1MOSQUITTO_SUB(1)                   Commands                   MOSQUITTO_SUB(1)
2
3
4

NAME

6       mosquitto_sub - an MQTT version 5/3.1.1/3.1 client for subscribing to
7       topics
8

SYNOPSIS

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
27       mosquitto_sub [--help]
28

DESCRIPTION

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
33       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

ENCRYPTED CONNECTIONS

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
43       To enable TLS connections when using x509 certificates, one of either
44       --cafile or --capath can be provided as an option.
45
46       Alternatively, if the -p 8883 option is used then the OS provided
47       certificates will be loaded and neither --cafile or --capath are needed
48
49       To enable TLS connections when using TLS-PSK, you must use the --psk
50       and the --psk-identity options.
51

OPTIONS

53       The options below may be given on the command line, but may also be
54       placed in a config file located at $XDG_CONFIG_HOME/mosquitto_sub or
55       $HOME/.config/mosquitto_sub with one pair of -option value per line.
56       The values in the config file will be used as defaults and can be
57       overridden by using the command line. The exceptions to this are -t and
58       -T, which if given in the config file will not be overridden. Note also
59       that currently some options cannot be negated, e.g.  -S. Config file
60       lines that have a # as the first character are treated as comments and
61       not processed any further.
62
63       -A
64           Bind the outgoing connection to a local ip address/hostname. Use
65           this argument if you need to restrict network communication to a
66           particular interface.
67
68       -c, --disable-clean-session
69           Disable 'clean session' / enable persistent client mode. When this
70           argument is used, the broker will be instructed not to clean
71           existing sessions for the same client id when the client connects,
72           and sessions will never expire when the client disconnects. MQTT v5
73           clients can change their session expiry interval with the -x
74           argument.
75
76           When a session is persisted on the broker, the subscriptions for
77           the client will be maintained after it disconnects, along with
78           subsequent QoS 1 and QoS 2 messages that arrive. When the client
79           reconnects and does not clean the session, it will receive all of
80           the queued messages.
81
82           If using this option, the client id must be set manually with --id
83
84       --cafile
85           Define the path to a file containing PEM encoded CA certificates
86           that are trusted. Used to enable SSL communication.
87
88           See also --capath
89
90       --capath
91           Define the path to a directory containing PEM encoded CA
92           certificates that are trusted. Used to enable SSL communication.
93
94           For --capath to work correctly, the certificate files must have
95           ".crt" as the file ending and you must run "openssl rehash <path to
96           capath>" each time you add/remove a certificate.
97
98           See also --cafile
99
100       --cert
101           Define the path to a file containing a PEM encoded certificate for
102           this client, if required by the server.
103
104           See also --key.
105
106       --ciphers
107           An openssl compatible list of TLS ciphers to support in the client.
108           See ciphers(1) for more information.
109
110       -C
111           Disconnect and exit the program immediately after the given count
112           of messages have been received. This may be useful in shell scripts
113           where on a single status value is required, for example.
114
115           Combine with -R to print only the first set of fresh messages (i.e.
116           that does not have the retained flag set), or with -T to filter
117           which topics are processed.
118
119       -d, --debug
120           Enable debug messages.
121
122       -D, --property
123           Use an MQTT v5 property with this publish. If you use this option,
124           the client will be set to be an MQTT v5 client. This option has two
125           forms:
126
127           -D command identifier value
128
129           -D command identifier name value
130
131           command is the MQTT command/packet identifier and can be one of
132           CONNECT, PUBACK, PUBREC, PUBCOMP, SUBSCRIBE, UNSUBSCRIBE,
133           DISCONNECT, AUTH, or WILL. The properties available for each
134           command are listed in the Properties section.
135
136           identifier is the name of the property to add. This is as described
137           in the specification, but with '-' as a word separator. For
138           example: payload-format-indicator. More details are in the
139           Properties section.
140
141           value is the value of the property to add, with a data type that is
142           property specific.
143
144           name is only used for the user-property property as the first of
145           the two strings in the string pair. In that case, value is the
146           second of the strings in the pair.
147
148       -E
149           If this option is given, mosquitto_sub will exit immediately that
150           all of its subscriptions have been acknowledged by the broker. In
151           conjunction with -c this allows a durable client session to be
152           initialised on the broker for future use without requiring any
153           messages to be received.
154
155       -F
156           Specify output printing format. This option allows you to choose
157           what information from each message is printed to the screen. See
158           the Output Format section below for full details.
159
160           This option overrides the -v option, but does not override the -N
161           option.
162
163       --help
164           Display usage information.
165
166       -h, --host
167           Specify the host to connect to. Defaults to localhost.
168
169       -i, --id
170           The id to use for this client. If not given, a client id will be
171           generated depending on the MQTT version being used. For
172           v3.1.1/v3.1, the client generates a client id in the format
173           mosq-XXXXXXXXXXXXXXXXXX, where the X are replaced with random
174           alphanumeric characters. For v5.0, the client sends a zero length
175           client id, and the server will generate a client id for the client.
176
177           This option cannot be used at the same time as the --id-prefix
178           argument.
179
180       -I, --id-prefix
181           Provide a prefix that the client id will be built from by appending
182           the process id of the client. This is useful where the broker is
183           using the clientid_prefixes option. Cannot be used at the same time
184           as the --id argument.
185
186       --insecure
187           When using certificate based encryption, this option disables
188           verification of the server hostname in the server certificate. This
189           can be useful when testing initial server configurations but makes
190           it possible for a malicious third party to impersonate your server
191           through DNS spoofing, for example. Use this option in testing only.
192           If you need to resort to using this option in a production
193           environment, your setup is at fault and there is no point using
194           encryption.
195
196       -k, --keepalive
197           The number of seconds between sending PING commands to the broker
198           for the purposes of informing it we are still connected and
199           functioning. Defaults to 60 seconds.
200
201       --key
202           Define the path to a file containing a PEM encoded private key for
203           this client, if required by the server.
204
205           See also --cert.
206
207       --keyform
208           Specifies the type of private key in use when making TLS
209           connections.. This can be "pem" or "engine". This parameter is
210           useful when a TPM module is being used and the private key has been
211           created with it. Defaults to "pem", which means normal private key
212           files are used.
213
214           See also --tls-engine.
215
216       -L, --url
217           Specify specify user, password, hostname, port and topic at once as
218           a URL. The URL must be in the form:
219           mqtt(s)://[username[:password]@]host[:port]/topic
220
221           If the scheme is mqtt:// then the port defaults to 1883. If the
222           scheme is mqtts:// then the port defaults to 8883.
223
224       -N
225           Do not append an end of line character to the payload when
226           printing. This allows streaming of payload data from multiple
227           messages directly to another application unmodified. Only really
228           makes sense when not using -v.
229
230       --nodelay
231           Disable Nagle's algorithm for the socket. This means that latency
232           of sent messages is reduced, which is particularly noticeable for
233           small, reasonably infrequent messages. Using this option may result
234           in more packets being sent than would normally be necessary.
235
236       -p, --port
237           Connect to the port specified. If not given, the default of 1883
238           for plain MQTT or 8883 for MQTT over TLS will be used.
239
240       -P, --pw
241           Provide a password to be used for authenticating with the broker.
242           Using this argument without also specifying a username is invalid
243           when using MQTT v3.1 or v3.1.1. See also the --username option.
244
245       --pretty
246           When using the JSON output format %j or %J, the default is to print
247           in an unformatted fashion. Specifying --pretty prints messages in a
248           prettier, more human readable format.
249
250       --proxy
251           Specify a SOCKS5 proxy to connect through. "None" and "username"
252           authentication types are supported. The socks-url must be of the
253           form socks5h://[username[:password]@]host[:port]. The protocol
254           prefix socks5h means that hostnames are resolved by the proxy. The
255           symbols %25, %3A and %40 are URL decoded into %, : and @
256           respectively, if present in the username or password.
257
258           If username is not given, then no authentication is attempted. If
259           the port is not given, then the default of 1080 is used.
260
261           More SOCKS versions may be available in the future, depending on
262           demand, and will use different protocol prefixes as described in
263           curl(1).
264
265       --psk
266           Provide the hexadecimal (no leading 0x) pre-shared-key matching the
267           one used on the broker to use TLS-PSK encryption support.
268           --psk-identity must also be provided to enable TLS-PSK.
269
270       --psk-identity
271           The client identity to use with TLS-PSK support. This may be used
272           instead of a username if the broker is configured to do so.
273
274       -q, --qos
275           Specify the quality of service desired for the incoming messages,
276           from 0, 1 and 2. Defaults to 0. See mqtt(7) for more information on
277           QoS.
278
279           The QoS is identical for all topics subscribed to in a single
280           instance of mosquitto_sub.
281
282       --quiet
283           If this argument is given, no runtime errors will be printed. This
284           excludes any error messages given in case of invalid user input
285           (e.g. using --port without a port).
286
287       -R
288           If this argument is given, messages that are received that have the
289           retain bit set will not be printed. Messages with retain set are
290           "stale", in that it is not known when they were originally
291           published. When subscribing to a wildcard topic there may be a
292           large number of retained messages. This argument suppresses their
293           display.
294
295       --random-filter
296           This option can be used to reduce the proportion of messages that
297           mosquitto_sub prints. The default behaviour is to print all
298           incoming messages. Setting the chance to a floating point value
299           between 0.1 and 100.0 will ensure that on average that percentage
300           of messages will be printed.
301
302       --remove-retained
303           If this argument is given, the when mosquitto_sub receives a
304           message with the retained bit set, it will send a message to the
305           broker to clear that retained message. This applies to all received
306           messages except those that are filtered out by the -T option. This
307           option still takes effect even if -R is used. See also the
308           --retain-as-published and --retained-only options.
309
310           Example 1.  Remove all retained messages on the server, assuming we
311           have access to do so, and then exit:
312
313               mosquitto_sub -t '#' --remove-retained --retained-only
314
315           Example 2.  Remove a whole tree, with the exception of a single
316           topic:
317
318               mosquitto_sub -t 'bbc/#' -T bbc/bbc1 --remove-retained
319
320       --retained-only
321           If this argument is given, only messages that are received that
322           have the retain bit set will be printed. Messages with retain set
323           are "stale", in that it is not known when they were originally
324           published. With this argument in use, the receipt of the first
325           non-stale message will cause the client to exit. See also the
326           --retain-as-published option.
327
328       --retain-as-published
329           If this argument is given, the subscriptions will have the "retain
330           as published" option set. This means that the retain flag on an
331           incoming message will be exactly as set by the publishing client,
332           rather than indicating whether the message is fresh/stale.
333
334           This option is not valid for MQTT v3.1/v3.1.1 clients.
335
336       -S
337           Use SRV lookups to determine which host to connect to. Performs
338           lookups to _mqtt._tcp.<host> when used in conjunction with -h,
339           otherwise uses _mqtt._tcp.<local dns domain>.
340
341       -t, --topic
342           The MQTT topic to subscribe to. See mqtt(7) for more information on
343           MQTT topics.
344
345           This option may be repeated to subscribe to multiple topics.
346
347       -T, --filter-out
348           Suppress printing of topics that match the filter. This allows
349           subscribing to a wildcard topic and only printing a partial set of
350           the wildcard hierarchy.
351
352           For example, subscribe to the BBC tree, but suppress output from
353           Radio 3:
354
355           •   mosquitto_sub -t bbc/# -T bbc/radio3
356
357           This option may be repeated to filter out multiple topics or topic
358           trees.
359
360       --tls-alpn
361           Provide a protocol to use when connecting to a broker that has
362           multiple protocols available on a single port, e.g. MQTT and
363           WebSockets.
364
365       --tls-engine
366           A valid openssl engine id. These can be listed with openssl engine
367           command.
368
369           See also --keyform.
370
371       --tls-engine-kpass-sha1
372           SHA1 of the private key password when using an TLS engine. Some TLS
373           engines such as the TPM engine may require the use of a password in
374           order to be accessed. This option allows a hex encoded SHA1 hash of
375           the password to the engine directly, instead of the user being
376           prompted for the password.
377
378           See also --tls-engine.
379
380       --tls-use-os-certs
381           If used, this will load and trust the OS provided CA certificates.
382           This can be used in conjunction with --cafile and --capath and can
383           be used on its own to enable TLS mode. This will be set by default
384           if -L mqtts://...  is used, or if port is 8883 and no other
385           certificate options are used.
386
387       --tls-version
388           Choose which TLS protocol version to use when communicating with
389           the broker. Valid options are tlsv1.3, tlsv1.2 and tlsv1.1. The
390           default value is tlsv1.2. Must match the protocol version used by
391           the broker.
392
393       -u, --username
394           Provide a username to be used for authenticating with the broker.
395           See also the --pw argument.
396
397       --unix
398           Connect to a broker through a local unix domain socket instead of a
399           TCP socket. This is a replacement for -h and -L. For example:
400           mosquitto_pub --unix /tmp/mosquitto.sock ...
401
402           See the socket_domain option in mosquitto.conf(5) to configure
403           Mosquitto to listen on a unix socket.
404
405       -U, --unsubscribe
406           A topic that will be unsubscribed from. This may be used on its own
407           or in conjunction with the --topic option and only makes sense when
408           used in conjunction with --clean-session.
409
410           If used with --topic then subscriptions will be processed before
411           unsubscriptions.
412
413           Note that it is only possible to unsubscribe from subscriptions
414           that have previously been made. It is not possible to punch holes
415           in wildcard subscriptions. For example, subscribing to sensors/#
416           and then unsubscribing from sensors/+/temperature as shown below
417           will still result in messages matching the sensors/+/temperature
418           being delivered to the client.
419
420           •   mosquitto_sub -t sensors/# -U sensors/+/temperature -v
421
422           Note also that because retained messages are published by the
423           broker on receipt of a SUBSCRIBE command, subscribing and
424           unsubscribing to the same topic may result in messages being
425           received at the client.
426
427           This option may be repeated to unsubscribe from multiple topics.
428
429       -v, --verbose
430           Print received messages verbosely. With this argument, messages
431           will be printed as "topic payload". When this argument is not
432           given, the messages are printed as "payload".
433
434       -V, --protocol-version
435           Specify which version of the MQTT protocol should be used when
436           connecting to the remote broker. Can be 5, 311, 31, or the more
437           verbose mqttv5, mqttv311, or mqttv31. Defaults to 311.
438
439       -W
440           Provide a timeout as an integer number of seconds. mosquitto_sub
441           will stop processing messages and disconnect after this number of
442           seconds has passed. The timeout starts just after the client has
443           connected to the broker.
444
445       --will-payload
446           Specify a message that will be stored by the broker and sent out if
447           this client disconnects unexpectedly. This must be used in
448           conjunction with --will-topic.
449
450       --will-qos
451           The QoS to use for the Will. Defaults to 0. This must be used in
452           conjunction with --will-topic.
453
454       --will-retain
455           If given, if the client disconnects unexpectedly the message sent
456           out will be treated as a retained message. This must be used in
457           conjunction with --will-topic.
458
459       --will-topic
460           The topic on which to send a Will, in the event that the client
461           disconnects unexpectedly.
462
463       -x
464           Set the session-expiry-interval property on the CONNECT packet.
465           Applies to MQTT v5 clients only. Set to 0-4294967294 to specify the
466           session will expire in that many seconds after the client
467           disconnects, or use -1, 4294967295, or ∞ for a session that does
468           not expire. Defaults to -1 if -c is also given, or 0 if -c not
469           given.
470
471           If the session is set to never expire, either with -x or -c, then a
472           client id must be provided.
473

OUTPUT FORMAT

475       There are three ways of formatting the output from mosquitto_sub. In
476       all cases a new-line character is appended for each message received
477       unless the -N argument is passed to mosquitto_sub.
478
479       Payload-only is the default output format and will print the payload
480       exactly as it is received.
481
482       Verbose mode is activated with -v and prints the message topic and the
483       payload, separated by a space.
484
485       The final option is formatted output, which allows the user to define a
486       custom output format. The behaviour is controlled with the -F
487       format-string option. The format string is a free text string where
488       interpreted sequences are replaced by different parameters. The
489       available interpreted sequences are described below.
490
491       Three characters are used to start an interpreted sequence: %, @ and \.
492       Sequences starting with % are either parameters related to the MQTT
493       message being printed, or are helper sequences to avoid the need to
494       type long date format strings for example. Sequences starting with @
495       are passed to the strftime(3) function (with the @ replaced with a % -
496       note that only the character immediately after the @ is passed to
497       strftime). This allows the construction of a wide variety of time based
498       outputs. The output options for strftime vary from platform to
499       platform, so please check what is available for your platform.
500       mosquitto_sub does provide one extension to strftime which is @N, which
501       can be used to obtain the number of nanoseconds passed in the current
502       second. The resolution of this option varies depending on the platform.
503       The final sequence character is \, which is used to input some
504       characters that would otherwise be difficult to enter.
505
506   Flag characters
507       The parameters %A, %C, %E, %F, %I, %l, %m, %p, %R, %S, %t, %x, and %X
508       can have optional flags immediately after the % character.
509
510       0
511           The value should be zero padded. This applies to the parameters %A,
512           %E, %F, %l, %m, %S, %X, and %x. It will be ignored for other
513           parameters. If used with the - flag, the 0 flag will be ignored.
514
515       -
516           The value will be left aligned to the field width, padded with
517           blanks. The default is right alignment, with either 0 or blank
518           padding.
519
520   Field width
521       Some of the MQTT related parameters can be formatted with an option to
522       set their field width in a similar way to regular printf style formats,
523       i.e. this sets the minimum width when printing this parameter. This
524       applies to the options %A, %C, %E, %F, %I, %l, %m, %p, %R, %S, %t, %x,
525       %X.
526
527       For example %10t would set the minimum topic field width to 10
528       characters.
529
530   Maximum width
531       Some of the MQTT related parameters can be formatted with an option to
532       set a maximum field width in a similar way to regular printf style
533       formats. This applies to the options %C, %I, %R, %t.
534
535       For example %10.10t would set the minimum topic field width to 10
536       characters, and the maximum topic width to 10 characters, i.e. the
537       field will always be exactly 10 characters long.
538
539   MQTT related parameters
540%% a literal %.
541
542%A the MQTT v5 topic-alias property, if present.
543
544%C the MQTT v5 content-type property, if present.
545
546%D the MQTT v5 correlation-data property, if present. Note that
547           this property is specified as binary data, so may produce
548           non-printable characters.
549
550%E the MQTT v5 message-expiry-interval property, if present.
551
552%F the MQTT v5 payload-format-indicator property, if present.
553
554%l the length of the payload in bytes.
555
556%m the message id (only relevant for messages with QoS>0).
557
558%P the MQTT v5 user-property property, if present. This will be
559           printed in the form key:value. It is possible for any number of
560           user properties to be attached to a message, and to have duplicate
561           keys.
562
563%p the payload raw bytes (may produce non-printable characters
564           depending on the payload).
565
566%q the message QoS.
567
568%R the MQTT v5 response-topic property, if present.
569
570%r the retained flag for the message.
571
572%S the MQTT v5 subscription-identifier property, if present.
573
574%t the message topic.
575
576%x the payload with each byte as a hexadecimal number (lower case).
577
578%X the payload with each byte as a hexadecimal number (upper case).
579
580   Helpers
581%I ISO-8601 format date and time, e.g. 2016-08-10T09:47:38+0100
582
583%j JSON output of message parameters and timestamp, with a quoted
584           and escaped payload. For example
585           {"tst":"2020-05-06T22:12:00.000000+0100","topic":"greeting","qos":0,"retain":0,"payload":"hello
586           world"}
587
588%J JSON output of message parameters and timestamp, with a
589           non-quoted and non-escaped payload - this means the payload must
590           itself be valid JSON. For example:
591           {"tst":"2020-05-06T22:12:00.000000+0100","topic":"foo","qos":0,"retain":0,"payload":{"temperature":27.0,"humidity":57}}.
592
593           If the payload is not valid JSON, then the error message "Error:
594           Message payload is not valid JSON on topic <topic>" will be printed
595           to stderr.
596
597%I ISO-8601 format date and time, e.g. 2016-08-10T09:47:38+0100
598
599%U Unix timestamp with nanoseconds, e.g. 1470818943.786368637
600
601   Time related parameters
602@@ a literal @.
603
604@X pass the character represented by X to the strftime function as
605           %X. The options supported are platform dependent.
606
607@N the number of nanoseconds that have passed in the current
608           second, with varying timing resolution depending on platform.
609
610   Escape characters
611\\ a literal \.
612
613\0 a null character. Can be used to separate different parameters
614           that may contain spaces (e.g. topic, payload) so that processing
615           with tools such as xargs(1) is easier.
616
617\a alert/bell.
618
619\e the escape sequence, which can be used with ANSI colour codes to
620           provide coloured output for example.
621
622\n end of line.
623
624\r carriage return.
625
626\t horizontal tab.
627
628\v vertical tab.
629

WILLS

631       mosquitto_sub can register a message with the broker that will be sent
632       out if it disconnects unexpectedly. See mqtt(7) for more information.
633
634       The minimum requirement for this is to use --will-topic to specify
635       which topic the will should be sent out on. This will result in a
636       non-retained, zero length message with QoS 0.
637
638       Use the --will-retain, --will-payload and --will-qos arguments to
639       modify the other will parameters.
640

PROPERTIES

642       The -D / --property option allows adding properties to different stages
643       of the mosquitto_sub run. The properties supported for each command are
644       as follows:
645
646   Connect
647authentication-data (binary data - note treated as a string in
648           mosquitto_sub)
649
650authentication-method (UTF-8 string)
651
652maximum-packet-size (32-bit unsigned integer)
653
654receive-maximum (16-bit unsigned integer)
655
656request-problem-information (8-bit unsigned integer)
657
658request-response-information (8-bit unsigned integer)
659
660session-expiry-interval (32-bit unsigned integer, note use -x
661           instead)
662
663topic-alias-maximum (16-bit unsigned integer)
664
665user-property (UTF-8 string pair)
666
667   Subscribe
668user-property (UTF-8 string pair)
669
670   Unsubscribe
671user-property (UTF-8 string pair)
672
673   Disconnect
674session-expiry-interval (32-bit unsigned integer)
675
676user-property (UTF-8 string pair)
677
678   Will properties
679content-type (UTF-8 string)
680
681correlation-data (binary data - note treated as a string in
682           mosquitto_sub)
683
684message-expiry-interval (32-bit unsigned integer)
685
686payload-format-indicator (8-bit unsigned integer)
687
688response-topic (UTF-8 string)
689
690user-property (UTF-8 string pair)
691
692will-delay-interval (32-bit unsigned integer)
693

EXIT STATUS

695       mosquitto_sub returns zero on success, or non-zero on error. If the
696       connection is refused by the broker at the MQTT level, then the exit
697       code is the CONNACK reason code. If another error occurs, the exit code
698       is a libmosquitto return value.
699
700       MQTT v3.1.1 CONNACK codes:
701
7020 Success
703
7041 Connection refused: Bad protocol version
705
7062 Connection refused: Identifier rejected
707
7083 Connection refused: Server unavailable
709
7104 Connection refused: Bad username/password
711
7125 Connection refused: Not authorized
713
714       MQTT v5 CONNACK codes:
715
7160 Success
717
718128 Unspecified error
719
720129 Malformed packet
721
722130 Protocol error
723
724131 Implementation specific error
725
726132 Unsupported protocol version
727
728133 Client ID not valid
729
730134 Bad username or password
731
732135 Not authorized
733
734136 Server unavailable
735
736137 Server busy
737
738138 Banned
739
740139 Server shutting down
741
742140 Bad authentication method
743
744141 Keep alive timeout
745
746142 Session taken over
747
748143 Topic filter invalid
749
750144 Topic name invalid
751
752147 Receive maximum exceeded
753
754148 Topic alias invalid
755
756149 Packet too large
757
758148 Message rate too high
759
760151 Quota exceeded
761
762152 Administrative action
763
764153 Payload format invalid
765
766154 Retain not supported
767
768155 QoS not supported
769
770156 Use another server
771
772157 Server moved
773
774158 Shared subscriptions not supported
775
776159 Connection rate exceeded
777
778160 Maximum connect time
779
780161 Subscription IDs not supported
781
782162 Wildcard subscriptions not supported
783

EXAMPLES

785       Note that these really are examples - the subscriptions will work if
786       you run them as shown, but there must be something publishing messages
787       on those topics for you to receive anything.
788
789       Subscribe to temperature information on localhost with QoS 1:
790
791       •   mosquitto_sub -t sensors/temperature -q 1
792
793       Subscribe to hard drive temperature updates on multiple machines/hard
794       drives. This expects each machine to be publishing its hard drive
795       temperature to sensors/machines/HOSTNAME/temperature/HD_NAME.
796
797       •   mosquitto_sub -t sensors/machines/+/temperature/+
798
799       Subscribe to all broker status messages:
800
801       •   mosquitto_sub -v -t \$SYS/#
802
803       Specify the output format as "ISO-8601 date : topic : payload in hex"
804
805       •   mosquitto_sub -F '@Y-@m-@dT@H:@M:@S@z : %t : %x' -t '#'
806
807       Specify the output format as "seconds since epoch.nanoseconds :
808       retained flag : qos : mid : payload length"
809
810       •   mosquitto_sub -F '%@s.@N : %r : %q : %m : %l' -q 2 -t '#'
811
812       Topic and payload output, but with colour where supported.
813
814       •   mosquitto_sub -F '\e[92m%t \e[96m%p\e[0m' -q 2 -t '#'
815

EXIT VALUES

817       0
818           Success
819
820       27
821           Timed out waiting for message
822
823       Other non-zero value
824           Unspecified failure
825

FILES

827       $XDG_CONFIG_HOME/mosquitto_sub, $HOME/.config/mosquitto_sub
828           Configuration file for default options.
829

BUGS

831       mosquitto bug information can be found at
832       https://github.com/eclipse/mosquitto/issues
833

SEE ALSO

835       mqtt(7), mosquitto_pub(1), mosquitto_rr(1), mosquitto(8),
836       libmosquitto(3), mosquitto-tls(7)
837

AUTHOR

839       Roger Light <roger@atchoo.org>
840
841
842
843Mosquitto Project                 08/16/2022                  MOSQUITTO_SUB(1)
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