systemd/man/less-variables.xml

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<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
                 "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">

<refsect1>
  <title>Environment</title>

  <variablelist class='environment-variables'>
    <varlistentry id='pager'>
      <term><varname>$SYSTEMD_PAGER</varname></term>

      <listitem><para>Pager to use when <option>--no-pager</option> is not given; overrides
      <varname>$PAGER</varname>. If neither <varname>$SYSTEMD_PAGER</varname> nor <varname>$PAGER</varname> are set, a
      set of well-known pager implementations are tried in turn, including
      <citerefentry><refentrytitle>less</refentrytitle><manvolnum>1</manvolnum></citerefentry> and
      <citerefentry><refentrytitle>more</refentrytitle><manvolnum>1</manvolnum></citerefentry>, until one is found. If
      no pager implementation is discovered no pager is invoked. Setting this environment variable to an empty string
      or the value <literal>cat</literal> is equivalent to passing <option>--no-pager</option>.</para></listitem>
    </varlistentry>

    <varlistentry id='less'>
      <term><varname>$SYSTEMD_LESS</varname></term>

      <listitem><para>Override the options passed to <command>less</command> (by default
      <literal>FRSXMK</literal>).</para></listitem>
    </varlistentry>

    <varlistentry id='lesscharset'>
      <term><varname>$SYSTEMD_LESSCHARSET</varname></term>

      <listitem><para>Override the charset passed to <command>less</command> (by default <literal>utf-8</literal>, if
      the invoking terminal is determined to be UTF-8 compatible).</para></listitem>
    </varlistentry>

    </variablelist>
</refsect1>