70449379def39da2a3efbd7c7da27a4745702b08Lennart Poettering<?xml version='1.0'?> <!--*-nxml-*-->

70449379def39da2a3efbd7c7da27a4745702b08Lennart Poettering<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"

70449379def39da2a3efbd7c7da27a4745702b08Lennart Poettering "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

5430f7f2bc7330f3088b894166bf3524a067e3d8Lennart Poettering

<refentry id="sd_booted">

<refentryinfo>

<title>sd_booted</title>

<productname>systemd</productname>

<authorgroup>

<author>

<contrib>Developer</contrib>

<firstname>Lennart</firstname>

<surname>Poettering</surname>

<email>lennart@poettering.net</email>

</author>

</authorgroup>

</refentryinfo>

<refmeta>

<refentrytitle>sd_booted</refentrytitle>

<manvolnum>3</manvolnum>

</refmeta>

<refnamediv>

<refname>sd_booted</refname>

<refpurpose>Test whether the system is running the systemd init system.</refpurpose>

</refnamediv>

<refsynopsisdiv>

<funcsynopsis>

<funcsynopsisinfo>#include "sd-daemon.h"</funcsynopsisinfo>

<funcprototype>

<funcdef>int <function>sd_booted</function></funcdef>

<paramdef>void</paramdef>

</funcprototype>

</funcsynopsis>

</refsynopsisdiv>

<refsect1>

<title>Description</title>

<para><function>sd_booted()</function> checks whether

the system was booted up using the systemd init system.</para>

</refsect1>

<refsect1>

<title>Return Value</title>

<para>On failure, this call returns a negative

errno-style error code. If the system was booted up

with systemd as init system this call returns a

postive return value, zero otherwise.</para>

</refsect1>

<refsect1>

<title>Notes</title>

<para>This function is provided by the reference

implementation of APIs for new-style daemons and

distributed with the systemd package. The algorithm it

implements is simple, and can easily be reimplemented

in daemons if it is important to support this

interface without using the reference

implementation.</para>

<para>Internally, this function checks whether the

<filename>/cgroup/systemd</filename> virtual file

system is mounted, by comparing the st_dev value of

the <function>stat()</function> data of

<filename>/cgroup</filename> and

<filename>/cgroup/systemd</filename>.</para>

<para>For details about the algorithm check the

liberally licensed reference implementation sources:

<ulink url="http://cgit.freedesktop.org/systemd/tree/src/sd-daemon.c"/>

resp. <ulink

url="http://cgit.freedesktop.org/systemd/tree/src/sd-daemon.h"/></para>

<para><function>sd_booted()</function> is implemented

in the reference implementation's drop-in

<filename>sd-daemon.c</filename> and

<filename>sd-daemon.h</filename> files. It is

recommended that applications consuming these APIs

copy the implementation into their source tree. For

more details about the reference implementation see

<citerefentry><refentrytitle>sd_daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry></para>

<para>If -DDISABLE_SYSTEMD is set during compilation

this function will always return 0 and otherwise

become a NOP.</para>

</refsect1>

<refsect1>

<title>See Also</title>

<para>

<citerefentry><refentrytitle>sd_daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>

</para>

</refsect1>

</refentry>