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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"

"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

<refentry id="busctl"

xmlns:xi="http://www.w3.org/2001/XInclude">

<refentryinfo>

<title>busctl</title>

<productname>systemd</productname>

<authorgroup>

<author>

<contrib>A monkey with a typewriter</contrib>

<firstname>Zbigniew</firstname>

<surname>Jędrzejewski-Szmek</surname>

<email>zbyszek@in.waw.pl</email>

</author>

</authorgroup>

</refentryinfo>

<refmeta>

<refentrytitle>busctl</refentrytitle>

<manvolnum>1</manvolnum>

</refmeta>

<refnamediv>

<refname>busctl</refname>

<refpurpose>Introspect the bus</refpurpose>

</refnamediv>

<refsynopsisdiv>

<cmdsynopsis>

<command>busctl</command>

<arg choice="opt" rep="repeat">OPTIONS</arg>

<arg choice="opt">COMMAND</arg>

<arg choice="opt" rep="repeat"><replaceable>NAME</replaceable></arg>

</cmdsynopsis>

</refsynopsisdiv>

<refsect1>

<title>Description</title>

<para><command>busctl</command> may be used to

introspect and monitor the D-Bus bus.</para>

</refsect1>

<refsect1>

<title>Options</title>

<para>The following options are understood:</para>

<variablelist>

<varlistentry>

<term><option>--address=<replaceable>ADDRESS</replaceable></option></term>

<listitem><para>Connect to the bus specified by

<replaceable>ADDRESS</replaceable> instead of using suitable

defaults for either the system or user bus (see

<option>--system</option> and <option>--user</option>

options).</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--show-machine</option></term>

<listitem><para>When showing the list of endpoints, show a

column containing the names of containers they belong to.

See

<citerefentry><refentrytitle>systemd-machined.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.

</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--unique</option></term>

<listitem><para>When showing the list of endpoints, show

only "unique" names (of the form

<literal>:<replaceable>number</replaceable>.<replaceable>number</replaceable></literal>).

</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--acquired</option></term>

<listitem><para>The opposite of <option>--unique</option> —

only "well-known" names will be shown.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--activatable</option></term>

<listitem><para>When showing the list of endpoints, show

only endpoints which have actually not been activated yet,

but may be started automatically if accessed.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--match=<replaceable>MATCH</replaceable></option></term>

<listitem><para>When showing messages being exchanged, show only the

subset matching <replaceable>MATCH</replaceable>.</para></listitem>

<!-- TODO: link to sd_bus_add_match when it is written? -->

</varlistentry>

<varlistentry>

<term><option>--size=</option></term>

<listitem>

<para>When used with the <command>capture</command> command

specifies the maximum bus message size to capture

("snaplen"). Defaults to 4096 bytes.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--list</option></term>

<listitem>

<para>When used with the <command>tree</command> command shows a

flat list of object paths instead of a tree.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--quiet</option></term>

<listitem>

<para>When used with the <command>call</command> command

suppresses display of the response message payload. Note that even

if this option is specified errors returned will still be

printed and the tool will indicate success or failure with

the process exit code.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--verbose</option></term>

<listitem>

<para>When used with the <command>call</command> or

<command>get-property</command> command shows output in a

more verbose format.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--expect-reply=</option><replaceable>BOOL</replaceable></term>

<listitem>

<para>When used with the <command>call</command> command

specifies whether <command>busctl</command> shall wait for

completion of the method call, output the returned method

response data, and return success or failure via the process

exit code. If this is set to <literal>no</literal> the

method call will be issued but no response is expected, the

tool terminates immediately, and thus no response can be

shown, and no success or failure is returned via the exit

code. To only suppress output of the reply message payload

use <option>--quiet</option> above. Defaults to

<literal>yes</literal>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--auto-start=</option><replaceable>BOOL</replaceable></term>

<listitem>

<para>When used with the <command>call</command> command specifies

whether the method call should implicitly activate the

called service should it not be running yet but is

configured to be auto-started. Defaults to

<literal>yes</literal>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--allow-interactive-authorization=</option><replaceable>BOOL</replaceable></term>

<listitem>

<para>When used with the <command>call</command> command

specifies whether the services may enforce interactive

authorization while executing the operation, if the security

policy is configured for this. Defaults to

<literal>yes</literal>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--timeout=</option><replaceable>SECS</replaceable></term>

<listitem>

<para>When used with the <command>call</command> command

specifies the maximum time to wait for method call

completion. If no time unit is specified assumes

seconds. The usual other units are understood, too (ms, us,

s, min, h, d, w, month, y). Note that this timeout does not

apply if <option>--expect-reply=no</option> is used as the

tool does not wait for any reply message then. When not

specified or when set to 0 the default of

<literal>25s</literal> is assumed.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--augment-creds=</option><replaceable>BOOL</replaceable></term>

<listitem>

<para>Controls whether credential data reported by

<command>list</command> or <command>status</command> shall

be augmented with data from

<filename>/proc</filename>. When this is turned on the data

shown is possibly inconsistent, as the data read from

<filename>/proc</filename> might be more recent than rest of

the credential information. Defaults to <literal>yes</literal>.</para>

</listitem>

</varlistentry>

<xi:include href="user-system-options.xml" xpointer="user" />

<xi:include href="user-system-options.xml" xpointer="system" />

<xi:include href="user-system-options.xml" xpointer="host" />

<xi:include href="user-system-options.xml" xpointer="machine" />

<xi:include href="standard-options.xml" xpointer="no-pager" />

<xi:include href="standard-options.xml" xpointer="no-legend" />

<xi:include href="standard-options.xml" xpointer="help" />

<xi:include href="standard-options.xml" xpointer="version" />

</variablelist>

</refsect1>

<refsect1>

<title>Commands</title>

<para>The following commands are understood:</para>

<variablelist>

<varlistentry>

<term><command>list</command></term>

<listitem><para>Show service names on the bus. This is the

default if no command is specified.</para></listitem>

</varlistentry>

<varlistentry>

<term><command>status</command> <arg choice="opt"><replaceable>SERVICE</replaceable></arg></term>

<listitem><para>Show process information and credentials of a

bus service (if one is specified by its unique or well-known

name), a process (if one is specified by its numeric PID), or

the owner of the bus (if no parameter is

specified).</para></listitem>

</varlistentry>

<varlistentry>

<term><command>monitor</command> <arg choice="opt" rep="repeat"><replaceable>SERVICE</replaceable></arg></term>

<listitem><para>Dump messages being exchanged. If

<replaceable>SERVICE</replaceable> is specified, show messages

to or from this endpoint. Otherwise, show all messages on the

bus. Use Ctrl-C to terminate dump.</para></listitem>

</varlistentry>

<varlistentry>

<term><command>capture</command> <arg choice="opt" rep="repeat"><replaceable>SERVICE</replaceable></arg></term>

<listitem><para>Similar to <command>monitor</command> but

writes the output in pcap format (for details see the <ulink

url="http://wiki.wireshark.org/Development/LibpcapFileFormat">Libpcap

File Format</ulink> description. Make sure to redirect the

output to STDOUT to a file. Tools like

<citerefentry project='die-net'><refentrytitle>wireshark</refentrytitle><manvolnum>1</manvolnum></citerefentry>

may be used to dissect and view the generated

files.</para></listitem>

</varlistentry>

<varlistentry>

<term><command>tree</command> <arg choice="opt" rep="repeat"><replaceable>SERVICE</replaceable></arg></term>

<listitem><para>Shows an object tree of one or more

services. If <replaceable>SERVICE</replaceable> is specified,

show object tree of the specified services only. Otherwise,

show all object trees of all services on the bus that acquired

at least one well-known name.</para></listitem>

</varlistentry>

<varlistentry>

<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>

<listitem><para>Show interfaces, methods, properties and

signals of the specified object (identified by its path) on

the specified service. If the interface argument is passed the

output is limited to members of the specified

interface.</para></listitem>

</varlistentry>

<varlistentry>

<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>

<listitem><para>Invoke a method and show the response. Takes a

service name, object path, interface name and method name. If

parameters shall be passed to the method call a signature

string is required, followed by the arguments, individually

formatted as strings. For details on the formatting used, see

below. To suppress output of the returned data use the

<option>--quiet</option> option.</para></listitem>

</varlistentry>

<varlistentry>

<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>

<listitem><para>Retrieve the current value of one or more

object properties. Takes a service name, object path,

interface name and property name. Multiple properties may be

specified at once in which case their values will be shown one

after the other, separated by newlines. The output is by

default in terse format. Use <option>--verbose</option> for a

more elaborate output format.</para></listitem>

</varlistentry>

<varlistentry>

<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>

<listitem><para>Set the current value an object

property. Takes a service name, object path, interface name,

property name, property signature, followed by a list of

parameters formatted as strings.</para></listitem>

</varlistentry>

<varlistentry>

<term><command>help</command></term>

<listitem><para>Show command syntax help.</para></listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>Parameter Formatting</title>

<para>The <command>call</command> and

<command>set-property</command> commands take a signature string

followed by a list of parameters formatted as string (for details

on D-Bus signature strings see the <ulink

url="http://dbus.freedesktop.org/doc/dbus-specification.html#type-system">Type

system chapter of the D-Bus specification</ulink>). For simple

types each parameter following the signature should simply be the

parameter's value formatted as string. Positive boolean values may

be formatted as <literal>true</literal>, <literal>yes</literal>,

<literal>on</literal>, <literal>1</literal>; negative boolean

values may be specified as <literal>false</literal>,

<literal>no</literal>, <literal>off</literal>,

<literal>0</literal>. For arrays, a numeric argument for the

number of entries followed by the entries shall be specified. For

variants the signature of the contents shall be specified,

followed by the contents. For dictionaries and structs the

contents of them shall be directly specified.</para>

<para>For example,

<programlisting>s jawoll</programlisting> is the formatting

of a single string <literal>jawoll</literal>.</para>

<para>

<programlisting>as 3 hello world foobar</programlisting>

is the formatting of a string array with three entries,

<literal>hello</literal>, <literal>world</literal> and

<literal>foobar</literal>.</para>

<para>

<programlisting>a{sv} 3 One s Eins Two u 2 Yes b true</programlisting>

is the formatting of a dictionary

array that maps strings to variants, consisting of three

entries. The string <literal>One</literal> is assigned the

string <literal>Eins</literal>. The string

<literal>Two</literal> is assigned the 32bit unsigned

integer 2. The string <literal>Yes</literal> is assigned a

positive boolean.</para>

<para>Note that the <command>call</command>,

<command>get-property</command>, <command>introspect</command>

commands will also generate output in this format for the returned

data. Since this format is sometimes too terse to be easily

understood, the <command>call</command> and

<command>get-property</command> commands may generate a more

verbose, multi-line output when passed the

<option>--verbose</option> option.</para>

</refsect1>

<refsect1>

<title>Examples</title>

<example>

<title>Write and Read a Property</title>

<para>The following two commands first write a property and then

read it back. The property is found on the

<literal>/org/freedesktop/systemd1</literal> object of the

<literal>org.freedesktop.systemd1</literal> service. The name of

the property is <literal>LogLevel</literal> on the

<literal>org.freedesktop.systemd1.Manager</literal>

interface. The property contains a single string:</para>

<programlisting># busctl set-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager LogLevel s debug

# busctl get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager LogLevel

s "debug"</programlisting>

</example>

<example>

<title>Terse and Verbose Output</title>

<para>The following two commands read a property that contains

an array of strings, and first show it in terse format, followed

by verbose format:</para>

<programlisting>$ busctl get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager Environment

as 2 "LANG=en_US.UTF-8" "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin"

$ busctl get-property --verbose org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager Environment

ARRAY "s" {

STRING "LANG=en_US.UTF-8";

STRING "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin";

};</programlisting>

</example>

<example>

<title>Invoking a Method</title>

<para>The following command invokes a the

<literal>StartUnit</literal> method on the

<literal>org.freedesktop.systemd1.Manager</literal>

interface of the

<literal>/org/freedesktop/systemd1</literal> object

of the <literal>org.freedesktop.systemd1</literal>

service, and passes it two strings

<literal>cups.service</literal> and

<literal>replace</literal>. As result of the method

call a single object path parameter is received and

shown:</para>

<programlisting># busctl call org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager StartUnit ss "cups.service" "replace"

o "/org/freedesktop/systemd1/job/42684"</programlisting>

</example>

</refsect1>

<refsect1>

<title>See Also</title>

<para>

<citerefentry project='dbus'><refentrytitle>dbus-daemon</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<ulink url="http://freedesktop.org/wiki/Software/dbus">D-Bus</ulink>,

<ulink url="https://code.google.com/p/d-bus/">kdbus</ulink>,

<citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemd-bus-proxyd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,

<citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,

<citerefentry project='die-net'><refentrytitle>wireshark</refentrytitle><manvolnum>1</manvolnum></citerefentry>

</para>

</refsect1>

</refentry>