systemd/man/sd_booted.xml

<?xml version='1.0'?> <!--*-nxml-*-->
<!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_booted"
  xmlns:xi="http://www.w3.org/2001/XInclude">

  <refentryinfo>
    <title>sd_booted</title>
    <productname>systemd</productname>
  </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 &lt;systemd/sd-daemon.h&gt;</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 positive return value, zero otherwise.</para>
  </refsect1>

  <refsect1>
    <title>Notes</title>

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

    <para>Internally, this function checks whether the directory
    <filename>/run/systemd/system/</filename> exists. A simple check
    like this can also be implemented trivially in shell or any other
    language.</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-daemon</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
    </simplelist></para>
  </refsect1>

</refentry>