Small example of using MQTT NIO to write a chat client.
The sample is setup to use a local MQTT server. There is a script to run the Mosquitto MQTT server in Docker.
The sample uses ANSI escape codes to move the cursor and clear lines. These do not work inside the Xcode console so it is better to run the sample from the command line. When running you need to supply your username and the topic you are subscribing to as command line parameters.
swift run MQTTNIOChat --username <name> -topic <topic> If you don't have Docker or would like to test the client on another server than one run locally you can use the --server and --port command line parameters to set what server you use. Remember if you use a public server like test.mosquitto.org or broker.hivemq.com everyone can see everything you publish.