man/sd_bus_set_property.xml

   1 <?xml version='1.0'?>
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
   5
   6 <refentry id="sd_bus_set_property"
   7           xmlns:xi="http://www.w3.org/2001/XInclude">
   8
   9   <refentryinfo>
  10     <title>sd_bus_set_property</title>
  11     <productname>systemd</productname>
  12   </refentryinfo>
  13
  14   <refmeta>
  15     <refentrytitle>sd_bus_set_property</refentrytitle>
  16     <manvolnum>3</manvolnum>
  17   </refmeta>
  18
  19   <refnamediv>
  20     <refname>sd_bus_set_property</refname>
  21     <refname>sd_bus_set_propertyv</refname>
  22     <refname>sd_bus_get_property</refname>
  23     <refname>sd_bus_get_property_trivial</refname>
  24     <refname>sd_bus_get_property_string</refname>
  25     <refname>sd_bus_get_property_strv</refname>
  26
  27     <refpurpose>Set or query D-Bus service properties</refpurpose>
  28   </refnamediv>
  29
  30   <refsynopsisdiv>
  31     <funcsynopsis>
  32       <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
  33
  34       <funcprototype>
  35         <funcdef>int <function>sd_bus_set_property</function></funcdef>
  36         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
  37         <paramdef>const char *<parameter>destination</parameter></paramdef>
  38         <paramdef>const char *<parameter>path</parameter></paramdef>
  39         <paramdef>const char *<parameter>interface</parameter></paramdef>
  40         <paramdef>const char *<parameter>member</parameter></paramdef>
  41         <paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
  42         <paramdef>const char *<parameter>type</parameter></paramdef>
  43         <paramdef>...</paramdef>
  44       </funcprototype>
  45
  46       <funcprototype>
  47         <funcdef>int <function>sd_bus_set_propertyv</function></funcdef>
  48         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
  49         <paramdef>const char *<parameter>destination</parameter></paramdef>
  50         <paramdef>const char *<parameter>path</parameter></paramdef>
  51         <paramdef>const char *<parameter>interface</parameter></paramdef>
  52         <paramdef>const char *<parameter>member</parameter></paramdef>
  53         <paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
  54         <paramdef>const char *<parameter>type</parameter></paramdef>
  55         <paramdef>va_list <parameter>ap</parameter></paramdef>
  56       </funcprototype>
  57
  58       <funcprototype>
  59         <funcdef>int <function>sd_bus_get_property</function></funcdef>
  60         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
  61         <paramdef>const char *<parameter>destination</parameter></paramdef>
  62         <paramdef>const char *<parameter>path</parameter></paramdef>
  63         <paramdef>const char *<parameter>interface</parameter></paramdef>
  64         <paramdef>const char *<parameter>member</parameter></paramdef>
  65         <paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
  66         <paramdef>sd_bus_message **<parameter>reply</parameter></paramdef>
  67         <paramdef>const char *<parameter>type</parameter></paramdef>
  68       </funcprototype>
  69
  70       <funcprototype>
  71         <funcdef>int <function>sd_bus_get_property_trivial</function></funcdef>
  72         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
  73         <paramdef>const char *<parameter>destination</parameter></paramdef>
  74         <paramdef>const char *<parameter>path</parameter></paramdef>
  75         <paramdef>const char *<parameter>interface</parameter></paramdef>
  76         <paramdef>const char *<parameter>member</parameter></paramdef>
  77         <paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
  78         <paramdef>char <parameter>type</parameter></paramdef>
  79         <paramdef>void *<parameter>ret_ptr</parameter></paramdef>
  80       </funcprototype>
  81
  82       <funcprototype>
  83         <funcdef>int <function>sd_bus_get_property_string</function></funcdef>
  84         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
  85         <paramdef>const char *<parameter>destination</parameter></paramdef>
  86         <paramdef>const char *<parameter>path</parameter></paramdef>
  87         <paramdef>const char *<parameter>interface</parameter></paramdef>
  88         <paramdef>const char *<parameter>member</parameter></paramdef>
  89         <paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
  90         <paramdef>char **<parameter>ret</parameter></paramdef>
  91       </funcprototype>
  92
  93       <funcprototype>
  94         <funcdef>int <function>sd_bus_get_property_strv</function></funcdef>
  95         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
  96         <paramdef>const char *<parameter>destination</parameter></paramdef>
  97         <paramdef>const char *<parameter>path</parameter></paramdef>
  98         <paramdef>const char *<parameter>interface</parameter></paramdef>
  99         <paramdef>const char *<parameter>member</parameter></paramdef>
 100         <paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
 101         <paramdef>char ***<parameter>ret</parameter></paramdef>
 102       </funcprototype>
 103     </funcsynopsis>
 104   </refsynopsisdiv>
 105
 106   <refsect1>
 107     <title>Description</title>
 108
 109     <para>These functions set or query D-Bus properties. D-Bus properties are service fields exposed
 110     via the <constant>org.freedesktop.DBus.Properties</constant> interface. Under the hood, these
 111     functions call methods of the <constant>org.freedesktop.DBus.Properties</constant> interface and
 112     as a result their semantics are similar to
 113     <citerefentry><refentrytitle>sd_bus_call_method</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
 114     </para>
 115
 116     <para><function>sd_bus_set_property()</function> sets a D-Bus property. If setting the property
 117     fails or an internal error occurs, an error is returned and an extended description of the error
 118     is optionally stored in <parameter>ret_error</parameter> if it is not <constant>NULL</constant>.
 119     <parameter>type</parameter> and the arguments that follow it describe the new value of the
 120     property and must follow the format described in
 121     <citerefentry><refentrytitle>sd_bus_message_append</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
 122     </para>
 123
 124     <para><function>sd_bus_set_propertyv()</function> is equivalent to
 125     <function>sd_bus_set_property()</function>, except that it is called with a
 126     <literal>va_list</literal> instead of a variable number of arguments.</para>
 127
 128     <para><function>sd_bus_get_property()</function> queries a D-Bus property. If retrieving the
 129     property fails or an internal error occurs, an error is returned and an extended description of
 130     the error is optionally stored in <parameter>ret_error</parameter> if it is not
 131     <constant>NULL</constant>. On success, the property is stored in <parameter>reply</parameter>.
 132     <parameter>type</parameter> describes the property type and must follow the format described in
 133     <citerefentry><refentrytitle>sd_bus_message_append</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
 134     </para>
 135
 136     <para><function>sd_bus_get_property_trivial()</function>,
 137     <function>sd_bus_get_property_string()</function> and
 138     <function>sd_bus_get_property_strv()</function> are shorthands for
 139     <function>sd_bus_get_property()</function> that are used to query basic, string and string
 140     vector properties respectively. The caller is responsible for freeing the string and string
 141     vector results stored in <parameter>ret</parameter> by
 142     <function>sd_bus_get_property_string()</function> and
 143     <function>sd_bus_get_property_strv()</function>.</para>
 144   </refsect1>
 145
 146   <refsect1>
 147     <title>Return Value</title>
 148
 149     <para>On success, these functions return a non-negative integer. On failure, they return a
 150     negative errno-style error code.</para>
 151
 152     <refsect2 id='errors'>
 153       <title>Errors</title>
 154
 155       <para>See the
 156       <citerefentry><refentrytitle>sd_bus_call_method</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 157       man page for a list of possible errors.</para>
 158     </refsect2>
 159   </refsect1>
 160
 161   <xi:include href="libsystemd-pkgconfig.xml" />
 162
 163   <refsect1>
 164     <title>History</title>
 165     <para><function>sd_bus_set_property()</function>,
 166     <function>sd_bus_set_propertyv()</function>,
 167     <function>sd_bus_get_property()</function>,
 168     <function>sd_bus_get_property_trivial()</function>,
 169     <function>sd_bus_get_property_string()</function>, and
 170     <function>sd_bus_get_property_strv()</function> were added in version 246.</para>
 171   </refsect1>
 172
 173   <refsect1>
 174     <title>See Also</title>
 175
 176     <para><simplelist type="inline">
 177       <member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
 178       <member><citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
 179       <member><citerefentry><refentrytitle>sd_bus_call_method</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
 180     </simplelist></para>
 181   </refsect1>
 182
 183 </refentry>