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></term>
318 <listitem><para>Show interfaces, methods, properties and
319 signals of the specified object (identified by its path) on
320 the specified service.</para></listitem>
324 <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>
326 <listitem><para>Invoke a method and show the response. Takes a
327 service name, object path, interface name and method name. If
328 parameters shall be passed to the method call a signature
329 string is required, followed by the arguments, individually
330 formatted as strings. For details on the formatting used, see
331 below. To suppress output of the returned data use the
332 <option>--quiet</option> option.</para></listitem>
336 <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>
338 <listitem><para>Retrieve the current value of one or more
339 object properties. Takes a service name, object path,
340 interface name and property name. Multiple properties may be
341 specified at once in which case their values will be shown one
342 after the other, separated by newlines. The output is by
343 default in terse format. Use <option>--verbose</option> for a
344 more elaborate output format.</para></listitem>
348 <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>
350 <listitem><para>Set the current value an object
351 property. Takes a service name, object path, interface name,
352 property name, property signature, followed by a list of
353 parameters formatted as strings.</para></listitem>
357 <term><command>help</command></term>
359 <listitem><para>Show command syntax help.</para></listitem>
365 <title>Parameter Formatting</title>
367 <para>The <command>call</command> and
368 <command>set-property</command> commands take a signature string
369 followed by a list of parameters formatted as string (for details
370 on D-Bus signature strings see the <ulink
371 url="http://dbus.freedesktop.org/doc/dbus-specification.html#type-system">Type
372 system chapter of the D-Bus specification</ulink>). For simple
373 types each parameter following the signature should simply be the
374 parameter's value formatted as string. Positive boolean values may
375 be formatted as <literal>true</literal>, <literal>yes</literal>,
376 <literal>on</literal>, <literal>1</literal>; negative boolean
377 values may be specified as <literal>false</literal>,
378 <literal>no</literal>, <literal>off</literal>,
379 <literal>0</literal>. For arrays, a numeric argument for the
380 number of entries followed by the entries shall be specified. For
381 variants the signature of the contents shall be specified,
382 followed by the contents. For dictionaries and structs the
383 contents of them shall be directly specified.</para>
386 <programlisting>s jawoll</programlisting> is the formatting
387 of a single string <literal>jawoll</literal>.</para>
390 <programlisting>as 3 hello world foobar</programlisting>
391 is the formatting of a string array with three entries,
392 <literal>hello</literal>, <literal>world</literal> and
393 <literal>foobar</literal>.</para>
396 <programlisting>a{sv} 3 One s Eins Two u 2 Yes b true</programlisting>
397 is the formatting of a dictionary
398 array that maps strings to variants, consisting of three
399 entries. The string <literal>One</literal> is assigned the
400 string <literal>Eins</literal>. The string
401 <literal>Two</literal> is assigned the 32bit unsigned
402 integer 2. The string <literal>Yes</literal> is assigned a
403 positive boolean.</para>
405 <para>Note that the <command>call</command>,
406 <command>get-property</command>, <command>introspect</command>
407 commands will also generate output in this format for the returned
408 data. Since this format is sometimes too terse to be easily
409 understood, the <command>call</command> and
410 <command>get-property</command> commands may generate a more
411 verbose, multi-line output when passed the
412 <option>--verbose</option> option.</para>
416 <title>Examples</title>
419 <title>Write and Read a Property</title>
421 <para>The following two commands first write a property and then
422 read it back. The property is found on the
423 <literal>/org/freedesktop/systemd1</literal> object of the
424 <literal>org.freedesktop.systemd1</literal> service. The name of
425 the property is <literal>LogLevel</literal> on the
426 <literal>org.freedesktop.systemd1.Manager</literal>
427 interface. The property contains a single string:</para>
429 <programlisting># busctl set-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager LogLevel s debug
430 # busctl get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager LogLevel
431 s "debug"</programlisting>
436 <title>Terse and Verbose Output</title>
438 <para>The following two commands read a property that contains
439 an array of strings, and first show it in terse format, followed
440 by verbose format:</para>
442 <programlisting>$ busctl get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager Environment
443 as 2 "LANG=en_US.UTF-8" "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin"
444 $ busctl get-property --verbose org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager Environment
446 STRING "LANG=en_US.UTF-8";
447 STRING "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin";
452 <title>Invoking a Method</title>
454 <para>The following command invokes a the
455 <literal>StartUnit</literal> method on the
456 <literal>org.freedesktop.systemd1.Manager</literal>
458 <literal>/org/freedesktop/systemd1</literal> object
459 of the <literal>org.freedesktop.systemd1</literal>
460 service, and passes it two strings
461 <literal>cups.service</literal> and
462 <literal>replace</literal>. As result of the method
463 call a single object path parameter is received and
466 <programlisting># busctl call org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager StartUnit ss "cups.service" "replace"
467 o "/org/freedesktop/systemd1/job/42684"</programlisting>
472 <title>See Also</title>
475 <citerefentry><refentrytitle>dbus-daemon</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
476 <ulink url="http://freedesktop.org/wiki/Software/dbus">D-Bus</ulink>,
477 <ulink url="https://code.google.com/p/d-bus/">kdbus</ulink>,
478 <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
479 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
480 <citerefentry><refentrytitle>systemd-bus-proxyd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
481 <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
482 <citerefentry><refentrytitle>wireshark</refentrytitle><manvolnum>1</manvolnum></citerefentry>