man/sd_bus_call_method.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/4.2/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
   5
   6 <refentry id="sd_bus_call_method"
   7           xmlns:xi="http://www.w3.org/2001/XInclude">
   8
   9   <refentryinfo>
  10     <title>sd_bus_call_method</title>
  11     <productname>systemd</productname>
  12   </refentryinfo>
  13
  14   <refmeta>
  15     <refentrytitle>sd_bus_call_method</refentrytitle>
  16     <manvolnum>3</manvolnum>
  17   </refmeta>
  18
  19   <refnamediv>
  20     <refname>sd_bus_call_method</refname>
  21     <refname>sd_bus_call_methodv</refname>
  22     <refname>sd_bus_call_method_async</refname>
  23     <refname>sd_bus_call_method_asyncv</refname>
  24
  25     <refpurpose>Initialize a bus message object and invoke the corresponding D-Bus method call
  26     </refpurpose>
  27   </refnamediv>
  28
  29   <refsynopsisdiv>
  30     <funcsynopsis>
  31       <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
  32
  33       <xi:include href="sd_bus_add_match.xml" xpointer="sd_bus_message_handler_t"/>
  34
  35       <funcprototype>
  36         <funcdef>int <function>sd_bus_call_method</function></funcdef>
  37         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
  38         <paramdef>const char *<parameter>destination</parameter></paramdef>
  39         <paramdef>const char *<parameter>path</parameter></paramdef>
  40         <paramdef>const char *<parameter>interface</parameter></paramdef>
  41         <paramdef>const char *<parameter>member</parameter></paramdef>
  42         <paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
  43         <paramdef>sd_bus_message **<parameter>reply</parameter></paramdef>
  44         <paramdef>const char *<parameter>types</parameter></paramdef>
  45         <paramdef>...</paramdef>
  46       </funcprototype>
  47
  48       <funcprototype>
  49         <funcdef>int <function>sd_bus_call_methodv</function></funcdef>
  50         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
  51         <paramdef>const char *<parameter>destination</parameter></paramdef>
  52         <paramdef>const char *<parameter>path</parameter></paramdef>
  53         <paramdef>const char *<parameter>interface</parameter></paramdef>
  54         <paramdef>const char *<parameter>member</parameter></paramdef>
  55         <paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
  56         <paramdef>sd_bus_message **<parameter>reply</parameter></paramdef>
  57         <paramdef>const char *<parameter>types</parameter></paramdef>
  58         <paramdef>va_list <parameter>ap</parameter></paramdef>
  59       </funcprototype>
  60
  61       <funcprototype>
  62         <funcdef>int <function>sd_bus_call_method_async</function></funcdef>
  63         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
  64         <paramdef>sd_bus_slot **<parameter>slot</parameter></paramdef>
  65         <paramdef>const char *<parameter>destination</parameter></paramdef>
  66         <paramdef>const char *<parameter>path</parameter></paramdef>
  67         <paramdef>const char *<parameter>interface</parameter></paramdef>
  68         <paramdef>const char *<parameter>member</parameter></paramdef>
  69         <paramdef>sd_bus_message_handler_t <parameter>callback</parameter></paramdef>
  70         <paramdef>void *<parameter>userdata</parameter></paramdef>
  71         <paramdef>const char *<parameter>types</parameter></paramdef>
  72         <paramdef>...</paramdef>
  73       </funcprototype>
  74
  75       <funcprototype>
  76         <funcdef>int <function>sd_bus_call_method_asyncv</function></funcdef>
  77         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
  78         <paramdef>sd_bus_slot **<parameter>slot</parameter></paramdef>
  79         <paramdef>const char *<parameter>destination</parameter></paramdef>
  80         <paramdef>const char *<parameter>path</parameter></paramdef>
  81         <paramdef>const char *<parameter>interface</parameter></paramdef>
  82         <paramdef>const char *<parameter>member</parameter></paramdef>
  83         <paramdef>sd_bus_message_handler_t <parameter>callback</parameter></paramdef>
  84         <paramdef>void *<parameter>userdata</parameter></paramdef>
  85         <paramdef>const char *<parameter>types</parameter></paramdef>
  86         <paramdef>va_list <parameter>ap</parameter></paramdef>
  87       </funcprototype>
  88     </funcsynopsis>
  89   </refsynopsisdiv>
  90
  91   <refsect1>
  92     <title>Description</title>
  93
  94     <para><function>sd_bus_call_method()</function> is a convenience function for initializing a
  95     bus message object and calling the corresponding D-Bus method. It combines the
  96     <citerefentry><refentrytitle>sd_bus_message_new_method_call</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
  97     <citerefentry><refentrytitle>sd_bus_message_append</refentrytitle><manvolnum>3</manvolnum></citerefentry> and
  98     <citerefentry><refentrytitle>sd_bus_call</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  99     functions into a single function call.</para>
 100
 101     <para><function>sd_bus_call_method_async()</function> is a convenience function for initializing
 102     a bus message object and calling the corresponding D-Bus method asynchronously. It combines the
 103     <citerefentry><refentrytitle>sd_bus_message_new_method_call</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 104     <citerefentry><refentrytitle>sd_bus_message_append</refentrytitle><manvolnum>3</manvolnum></citerefentry> and
 105     <citerefentry><refentrytitle>sd_bus_call_async</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 106     functions into a single function call.</para>
 107   </refsect1>
 108
 109   <refsect1>
 110     <title>Return Value</title>
 111
 112     <para>On success, these functions return a non-negative integer. On failure, they return a
 113     negative errno-style error code.</para>
 114
 115     <refsect2 id='errors'>
 116       <title>Errors</title>
 117
 118       <para>See the man pages of
 119       <citerefentry><refentrytitle>sd_bus_message_new_method_call</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 120       <citerefentry><refentrytitle>sd_bus_message_append</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 121       <citerefentry><refentrytitle>sd_bus_call</refentrytitle><manvolnum>3</manvolnum></citerefentry> and
 122       <citerefentry><refentrytitle>sd_bus_call_async</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 123       for a list of possible errors.</para>
 124     </refsect2>
 125   </refsect1>
 126
 127   <xi:include href="libsystemd-pkgconfig.xml" />
 128
 129   <refsect1>
 130     <title>Examples</title>
 131
 132     <example>
 133       <title>Make a call to a D-Bus method that takes a single parameter</title>
 134
 135       <programlisting><xi:include href="print-unit-path-call-method.c" parse="text" /></programlisting>
 136       <para>This defines a minimally useful program that will open a connection to the bus, call a method,
 137       wait for the reply, and finally extract and print the answer. It does error handling and proper
 138       memory management.</para>
 139     </example>
 140   </refsect1>
 141
 142   <refsect1>
 143     <title>History</title>
 144     <para><function>sd_bus_call_method()</function>,
 145     <function>sd_bus_call_methodv()</function>,
 146     <function>sd_bus_call_method_async()</function>, and
 147     <function>sd_bus_call_method_asyncv()</function> were added in version 246.</para>
 148   </refsect1>
 149
 150   <refsect1>
 151     <title>See Also</title>
 152
 153     <para>
 154       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 155       <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 156       <citerefentry><refentrytitle>sd_bus_message_new_method_call</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 157       <citerefentry><refentrytitle>sd_bus_message_append</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 158       <citerefentry><refentrytitle>sd_bus_call</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 159       <citerefentry><refentrytitle>sd_bus_set_property</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 160       <citerefentry><refentrytitle>sd_bus_emit_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 161     </para>
 162   </refsect1>
 163
 164 </refentry>