+ <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>
+
~ianmdlvl / elogind.git / blobdiff