1
0
mirror of https://github.com/systemd/systemd.git synced 2024-10-31 07:51:21 +03:00
systemd/man/sd_event_get_fd.xml
Zbigniew Jędrzejewski-Szmek ba4b35669e man: add sd_event_get_fd(3)
Example from Tom Gundersen is included using xi:include.
The copyright notice stands out a bit. Maybe it should be removed,
and the code placed in public domain.
2014-10-02 20:49:55 -04:00

138 lines
4.2 KiB
XML
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
This file is part of systemd.
Copyright 2014 Zbigniew Jędrzejewski-Szmek
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
-->
<refentry id="sd_event_get_fd" conditional="ENABLE_KDBUS"
xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>sd_event_get_fd</title>
<productname>systemd</productname>
<authorgroup>
<author>
<contrib>More text</contrib>
<firstname>Zbigniew</firstname>
<surname>Jędrzejewski-Szmek</surname>
<email>zbyszek@in.waw.pl</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta>
<refentrytitle>sd_event_get_fd</refentrytitle>
<manvolnum>3</manvolnum>
</refmeta>
<refnamediv>
<refname>sd_event_get_fd</refname>
<refpurpose>Obtain a file descriptor to poll for event loop events</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
<funcprototype>
<funcdef>int <function>sd_event_get_fd</function></funcdef>
<paramdef>sd_bus *<parameter>event</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><function>sd_event_get_fd()</function> returns the file
descriptor that the event loop object returned by the
<citerefentry><refentrytitle>sd_event_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>
function uses to wait for events. This file descriptor can be
polled for events. This makes it possible to embed the
<citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>
event loop inside of another event loop.</para>
</refsect1>
<refsect1>
<title>Return Value</title>
<para>On success, <function>sd_event_get_fd()</function> returns a
non-negative integer. On failure, it returns a negative
errno-style error code.</para>
</refsect1>
<refsect1>
<title>Errors</title>
<para>Returned errors may indicate the following problems:</para>
<variablelist>
<varlistentry>
<term><constant>-EINVAL</constant></term>
<listitem><para><parameter>event</parameter> is not a valid
pointer to an <structname>sd_event</structname> structure.
</para></listitem>
</varlistentry>
<varlistentry>
<term><constant>-ECHILD</constant></term>
<listitem><para>The event loop has been created in a different process.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>Examples</title>
<example>
<title>Integration in glib event loop</title>
<programlisting><xi:include href="glib-event-glue.c" parse="text" /></programlisting>
</example>
</refsect1>
<refsect1>
<title>Notes</title>
<para><function>sd_event_get_fd()</function> is available as a
shared library, which can be compiled and linked to with the
<constant>libsystemd</constant> <citerefentry
project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
file.</para>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_event_ref</refentrytitle><manvolnum>3</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>