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 This file is part of systemd.
8 Copyright 2014 Zbigniew Jędrzejewski-Szmek
10 systemd is free software; you can redistribute it and/or modify it
11 under the terms of the GNU Lesser General Public License as published by
12 the Free Software Foundation; either version 2.1 of the License, or
13 (at your option) any later version.
15 systemd is distributed in the hope that it will be useful, but
16 WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 Lesser General Public License for more details.
20 You should have received a copy of the GNU Lesser General Public License
21 along with systemd; If not, see <http://www.gnu.org/licenses/>.
25 xmlns:xi="http://www.w3.org/2001/XInclude">
29 <productname>systemd</productname>
33 <contrib>A monkey with a typewriter</contrib>
34 <firstname>Zbigniew</firstname>
35 <surname>Jędrzejewski-Szmek</surname>
36 <email>zbyszek@in.waw.pl</email>
42 <refentrytitle>busctl</refentrytitle>
43 <manvolnum>1</manvolnum>
47 <refname>busctl</refname>
48 <refpurpose>Introspect the bus</refpurpose>
53 <command>busctl</command>
54 <arg choice="opt" rep="repeat">OPTIONS</arg>
55 <arg choice="opt">COMMAND</arg>
56 <arg choice="opt" rep="repeat"><replaceable>NAME</replaceable></arg>
61 <title>Description</title>
63 <para><command>busctl</command> may be used to
64 introspect and monitor the D-Bus bus.</para>
68 <title>Options</title>
70 <para>The following options are understood:</para>
74 <term><option>--address=<replaceable>ADDRESS</replaceable></option></term>
76 <listitem><para>Connect to the bus specified by
77 <replaceable>ADDRESS</replaceable> instead of using suitable
78 defaults for either the system or user bus (see
79 <option>--system</option> and <option>--user</option>
80 options).</para></listitem>
84 <term><option>--show-machine</option></term>
86 <listitem><para>When showing the list of endpoints, show a
87 column containing the names of containers they belong to.
89 <citerefentry><refentrytitle>systemd-machined.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
94 <term><option>--unique</option></term>
96 <listitem><para>When showing the list of endpoints, show
97 only "unique" names (of the form
98 <literal>:<replaceable>number</replaceable>.<replaceable>number</replaceable></literal>).
103 <term><option>--acquired</option></term>
105 <listitem><para>The opposite of <option>--unique</option> —
106 only "well-known" names will be shown.</para></listitem>
110 <term><option>--activatable</option></term>
112 <listitem><para>When showing the list of endpoints, show
113 only endpoints which have actually not been activated yet,
114 but may be started automatically if accessed.</para>
119 <term><option>--match=<replaceable>MATCH</replaceable></option></term>
121 <listitem><para>When showing messages being exchanged, show only the
122 subset matching <replaceable>MATCH</replaceable>.</para></listitem>
123 <!-- TODO: link to sd_bus_add_match when it is written? -->
127 <term><option>--no-legend</option></term>
130 <para>Do not print the legend,
131 i.e. the column headers and the
137 <term><option>--size=</option></term>
140 <para>When used with the <command>capture</command> command
141 specifies the maximum bus message size to capture
142 ("snaplen"). Defaults to 4096 bytes.</para>
147 <term><option>--list</option></term>
150 <para>When used with the <command>tree</command> command shows a
151 flat list of object paths instead of a tree.</para>
156 <term><option>--quiet</option></term>
159 <para>When used with the <command>call</command> command
160 suppresses display of the response message payload. Note that even
161 if this option is specified errors returned will still be
162 printed and the tool will indicate success or failure with
163 the process exit code.</para>
168 <term><option>--verbose</option></term>
171 <para>When used with the <command>call</command> or
172 <command>get-property</command> command shows output in a
173 more verbose format.</para>
178 <term><option>--expect-reply=</option><replaceable>BOOL</replaceable></term>
181 <para>When used with the <command>call</command> command
182 specifies whether <command>busctl</command> shall wait for
183 completion of the method call, output the returned method
184 response data, and return success or failure via the process
185 exit code. If this is set to <literal>no</literal> the
186 method call will be issued but no response is expected, the
187 tool terminates immediately, and thus no response can be
188 shown, and no success or failure is returned via the exit
189 code. To only suppress output of the reply message payload
190 use <option>--quiet</option> above. Defaults to
191 <literal>yes</literal>.</para>
196 <term><option>--auto-start=</option><replaceable>BOOL</replaceable></term>
199 <para>When used with the <command>call</command> command specifies
200 whether the method call should implicitly activate the
201 called service should it not be running yet but is
202 configured to be auto-started. Defaults to
203 <literal>yes</literal>.</para>
208 <term><option>--allow-interactive-authorization=</option><replaceable>BOOL</replaceable></term>
211 <para>When used with the <command>call</command> command
212 specifies whether the services may enforce interactive
213 authorization while executing the operation, if the security
214 policy is configured for this. Defaults to
215 <literal>yes</literal>.</para>
220 <term><option>--timeout=</option><replaceable>SECS</replaceable></term>
223 <para>When used with the <command>call</command> command
224 specifies the maximum time to wait for method call
225 completion. If no time unit is specified assumes
226 seconds. The usual other units are understood, too (ms, us,
227 s, min, h, d, w, month, y). Note that this timeout does not
228 apply if <option>--expect-reply=no</option> is used as the
229 tool does not wait for any reply message then. When not
230 specified or when set to 0 the default of
231 <literal>25s</literal> is assumed.</para>
236 <term><option>--augment-creds=</option><replaceable>BOOL</replaceable></term>
239 <para>Controls whether credential data reported by
240 <command>list</command> or <command>status</command> shall
241 be augmented with data from
242 <filename>/proc</filename>. When this is turned on the data
243 shown is possibly inconsistent, as the data read from
244 <filename>/proc</filename> might be more recent than rest of
245 the credential information. Defaults to <literal>yes</literal>.</para>
249 <xi:include href="user-system-options.xml" xpointer="user" />
250 <xi:include href="user-system-options.xml" xpointer="system" />
251 <xi:include href="user-system-options.xml" xpointer="host" />
252 <xi:include href="user-system-options.xml" xpointer="machine" />
254 <xi:include href="standard-options.xml" xpointer="help" />
255 <xi:include href="standard-options.xml" xpointer="version" />
256 <xi:include href="standard-options.xml" xpointer="no-pager" />
261 <title>Commands</title>
263 <para>The following commands are understood:</para>
267 <term><command>list</command></term>
269 <listitem><para>Show service names on the bus. This is the
270 default if no command is specified.</para></listitem>
274 <term><command>status</command> <arg choice="opt"><replaceable>SERVICE</replaceable></arg></term>
276 <listitem><para>Show process information and credentials of a
277 bus service (if one is specified by its unique or well-known
278 name), a process (if one is specified by its numeric PID), or
279 the owner of the bus (if no parameter is
280 specified).</para></listitem>
284 <term><command>monitor</command> <arg choice="opt" rep="repeat"><replaceable>SERVICE</replaceable></arg></term>
286 <listitem><para>Dump messages being exchanged. If
287 <replaceable>SERVICE</replaceable> is specified, show messages
288 to or from this endpoint. Otherwise, show all messages on the
289 bus. Use Ctrl-C to terminate dump.</para></listitem>
293 <term><command>capture</command> <arg choice="opt" rep="repeat"><replaceable>SERVICE</replaceable></arg></term>
295 <listitem><para>Similar to <command>monitor</command> but
296 writes the output in pcap format (for details see the <ulink
297 url="http://wiki.wireshark.org/Development/LibpcapFileFormat">Libpcap
298 File Format</ulink> description. Make sure to redirect the
299 output to STDOUT to a file. Tools like
300 <citerefentry><refentrytitle>wireshark</refentrytitle><manvolnum>1</manvolnum></citerefentry>
301 may be used to dissect and view the generated
302 files.</para></listitem>
306 <term><command>tree</command> <arg choice="opt" rep="repeat"><replaceable>SERVICE</replaceable></arg></term>
308 <listitem><para>Shows an object tree of one or more
309 services. If <replaceable>SERVICE</replaceable> is specified,
310 show object tree of the specified services only. Otherwise,
311 show all object trees of all services on the bus that acquired
312 at least one well-known name.</para></listitem>
316 <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>
318 <listitem><para>Show interfaces, methods, properties and
319 signals of the specified object (identified by its path) on
320 the specified service. If the interface argument is passed the
321 output is limited to members of the specified
322 interface.</para></listitem>
326 <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>
328 <listitem><para>Invoke a method and show the response. Takes a
329 service name, object path, interface name and method name. If
330 parameters shall be passed to the method call a signature
331 string is required, followed by the arguments, individually
332 formatted as strings. For details on the formatting used, see
333 below. To suppress output of the returned data use the
334 <option>--quiet</option> option.</para></listitem>
338 <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>
340 <listitem><para>Retrieve the current value of one or more
341 object properties. Takes a service name, object path,
342 interface name and property name. Multiple properties may be
343 specified at once in which case their values will be shown one
344 after the other, separated by newlines. The output is by
345 default in terse format. Use <option>--verbose</option> for a
346 more elaborate output format.</para></listitem>
350 <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>
352 <listitem><para>Set the current value an object
353 property. Takes a service name, object path, interface name,
354 property name, property signature, followed by a list of
355 parameters formatted as strings.</para></listitem>
359 <term><command>help</command></term>
361 <listitem><para>Show command syntax help.</para></listitem>
367 <title>Parameter Formatting</title>
369 <para>The <command>call</command> and
370 <command>set-property</command> commands take a signature string
371 followed by a list of parameters formatted as string (for details
372 on D-Bus signature strings see the <ulink
373 url="http://dbus.freedesktop.org/doc/dbus-specification.html#type-system">Type
374 system chapter of the D-Bus specification</ulink>). For simple
375 types each parameter following the signature should simply be the
376 parameter's value formatted as string. Positive boolean values may
377 be formatted as <literal>true</literal>, <literal>yes</literal>,
378 <literal>on</literal>, <literal>1</literal>; negative boolean
379 values may be specified as <literal>false</literal>,
380 <literal>no</literal>, <literal>off</literal>,
381 <literal>0</literal>. For arrays, a numeric argument for the
382 number of entries followed by the entries shall be specified. For
383 variants the signature of the contents shall be specified,
384 followed by the contents. For dictionaries and structs the
385 contents of them shall be directly specified.</para>
388 <programlisting>s jawoll</programlisting> is the formatting
389 of a single string <literal>jawoll</literal>.</para>
392 <programlisting>as 3 hello world foobar</programlisting>
393 is the formatting of a string array with three entries,
394 <literal>hello</literal>, <literal>world</literal> and
395 <literal>foobar</literal>.</para>
398 <programlisting>a{sv} 3 One s Eins Two u 2 Yes b true</programlisting>
399 is the formatting of a dictionary
400 array that maps strings to variants, consisting of three
401 entries. The string <literal>One</literal> is assigned the
402 string <literal>Eins</literal>. The string
403 <literal>Two</literal> is assigned the 32bit unsigned
404 integer 2. The string <literal>Yes</literal> is assigned a
405 positive boolean.</para>
407 <para>Note that the <command>call</command>,
408 <command>get-property</command>, <command>introspect</command>
409 commands will also generate output in this format for the returned
410 data. Since this format is sometimes too terse to be easily
411 understood, the <command>call</command> and
412 <command>get-property</command> commands may generate a more
413 verbose, multi-line output when passed the
414 <option>--verbose</option> option.</para>
418 <title>Examples</title>
421 <title>Write and Read a Property</title>
423 <para>The following two commands first write a property and then
424 read it back. The property is found on the
425 <literal>/org/freedesktop/systemd1</literal> object of the
426 <literal>org.freedesktop.systemd1</literal> service. The name of
427 the property is <literal>LogLevel</literal> on the
428 <literal>org.freedesktop.systemd1.Manager</literal>
429 interface. The property contains a single string:</para>
431 <programlisting># busctl set-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager LogLevel s debug
432 # busctl get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager LogLevel
433 s "debug"</programlisting>
438 <title>Terse and Verbose Output</title>
440 <para>The following two commands read a property that contains
441 an array of strings, and first show it in terse format, followed
442 by verbose format:</para>
444 <programlisting>$ busctl get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager Environment
445 as 2 "LANG=en_US.UTF-8" "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin"
446 $ busctl get-property --verbose org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager Environment
448 STRING "LANG=en_US.UTF-8";
449 STRING "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin";
454 <title>Invoking a Method</title>
456 <para>The following command invokes a the
457 <literal>StartUnit</literal> method on the
458 <literal>org.freedesktop.systemd1.Manager</literal>
460 <literal>/org/freedesktop/systemd1</literal> object
461 of the <literal>org.freedesktop.systemd1</literal>
462 service, and passes it two strings
463 <literal>cups.service</literal> and
464 <literal>replace</literal>. As result of the method
465 call a single object path parameter is received and
468 <programlisting># busctl call org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager StartUnit ss "cups.service" "replace"
469 o "/org/freedesktop/systemd1/job/42684"</programlisting>
474 <title>See Also</title>
477 <citerefentry><refentrytitle>dbus-daemon</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
478 <ulink url="http://freedesktop.org/wiki/Software/dbus">D-Bus</ulink>,
479 <ulink url="https://code.google.com/p/d-bus/">kdbus</ulink>,
480 <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
481 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
482 <citerefentry><refentrytitle>systemd-bus-proxyd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
483 <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
484 <citerefentry><refentrytitle>wireshark</refentrytitle><manvolnum>1</manvolnum></citerefentry>