mosquitto_pub
A simple MQTT version 3.1.1 client that will publish a single message on a topic and exit. More information: https://mosquitto.org/man/mosquitto_pub-1.html.
- Publish a temperature value of 32 on the topic 
sensors/temperatureto 192.168.1.1 (defaults tolocalhost) with Quality of Service (QoS) set to 1: 
mosquitto_pub -h {{192.168.1.1}} -t {{sensors/temperature}} -m {{32}} -q {{1}}
- Publish timestamp and temperature data on the topic 
sensors/temperatureto a remote host on a non-standard port: 
mosquitto_pub -h {{192.168.1.1}} -p {{1885}} -t {{sensors/temperature}} -m "{{1266193804 32}}"
- Publish light switch status and retain the message on the topic 
switches/kitchen_lights/statusto a remote host because there may be a long period of time between light switch events: 
mosquitto_pub -r -h "{{iot.eclipse.org}}" -t {{switches/kitchen_lights/status}} -m "{{on}}"
- Send the contents of a file (
data.txt) as a message and publish it tosensors/temperaturetopic: 
mosquitto_pub -t {{sensors/temperature}} -f {{data.txt}}
- Send the contents of a file (
data.txt), by reading from stdin and send the entire input as a message and publish it tosensors/temperaturetopic: 
mosquitto_pub -t {{sensors/temperature}} -s < {{data.txt}}
- Read newline delimited data from stdin as a message and publish it to 
sensors/temperaturetopic: 
{{echo data.txt}} | mosquitto_pub -t {{sensors/temperature}} -l