_puback = false
  puts "Message Acknowledged by Broker"
end

### Connect to the test broker on port 1883 (Unencrypted mode)
client.connect('localhost', 1883)

topic = "/test/"
message = "Hello there!"
puts("Sending: \nTopic: #{topic}\nMessage: #{message}")

client.publish(topic, message, false, 1) 

while waiting_puback do 
    sleep(0.001)
end   

### Call an explicit disconnect
client.disconnect