MOSQUITTO_SUB(1) | Commands | MOSQUITTO_SUB(1) |
NAME¶
mosquitto_sub - an MQTT version 3.1 client for subscribing to topicsSYNOPSIS¶
mosquitto_sub [-A bind_address] [-c] [-C msg count] [-d] [-h hostname] [-i client_id] [-I client id prefix] [-k keepalive time] [-p port number] [-q message QoS] [-R] [-S] [-N] [--quiet] [-v] [[-u username] [-P password]] [--will-topic topic [--will-payload payload] [--will-qos qos] [--will-retain]] [[{--cafile file | --capath dir} [--cert file] [--key file] [--tls-version version] [--insecure]] | [--psk hex-key --psk-identity identity [--tls-version version]]] [--proxy socks-url] [-V protocol-version] [-T filter-out...] -t message-topic...
mosquitto_sub [--help]
DESCRIPTION¶
mosquitto_sub is a simple MQTT version 3.1 client that will subscribe to a topic and print the messages that it receives.OPTIONS¶
The options below may be given on the command line, but may also be placed in a config file located at $XDG_CONFIG_HOME/mosquitto_sub or $HOME/.config/mosquitto_sub with one pair of -option value per line. The values in the config file will be used as defaults and can be overridden by using the command line. The exceptions to this are -t and -T, which if given in the config file will not be overridden. Note also that currently some options cannot be negated, e.g. -S. Config file lines that have a # as the first character are treated as comments and not processed any further.-A
-c, --disable-clean-session
If using this option, it is recommended that the client id is set manually with --id
--cafile
See also --capath
--capath
For --capath to work correctly, the certificate files must have ".crt" as the file ending and you must run "c_rehash <path to capath>" each time you add/remove a certificate.
See also --cafile
--cert
See also --key.
--ciphers
-C
Combine with -R to print only the first set of fresh messages (i.e. that does not have the retained flag set), or with -T to filter which topics are processed.
-d, --debug
--help
-h, --host
-i, --id
-I, --id-prefix
--insecure
-k, --keepalive
--key
See also --cert.
-N
-p, --port
-P, --pw
--proxy
If username is not given, then no authentication is attempted. If the port is not given, then the default of 1080 is used.
More SOCKS versions may be available in the future, depending on demand, and will use different protocol prefixes as described in curl(1).
--psk
--psk-identity
-q, --qos
The QoS is identical for all topics subscribed to in a single instance of mosquitto_sub.
--quiet
-R
-S
-t, --topic
This option may be repeated to subscribe to multiple topics.
-T, --filter-out
For example, subscribe to the BBC tree, but suppress output from Radio 3:
This option may be repeated to filter out multiple topics or topic trees.
--tls-version
-u, --username
-v, --verbose
-V, --protocol-version
--will-payload
--will-qos
--will-retain
--will-topic
WILLS¶
mosquitto_sub can register a message with the broker that will be sent out if it disconnects unexpectedly. See mqtt(7) for more information.The minimum requirement for this is to use --will-topic to specify which topic the will should be sent out on. This will result in a non-retained, zero length message with QoS 0.
Use the --will-retain, --will-payload and --will-qos arguments to modify the other will parameters.
EXAMPLES¶
Note that these really are examples - the subscriptions will work if you run them as shown, but there must be something publishing messages on those topics for you to receive anything.Subscribe to temperature information on localhost with QoS 1:
Subscribe to hard drive temperature updates on multiple machines/hard drives. This expects each machine to be publishing its hard drive temperature to sensors/machines/HOSTNAME/temperature/HD_NAME.
Subscribe to all broker status messages:
FILES¶
$XDG_CONFIG_HOME/mosquitto_sub, $HOME/.config/mosquitto_subBUGS¶
mosquitto_sub bug information can be found at https://bugs.eclipse.org/bugs/describecomponents.cgi?product=MosquittoSEE ALSO¶
mqtt(7), mosquitto_pub(1), mosquitto(8), libmosquitto(3), mosquitto-tls(7)AUTHOR¶
Roger Light <roger@atchoo.org>08/16/2016 | Mosquitto Project |