mosquitto:tldr:9179a

The mosquitto command is used to start the Mosquitto MQTT broker, which is a widely used open-source message broker that implements the MQTT protocol. The --config-file option is used to specify the path to the configuration file that should be used by the Mosquitto broker.

In the command mosquitto --config-file ${filename-conf}, ${filename-conf} is a placeholder for the actual path and filename of the configuration file. It is expected that you replace ${filename-conf} with the actual path and filename when running the command.

By providing a configuration file, you can customize various aspects of the Mosquitto broker's behavior, such as network settings, authentication and security options, log file locations, and more. The configuration file contains key-value pairs that define these settings, typically written in plain text format.

Using the --config-file option allows you to specify the exact configuration file that Mosquitto should use, giving you the flexibility to have different configurations for different scenarios or deployments.