<?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_slot_set_description" xmlns:xi="http://www.w3.org/2001/XInclude">
  <refentryinfo>
    <title>sd_bus_slot_set_description</title>
    <productname>systemd</productname>
  </refentryinfo>

  <refmeta>
    <refentrytitle>sd_bus_slot_set_description</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>sd_bus_slot_set_description</refname>
    <refname>sd_bus_slot_get_description</refname>

    <refpurpose>Set or query the description of bus slot objects</refpurpose>
  </refnamediv>

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

      <funcprototype>
        <funcdef>int <function>sd_bus_slot_set_description</function></funcdef>
        <paramdef>sd_bus_slot* <parameter>slot</parameter></paramdef>
        <paramdef>const char *<parameter>description</parameter></paramdef>
      </funcprototype>

      <funcprototype>
        <funcdef>int <function>sd_bus_slot_get_description</function></funcdef>
        <paramdef>sd_bus_slot* <parameter>bus</parameter></paramdef>
        <paramdef>const char **<parameter>description</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para><function>sd_bus_slot_set_description()</function> sets the description string
    that is used in logging to the specified string. The string is copied internally
    and freed when the bus slot object is deallocated. The
    <parameter>description</parameter> argument may be <constant>NULL</constant>, in
    which case the description is unset.</para>

    <para><function>sd_bus_slot_get_description()</function> returns a description string in
    <parameter>description</parameter>. If the string is not set, e.g. with
    <function>sd_bus_slot_set_description()</function>, and the slot is a bus match callback slot,
    the match string will be returned. Otherwise, <constant>-ENXIO</constant> is returned.
    </para>
  </refsect1>

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

    <para>On success, these functions return 0 or a positive integer. On failure,
    they 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>An required argument is <constant>NULL</constant>.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><constant>-ENXIO</constant></term>

          <listitem><para>The bus slot object has no description.</para></listitem>
        </varlistentry>

        <varlistentry>
          <term><constant>-ENOMEM</constant></term>

          <listitem><para>Memory allocation failed.</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_slot_ref</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>sd_bus_slot_set_userdata</refentrytitle><manvolnum>3</manvolnum></citerefentry>
    </para>
  </refsect1>

</refentry>