mqttui-read-one(1)          General Commands Manual         mqttui-read-one(1)

NAME
       mqttui-read-one - Wait for the first message on the given topic(s) and
       return its payload to stdout

SYNOPSIS
       mqttui read-one [-r|--ignore-retained] [-p|--pretty] [-b|--broker]
       [-u|--username] [--password] [-i|--client-id] [--client-cert]
       [--client-key] [--insecure] [-h|--help] [TOPIC]

DESCRIPTION
       Wait for the first message on the given topic(s) and return its payload
       to stdout.

       Returns exactly one payload of the first received message on the given
       topic(s). The topic of the received message is printed to stderr. This
       means that you can handle stdout and stderr separately.

       This can be helpful for scripting to get the current temperature
       reading and pipe it to somewhere else:

       `echo "The temperature is $(mqttui read-one room/temp)"`

       The output is the exact payload in its binary form. This might be valid
       ASCII / Unicode but could also be something not intended to be
       displayed on a terminal. For a human readable format use `--pretty` or
       `mqttui log`.

OPTIONS
       -r, --ignore-retained
              Do not return on a retained message on connection, wait for
              another message to arrive

       -p, --pretty
              Parse the payload and print it in a human readable pretty form.

              This might not be useful for piping the data.

       -b, --broker=URL [default: mqtt://localhost]
              URL which represents how to connect to the MQTT broker.

              Examples: `mqtt://localhost` `mqtt://localhost:1883`
              `mqtts://localhost` `mqtts://localhost:8883`
              `ws://localhost/path` `ws://localhost:9001/path`
              `wss://localhost/path` `wss://localhost:9001/path`
              May also be specified with the MQTTUI_BROKER environment
              variable.

       -u, --username=STRING
              Username to access the mqtt broker.

              Anonymous access when not supplied.
              May also be specified with the MQTTUI_USERNAME environment
              variable.

       --password=STRING
              Password to access the mqtt broker.

              Consider using a connection with TLS to the broker. Otherwise
              the password will be transported in plaintext.

              Passing the password via command line is insecure as the
              password can be read from the history! You should pass it via
              environment variable.
              May also be specified with the MQTTUI_PASSWORD environment
              variable.

       -i, --client-id=STRING
              Specify the client id to connect with
              May also be specified with the MQTTUI_CLIENTID environment
              variable.

       --client-cert=FILEPATH
              Path to the TLS client certificate file.

              Used together with --client-key to enable TLS client
              authentication. The file has to be a DER-encoded X.509
              certificate serialized to PEM.
              May also be specified with the MQTTUI_CLIENT_CERTIFICATE
              environment variable.

       --client-key=FILEPATH
              Path to the TLS client private key.

              Used together with --client-cert to enable TLS client
              authentication. The file has to be a DER-encoded ASN.1 file in
              PKCS#8 form serialized to PEM.
              May also be specified with the MQTTUI_CLIENT_PRIVATE_KEY
              environment variable.

       --insecure
              Allow insecure TLS connections

       -h, --help
              Print help (see a summary with '-h')

       [TOPIC] [default: #]
              Topics to watch
              May also be specified with the MQTTUI_TOPIC environment
              variable.

                                   read-one                 mqttui-read-one(1)