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<?xml version='1.0'?>
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
<refentry id="sd_bus_set_property"
xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>sd_bus_set_property</title>
<productname>systemd</productname>
</refentryinfo>
<refmeta>
<refentrytitle>sd_bus_set_property</refentrytitle>
<manvolnum>3</manvolnum>
</refmeta>
<refnamediv>
<refname>sd_bus_set_property</refname>
<refname>sd_bus_set_propertyv</refname>
<refname>sd_bus_get_property</refname>
<refname>sd_bus_get_property_trivial</refname>
<refname>sd_bus_get_property_string</refname>
<refname>sd_bus_get_property_strv</refname>
<refpurpose>Set or query D-Bus service properties</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo>
<funcprototype>
<funcdef>int <function>sd_bus_set_property</function></funcdef>
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
<paramdef>const char *<parameter>destination</parameter></paramdef>
<paramdef>const char *<parameter>path</parameter></paramdef>
<paramdef>const char *<parameter>interface</parameter></paramdef>
<paramdef>const char *<parameter>member</parameter></paramdef>
<paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
<paramdef>const char *<parameter>type</parameter></paramdef>
<paramdef>...</paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_bus_set_propertyv</function></funcdef>
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
<paramdef>const char *<parameter>destination</parameter></paramdef>
<paramdef>const char *<parameter>path</parameter></paramdef>
<paramdef>const char *<parameter>interface</parameter></paramdef>
<paramdef>const char *<parameter>member</parameter></paramdef>
<paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
<paramdef>const char *<parameter>type</parameter></paramdef>
<paramdef>va_list <parameter>ap</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_bus_get_property</function></funcdef>
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
<paramdef>const char *<parameter>destination</parameter></paramdef>
<paramdef>const char *<parameter>path</parameter></paramdef>
<paramdef>const char *<parameter>interface</parameter></paramdef>
<paramdef>const char *<parameter>member</parameter></paramdef>
<paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
<paramdef>sd_bus_message **<parameter>reply</parameter></paramdef>
<paramdef>const char *<parameter>type</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_bus_get_property_trivial</function></funcdef>
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
<paramdef>const char *<parameter>destination</parameter></paramdef>
<paramdef>const char *<parameter>path</parameter></paramdef>
<paramdef>const char *<parameter>interface</parameter></paramdef>
<paramdef>const char *<parameter>member</parameter></paramdef>
<paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
<paramdef>char <parameter>type</parameter></paramdef>
<paramdef>void *<parameter>ret_ptr</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_bus_get_property_string</function></funcdef>
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
<paramdef>const char *<parameter>destination</parameter></paramdef>
<paramdef>const char *<parameter>path</parameter></paramdef>
<paramdef>const char *<parameter>interface</parameter></paramdef>
<paramdef>const char *<parameter>member</parameter></paramdef>
<paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
<paramdef>char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_bus_get_property_strv</function></funcdef>
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
<paramdef>const char *<parameter>destination</parameter></paramdef>
<paramdef>const char *<parameter>path</parameter></paramdef>
<paramdef>const char *<parameter>interface</parameter></paramdef>
<paramdef>const char *<parameter>member</parameter></paramdef>
<paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
<paramdef>char ***<parameter>ret</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para>These functions set or query D-Bus properties. D-Bus properties are service fields exposed
via the <constant>org.freedesktop.DBus.Properties</constant> interface. Under the hood, these
functions call methods of the <constant>org.freedesktop.DBus.Properties</constant> interface and
as a result their semantics are similar to
<citerefentry><refentrytitle>sd_bus_call_method</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
</para>
<para><function>sd_bus_set_property()</function> sets a D-Bus property. If setting the property
fails or an internal error occurs, an error is returned and an extended description of the error
is optionally stored in <parameter>ret_error</parameter> if it is not <constant>NULL</constant>.
<parameter>type</parameter> and the arguments that follow it describe the new value of the
property and must follow the format described in
<citerefentry><refentrytitle>sd_bus_message_append</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
</para>
<para><function>sd_bus_set_propertyv()</function> is equivalent to
<function>sd_bus_set_property()</function>, except that it is called with a
<literal>va_list</literal> instead of a variable number of arguments.</para>
<para><function>sd_bus_get_property()</function> queries a D-Bus property. If retrieving the
property fails or an internal error occurs, an error is returned and an extended description of
the error is optionally stored in <parameter>ret_error</parameter> if it is not
<constant>NULL</constant>. On success, the property is stored in <parameter>reply</parameter>.
<parameter>type</parameter> describes the property type and must follow the format described in
<citerefentry><refentrytitle>sd_bus_message_append</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
</para>
<para><function>sd_bus_get_property_trivial()</function>,
<function>sd_bus_get_property_string()</function> and
<function>sd_bus_get_property_strv()</function> are shorthands for
<function>sd_bus_get_property()</function> that are used to query basic, string and string
vector properties respectively. The caller is responsible for freeing the string and string
vector results stored in <parameter>ret</parameter> by
<function>sd_bus_get_property_string()</function> and
<function>sd_bus_get_property_strv()</function>.</para>
</refsect1>
<refsect1>
<title>Return Value</title>
<para>On success, these functions return a non-negative integer. On failure, they return a
negative errno-style error code.</para>
<refsect2 id='errors'>
<title>Errors</title>
<para>See the
<citerefentry><refentrytitle>sd_bus_call_method</refentrytitle><manvolnum>3</manvolnum></citerefentry>
man page for a list of possible errors.</para>
</refsect2>
</refsect1>
<xi:include href="libsystemd-pkgconfig.xml" />
<refsect1>
<title>History</title>
<para><function>sd_bus_set_property()</function>,
<function>sd_bus_set_propertyv()</function>,
<function>sd_bus_get_property()</function>,
<function>sd_bus_get_property_trivial()</function>,
<function>sd_bus_get_property_string()</function>, and
<function>sd_bus_get_property_strv()</function> were added in version 246.</para>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_bus_call_method</refentrytitle><manvolnum>3</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>
|
