1 <?xml version='
1.0'
?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
2 <!DOCTYPE refentry PUBLIC
"-//OASIS//DTD DocBook XML V4.2//EN"
3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
6 SPDX-License-Identifier: LGPL-2.1+
8 This file is part of systemd.
10 Copyright 2014 Zbigniew Jędrzejewski-Szmek
12 systemd is free software; you can redistribute it and/or modify it
13 under the terms of the GNU Lesser General Public License as published by
14 the Free Software Foundation; either version 2.1 of the License, or
15 (at your option) any later version.
17 systemd is distributed in the hope that it will be useful, but
18 WITHOUT ANY WARRANTY; without even the implied warranty of
19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20 Lesser General Public License for more details.
22 You should have received a copy of the GNU Lesser General Public License
23 along with systemd; If not, see <http://www.gnu.org/licenses/>.
27 xmlns:
xi=
"http://www.w3.org/2001/XInclude">
31 <productname>systemd
</productname>
35 <contrib>A monkey with a typewriter
</contrib>
36 <firstname>Zbigniew
</firstname>
37 <surname>Jędrzejewski-Szmek
</surname>
38 <email>zbyszek@in.waw.pl
</email>
44 <refentrytitle>busctl
</refentrytitle>
45 <manvolnum>1</manvolnum>
49 <refname>busctl
</refname>
50 <refpurpose>Introspect the bus
</refpurpose>
55 <command>busctl
</command>
56 <arg choice=
"opt" rep=
"repeat">OPTIONS
</arg>
57 <arg choice=
"opt">COMMAND
</arg>
58 <arg choice=
"opt" rep=
"repeat"><replaceable>NAME
</replaceable></arg>
63 <title>Description
</title>
65 <para><command>busctl
</command> may be used to
66 introspect and monitor the D-Bus bus.
</para>
70 <title>Options
</title>
72 <para>The following options are understood:
</para>
76 <term><option>--address=
<replaceable>ADDRESS
</replaceable></option></term>
78 <listitem><para>Connect to the bus specified by
79 <replaceable>ADDRESS
</replaceable> instead of using suitable
80 defaults for either the system or user bus (see
81 <option>--system
</option> and
<option>--user
</option>
82 options).
</para></listitem>
86 <term><option>--show-machine
</option></term>
88 <listitem><para>When showing the list of peers, show a
89 column containing the names of containers they belong to.
91 <citerefentry><refentrytitle>systemd-machined.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
96 <term><option>--unique
</option></term>
98 <listitem><para>When showing the list of peers, show only
99 "unique" names (of the form
100 <literal>:
<replaceable>number
</replaceable>.
<replaceable>number
</replaceable></literal>).
105 <term><option>--acquired
</option></term>
107 <listitem><para>The opposite of
<option>--unique
</option> —
108 only
"well-known" names will be shown.
</para></listitem>
112 <term><option>--activatable
</option></term>
114 <listitem><para>When showing the list of peers, show only
115 peers which have actually not been activated yet, but may be
116 started automatically if accessed.
</para>
121 <term><option>--match=
<replaceable>MATCH
</replaceable></option></term>
123 <listitem><para>When showing messages being exchanged, show only the
124 subset matching
<replaceable>MATCH
</replaceable>.
126 <citerefentry><refentrytitle>sd_bus_add_match
</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
131 <term><option>--size=
</option></term>
134 <para>When used with the
<command>capture
</command> command,
135 specifies the maximum bus message size to capture
136 (
"snaplen"). Defaults to
4096 bytes.
</para>
141 <term><option>--list
</option></term>
144 <para>When used with the
<command>tree
</command> command, shows a
145 flat list of object paths instead of a tree.
</para>
150 <term><option>-q
</option></term>
151 <term><option>--quiet
</option></term>
154 <para>When used with the
<command>call
</command> command,
155 suppresses display of the response message payload. Note that even
156 if this option is specified, errors returned will still be
157 printed and the tool will indicate success or failure with
158 the process exit code.
</para>
163 <term><option>--verbose
</option></term>
166 <para>When used with the
<command>call
</command> or
167 <command>get-property
</command> command, shows output in a
168 more verbose format.
</para>
173 <term><option>--expect-reply=
</option><replaceable>BOOL
</replaceable></term>
176 <para>When used with the
<command>call
</command> command,
177 specifies whether
<command>busctl
</command> shall wait for
178 completion of the method call, output the returned method
179 response data, and return success or failure via the process
180 exit code. If this is set to
<literal>no
</literal>, the
181 method call will be issued but no response is expected, the
182 tool terminates immediately, and thus no response can be
183 shown, and no success or failure is returned via the exit
184 code. To only suppress output of the reply message payload,
185 use
<option>--quiet
</option> above. Defaults to
186 <literal>yes
</literal>.
</para>
191 <term><option>--auto-start=
</option><replaceable>BOOL
</replaceable></term>
194 <para>When used with the
<command>call
</command> command, specifies
195 whether the method call should implicitly activate the
196 called service, should it not be running yet but is
197 configured to be auto-started. Defaults to
198 <literal>yes
</literal>.
</para>
203 <term><option>--allow-interactive-authorization=
</option><replaceable>BOOL
</replaceable></term>
206 <para>When used with the
<command>call
</command> command,
207 specifies whether the services may enforce interactive
208 authorization while executing the operation, if the security
209 policy is configured for this. Defaults to
210 <literal>yes
</literal>.
</para>
215 <term><option>--timeout=
</option><replaceable>SECS
</replaceable></term>
218 <para>When used with the
<command>call
</command> command,
219 specifies the maximum time to wait for method call
220 completion. If no time unit is specified, assumes
221 seconds. The usual other units are understood, too (ms, us,
222 s, min, h, d, w, month, y). Note that this timeout does not
223 apply if
<option>--expect-reply=no
</option> is used, as the
224 tool does not wait for any reply message then. When not
225 specified or when set to
0, the default of
226 <literal>25s
</literal> is assumed.
</para>
231 <term><option>--augment-creds=
</option><replaceable>BOOL
</replaceable></term>
234 <para>Controls whether credential data reported by
235 <command>list
</command> or
<command>status
</command> shall
236 be augmented with data from
237 <filename>/proc
</filename>. When this is turned on, the data
238 shown is possibly inconsistent, as the data read from
239 <filename>/proc
</filename> might be more recent than the rest of
240 the credential information. Defaults to
<literal>yes
</literal>.
</para>
245 <term><option>--watch-bind=
</option><replaceable>BOOL
</replaceable></term>
248 <para>Controls whether to wait for the specified
<constant>AF_UNIX
</constant> bus socket to appear in the
249 file system before connecting to it. Defaults to off. When enabled, the tool will watch the file system until
250 the socket is created and then connect to it.
</para>
254 <xi:include href=
"user-system-options.xml" xpointer=
"user" />
255 <xi:include href=
"user-system-options.xml" xpointer=
"system" />
256 <xi:include href=
"user-system-options.xml" xpointer=
"host" />
257 <xi:include href=
"user-system-options.xml" xpointer=
"machine" />
259 <xi:include href=
"standard-options.xml" xpointer=
"no-pager" />
260 <xi:include href=
"standard-options.xml" xpointer=
"no-legend" />
261 <xi:include href=
"standard-options.xml" xpointer=
"help" />
262 <xi:include href=
"standard-options.xml" xpointer=
"version" />
267 <title>Commands
</title>
269 <para>The following commands are understood:
</para>
273 <term><command>list
</command></term>
275 <listitem><para>Show all peers on the bus, by their service
276 names. By default, shows both unique and well-known names, but
277 this may be changed with the
<option>--unique
</option> and
278 <option>--acquired
</option> switches. This is the default
279 operation if no command is specified.
</para></listitem>
283 <term><command>status
</command> <arg choice=
"opt"><replaceable>SERVICE
</replaceable></arg></term>
285 <listitem><para>Show process information and credentials of a
286 bus service (if one is specified by its unique or well-known
287 name), a process (if one is specified by its numeric PID), or
288 the owner of the bus (if no parameter is
289 specified).
</para></listitem>
293 <term><command>monitor
</command> <arg choice=
"opt" rep=
"repeat"><replaceable>SERVICE
</replaceable></arg></term>
295 <listitem><para>Dump messages being exchanged. If
296 <replaceable>SERVICE
</replaceable> is specified, show messages
297 to or from this peer, identified by its well-known or unique
298 name. Otherwise, show all messages on the bus. Use Ctrl-C to
299 terminate the dump.
</para></listitem>
303 <term><command>capture
</command> <arg choice=
"opt" rep=
"repeat"><replaceable>SERVICE
</replaceable></arg></term>
305 <listitem><para>Similar to
<command>monitor
</command> but
306 writes the output in pcap format (for details, see the
<ulink
307 url=
"https://wiki.wireshark.org/Development/LibpcapFileFormat">Libpcap
308 File Format
</ulink> description). Make sure to redirect
309 standard output to a file. Tools like
310 <citerefentry project='die-net'
><refentrytitle>wireshark
</refentrytitle><manvolnum>1</manvolnum></citerefentry>
311 may be used to dissect and view the resulting
312 files.
</para></listitem>
316 <term><command>tree
</command> <arg choice=
"opt" rep=
"repeat"><replaceable>SERVICE
</replaceable></arg></term>
318 <listitem><para>Shows an object tree of one or more
319 services. If
<replaceable>SERVICE
</replaceable> is specified,
320 show object tree of the specified services only. Otherwise,
321 show all object trees of all services on the bus that acquired
322 at least one well-known name.
</para></listitem>
326 <term><command>introspect
</command> <arg choice=
"plain"><replaceable>SERVICE
</replaceable></arg> <arg choice=
"plain"><replaceable>OBJECT
</replaceable></arg> <arg choice=
"opt"><replaceable>INTERFACE
</replaceable></arg></term>
328 <listitem><para>Show interfaces, methods, properties and
329 signals of the specified object (identified by its path) on
330 the specified service. If the interface argument is passed, the
331 output is limited to members of the specified
332 interface.
</para></listitem>
336 <term><command>call
</command> <arg choice=
"plain"><replaceable>SERVICE
</replaceable></arg> <arg choice=
"plain"><replaceable>OBJECT
</replaceable></arg> <arg choice=
"plain"><replaceable>INTERFACE
</replaceable></arg> <arg choice=
"plain"><replaceable>METHOD
</replaceable></arg> <arg choice=
"opt"><replaceable>SIGNATURE
</replaceable> <arg choice=
"opt" rep=
"repeat"><replaceable>ARGUMENT
</replaceable></arg></arg></term>
338 <listitem><para>Invoke a method and show the response. Takes a
339 service name, object path, interface name and method name. If
340 parameters shall be passed to the method call, a signature
341 string is required, followed by the arguments, individually
342 formatted as strings. For details on the formatting used, see
343 below. To suppress output of the returned data, use the
344 <option>--quiet
</option> option.
</para></listitem>
348 <term><command>get-property
</command> <arg choice=
"plain"><replaceable>SERVICE
</replaceable></arg> <arg choice=
"plain"><replaceable>OBJECT
</replaceable></arg> <arg choice=
"plain"><replaceable>INTERFACE
</replaceable></arg> <arg choice=
"plain" rep=
"repeat"><replaceable>PROPERTY
</replaceable></arg></term>
350 <listitem><para>Retrieve the current value of one or more
351 object properties. Takes a service name, object path,
352 interface name and property name. Multiple properties may be
353 specified at once, in which case their values will be shown one
354 after the other, separated by newlines. The output is, by
355 default, in terse format. Use
<option>--verbose
</option> for a
356 more elaborate output format.
</para></listitem>
360 <term><command>set-property
</command> <arg choice=
"plain"><replaceable>SERVICE
</replaceable></arg> <arg choice=
"plain"><replaceable>OBJECT
</replaceable></arg> <arg choice=
"plain"><replaceable>INTERFACE
</replaceable></arg> <arg choice=
"plain"><replaceable>PROPERTY
</replaceable></arg> <arg choice=
"plain"><replaceable>SIGNATURE
</replaceable></arg> <arg choice=
"plain" rep=
"repeat"><replaceable>ARGUMENT
</replaceable></arg></term>
362 <listitem><para>Set the current value of an object
363 property. Takes a service name, object path, interface name,
364 property name, property signature, followed by a list of
365 parameters formatted as strings.
</para></listitem>
369 <term><command>help
</command></term>
371 <listitem><para>Show command syntax help.
</para></listitem>
377 <title>Parameter Formatting
</title>
379 <para>The
<command>call
</command> and
380 <command>set-property
</command> commands take a signature string
381 followed by a list of parameters formatted as string (for details
382 on D-Bus signature strings, see the
<ulink
383 url=
"http://dbus.freedesktop.org/doc/dbus-specification.html#type-system">Type
384 system chapter of the D-Bus specification
</ulink>). For simple
385 types, each parameter following the signature should simply be the
386 parameter's value formatted as string. Positive boolean values may
387 be formatted as
<literal>true
</literal>,
<literal>yes
</literal>,
388 <literal>on
</literal>, or
<literal>1</literal>; negative boolean
389 values may be specified as
<literal>false
</literal>,
390 <literal>no
</literal>,
<literal>off
</literal>, or
391 <literal>0</literal>. For arrays, a numeric argument for the
392 number of entries followed by the entries shall be specified. For
393 variants, the signature of the contents shall be specified,
394 followed by the contents. For dictionaries and structs, the
395 contents of them shall be directly specified.
</para>
398 <programlisting>s jawoll
</programlisting> is the formatting
399 of a single string
<literal>jawoll
</literal>.
</para>
402 <programlisting>as
3 hello world foobar
</programlisting>
403 is the formatting of a string array with three entries,
404 <literal>hello
</literal>,
<literal>world
</literal> and
405 <literal>foobar
</literal>.
</para>
408 <programlisting>a{sv}
3 One s Eins Two u
2 Yes b true
</programlisting>
409 is the formatting of a dictionary
410 array that maps strings to variants, consisting of three
411 entries. The string
<literal>One
</literal> is assigned the
412 string
<literal>Eins
</literal>. The string
413 <literal>Two
</literal> is assigned the
32-bit unsigned
414 integer
2. The string
<literal>Yes
</literal> is assigned a
415 positive boolean.
</para>
417 <para>Note that the
<command>call
</command>,
418 <command>get-property
</command>,
<command>introspect
</command>
419 commands will also generate output in this format for the returned
420 data. Since this format is sometimes too terse to be easily
421 understood, the
<command>call
</command> and
422 <command>get-property
</command> commands may generate a more
423 verbose, multi-line output when passed the
424 <option>--verbose
</option> option.
</para>
428 <title>Examples
</title>
431 <title>Write and Read a Property
</title>
433 <para>The following two commands first write a property and then
434 read it back. The property is found on the
435 <literal>/org/freedesktop/systemd1
</literal> object of the
436 <literal>org.freedesktop.systemd1
</literal> service. The name of
437 the property is
<literal>LogLevel
</literal> on the
438 <literal>org.freedesktop.systemd1.Manager
</literal>
439 interface. The property contains a single string:
</para>
441 <programlisting># busctl set-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager LogLevel s debug
442 # busctl get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager LogLevel
443 s
"debug"</programlisting>
448 <title>Terse and Verbose Output
</title>
450 <para>The following two commands read a property that contains
451 an array of strings, and first show it in terse format, followed
452 by verbose format:
</para>
454 <programlisting>$ busctl get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager Environment
455 as
2 "LANG=en_US.UTF-8" "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin"
456 $ busctl get-property --verbose org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager Environment
458 STRING
"LANG=en_US.UTF-8";
459 STRING
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin";
464 <title>Invoking a Method
</title>
466 <para>The following command invokes the
467 <literal>StartUnit
</literal> method on the
468 <literal>org.freedesktop.systemd1.Manager
</literal>
470 <literal>/org/freedesktop/systemd1
</literal> object
471 of the
<literal>org.freedesktop.systemd1
</literal>
472 service, and passes it two strings
473 <literal>cups.service
</literal> and
474 <literal>replace
</literal>. As a result of the method
475 call, a single object path parameter is received and
478 <programlisting># busctl call org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager StartUnit ss
"cups.service" "replace"
479 o
"/org/freedesktop/systemd1/job/42684"</programlisting>
484 <title>See Also
</title>
487 <citerefentry project='dbus'
><refentrytitle>dbus-daemon
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
488 <ulink url=
"https://www.freedesktop.org/wiki/Software/dbus">D-Bus
</ulink>,
489 <citerefentry><refentrytitle>sd-bus
</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
490 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
491 <citerefentry><refentrytitle>machinectl
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
492 <citerefentry project='die-net'
><refentrytitle>wireshark
</refentrytitle><manvolnum>1</manvolnum></citerefentry>