MQTT client examples based emqtt

• Connecting via TCP/TLS/WS/WSS examples.
• Publish/Subscribe examples.
• Async publish examples.
• Receiving messages example.

1. Compile it first

rebar3 compile

2. Start application

rebar3 shell

3. Run the TCP examples, i.e:

1> mqttex:run(tcp).
publish msg[1] success!
publish msg[2] success!
publish msg[3] success!
async publish msg[1] success
async publish msg[2] success
async publish msg[3] success
subscribe/unsubscribe success
publisher publish success
received message topic: <<"testtopic/1">>, payload: <<"123456">>
ok
2>

Of course, you can also run example programs based on other communication layers by executing mqttex:run(tls) or mqttex:run(ws) or mqttex:run(wss).