man/sd_bus_message_set_expect_reply.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1+ -->
   5
   6 <refentry id="sd_bus_message_set_expect_reply" xmlns:xi="http://www.w3.org/2001/XInclude">
   7
   8   <refentryinfo>
   9     <title>sd_bus_message_set_expect_reply</title>
  10     <productname>systemd</productname>
  11   </refentryinfo>
  12
  13   <refmeta>
  14     <refentrytitle>sd_bus_message_set_expect_reply</refentrytitle>
  15     <manvolnum>3</manvolnum>
  16   </refmeta>
  17
  18   <refnamediv>
  19     <refname>sd_bus_message_set_expect_reply</refname>
  20     <refname>sd_bus_message_get_expect_reply</refname>
  21     <refname>sd_bus_message_set_auto_start</refname>
  22     <refname>sd_bus_message_get_auto_start</refname>
  23
  24     <refpurpose>Set and query bus message metadata</refpurpose>
  25   </refnamediv>
  26
  27   <refsynopsisdiv>
  28     <funcsynopsis>
  29       <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
  30
  31       <funcprototype>
  32         <funcdef>int <function>sd_bus_message_set_expect_reply</function></funcdef>
  33         <paramdef>sd_bus_message *<parameter>message</parameter></paramdef>
  34         <paramdef>int <parameter>b</parameter></paramdef>
  35       </funcprototype>
  36
  37       <funcprototype>
  38         <funcdef>int <function>sd_bus_message_get_expect_reply</function></funcdef>
  39         <paramdef>sd_bus_message *<parameter>message</parameter></paramdef>
  40       </funcprototype>
  41
  42       <funcprototype>
  43         <funcdef>int <function>sd_bus_message_set_auto_start</function></funcdef>
  44         <paramdef>sd_bus_message *<parameter>message</parameter></paramdef>
  45         <paramdef>int <parameter>b</parameter></paramdef>
  46       </funcprototype>
  47
  48       <funcprototype>
  49         <funcdef>int <function>sd_bus_message_get_auto_start</function></funcdef>
  50         <paramdef>sd_bus_message *<parameter>message</parameter></paramdef>
  51       </funcprototype>
  52     </funcsynopsis>
  53
  54   </refsynopsisdiv>
  55
  56   <refsect1>
  57     <title>Description</title>
  58
  59     <para><function>sd_bus_message_set_expect_reply()</function> sets or clears the
  60     <constant>NO_REPLY_EXPECTED</constant> flag on the message <parameter>m</parameter>. This flag
  61     matters only for method call messages and is used to specify that no method return or error
  62     reply is expected. It is ignored for other types. Thus, for a method call message, calling
  63     <programlisting>sd_bus_message_set_expect_reply(…, 0)</programlisting> sets the flag and
  64     suppresses the reply.</para>
  65
  66     <para><function>sd_bus_message_get_expect_reply()</function> checks if the
  67     <constant>NO_REPLY_EXPECTED</constant> flag is set on the message <parameter>m</parameter>. It
  68     will return positive if it is not set, and zero if it is.</para>
  69
  70     <para><function>sd_bus_message_set_auto_start()</function> sets or clears the
  71     <constant>NO_AUTO_START</constant> flag on the message <parameter>m</parameter>. When the flag
  72     is set the bus must not launch an owner for the destination name in response to this message.
  73     Calling
  74     <programlisting>sd_bus_message_set_auto_start(…, 0)</programlisting> sets the flag.
  75     </para>
  76
  77     <para><function>sd_bus_message_get_auto_start()</function> checks if the
  78     <constant>NO_AUTO_START</constant> flag is set on the message <parameter>m</parameter>. It
  79     will return positive if it is not set, and zero if it is.</para>
  80   </refsect1>
  81
  82   <refsect1>
  83     <title>Return Value</title>
  84
  85     <para>On success, these functions return 0 or a positive integer. On failure, they return a
  86     negative errno-style error code.</para>
  87
  88     <refsect2>
  89       <title>Errors</title>
  90
  91       <para>Returned errors may indicate the following problems:</para>
  92
  93       <variablelist>
  94         <varlistentry>
  95           <term><constant>-EINVAL</constant></term>
  96
  97           <listitem><para>The <parameter>message</parameter> parameter is
  98           <constant>NULL</constant>.</para></listitem>
  99         </varlistentry>
 100
 101         <varlistentry>
 102           <term><constant>-EPERM</constant></term>
 103
 104           <listitem><para>The message <parameter>message</parameter> is sealed
 105           when trying to set a flag.</para>
 106
 107           <para>The message <parameter>message</parameter> has wrong
 108           type.</para>
 109           </listitem>
 110         </varlistentry>
 111       </variablelist>
 112     </refsect2>
 113   </refsect1>
 114
 115   <xi:include href="libsystemd-pkgconfig.xml" />
 116
 117   <refsect1>
 118     <title>See Also</title>
 119
 120     <para>
 121       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 122       <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 123       <citerefentry><refentrytitle>sd_bus_set_description</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 124     </para>
 125   </refsect1>
 126
 127 </refentry>