man/busctl.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
   3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4
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   6 This file is part of systemd.
   7
   8 Copyright 2014 Zbigniew Jędrzejewski-Szmek
   9
  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.
  14
  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.
  19
  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/>.
  22 -->
  23
  24 <refentry id="busctl"
  25           xmlns:xi="http://www.w3.org/2001/XInclude">
  26
  27   <refentryinfo>
  28     <title>busctl</title>
  29     <productname>systemd</productname>
  30
  31     <authorgroup>
  32       <author>
  33         <contrib>A monkey with a typewriter</contrib>
  34         <firstname>Zbigniew</firstname>
  35         <surname>Jędrzejewski-Szmek</surname>
  36         <email>zbyszek@in.waw.pl</email>
  37       </author>
  38     </authorgroup>
  39   </refentryinfo>
  40
  41   <refmeta>
  42     <refentrytitle>busctl</refentrytitle>
  43     <manvolnum>1</manvolnum>
  44   </refmeta>
  45
  46   <refnamediv>
  47     <refname>busctl</refname>
  48     <refpurpose>Introspect the bus</refpurpose>
  49   </refnamediv>
  50
  51   <refsynopsisdiv>
  52     <cmdsynopsis>
  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>
  57     </cmdsynopsis>
  58   </refsynopsisdiv>
  59
  60   <refsect1>
  61     <title>Description</title>
  62
  63     <para><command>busctl</command> may be used to
  64     introspect and monitor the D-Bus bus.</para>
  65   </refsect1>
  66
  67   <refsect1>
  68     <title>Options</title>
  69
  70     <para>The following options are understood:</para>
  71
  72     <variablelist>
  73       <varlistentry>
  74           <term><option>--address=<replaceable>ADDRESS</replaceable></option></term>
  75
  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>
  81       </varlistentry>
  82
  83       <varlistentry>
  84           <term><option>--show-machine</option></term>
  85
  86           <listitem><para>When showing the list of endpoints, show a
  87           column containing the names of containers they belong to.
  88           See
  89           <citerefentry><refentrytitle>systemd-machined.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
  90           </para></listitem>
  91       </varlistentry>
  92
  93       <varlistentry>
  94           <term><option>--unique</option></term>
  95
  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>).
  99           </para></listitem>
 100       </varlistentry>
 101
 102       <varlistentry>
 103           <term><option>--acquired</option></term>
 104
 105           <listitem><para>The opposite of <option>--unique</option> —
 106           only "well-known" names will be shown.</para></listitem>
 107       </varlistentry>
 108
 109       <varlistentry>
 110           <term><option>--activatable</option></term>
 111
 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>
 115           </listitem>
 116       </varlistentry>
 117
 118       <varlistentry>
 119           <term><option>--match=<replaceable>MATCH</replaceable></option></term>
 120
 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? -->
 124       </varlistentry>
 125
 126       <varlistentry>
 127         <term><option>--no-legend</option></term>
 128
 129         <listitem>
 130           <para>Do not print the legend,
 131           i.e. the column headers and the
 132           footer.</para>
 133         </listitem>
 134       </varlistentry>
 135
 136       <varlistentry>
 137         <term><option>--size=</option></term>
 138
 139         <listitem>
 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>
 143         </listitem>
 144       </varlistentry>
 145
 146       <varlistentry>
 147         <term><option>--list</option></term>
 148
 149         <listitem>
 150           <para>When used with the <command>tree</command> command shows a
 151           flat list of object paths instead of a tree.</para>
 152         </listitem>
 153       </varlistentry>
 154
 155       <varlistentry>
 156         <term><option>--quiet</option></term>
 157
 158         <listitem>
 159           <para>When used with the <command>call</command> command suppresses
 160           display of the response message.</para>
 161         </listitem>
 162       </varlistentry>
 163
 164
 165       <varlistentry>
 166         <term><option>--verbose</option></term>
 167
 168         <listitem>
 169           <para>When used with the <command>call</command> or
 170           <command>get-property</command> command shows output in a
 171           more verbose format.</para>
 172         </listitem>
 173       </varlistentry>
 174
 175       <xi:include href="user-system-options.xml" xpointer="user" />
 176       <xi:include href="user-system-options.xml" xpointer="system" />
 177       <xi:include href="user-system-options.xml" xpointer="host" />
 178       <xi:include href="user-system-options.xml" xpointer="machine" />
 179
 180       <xi:include href="standard-options.xml" xpointer="help" />
 181       <xi:include href="standard-options.xml" xpointer="version" />
 182       <xi:include href="standard-options.xml" xpointer="no-pager" />
 183     </variablelist>
 184   </refsect1>
 185
 186   <refsect1>
 187     <title>Commands</title>
 188
 189     <para>The following commands are understood:</para>
 190
 191     <variablelist>
 192       <varlistentry>
 193         <term><command>list</command></term>
 194
 195         <listitem><para>Show service names on the bus. This is the
 196         default if no command is specified.</para></listitem>
 197       </varlistentry>
 198
 199       <varlistentry>
 200         <term><command>status</command> <arg choice="plain"><replaceable>SERVICE</replaceable></arg></term>
 201
 202         <listitem><para>Show process information and credentials of a
 203         bus service.</para></listitem>
 204       </varlistentry>
 205
 206       <varlistentry>
 207         <term><command>monitor</command> <arg choice="opt" rep="repeat"><replaceable>SERVICE</replaceable></arg></term>
 208
 209         <listitem><para>Dump messages being exchanged. If
 210         <replaceable>SERVICE</replaceable> is specified, show messages
 211         to or from this endpoint. Otherwise, show all messages on the
 212         bus. Use Ctrl-C to terminate dump.</para></listitem>
 213       </varlistentry>
 214
 215       <varlistentry>
 216         <term><command>capture</command> <arg choice="opt" rep="repeat"><replaceable>SERVICE</replaceable></arg></term>
 217
 218         <listitem><para>Similar to <command>monitor</command> but
 219         writes the output in pcap format (for details see the <ulink
 220         url="http://wiki.wireshark.org/Development/LibpcapFileFormat">Libpcap
 221         File Format</ulink> description. Make sure to redirect the
 222         output to STDOUT to a file. Tools like
 223         <citerefentry><refentrytitle>wireshark</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 224         may be used to dissect and view the generated
 225         files.</para></listitem>
 226       </varlistentry>
 227
 228       <varlistentry>
 229         <term><command>tree</command> <arg choice="opt" rep="repeat"><replaceable>SERVICE</replaceable></arg></term>
 230
 231         <listitem><para>Shows an object tree of one or more
 232         services. If <replaceable>SERVICE</replaceable> is specified,
 233         show object tree of the specified services only. Otherwise,
 234         show all object trees of all services on the bus that acquired
 235         at least one well-known name.</para></listitem>
 236       </varlistentry>
 237
 238       <varlistentry>
 239         <term><command>introspect</command> <arg choice="plain"><replaceable>SERVICE</replaceable></arg> <arg choice="plain"><replaceable>OBJECT</replaceable></arg></term>
 240
 241         <listitem><para>Show interfaces, methods, properties and
 242         signals of the specified object (identified by its path) on
 243         the specified service.</para></listitem>
 244       </varlistentry>
 245
 246       <varlistentry>
 247         <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>
 248
 249         <listitem><para>Invoke a method and show the response. Takes a
 250         service name, object path, interface name and method name. If
 251         parameters shall be passed to the method call a signature
 252         string is required, followed by the arguments, individually
 253         formatted as strings. For details on the formatting used, see
 254         below. To suppress output of the returned data use the
 255         <option>--quiet</option> option.</para></listitem>
 256       </varlistentry>
 257
 258       <varlistentry>
 259         <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>
 260
 261         <listitem><para>Retrieve the current value of one or more
 262         object properties. Takes a service name, object path,
 263         interface name and property name. Multiple properties may be
 264         specified at once in which case their values will be shown one
 265         after the other, separated by newlines. The output is by
 266         default in terse format. Use <option>--verbose</option> for a
 267         more elaborate output format.</para></listitem>
 268       </varlistentry>
 269
 270       <varlistentry>
 271         <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>
 272
 273         <listitem><para>Set the current value an object
 274         property. Takes a service name, object path, interface name,
 275         property name, property signature, followed by a list of
 276         parameters formatted as strings.</para></listitem>
 277       </varlistentry>
 278
 279       <varlistentry>
 280         <term><command>help</command></term>
 281
 282         <listitem><para>Show command syntax help.</para></listitem>
 283       </varlistentry>
 284     </variablelist>
 285   </refsect1>
 286
 287   <refsect1>
 288           <title>Parameter Formatting</title>
 289
 290           <para>The <command>call</command> and
 291           <command>set-property</command> commands take a signature
 292           string followed by a list of parameters formatted as string
 293           (for details on D-Bus signature strings see the <ulink
 294           url="http://dbus.freedesktop.org/doc/dbus-specification.html#type-system">Type
 295           system chapter of the D-Bus specification</ulink>). For
 296           simple types each parameter following the signature should
 297           simply be the parameter's value formatted as
 298           string. Positive boolean values may be formatted as
 299           <literal>true</literal>, <literal>yes</literal>,
 300           <literal>on</literal>, <literal>1</literal>; negative
 301           boolean values may be specified as <literal>false</literal>,
 302           <literal>no</literal>, <literal>off</literal>,
 303           <literal>0</literal>. For arrays, a numeric argument for the
 304           number of entries followed by the entries shall be
 305           specified. For variants the signature of the contents shall
 306           be specified, followed by the contents. For dictionaries and
 307           structs the contents of them shall be directly
 308           specified.</para>
 309
 310           <para>For example,
 311           <programlisting>s jawoll</programlisting> is the formatting
 312           of a single string <literal>jawoll</literal>.</para>
 313
 314           <para>
 315           <programlisting>as 3 hello world foobar</programlisting>
 316           is the formatting of a string array with three entries,
 317           <literal>hello</literal>, <literal>world</literal> and
 318           <literal>foobar</literal>.</para>
 319
 320           <para>
 321           <programlisting>a{sv} 3 One s Eins Two u 2 Yes b true</programlisting>
 322           is the formatting of a dictionary
 323           array that maps strings to variants, consisting of three
 324           entries. The string <literal>One</literal> is assigned the
 325           string <literal>Eins</literal>. The string
 326           <literal>Two</literal> is assigned the 32bit unsigned
 327           integer 2. The string <literal>Yes</literal> is assigned a
 328           positive boolean.</para>
 329
 330           <para>Note that the <command>call</command>,
 331           <command>get-property</command>,
 332           <command>introspect</command> commands will also generate
 333           output in this format for the returned data. Since this
 334           format is sometimes too terse to be easily understood, the
 335           <command>call</command> and <command>get-property</command>
 336           commands may generate a more verbose, multi-line output when
 337           passed the <option>--verbose</option> option.</para>
 338   </refsect1>
 339
 340   <refsect1>
 341           <title>Examples</title>
 342
 343           <example>
 344                   <title>Write and Read a Property</title>
 345
 346                   <para>The following two commands first write a
 347                   property and then read it back. The property is
 348                   found on the
 349                   <literal>/org/freedesktop/systemd1</literal> object
 350                   of the <literal>org.freedesktop.systemd1</literal>
 351                   service. The name of the property is
 352                   <literal>LogLevel</literal> on the
 353                   <literal>org.freedesktop.systemd1.Manager</literal>
 354                   interface. The property contains a single
 355                   string:</para>
 356
 357                   <programlisting># busctl set-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager LogLevel s debug
 358 # busctl get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager LogLevel
 359 s "debug"</programlisting>
 360
 361           </example>
 362
 363           <example>
 364                   <title>Terse and Verbose Output</title>
 365
 366                   <para>The following two commands read a property that
 367                   contains an array of strings, and first show it in
 368                   terse format, followed by verbose format:</para>
 369
 370                   <programlisting>$ busctl get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager Environment
 371 as 2 "LANG=en_US.UTF-8" "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin"
 372 $ busctl get-property --verbose org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager Environment
 373 ARRAY "s" {
 374         STRING "LANG=en_US.UTF-8";
 375         STRING "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin";
 376 };</programlisting>
 377           </example>
 378
 379         <example>
 380                   <title>Invoking a Method</title>
 381
 382                   <para>The following command invokes a the
 383                   <literal>StartUnit</literal> method on the
 384                   <literal>org.freedesktop.systemd1.Manager</literal>
 385                   interface of the
 386                   <literal>/org/freedesktop/systemd1</literal> object
 387                   of the <literal>org.freedesktop.systemd1</literal>
 388                   service, and passes it two strings
 389                   <literal>cups.service</literal> and
 390                   <literal>replace</literal>. As result of the method
 391                   call a single object path parameter is received and
 392                   shown:</para>
 393
 394                   <programlisting># busctl call org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager StartUnit ss "cups.service" "replace"
 395 o "/org/freedesktop/systemd1/job/42684"</programlisting>
 396         </example>
 397   </refsect1>
 398
 399   <refsect1>
 400     <title>See Also</title>
 401
 402     <para>
 403       <citerefentry><refentrytitle>dbus-daemon</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 404       <ulink url="http://freedesktop.org/wiki/Software/dbus">D-Bus</ulink>,
 405       <ulink url="https://code.google.com/p/d-bus/">kdbus</ulink>,
 406       <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 407       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 408       <citerefentry><refentrytitle>systemd-bus-proxyd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 409       <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 410       <citerefentry><refentrytitle>wireshark</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 411     </para>
 412   </refsect1>
 413 </refentry>