1MOSQUITTO_SUB(1) Commands MOSQUITTO_SUB(1)
2
6 mosquitto_sub - an MQTT version 5/3.1.1/3.1 client for subscribing to
7 topics
8
10 mosquitto_sub
11 {[-h hostname] [--unix socket path] [-p port-number] [-u username] [-P password] -t message-topic...
12 | -L URL [-t message-topic...] } [-A bind-address] [-c]
13 [-C msg-count] [-d] [-D command identifier value] [-E]
14 [-i client-id] [-I client-id-prefix] [-k keepalive-time]
15 [-N] [--nodelay] [--pretty] [-q message-QoS]
16 [--random-filter chance] [--remove-retained] [-R |
17 --retained-only] [--retain-as-published] [-S]
18 [-T filter-out...] [-U unsub-topic...] [-v]
19 [-V protocol-version] [-W message-processing-timeout]
20 [-x session-expiry-interval] [--proxy socks-url]
21 [--quiet]
22 [--will-topic topic [--will-payload payload] [--will-qos qos] [--will-retain]]
23 [[{--cafile file | --capath dir} [--cert file] [--key file] [--tls-version version] [--tls-alpn protocol] [--tls-engine engine] [--keyform {pem | engine}] [--tls-engine-kpass-sha1 kpass-sha1] [--tls-use-os-certs] [--insecure]]
24 |
25 [--psk hex-key --psk-identity identity [--tls-version version]]]
26 mosquitto_sub [--help]
28
30 mosquitto_sub is a simple MQTT version 5/3.1.1 client that will
31 subscribe to topics and print the messages that it receives.
32 In addition to subscribing to topics, mosquitto_sub can filter out
34 received messages so they are not printed (see the -T option) or
35 unsubscribe from topics (see the -U option). Unsubscribing from topics
36 is useful for clients connecting with clean session set to false.
37
39 mosquitto_sub supports TLS encrypted connections. It is strongly
40 recommended that you use an encrypted connection for anything more than
41 the most basic setup.
42 To enable TLS connections when using x509 certificates, one of either
44 --cafile or --capath must be provided as an option.
45 To enable TLS connections when using TLS-PSK, you must use the --psk
47 and the --psk-identity options.
48
50 The options below may be given on the command line, but may also be
51 placed in a config file located at $XDG_CONFIG_HOME/mosquitto_sub or
52 $HOME/.config/mosquitto_sub with one pair of -option value per line.
53 The values in the config file will be used as defaults and can be
54 overridden by using the command line. The exceptions to this are -t and
55 -T, which if given in the config file will not be overridden. Note also
56 that currently some options cannot be negated, e.g. -S. Config file
57 lines that have a # as the first character are treated as comments and
58 not processed any further.
59 -A
61 Bind the outgoing connection to a local ip address/hostname. Use
62 this argument if you need to restrict network communication to a
63 particular interface.
64 -c, --disable-clean-session
66 Disable 'clean session' / enable persistent client mode. When this
67 argument is used, the broker will be instructed not to clean
68 existing sessions for the same client id when the client connects,
69 and sessions will never expire when the client disconnects. MQTT v5
70 clients can change their session expiry interval with the -x
71 argument.
72 When a session is persisted on the broker, the subscriptions for
74 the client will be maintained after it disconnects, along with
75 subsequent QoS 1 and QoS 2 messages that arrive. When the client
76 reconnects and does not clean the session, it will receive all of
77 the queued messages.
78 If using this option, the client id must be set manually with --id
80 --cafile
82 Define the path to a file containing PEM encoded CA certificates
83 that are trusted. Used to enable SSL communication.
84 See also --capath
86 --capath
88 Define the path to a directory containing PEM encoded CA
89 certificates that are trusted. Used to enable SSL communication.
90 For --capath to work correctly, the certificate files must have
92 ".crt" as the file ending and you must run "openssl rehash <path to
93 capath>" each time you add/remove a certificate.
94 See also --cafile
96 --cert
98 Define the path to a file containing a PEM encoded certificate for
99 this client, if required by the server.
100 See also --key.
102 --ciphers
104 An openssl compatible list of TLS ciphers to support in the client.
105 See ciphers(1) for more information.
106 -C
108 Disconnect and exit the program immediately after the given count
109 of messages have been received. This may be useful in shell scripts
110 where on a single status value is required, for example.
111 Combine with -R to print only the first set of fresh messages (i.e.
113 that does not have the retained flag set), or with -T to filter
114 which topics are processed.
115 -d, --debug
117 Enable debug messages.
118 -D, --property
120 Use an MQTT v5 property with this publish. If you use this option,
121 the client will be set to be an MQTT v5 client. This option has two
122 forms:
123 -D command identifier value
125 -D command identifier name value
127 command is the MQTT command/packet identifier and can be one of
129 CONNECT, PUBACK, PUBREC, PUBCOMP, SUBSCRIBE, UNSUBSCRIBE,
130 DISCONNECT, AUTH, or WILL. The properties available for each
131 command are listed in the Properties section.
132 identifier is the name of the property to add. This is as described
134 in the specification, but with '-' as a word separator. For
135 example: payload-format-indicator. More details are in the
136 Properties section.
137 value is the value of the property to add, with a data type that is
139 property specific.
140 name is only used for the user-property property as the first of
142 the two strings in the string pair. In that case, value is the
143 second of the strings in the pair.
144 -E
146 If this option is given, mosquitto_sub will exit immediately that
147 all of its subscriptions have been acknowledged by the broker. In
148 conjunction with -c this allows a durable client session to be
149 initialised on the broker for future use without requiring any
150 messages to be received.
151 -F
153 Specify output printing format. This option allows you to choose
154 what information from each message is printed to the screen. See
155 the Output Format section below for full details.
156 This option overrides the -v option, but does not override the -N
158 option.
159 --help
161 Display usage information.
162 -h, --host
164 Specify the host to connect to. Defaults to localhost.
165 -i, --id
167 The id to use for this client. If not given, a client id will be
168 generated depending on the MQTT version being used. For
169 v3.1.1/v3.1, the client generates a client id in the format
170 mosq-XXXXXXXXXXXXXXXXXX, where the X are replaced with random
171 alphanumeric characters. For v5.0, the client sends a zero length
172 client id, and the server will generate a client id for the client.
173 This option cannot be used at the same time as the --id-prefix
175 argument.
176 -I, --id-prefix
178 Provide a prefix that the client id will be built from by appending
179 the process id of the client. This is useful where the broker is
180 using the clientid_prefixes option. Cannot be used at the same time
181 as the --id argument.
182 --insecure
184 When using certificate based encryption, this option disables
185 verification of the server hostname in the server certificate. This
186 can be useful when testing initial server configurations but makes
187 it possible for a malicious third party to impersonate your server
188 through DNS spoofing, for example. Use this option in testing only.
189 If you need to resort to using this option in a production
190 environment, your setup is at fault and there is no point using
191 encryption.
192 -k, --keepalive
194 The number of seconds between sending PING commands to the broker
195 for the purposes of informing it we are still connected and
196 functioning. Defaults to 60 seconds.
197 --key
199 Define the path to a file containing a PEM encoded private key for
200 this client, if required by the server.
201 See also --cert.
203 --keyform
205 Specifies the type of private key in use when making TLS
206 connections.. This can be "pem" or "engine". This parameter is
207 useful when a TPM module is being used and the private key has been
208 created with it. Defaults to "pem", which means normal private key
209 files are used.
210 See also --tls-engine.
212 -L, --url
214 Specify specify user, password, hostname, port and topic at once as
215 a URL. The URL must be in the form:
216 mqtt(s)://[username[:password]@]host[:port]/topic
217 If the scheme is mqtt:// then the port defaults to 1883. If the
219 scheme is mqtts:// then the port defaults to 8883.
220 -N
222 Do not append an end of line character to the payload when
223 printing. This allows streaming of payload data from multiple
224 messages directly to another application unmodified. Only really
225 makes sense when not using -v.
226 --nodelay
228 Disable Nagle's algorithm for the socket. This means that latency
229 of sent messages is reduced, which is particularly noticable for
230 small, reasonably infrequent messages. Using this option may result
231 in more packets being sent than would normally be necessary.
232 -p, --port
234 Connect to the port specified. If not given, the default of 1883
235 for plain MQTT or 8883 for MQTT over TLS will be used.
236 -P, --pw
238 Provide a password to be used for authenticating with the broker.
239 Using this argument without also specifying a username is invalid
240 when using MQTT v3.1 or v3.1.1. See also the --username option.
241 --pretty
243 When using the JSON output format %j or %J, the default is to print
244 in an unformatted fashion. Specifying --pretty prints messages in a
245 prettier, more human readable format.
246 --proxy
248 Specify a SOCKS5 proxy to connect through. "None" and "username"
249 authentication types are supported. The socks-url must be of the
250 form socks5h://[username[:password]@]host[:port]. The protocol
251 prefix socks5h means that hostnames are resolved by the proxy. The
252 symbols %25, %3A and %40 are URL decoded into %, : and @
253 respectively, if present in the username or password.
254 If username is not given, then no authentication is attempted. If
256 the port is not given, then the default of 1080 is used.
257 More SOCKS versions may be available in the future, depending on
259 demand, and will use different protocol prefixes as described in
260 curl(1).
261 --psk
263 Provide the hexadecimal (no leading 0x) pre-shared-key matching the
264 one used on the broker to use TLS-PSK encryption support.
265 --psk-identity must also be provided to enable TLS-PSK.
266 --psk-identity
268 The client identity to use with TLS-PSK support. This may be used
269 instead of a username if the broker is configured to do so.
270 -q, --qos
272 Specify the quality of service desired for the incoming messages,
273 from 0, 1 and 2. Defaults to 0. See mqtt(7) for more information on
274 QoS.
275 The QoS is identical for all topics subscribed to in a single
277 instance of mosquitto_sub.
278 --quiet
280 If this argument is given, no runtime errors will be printed. This
281 excludes any error messages given in case of invalid user input
282 (e.g. using --port without a port).
283 -R
285 If this argument is given, messages that are received that have the
286 retain bit set will not be printed. Messages with retain set are
287 "stale", in that it is not known when they were originally
288 published. When subscribing to a wildcard topic there may be a
289 large number of retained messages. This argument suppresses their
290 display.
291 --random-filter
293 This option can be used to reduce the proportion of messages that
294 mosquitto_sub prints. The default behaviour is to print all
295 incoming messages. Setting the chance to a floating point value
296 between 0.1 and 100.0 will ensure that on average that percentage
297 of messages will be printed.
298 --remove-retained
300 If this argument is given, the when mosquitto_sub receives a
301 message with the retained bit set, it will send a message to the
302 broker to clear that retained message. This applies to all received
303 messages except those that are filtered out by the -T option. This
304 option still takes effect even if -R is used. See also the
305 --retain-as-published and --retained-only options.
306 Example 1. Remove all retained messages on the server, assuming we
308 have access to do so, and then exit:
309 mosquitto_sub -t '#' --remove-retained --retained-only
311 Example 2. Remove a whole tree, with the exception of a single
313 topic:
314 mosquitto_sub -t 'bbc/#' -T bbc/bbc1 --remove-retained
316 --retained-only
318 If this argument is given, only messages that are received that
319 have the retain bit set will be printed. Messages with retain set
320 are "stale", in that it is not known when they were originally
321 published. With this argument in use, the receipt of the first
322 non-stale message will cause the client to exit. See also the
323 --retain-as-published option.
324 --retain-as-published
326 If this argument is given, the subscriptions will have the "retain
327 as published" option set. This means that the retain flag on an
328 incoming message will be exactly as set by the publishing client,
329 rather than indicating whether the message is fresh/stale.
330 This option is not valid for MQTT v3.1/v3.1.1 clients.
332 -S
334 Use SRV lookups to determine which host to connect to. Performs
335 lookups to _mqtt._tcp.<host> when used in conjunction with -h,
336 otherwise uses _mqtt._tcp.<local dns domain>.
337 -t, --topic
339 The MQTT topic to subscribe to. See mqtt(7) for more information on
340 MQTT topics.
341 This option may be repeated to subscribe to multiple topics.
343 -T, --filter-out
345 Suppress printing of topics that match the filter. This allows
346 subscribing to a wildcard topic and only printing a partial set of
347 the wildcard hierarchy.
348 For example, subscribe to the BBC tree, but suppress output from
350 Radio 3:
351 • mosquitto_sub -t bbc/# -T bbc/radio3
353 This option may be repeated to filter out multiple topics or topic
355 trees.
356 --tls-alpn
358 Provide a protocol to use when connecting to a broker that has
359 multiple protocols available on a single port, e.g. MQTT and
360 WebSockets.
361 --tls-engine
363 A valid openssl engine id. These can be listed with openssl engine
364 command.
365 See also --keyform.
367 --tls-engine-kpass-sha1
369 SHA1 of the private key password when using an TLS engine. Some TLS
370 engines such as the TPM engine may require the use of a password in
371 order to be accessed. This option allows a hex encoded SHA1 hash of
372 the password to the engine directly, instead of the user being
373 prompted for the password.
374 See also --tls-engine.
376 --tls-use-os-certs
378 If used, this will load and trust the OS provided CA certificates.
379 This can be used in conjunction with --cafile and --capath and can
380 be used on its own to enable TLS mode. This will be set by default
381 if -L mqtts://... is used, or if port is 8883 and no other
382 certificate options are used.
383 --tls-version
385 Choose which TLS protocol version to use when communicating with
386 the broker. Valid options are tlsv1.3, tlsv1.2 and tlsv1.1. The
387 default value is tlsv1.2. Must match the protocol version used by
388 the broker.
389 -u, --username
391 Provide a username to be used for authenticating with the broker.
392 See also the --pw argument.
393 --unix
395 Connect to a broker through a local unix domain socket instead of a
396 TCP socket. This is a replacement for -h and -L. For example:
397 mosquitto_pub --unix /tmp/mosquitto.sock ...
398 See the socket_domain option in mosquitto.conf[1m(5) to configure
400 Mosquitto to listen on a unix socket.
401 -U, --unsubscribe
403 A topic that will be unsubscribed from. This may be used on its own
404 or in conjunction with the --topic option and only makes sense when
405 used in conjunction with --clean-session.
406 If used with --topic then subscriptions will be processed before
408 unsubscriptions.
409 Note that it is only possible to unsubscribe from subscriptions
411 that have previously been made. It is not possible to punch holes
412 in wildcard subscriptions. For example, subscribing to sensors/#
413 and then unsubscribing from sensors/+/temperature as shown below
414 will still result in messages matching the sensors/+/temperature
415 being delivered to the client.
416 • mosquitto_sub -t sensors/# -U sensors/+/temperature -v
418 Note also that because retained messages are published by the
420 broker on receipt of a SUBSCRIBE command, subscribing and
421 unsubscribing to the same topic may result in messages being
422 received at the client.
423 This option may be repeated to unsubscribe from multiple topics.
425 -v, --verbose
427 Print received messages verbosely. With this argument, messages
428 will be printed as "topic payload". When this argument is not
429 given, the messages are printed as "payload".
430 -V, --protocol-version
432 Specify which version of the MQTT protocol should be used when
433 connecting to the remote broker. Can be 5, 311, 31, or the more
434 verbose mqttv5, mqttv311, or mqttv31. Defaults to 311.
435 -W
437 Provide a timeout as an integer number of seconds. mosquitto_sub
438 will stop processing messages and disconnect after this number of
439 seconds has passed. The timeout starts just after the client has
440 connected to the broker.
441 --will-payload
443 Specify a message that will be stored by the broker and sent out if
444 this client disconnects unexpectedly. This must be used in
445 conjunction with --will-topic.
446 --will-qos
448 The QoS to use for the Will. Defaults to 0. This must be used in
449 conjunction with --will-topic.
450 --will-retain
452 If given, if the client disconnects unexpectedly the message sent
453 out will be treated as a retained message. This must be used in
454 conjunction with --will-topic.
455 --will-topic
457 The topic on which to send a Will, in the event that the client
458 disconnects unexpectedly.
459 -x
461 Set the session-expiry-interval property on the CONNECT packet.
462 Applies to MQTT v5 clients only. Set to 0-4294967294 to specify the
463 session will expire in that many seconds after the client
464 disconnects, or use -1, 4294967295, or ∞ for a session that does
465 not expire. Defaults to -1 if -c is also given, or 0 if -c not
466 given.
467 If the session is set to never expire, either with -x or -c, then a
469 client id must be provided.
470
472 There are three ways of formatting the output from mosquitto_sub. In
473 all cases a new-line character is appended for each message received
474 unless the -N argument is passed to mosquitto_sub.
475 Payload-only is the default output format and will print the payload
477 exactly as it is received.
478 Verbose mode is activated with -v and prints the message topic and the
480 payload, separated by a space.
481 The final option is formatted output, which allows the user to define a
483 custom output format. The behaviour is controlled with the -F
484 format-string option. The format string is a free text string where
485 interpreted sequences are replaced by different parameters. The
486 available interpreted sequences are described below.
487 Three characters are used to start an interpreted sequence: %, @ and \.
489 Sequences starting with % are either parameters related to the MQTT
490 message being printed, or are helper sequences to avoid the need to
491 type long date format strings for example. Sequences starting with @
492 are passed to the strftime(3) function (with the @ replaced with a % -
493 note that only the character immediately after the @ is passed to
494 strftime). This allows the construction of a wide variety of time based
495 outputs. The output options for strftime vary from platform to
496 platform, so please check what is available for your platform.
497 mosquitto_sub does provide one extension to strftime which is @N, which
498 can be used to obtain the number of nanoseconds passed in the current
499 second. The resolution of this option varies depending on the platform.
500 The final sequence character is \, which is used to input some
501 characters that would otherwise be difficult to enter.
502 Flag characters
504 The parameters %A, %C, %E, %F, %I, %l, %m, %p, %R, %S, %t, %x, and %X
505 can have optional flags immediately after the % character.
506 0
508 The value should be zero padded. This applies to the parameters %A,
509 %E, %F, %l, %m, %S, %X, and %x. It will be ignored for other
510 parameters. If used with the - flag, the 0 flag will be ignored.
511 -
513 The value will be left aligned to the field width, padded with
514 blanks. The default is right alignment, with either 0 or blank
515 padding.
516 Field width
518 Some of the MQTT related parameters can be formatted with an option to
519 set their field width in a similar way to regular printf style formats,
520 i.e. this sets the minimum width when printing this parameter. This
521 applies to the options %A, %C, %E, %F, %I, %l, %m, %p, %R, %S, %t, %x,
522 %X.
523 For example %10t would set the minimum topic field width to 10
525 characters.
526 Maximum width
528 Some of the MQTT related parameters can be formatted with an option to
529 set a maximum field width in a similar way to regular printf style
530 formats. This applies to the options %C, %I, %R, %t.
531 For example %10.10t would set the minimum topic field width to 10
533 characters, and the maximum topic width to 10 characters, i.e. the
534 field will always be exactly 10 characters long.
535 MQTT related parameters
537 • %% a literal %.
538 • %A the MQTT v5 topic-alias property, if present.
540 • %C the MQTT v5 content-type property, if present.
542 • %D the MQTT v5 correlation-data property, if present. Note that
544 this property is specified as binary data, so may produce
545 non-printable characters.
546 • %E the MQTT v5 message-expiry-interval property, if present.
548 • %F the MQTT v5 payload-format-indicator property, if present.
550 • %l the length of the payload in bytes.
552 • %m the message id (only relevant for messages with QoS>0).
554 • %P the MQTT v5 user-property property, if present. This will be
556 printed in the form key:value. It is possible for any number of
557 user properties to be attached to a message, and to have duplicate
558 keys.
559 • %p the payload raw bytes (may produce non-printable characters
561 depending on the payload).
562 • %q the message QoS.
564 • %R the MQTT v5 response-topic property, if present.
566 • %r the retained flag for the message.
568 • %S the MQTT v5 subscription-identifier property, if present.
570 • %t the message topic.
572 • %x the payload with each byte as a hexadecimal number (lower case).
574 • %X the payload with each byte as a hexadecimal number (upper case).
576 Helpers
578 • %I ISO-8601 format date and time, e.g. 2016-08-10T09:47:38+0100
579 • %j JSON output of message parameters and timestamp, with a quoted
581 and escaped payload. For example
582 {"tst":"2020-05-06T22:12:00.000000+0100","topic":"greeting","qos":0,"retain":0,"payload":"hello
583 world"}
584 • %J JSON output of message parameters and timestamp, with a
586 non-quoted and non-escaped payload - this means the payload must
587 itself be valid JSON. For example:
588 {"tst":"2020-05-06T22:12:00.000000+0100","topic":"foo","qos":0,"retain":0,"payload":{"temperature":27.0,"humidity":57}}.
589 If the payload is not valid JSON, then the error message "Error:
591 Message payload is not valid JSON on topic <topic>" will be printed
592 to stderr.
593 • %I ISO-8601 format date and time, e.g. 2016-08-10T09:47:38+0100
595 • %U Unix timestamp with nanoseconds, e.g. 1470818943.786368637
597 Time related parameters
599 • @@ a literal @.
600 • @X pass the character represented by X to the strftime function as
602 %X. The options supported are platform dependent.
603 • @N the number of nanoseconds that have passed in the current
605 second, with varying timing resolution depending on platform.
606 Escape characters
608 • \\ a literal \.
609 • \0 a null character. Can be used to separate different parameters
611 that may contain spaces (e.g. topic, payload) so that processing
612 with tools such as xargs(1) is easier.
613 • \a alert/bell.
615 • \e the escape sequence, which can be used with ANSI colour codes to
617 provide coloured output for example.
618 • \n end of line.
620 • \r carriage return.
622 • \t horizontal tab.
624 • \v vertical tab.
626
628 mosquitto_sub can register a message with the broker that will be sent
629 out if it disconnects unexpectedly. See mqtt(7) for more information.
630 The minimum requirement for this is to use --will-topic to specify
632 which topic the will should be sent out on. This will result in a
633 non-retained, zero length message with QoS 0.
634 Use the --will-retain, --will-payload and --will-qos arguments to
636 modify the other will parameters.
637
639 The -D / --property option allows adding properties to different stages
640 of the mosquitto_sub run. The properties supported for each command are
641 as follows:
642 Connect
644 • authentication-data (binary data - note treated as a string in
645 mosquitto_sub)
646 • authentication-method (UTF-8 string)
648 • maximum-packet-size (32-bit unsigned integer)
650 • receive-maximum (16-bit unsigned integer)
652 • request-problem-information (8-bit unsigned integer)
654 • request-response-information (8-bit unsigned integer)
656 • session-expiry-interval (32-bit unsigned integer, note use -x
658 instead)
659 • topic-alias-maximum (16-bit unsigned integer)
661 • user-property (UTF-8 string pair)
663 Subscribe
665 • user-property (UTF-8 string pair)
666 Unsubscribe
668 • user-property (UTF-8 string pair)
669 Disconnect
671 • session-expiry-interval (32-bit unsigned integer)
672 • user-property (UTF-8 string pair)
674 Will properties
676 • content-type (UTF-8 string)
677 • correlation-data (binary data - note treated as a string in
679 mosquitto_sub)
680 • message-expiry-interval (32-bit unsigned integer)
682 • payload-format-indicator (8-bit unsigned integer)
684 • response-topic (UTF-8 string)
686 • user-property (UTF-8 string pair)
688 • will-delay-interval (32-bit unsigned integer)
690
692 mosquitto_sub returns zero on success, or non-zero on error. If the
693 connection is refused by the broker at the MQTT level, then the exit
694 code is the CONNACK reason code. If another error occurs, the exit code
695 is a libmosquitto return value.
696 MQTT v3.1.1 CONNACK codes:
698 • 0 Success
700 • 1 Connection refused: Bad protocol version
702 • 2 Connection refused: Identifier rejected
704 • 3 Connection refused: Server unavailable
706 • 4 Connection refused: Bad username/password
708 • 5 Connection refused: Not authorized
710 MQTT v5 CONNACK codes:
712 • 0 Success
714 • 128 Unspecified error
716 • 129 Malformed packet
718 • 130 Protocol error
720 • 131 Implementation specific error
722 • 132 Unsupported protocol version
724 • 133 Client ID not valid
726 • 134 Bad username or password
728 • 135 Not authorized
730 • 136 Server unavailable
732 • 137 Server busy
734 • 138 Banned
736 • 139 Server shutting down
738 • 140 Bad authentication method
740 • 141 Keep alive timeout
742 • 142 Session taken over
744 • 143 Topic filter invalid
746 • 144 Topic name invalid
748 • 147 Receive maximum exceeded
750 • 148 Topic alias invalid
752 • 149 Packet too large
754 • 148 Message rate too high
756 • 151 Quota exceeded
758 • 152 Administrative action
760 • 153 Payload format invalid
762 • 154 Retain not supported
764 • 155 QoS not supported
766 • 156 Use another server
768 • 157 Server moved
770 • 158 Shared subscriptions not supported
772 • 159 Connection rate exceeded
774 • 160 Maximum connect time
776 • 161 Subscription IDs not supported
778 • 162 Wildcard subscriptions not supported
780
782 Note that these really are examples - the subscriptions will work if
783 you run them as shown, but there must be something publishing messages
784 on those topics for you to receive anything.
785 Subscribe to temperature information on localhost with QoS 1:
787 • mosquitto_sub -t sensors/temperature -q 1
789 Subscribe to hard drive temperature updates on multiple machines/hard
791 drives. This expects each machine to be publishing its hard drive
792 temperature to sensors/machines/HOSTNAME/temperature/HD_NAME.
793 • mosquitto_sub -t sensors/machines/+/temperature/+
795 Subscribe to all broker status messages:
797 • mosquitto_sub -v -t \$SYS/#
799 Specify the output format as "ISO-8601 date : topic : payload in hex"
801 • mosquitto_sub -F '@Y-@m-@dT@H:@M:@S@z : %t : %x' -t '#'
803 Specify the output format as "seconds since epoch.nanoseconds :
805 retained flag : qos : mid : payload length"
806 • mosquitto_sub -F '%@s.@N : %r : %q : %m : %l' -q 2 -t '#'
808 Topic and payload output, but with colour where supported.
810 • mosquitto_sub -F '\e[92m%t \e[96m%p\e[0m' -q 2 -t '#'
812
814 0
815 Success
816 27
818 Timed out waiting for message
819 Other non-zero value
821 Unspecified failure
822
824 $XDG_CONFIG_HOME/mosquitto_sub, $HOME/.config/mosquitto_sub
825 Configuration file for default options.
826
828 mosquitto bug information can be found at
829 https://github.com/eclipse/mosquitto/issues
830
832 mqtt(7), mosquitto_pub(1), mosquitto_rr(1), mosquitto(8),
833 libmosquitto(3), mosquitto-tls(7)
834
836 Roger Light <roger@atchoo.org>
837Mosquitto Project 04/03/2021 MOSQUITTO_SUB(1)