systemd/man/runlevel.xml

<?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">

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

  <refentryinfo>
    <title>runlevel</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>runlevel</refentrytitle>
    <manvolnum>8</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>runlevel</refname>
    <refpurpose>Print previous and current SysV runlevel</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <cmdsynopsis>
      <command>runlevel <arg choice="opt" rep="repeat">options</arg></command>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para><command>runlevel</command> prints the previous and current
    SysV runlevel if they are known.</para>

    <para>The two runlevel characters are separated by a single space
    character. If a runlevel cannot be determined, N is printed
    instead. If neither can be determined, the word "unknown" is
    printed.</para>

    <para>Unless overridden in the environment, this will check the
    utmp database for recent runlevel changes.</para>
  </refsect1>

  <refsect1>
    <title>Options</title>

    <para>The following option is understood:</para>

    <variablelist>
      <varlistentry>
        <term><option>--help</option></term>

        <xi:include href="standard-options.xml" xpointer="help-text" />
      </varlistentry>
    </variablelist>

  </refsect1>

  <refsect1>
    <title>Exit status</title>

    <para>If one or both runlevels could be determined, 0 is returned,
    a non-zero failure code otherwise.</para>

  </refsect1>

  <refsect1>
    <title>Environment</title>

    <variablelist class='environment-variables'>
      <varlistentry>
        <term><varname>$RUNLEVEL</varname></term>

        <listitem><para>If <varname>$RUNLEVEL</varname> is set,
        <command>runlevel</command> will print this value as current
        runlevel and ignore utmp.</para></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>$PREVLEVEL</varname></term>

        <listitem><para>If <varname>$PREVLEVEL</varname> is set,
        <command>runlevel</command> will print this value as previous
        runlevel and ignore utmp.</para></listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>Files</title>

    <variablelist>
      <varlistentry>
        <term><filename>/var/run/utmp</filename></term>

        <listitem><para>The utmp database <command>runlevel</command>
        reads the previous and current runlevel
        from.</para></listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1>
    <title>Notes</title>

    <para>This is a legacy command available for compatibility only.
    It should not be used anymore, as the concept of runlevels is
    obsolete.</para>
  </refsect1>

  <refsect1>
    <title>See Also</title>
    <para>
      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
      <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
    </para>
  </refsect1>

</refentry>