test: mark plymouth as optional dependency

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

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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

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  SPDX-License-Identifier: LGPL-2.1+
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<refentry id="sd_bus_reply_method_error"
          xmlns:xi="http://www.w3.org/2001/XInclude">

  <refentryinfo>
    <title>sd_bus_reply_method_error</title>
    <productname>systemd</productname>
  </refentryinfo>

  <refmeta>
    <refentrytitle>sd_bus_reply_method_error</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>sd_bus_reply_method_error</refname>
    <refname>sd_bus_reply_method_errorf</refname>
    <refname>sd_bus_reply_method_errno</refname>
    <refname>sd_bus_reply_method_errnof</refname>

    <refpurpose>Reply with an error to a method call</refpurpose>
  </refnamediv>

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

      <funcprototype>
        <funcdef>int sd_bus_reply_method_error</funcdef>
        <paramdef>sd_bus_message *<parameter>call</parameter></paramdef>
        <paramdef>const sd_bus_error *<parameter>e</parameter></paramdef>
      </funcprototype>

      <funcprototype>
        <funcdef>int sd_bus_reply_method_errorf</funcdef>
        <paramdef>sd_bus_message *<parameter>call</parameter></paramdef>
        <paramdef>const char *<parameter>name</parameter></paramdef>
        <paramdef>const char *<parameter>format</parameter></paramdef>
        <paramdef>…</paramdef>
      </funcprototype>

      <funcprototype>
        <funcdef>int sd_bus_reply_method_errno</funcdef>
        <paramdef>sd_bus_message *<parameter>call</parameter></paramdef>
        <paramdef>int <parameter>error</parameter></paramdef>
        <paramdef>const sd_bus_error *<parameter>p</parameter></paramdef>
      </funcprototype>

      <funcprototype>
        <funcdef>int sd_bus_reply_method_errnof</funcdef>
        <paramdef>sd_bus_message *<parameter>call</parameter></paramdef>
        <paramdef>int <parameter>error</parameter></paramdef>
        <paramdef>const char *<parameter>format</parameter></paramdef>
        <paramdef>…</paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para>The <function>sd_bus_reply_method_error()</function> function sends an
    error reply to the <parameter>call</parameter> message. The error structure
    <parameter>e</parameter> specifies the error to send, and is used as described in
    <citerefentry><refentrytitle>sd_bus_message_new_error</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
    If no reply is expected to <parameter>call</parameter>, this function returns
    success without sending reply.</para>

    <para>The <function>sd_bus_reply_method_errorf()</function> is to
    <function>sd_bus_reply_method_error()</function> what
    <function>sd_bus_message_new_method_errorf()</function> is to
    <function>sd_bus_message_new_method_error()</function>.</para>

    <para>The <function>sd_bus_reply_method_errno()</function> is to
    <function>sd_bus_reply_method_error()</function> what
    <function>sd_bus_message_new_method_errno()</function> is to
    <function>sd_bus_message_new_method_error()</function>.</para>

    <para>The <function>sd_bus_reply_method_errnof()</function> is to
    <function>sd_bus_reply_method_error()</function> what
    <function>sd_bus_message_new_method_errnof()</function> is to
    <function>sd_bus_message_new_method_error()</function>.</para>
  </refsect1>

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

    <para>These functions return 0 if the error reply was successfully sent or if
    none was expected, and a negative errno-style error code otherwise.</para>
  </refsect1>

  <refsect1 id='errors'>
    <title>Errors</title>

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

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

        <listitem><para>The call message <parameter>call</parameter> is
        <constant>NULL</constant>.</para>

        <para>Message <parameter>call</parameter> is not a method call message.
        </para>

        <para>Message <parameter>call</parameter> is not attached to a bus.</para>

        <para>The error <parameter>error</parameter> parameter to
        <function>sd_bus_reply_method_error</function> is not set, see
        <citerefentry><refentrytitle>sd_bus_error_is_set</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
        </para>
        </listitem>
      </varlistentry>

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

        <listitem><para>Message <parameter>call</parameter> has been sealed.
        </para></listitem>
      </varlistentry>

      <varlistentry>
        <term><constant>-ENOTCONN</constant></term>

        <listitem><para>The bus to which message <parameter>call</parameter> is
        attached is not connected.</para></listitem>
      </varlistentry>

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

        <listitem><para>Memory allocation failed.</para></listitem>
      </varlistentry>
    </variablelist>

    <para>In addition, any error message returned by
    <citerefentry><refentrytitle>sd_bus_send</refentrytitle><manvolnum>1</manvolnum></citerefentry>
    may be returned.</para>
  </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_message_new_method_error</refentrytitle><manvolnum>3</manvolnum></citerefentry>
    </para>
  </refsect1>

</refentry>