systemd/man/sd_bus_call_method.xml

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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
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<refentry id="sd_bus_call_method"
          xmlns:xi="http://www.w3.org/2001/XInclude">

  <refentryinfo>
    <title>sd_bus_call_method</title>
    <productname>systemd</productname>
  </refentryinfo>

  <refmeta>
    <refentrytitle>sd_bus_call_method</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>sd_bus_call_method</refname>
    <refname>sd_bus_call_methodv</refname>
    <refname>sd_bus_call_method_async</refname>
    <refname>sd_bus_call_method_asyncv</refname>

    <refpurpose>Initialize a bus message object and invoke the corresponding D-Bus method call
    </refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <funcsynopsis>
      <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>

      <xi:include href="sd_bus_add_match.xml" xpointer="sd_bus_message_handler_t"/>

      <funcprototype>
        <funcdef>int <function>sd_bus_call_method</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>types</parameter></paramdef>
        <paramdef>...</paramdef>
      </funcprototype>

      <funcprototype>
        <funcdef>int <function>sd_bus_call_methodv</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>types</parameter></paramdef>
        <paramdef>va_list <parameter>ap</parameter></paramdef>
      </funcprototype>

      <funcprototype>
        <funcdef>int <function>sd_bus_call_method_async</function></funcdef>
        <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
        <paramdef>sd_bus_slot **<parameter>slot</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_message_handler_t <parameter>callback</parameter></paramdef>
        <paramdef>void *<parameter>userdata</parameter></paramdef>
        <paramdef>const char *<parameter>types</parameter></paramdef>
        <paramdef>...</paramdef>
      </funcprototype>

      <funcprototype>
        <funcdef>int <function>sd_bus_call_method_asyncv</function></funcdef>
        <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
        <paramdef>sd_bus_slot **<parameter>slot</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_message_handler_t <parameter>callback</parameter></paramdef>
        <paramdef>void *<parameter>userdata</parameter></paramdef>
        <paramdef>const char *<parameter>types</parameter></paramdef>
        <paramdef>va_list <parameter>ap</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para><function>sd_bus_call_method()</function> is a convenience function for initializing a
    bus message object and calling the corresponding D-Bus method. It combines the
    <citerefentry><refentrytitle>sd_bus_message_new_method_call</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
    <citerefentry><refentrytitle>sd_bus_message_append</refentrytitle><manvolnum>3</manvolnum></citerefentry> and
    <citerefentry><refentrytitle>sd_bus_call</refentrytitle><manvolnum>3</manvolnum></citerefentry>
    functions into a single function call.</para>

    <para><function>sd_bus_call_method_async()</function> is a convenience function for initializing
    a bus message object and calling the corresponding D-Bus method asynchronously. It combines the
    <citerefentry><refentrytitle>sd_bus_message_new_method_call</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
    <citerefentry><refentrytitle>sd_bus_message_append</refentrytitle><manvolnum>3</manvolnum></citerefentry> and
    <citerefentry><refentrytitle>sd_bus_call_async</refentrytitle><manvolnum>3</manvolnum></citerefentry>
    functions into a single function call.</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 man pages of
      <citerefentry><refentrytitle>sd_bus_message_new_method_call</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>sd_bus_message_append</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>sd_bus_call</refentrytitle><manvolnum>3</manvolnum></citerefentry> and
      <citerefentry><refentrytitle>sd_bus_call_async</refentrytitle><manvolnum>3</manvolnum></citerefentry>
      for a list of possible errors.</para>
    </refsect2>
  </refsect1>

  <xi:include href="libsystemd-pkgconfig.xml" />

  <refsect1>
    <title>Examples</title>

    <example>
      <title>Make a call to a D-Bus method that takes a single parameter</title>

      <programlisting><xi:include href="print-unit-path-call-method.c" parse="text" /></programlisting>
      <para>This defines a minimally useful program that will open a connection to the bus, call a method,
      wait for the reply, and finally extract and print the answer. It does error handling and proper
      memory management.</para>
    </example>
  </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_message_new_method_call</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>sd_bus_message_append</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>sd_bus_call</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>sd_bus_set_property</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>sd_bus_emit_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>
    </para>
  </refsect1>

</refentry>