journald: enable persistent FD Store to fix logging during soft-reboot

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

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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->

<refentry id="sd_bus_message_seal"
          xmlns:xi="http://www.w3.org/2001/XInclude">

  <refentryinfo>
    <title>sd_bus_message_seal</title>
    <productname>systemd</productname>
  </refentryinfo>

  <refmeta>
    <refentrytitle>sd_bus_message_seal</refentrytitle>
    <manvolnum>3</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>sd_bus_message_seal</refname>

    <refpurpose>Prepare a D-Bus message for transmission</refpurpose>
  </refnamediv>

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

      <funcprototype>
        <funcdef>int <function>sd_bus_message_seal</function></funcdef>
        <paramdef>sd_bus_message *<parameter>m</parameter></paramdef>
        <paramdef>uint64_t <parameter>cookie</parameter></paramdef>
        <paramdef>uint64_t <parameter>timeout_usec</parameter></paramdef>
      </funcprototype>
    </funcsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para><function>sd_bus_message_seal()</function> finishes the message <parameter>m</parameter>
    and prepares it for transmission using
    <citerefentry><refentrytitle>sd_bus_send</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
    <parameter>cookie</parameter> specifies the identifier used to match the message reply to its
    corresponding request. <parameter>timeout_usec</parameter> specifies the maximum time in
    microseconds to wait for a reply to arrive.</para>

    <para>Note that in most scenarios, it's not necessary to call this function directly.
    <citerefentry><refentrytitle>sd_bus_call</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
    <citerefentry><refentrytitle>sd_bus_call_async</refentrytitle><manvolnum>3</manvolnum></citerefentry> and
    <citerefentry><refentrytitle>sd_bus_send</refentrytitle><manvolnum>3</manvolnum></citerefentry>
    will seal any given messages if they have not been sealed yet.</para>
  </refsect1>

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

    <para>On success, this function returns a non-negative integer. On failure, it returns 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>m</parameter> parameter is <constant>NULL</constant>.
          </para>

          <xi:include href="version-info.xml" xpointer="v246"/></listitem>
        </varlistentry>

         <varlistentry>
          <term><constant>-EBADMSG</constant></term>

          <listitem><para>The D-Bus message <parameter>m</parameter> has open containers.
          </para>

          <xi:include href="version-info.xml" xpointer="v246"/></listitem>
        </varlistentry>

        <varlistentry>
          <term><constant>-ENOMSG</constant></term>

          <listitem><para>The D-Bus message <parameter>m</parameter> is a reply but its type
          signature does not match the return type signature of its corresponding member in the
          object vtable.</para>

          <xi:include href="version-info.xml" xpointer="v246"/></listitem>
        </varlistentry>
      </variablelist>
    </refsect2>
  </refsect1>

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

  <refsect1>
    <title>History</title>
    <para><function>sd_bus_message_seal()</function> was added in version 246.</para>
  </refsect1>

  <refsect1>
    <title>See Also</title>

    <para><simplelist type="inline">
      <member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
      <member><citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
      <member><citerefentry><refentrytitle>sd_bus_call</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
      <member><citerefentry><refentrytitle>sd_bus_call_async</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
      <member><citerefentry><refentrytitle>sd_bus_send</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
    </simplelist></para>
  </refsect1>

</refentry>