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[thirdparty/systemd.git] / man / sd_bus_message_set_destination.xml

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  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1+ -->

<refentry id="sd_bus_message_set_destination" xmlns:xi="http://www.w3.org/2001/XInclude">
  <refentryinfo>
    <title>sd_bus_message_set_destination</title>
    <productname>systemd</productname>
  </refentryinfo>

  <refmeta>
    <refentrytitle>sd_bus_message_set_destination</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>sd_bus_message_set_destination</refname>
    <refname>sd_bus_message_get_destination</refname>
    <refname>sd_bus_message_get_path</refname>
    <refname>sd_bus_message_get_interface</refname>
    <refname>sd_bus_message_get_member</refname>
    <refname>sd_bus_message_set_sender</refname>
    <refname>sd_bus_message_get_sender</refname>

    <refpurpose>Set and query bus message addressing information</refpurpose>
  </refnamediv>

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

      <funcprototype>
        <funcdef>int <function>sd_bus_message_set_destination</function></funcdef>
        <paramdef>sd_bus_message *<parameter>message</parameter></paramdef>
        <paramdef>const char *<parameter>destination</parameter></paramdef>
      </funcprototype>

      <funcprototype>
        <funcdef>const char* <function>sd_bus_message_get_destination</function></funcdef>
        <paramdef>sd_bus_message *<parameter>message</parameter></paramdef>
      </funcprototype>

      <funcprototype>
        <funcdef>const char* <function>sd_bus_message_get_path</function></funcdef>
        <paramdef>sd_bus_message *<parameter>message</parameter></paramdef>
      </funcprototype>

      <funcprototype>
        <funcdef>const char* <function>sd_bus_message_get_interface</function></funcdef>
        <paramdef>sd_bus_message *<parameter>message</parameter></paramdef>
      </funcprototype>

      <funcprototype>
        <funcdef>const char* <function>sd_bus_message_get_member</function></funcdef>
        <paramdef>sd_bus_message *<parameter>message</parameter></paramdef>
      </funcprototype>

      <funcprototype>
        <funcdef>int <function>sd_bus_message_set_sender</function></funcdef>
        <paramdef>sd_bus_message *<parameter>message</parameter></paramdef>
        <paramdef>const char *<parameter>sender</parameter></paramdef>
      </funcprototype>

      <funcprototype>
        <funcdef>const char* <function>sd_bus_message_get_sender</function></funcdef>
        <paramdef>sd_bus_message *<parameter>message</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para><function>sd_bus_message_set_destination()</function> sets the destination service name
    for the specified bus message object. The specified name must be a valid unique or well-known
    service name.</para>

    <para><function>sd_bus_message_get_destination()</function>,
    <function>sd_bus_message_get_path()</function>,
    <function>sd_bus_message_get_interface()</function>, and
    <function>sd_bus_message_get_member()</function> return the destination, path, interface, and
    member fields from <parameter>message</parameter> header. The return value will be
    <constant>NULL</constant> is <parameter>message</parameter> is <constant>NULL</constant> or the
    message is of a type that doesn't use those fields or the message doesn't have them set. See
    <citerefentry><refentrytitle>sd_bus_message_new_method_call</refentrytitle><manvolnum>3</manvolnum></citerefentry>
    and
    <citerefentry><refentrytitle>sd_bus_message_set_destination</refentrytitle><manvolnum>3</manvolnum></citerefentry>
    for more discussion of those values.</para>


    <para><function>sd_bus_message_set_sender()</function> sets the sender service name for the specified bus message
    object. The specified name must be a valid unique or well-known service name. This function is useful only for
    messages to send on direct connections as for connections to bus brokers the broker will fill in the destination
    field anyway, and the sender field set by original sender is ignored.</para>

    <para><function>sd_bus_message_get_sender()</function> returns the sender field from
    <parameter>message</parameter>.</para>

    <para>When a string is returned, it is a pointer to internal storage, and may not be modified or
    freed. It is only valid as long as the <parameter>message</parameter> remains referenced and
    this field hasn't been changed by a different call.</para>
  </refsect1>

  <refsect1>
    <title>Return Value</title>

    <para>On success, these calls return 0 or a positive integer. On failure, these calls return a
    negative errno-style error code.</para>

    <refsect2>
      <title>Errors</title>

      <para>Returned errors may indicate the following problems:</para>

      <variablelist>
        <varlistentry>
          <term><constant>-EINVAL</constant></term>

          <listitem><para>The <parameter>message</parameter> parameter or the output parameter are
          <constant>NULL</constant>.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><constant>-EPERM</constant></term>

          <listitem><para>For <function>sd_bus_message_set_destination</function> or
          <function>sd_bus_message_set_sender</function>, the message is already
          sealed.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><constant>-EEXIST</constant></term>

          <listitem><para>The message already has a destination or sender field set.</para></listitem>
        </varlistentry>
      </variablelist>
    </refsect2>
  </refsect1>

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

  <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_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>sd_bus_set_sender</refentrytitle><manvolnum>3</manvolnum></citerefentry>
    </para>
  </refsect1>

</refentry>