Mosquitto test

1. Install Mosquitto broker
$ sudo  apt-get install mosquitto
$ netstat -nap | grep 1883
tcp        0      0 0.0.0.0:1883            0.0.0.0:*               LISTEN      -             
tcp6       0      0 :::1883                 :::*                    LISTEN      - 

2. Install Mosquitto client
$ sudo apt-get install mosquitto-clients

3. Test Pub/Sub
- subscribing "hello/world" Topic
$ mosquitto_sub -d -t hello/world
Client mosqsub/7013-dkyun77-Th sending CONNECT
Client mosqsub/7013-dkyun77-Th received CONNACK
Client mosqsub/7013-dkyun77-Th sending SUBSCRIBE (Mid: 1, Topic: hello/world, QoS: 0)
Client mosqsub/7013-dkyun77-Th received SUBACK
Subscribed (mid: 1): 0

(after executing the following command of mosquitto_pubg)
Client mosqsub/7013-dkyun77-Th received PUBLISH (d0, q0, r0, m0, 'hello/world', ... (11 bytes))
Hello World

$ mosquitto_pub -d -t hello/world -m "Hello World"
Client mosqpub/6973-dkyun77-Th sending CONNECT
Client mosqpub/6973-dkyun77-Th received CONNACK
Client mosqpub/6973-dkyun77-Th sending PUBLISH (d0, q0, r0, m1, 'hello/world', ... (11 bytes))
Client mosqpub/6973-dkyun77-Th sending DISCONNECT

4. Appendix
$ mosquitto_sub --help
-d : enable debug messages.
-t : mqtt topic to subscribe to. May be repeated multiple times.
...

$ mosquitto_pub --help
-d : enable debug messages.
-t : mqtt topic to publish to.
-m : message payload to send.
...