mosquitto_pub:tldr:cca3e

mosquitto_pub: Publish light switch status and retain the message on the topic `switches/kitchen_lights/status` to a remote host because there may be a long period of time between light switch events.

mosquitto_pub

$ mosquitto_pub -r -h "${iot-eclipse-org}" -t ${switches-kitchen_lights-status} -m "${on}"

try on your machine

The command you provided is related to the mosquitto_pub tool, which is part of the Mosquitto MQTT broker. This tool is used to publish messages to an MQTT broker.

Let's break down the command:

mosquitto_pub: This is the command itself, indicating that you want to use the mosquitto_pub tool.

-r: This flag indicates that the message being published should be retained by the broker. This means that even if there are no active subscribers at the moment, new subscribers will receive the last retained message.

-h "${iot-eclipse-org}": This flag specifies the hostname of the MQTT broker that the message should be published to. In this case, the value to be used is taken from the environment variable "iot-eclipse-org".

-t ${switches-kitchen_lights-status}: This flag specifies the topic to which the message will be published. The value is taken from the environment variable "switches-kitchen_lights-status".

-m "${on}": This flag specifies the payload or the message to be sent. In this case, the value is taken from the environment variable "on".

So, when you execute this command with the appropriate values for the environment variables, it will publish a message with the payload of "on" to the topic "${switches-kitchen_lights-status}" on the MQTT broker "${iot-eclipse-org}". The message will be retained by the broker.

This explanation was created by an AI. In most cases those are correct. But please always be careful and never run a command you are not sure if it is safe.

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