Name
mosquitto_rr — an MQTT version 5/3.1.1 client for request/response messaging
Synopsis
mosquitto_rr [options] -e response-topic -t message-topic... {payload-options}
options:
[auth-options] [connection-options] [misc-options] [mqtt-options] [output-options] [ tls-certificate-options | tls-psk-options ]
auth-options:
[-u username] [-P password]
connection-options:
{
[-h hostname]
[--unix socket path]
[-p port-number]
|
-L URL
}
[-A bind-address] [--nodelay] [-S] [--ws] [--proxy socks-url]
misc-options:
[--latency] [-W message-processing-timeout]
mqtt-options:
[-c] [-D command identifier value] [-i client-id] [-I client-id-prefix] [-k keepalive-time] [-q message-QoS] [--retain-handling always | new | never] [-V protocol-version] [-x session-expiry-interval]
[
--will-topic topic
[--will-payload payload]
[--will-qos qos]
[--will-retain]
]
output-options:
[-d] [-N] [--pretty] [--quiet] [-R] [-v]
payload-options: -f file | -m message | -n | -s
tls-certificate-options:
[--no-tls]
{ --cafile file | --capath dir }
[--tls-use-os-certs]
[--cert file] [--key file]
[--ciphers ciphers] [--insecure] [--tls-alpn protocol] [--tls-keylog file] [--tls-version version]
[--tls-engine engine] [--keyform
{ pem | engine }] [--tls-engine-kpass-sha1 kpass-sha1]
tls-psk-options: --psk hex-key --psk-identity identity [--ciphers ciphers] [--tls-version version]
mosquitto_rr [--help]
Description
mosquitto_rr is an MQTT version 5/3.1.1 client that can be used to publish a request message and wait for a response. When using MQTT v5, which is the default, mosquitto_rr will use the Request-Response feature.
The important options are -t, -e,
and one of -f, -m, -n,
and -s.
Example: mosquitto_rr -t request-topic -e response-topic -m message
Encrypted Connections
This client supports TLS encrypted connections. It is strongly recommended that you use an encrypted connection for anything more than the most basic setup.
To enable TLS connections when using x509 certificates, one of
either --cafile or --capath can
be provided as an option.
Alternatively, if the -p 8883 option is used
then the OS provided certificates will be loaded and neither
--cafile or --capath are
needed.
To enable TLS connections when using TLS-PSK, you must use the
--psk and the --psk-identity
options.
Options
There are three ways to provide options to mosquitto_rr: the default config file, a specified config file, or options on the command line.
The default config file is located at
$XDG_CONFIG_HOME/mosquitto_rr or
$HOME/.config/mosquitto_rr on POSIX systems, or
%USERPROFILE%\mosquitto_rr on Windows.
A config file can be specified on the command line using
-o .
If the config-file-o option is used, the default config
file will not be loaded.
In both cases, the contents of the config file should consist of
options, one per line in the format:
-option . If
options are also specified on the command line, those
options will override the same options set in the config
file. The exceptions to this are the message type options, of which
only one can be specified. Note also that currently some options
cannot be negated, e.g. value-S. TLS encryption options
can be negated with the --no-tls option.
Config file lines that have a # as the first
character are treated as comments and not processed any further.
It is suggested that config files are primarily used for authentication purposes. Use of a config file allows you to authenticate without the need to show the username and password on the command line.
-ABind the outgoing connection to a local ip address/hostname. Use this argument if you need to restrict network communication to a particular interface.
-
-c,--disable-clean-session -
Disable 'clean session' / enable persistent client mode. When this argument is used, the broker will be instructed not to clean existing sessions for the same client id when the client connects, and sessions will never expire when the client disconnects. MQTT v5 clients can change their session expiry interval with the
-xargument.When a session is persisted on the broker, the subscriptions for the client will be maintained after it disconnects, along with subsequent QoS 1 and QoS 2 messages that arrive. When the client reconnects and does not clean the session, it will receive all of the queued messages.
If using this option, the client id must be set manually with
--id. --cafile-
Define the path to a file containing PEM encoded CA certificates that are trusted. Used to enable SSL communication.
See also
--capath --capath-
Define the path to a directory containing PEM encoded CA certificates that are trusted. Used to enable SSL communication.
For
--capathto work correctly, the certificate files must have ".crt" as the file ending and you must run "openssl rehash <path to capath>" each time you add/remove a certificate.See also
--cafile --cert-
Define the path to a file containing a PEM encoded certificate for this client, if required by the server.
See also
--keyand the Encrypted Connections section. --ciphersAn openssl compatible list of TLS ciphers to support in the client. See ciphers(1) for more information.
-
-d,--debug Enable debug messages.
-
-D,--property -
Set MQTT v5 properties for with this client. If you use this option, the client will be set to be an MQTT v5 client. This option has two forms:
-D command identifier value-D command identifier name valuecommandis the MQTT command/packet identifier and can be one of CONNECT, PUBLISH, PUBACK, PUBREC, PUBCOMP, SUBSCRIBE, UNSUBSCRIBE, DISCONNECT, AUTH, or WILL. The properties available for each command are listed in the Properties section.identifieris the name of the property to add. This is as described in the specification, but with '-' as a word separator. For example:payload-format-indicator. More details are in the Properties section.valueis the value of the property to add, with a data type that is property specific.nameis only used for theuser-propertyproperty as the first of the two strings in the string pair. In that case,valueis the second of the strings in the pair. -eResponse topic. The client will subscribe to this topic to wait for a response.
-
-f,--file Send the contents of a file as the message.
-F-
Specify output printing format. This option allows you to choose what information from each message is printed to the screen. See the Output Format section below for full details.
This option overrides the
-voption, but does not override the-Noption. --helpDisplay usage information.
-
-h,--host Specify the host to connect to. Defaults to localhost.
-
-i,--id The id to use for this client. If not given, a client id will be generated depending on the MQTT version being used. For v3.1.1/v3.1, the client generates a client id in the format
mosq-XXXXXXXXXXXXXXXXXX, where theXare replaced with random alphanumeric characters. For v5.0, the client sends a zero length client id, and the server will generate a client id for the client.-
-I,--id-prefix Provide a prefix that the client id will be built from by appending the process id of the client. This is useful where the broker is using the clientid_prefixes option. Cannot be used at the same time as the
--idargument.--insecureWhen using certificate based encryption, this option disables verification of the server hostname in the server certificate. This can be useful when testing initial server configurations but makes it possible for a malicious third party to impersonate your server through DNS spoofing, for example. Use this option in testing only. If you need to resort to using this option in a production environment, your setup is at fault and there is no point using encryption.
-
-k,--keepalive The number of seconds between sending PING commands to the broker for the purposes of informing it we are still connected and functioning. Defaults to 60 seconds.
--key-
Define the path to a file containing a PEM encoded private key for this client, carrying out mutual TLS with the server.
See also
--certand the Encrypted Connections section. --keyform-
Specifies the type of private key in use when making TLS connections.. This can be "pem" or "engine". This parameter is useful when a TPM module is being used and the private key has been created with it. Defaults to "pem", which means normal private key files are used.
See also
--tls-engine. -
-L,--url -
Specify specify user, password, hostname, port and topic at once as a URL. The URL must be in the form: mqtt(s)://[username[:password]@]host[:port]/topic or ws(s)://[username[:password]@]host[:port]/path
Depending on the scheme, the port will default to different values. mqtt:// - 1883, mqtts:// - 8883, ws:// - 80, wss:// - 443.
--latency-
If this option is specified, mosquitto_rr will print out the latency between it starting to publish a request and the response arriving. This number includes both the broker and client processing times, as well as any inherent network latency.
This can be used to measure message delivery latency very simply by specifying an identical request and response topic.
The
--nodelayoption will be automatically used when--latencyis in use. -
-m,--message Send a single request message from the command line.
-NDo not append an end of line character to the payload when printing. This allows streaming of payload data from multiple messages directly to another application unmodified. Only really makes sense when not using
-v.-
-n,--null-message Send a null (zero length) message.
--nodelayDisable Nagle's algorithm for the socket. This means that latency of sent messages is reduced, which is particularly noticeable for small, reasonably infrequent messages. Using this option may result in more packets being sent than would normally be necessary.
--no-tlsDisable all use of TLS encryption. This is useful if you specify TLS options in a configuration file but want to disable those options. It also stops the automatic use of TLS when connecting to port 8883.
-
-p,--port Connect to the port specified. If not given, the default of 1883 for plain MQTT or 8883 for MQTT over TLS will be used.
-
-P,--pw -
Provide a password to be used for authenticating with the broker. Using this argument without also specifying a username is invalid when using MQTT v3.1 or v3.1.1.
See also the
--usernameoption. --prettyWhen using the JSON output format %j or %J, the default is to print in an unformatted fashion. Specifying
--prettyprints messages in a prettier, more human readable format.--proxy-
Specify a SOCKS5 proxy to connect through. "None" and "username" authentication types are supported. The
socks-urlmust be of the formsocks5h://[username[:password]@]host[:port]. The protocol prefixsocks5hmeans that hostnames are resolved by the proxy. The symbols %25, %3A and %40 are URL decoded into %, : and @ respectively, if present in the username or password.If username is not given, then no authentication is attempted. If the port is not given, then the default of 1080 is used.
If the host is given as an IPv6 address, it must be enclosed in square brackets, e.g.
socks5h://[::1]:1080. Note that square brackets have special meaning in some shells, so the proxy url may need quoting in double or single quotes.More SOCKS versions may be available in the future, depending on demand, and will use different protocol prefixes as described in curl(1).
--pskProvide the hexadecimal (no leading 0x) pre-shared-key matching the one used on the broker to use TLS-PSK encryption support.
--psk-identitymust also be provided to enable TLS-PSK.--psk-identityThe client identity to use with TLS-PSK support. This may be used instead of a username if the broker is configured to do so.
-
-q,--qos -
Specify the quality of service desired for the incoming messages, from 0, 1 and 2. Defaults to 0. See mqtt(7) for more information on QoS.
The QoS applies to all topics subscribed to in a single instance of this client.
--quietIf this argument is given, no runtime errors will be printed. This excludes any error messages given in case of invalid user input (e.g. using
--portwithout a port).-R-
If this argument is given, messages that are received that have the retain bit set will not be printed. Messages with retain set are "stale", in that it is not known when they were originally published. When subscribing to a wildcard topic there may be a large number of retained messages. This argument suppresses their display.
See also
--retain-handling. --retain-handlingalways | new | never-
Use this option to control the retain handling option when making a subscription. This controls under what circumstances an existing retained message is sent to the client when the subscription is made.
always- always deliver retained messagesnew- deliver retained messages the first time a subscription is made, but not on subsequent subscriptions. This is useful for the case where you have a long running client using a non-clean session. If the connection is dropped briefly, when the client reconnects you will not receive the retained messages again.never- never deliver retained messages
-SUse SRV lookups to determine which host to connect to. Performs lookups to
_mqtt._tcp.<host>when used in conjunction with-h, otherwise uses_mqtt._tcp.<local dns domain>.-
-s,--stdin-file Send a request message read from stdin, sending the entire content as a single message.
-
-t,--topic The MQTT topic where the request message will be sent.
--tls-alpnProvide a protocol to use when connecting to a broker that has multiple protocols available on a single port, e.g. MQTT and WebSockets.
--tls-engine-
A valid openssl engine id. These can be listed with the openssl engine command.
See also
--keyform. --tls-engine-kpass-sha1-
SHA1 of the private key password when using an TLS engine. Some TLS engines such as the TPM engine may require the use of a password in order to be accessed. This option allows a hex encoded SHA1 hash of the password to the engine directly, instead of the user being prompted for the password.
See also
--tls-engine. --tls-keylogfile-
Log TLS connection information to
file. This option allows tools such as tcpdump, wireshark and mqttshark to decrypt TLS traffic and inspect the MQTT traffic. In Wireshark this can be done by setting the(Pre)-Master-Secret log filenameoption for theTransport Layer Securityprotocol.This option should be used for debugging only.
--tls-use-os-certsIf used, this will load and trust the OS provided CA certificates. This can be used in conjunction with
--cafileand--capathand can be used on its own to enable TLS mode. This will be set by default if-L mqtts://...is used, or if port is 8883 and no other certificate options are used.--tls-versionChoose which TLS protocol version to use when communicating with the broker. Valid options are
tlsv1.3andtlsv1.2. The default value istlsv1.2. Must match the protocol version used by the broker.-
-u,--username -
Provide a username to be used for authenticating with the broker.
See also the
--pwargument. --unix-
Connect to a broker through a local unix domain socket instead of a TCP socket. This is a replacement for
-hand-L. For example:mosquitto_pub --unix /tmp/mosquitto.sock ...See the
socket_domainoption in mosquitto.conf(5) to configure Mosquitto to listen on a unix socket. -
-v,--verbose -
Print received messages verbosely. With this argument, messages will be printed as "topic payload". When this argument is not given, the messages are printed as "payload".
See also
-F. -
-V,--protocol-version Specify which version of the MQTT protocol should be used when connecting to the remote broker. Can be
5,311,31, or the more verbosemqttv5,mqttv311, ormqttv31. Defaults to311.-WProvide a timeout as an integer number of seconds. The client will stop processing messages and disconnect after this number of seconds has passed. The timeout starts just after the client has connected to the broker.
--will-payloadSpecify a message that will be stored by the broker and sent out if this client disconnects unexpectedly. This must be used in conjunction with
--will-topic.--will-qosThe QoS to use for the Will. Defaults to 0. This must be used in conjunction with
--will-topic.--will-retainIf given, if the client disconnects unexpectedly the message sent out will be treated as a retained message. This must be used in conjunction with
--will-topic.--will-topicThe topic on which to send a Will, in the event that the client disconnects unexpectedly.
--wsConnect using WebSockets instead of plain TCP.
-x-
Set the session-expiry-interval property on the CONNECT packet. If you use this option, the client will be set to be an MQTT v5 client. Set to 0-4294967294 to specify the session will expire in that many seconds after the client disconnects, or use -1, 4294967295, or ∞ for a session that does not expire. Defaults to -1 if -c is also given, or 0 if -c not given.
If the session is set to never expire, either with -x or -c, then a client id must be provided.
Output Format
There are three ways of formatting the printed output. In all cases a
new-line character is appended for each message received unless the
-N argument is given.
Payload-only is the default output format and will print the payload exactly as it is received.
Verbose mode is activated with -v and prints the
message topic and the payload, separated by a space.
The final option is formatted output, which allows the user to
define a custom output format. The behaviour is controlled with
the -F format-string option. The format string is
a free text string where interpreted sequences are replaced by
different parameters. The available interpreted sequences are
described below.
Three characters are used to start an interpreted sequence:
%, @ and \.
Sequences starting with % are either parameters
related to the MQTT message being printed, or are helper sequences
to avoid the need to type long date format strings for example.
Sequences starting with @ are passed to the
strftime(3)
function (with the @ replaced with a % - note that only the
character immediately after the @ is passed to strftime). This
allows the construction of a wide variety of time based outputs.
The output options for strftime vary from platform to platform, so
please check what is available for your platform. One extension to
strftime is provided which is @N, which can be
used to obtain the number of nanoseconds passed in the current
second. The resolution of this option varies depending on the
platform. The final sequence character is \,
which is used to input some characters that would otherwise be
difficult to enter.
Flag characters
The parameters %A, %C, %d, %E, %F, %f, %I, %l, %m, %p, %R, %S, %t, %x, and %X can have optional flags immediately after the % character.
0The value should be zero padded. This applies to the parameters %A, %E, %d, %F, %f, %l, %m, %S, %X, and %x. It will be ignored for other parameters. If used with the
-flag, the0flag will be ignored.-The value will be left aligned to the field width, padded with blanks. The default is right alignment, with either 0 or blank padding.
Field width
Some of the MQTT related parameters can be formatted with an option to set their field width in a similar way to regular printf style formats, i.e. this sets the minimum width when printing this parameter. If the output length is smaller than this width, the field will be padded to meet this width. This applies to the options %A, %C, %d, %E, %F, %f, %I, %l, %m, %p, %R, %S, %t, %x, %X.
For example %10t would set the minimum topic
field width to 10 characters.
Maximum width
Some of the MQTT related parameters can be formatted with an
option to set a maximum field width in a similar way to regular
printf style formats, for example %.20t for a
maximum width of 20. This applies to the options %C, %I, %R, %t.
For example %10.10t would set the minimum topic
field width to 10 characters, and the maximum topic width to
10 characters, i.e. the field will always be exactly 10
characters long.
Hexadecimal binary field width
The %x and %X parameters output the payload as a single
hexadecimal string by default. It is also possible to split the
hexadecimal payload into fields by a chosen length of nibbles.
For example, %.2x would split the payload into
two nibble or one byte values, separated by spaces and might produce
an output of 18 83.
The separator character is a space by default, but can be changed
to one of !"#$&'()*+,-./:;<=>?@[\]^_`{|}~
by adding that character after the binary field width. For example
%.2:x might produce an output of
18:83.
Floating point number printing consideration
The output format supports only the IEEE 754 floating point standard as described in Annex F of ISO/IEC 9899:1999. Don't try to use %f or %d if the platform of the publisher uses a different floating point representation standard than IEEE 754 or you will get invalid data. If you are unsure what floating representation your platform is using, then it is most likely IEEE 754. If you get malformed or unexpected values, check if the floating point number in the payload from the publisher is encoded in IEEE 754.
If want to print floats, make sure you only subscribe to topics that send only IEEE 754 formatted floats. The processing is very strict about floats and if anything that is not a float is received, an error message will be printed.
MQTT related parameters
%%a literal %.%Athe MQTT v5 topic-alias property, if present.%Cthe MQTT v5 content-type property, if present.%Dthe MQTT v5 correlation-data property, if present. Note that this property is specified as binary data, so may produce non-printable characters.%dthe payload treated as an 8 byte IEEE 754 float (double).%Ethe MQTT v5 message-expiry-interval property, if present.%Fthe MQTT v5 payload-format-indicator property, if present.%fthe payload treated as an 4 byte IEEE 754 float.%lthe length of the payload in bytes.%mthe message id (only relevant for messages with QoS>0).%Pthe MQTT v5 user-property property, if present. This will be printed in the form key:value. It is possible for any number of user properties to be attached to a message, and to have duplicate keys.%pthe payload raw bytes (may produce non-printable characters depending on the payload).%qthe message QoS.%Rthe MQTT v5 response-topic property, if present.%rthe retained flag for the message.%Sthe MQTT v5 subscription-identifier property, if present.%tthe message topic.%xthe payload with each byte as a hexadecimal number (lower case).%Xthe payload with each byte as a hexadecimal number (upper case).
Helpers
%IISO-8601 format date and time, e.g. 2016-08-10T09:47:38+0100%jJSON output of message parameters and timestamp, with a quoted and escaped payload. For example{"tst":"2020-05-06T22:12:00.000000+0100","topic":"greeting","qos":0,"retain":0,"payload":"hello world"}-
%JJSON output of message parameters and timestamp, with a non-quoted and non-escaped payload - this means the payload must itself be valid JSON. For example:{"tst":"2020-05-06T22:12:00.000000+0100","topic":"foo","qos":0,"retain":0,"payload":{"temperature":27.0,"humidity":57}}.If the payload is not valid JSON, then the error message "Error: Message payload is not valid JSON on topic <topic>" will be printed to stderr.
%UUnix timestamp with nanoseconds, e.g. 1470818943.786368637
Time related parameters
@@a literal @.@Xpass the character represented byXto the strftime function as%X. The options supported are platform dependent.@Nthe number of nanoseconds that have passed in the current second, with varying timing resolution depending on platform.
Escape characters
\\a literal \.\0a null character. Can be used to separate different parameters that may contain spaces (e.g. topic, payload) so that processing with tools such as xargs(1) is easier.\aalert/bell.\ethe escape sequence, which can be used with ANSI colour codes to provide coloured output for example.\nend of line.\rcarriage return.\thorizontal tab.\vvertical tab.
Wills
The client 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.
Properties
The -D / --property option
allows adding properties to different stages of the mosquitto_rr
run. The properties supported for each command are as
follows:
Connect
authentication-data(binary data - note treated as a string)authentication-method(UTF-8 string pair)maximum-packet-size(32-bit unsigned integer)receive-maximum(16-bit unsigned integer)request-problem-information(8-bit unsigned integer)request-response-information(8-bit unsigned integer)session-expiry-interval(32-bit unsigned integer, note use-xinstead)topic-alias-maximum(16-bit unsigned integer)user-property(UTF-8 string pair)
Publish
content-type(UTF-8 string)correlation-data(binary data - note treated as a string)message-expiry-interval(32-bit unsigned integer)payload-format-indicator(8-bit unsigned integer)response-topic(UTF-8 string)topic-alias(16-bit unsigned integer)user-property(UTF-8 string pair)
Will properties
content-type(UTF-8 string)correlation-data(binary data - note treated as a string)message-expiry-interval(32-bit unsigned integer)payload-format-indicator(8-bit unsigned integer)response-topic(UTF-8 string)user-property(UTF-8 string pair)will-delay-interval(32-bit unsigned integer)
Exit Status
Zero on success, or non-zero on error. If the connection is refused by the broker at the MQTT level, then the exit code is the CONNACK reason code. If another error occurs, the exit code is a libmosquitto return value.
MQTT v3.1.1 CONNACK codes:
0Success1Connection refused: Bad protocol version2Connection refused: Identifier rejected3Connection refused: Server unavailable4Connection refused: Bad username/password5Connection refused: Not authorized
MQTT v5 CONNACK codes:
0Success128Unspecified error129Malformed packet130Protocol error131Implementation specific error132Unsupported protocol version133Client ID not valid134Bad username or password135Not authorized136Server unavailable137Server busy138Banned139Server shutting down140Bad authentication method141Keep alive timeout142Session taken over143Topic filter invalid144Topic name invalid147Receive maximum exceeded148Topic alias invalid149Packet too large148Message rate too high151Quota exceeded152Administrative action153Payload format invalid154Retain not supported155QoS not supported156Use another server157Server moved158Shared subscriptions not supported159Connection rate exceeded160Maximum connect time161Subscription IDs not supported162Wildcard subscriptions not supported
Other codes:
27Timed out waiting for message
Files
-
$XDG_CONFIG_HOME/mosquitto_rr,$HOME/.config/mosquitto_rr,$HOME/snap/mosquitto/current/.config/mosquitto_rr(for snap installs) Configuration file for default options.
Bugs
mosquitto bug information can be found at https://github.com/eclipse-mosquitto/mosquitto/issues