shadow/man/lastlog.8.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--
   SPDX-FileCopyrightText: 1992       , Julianne Frances Haugh
   SPDX-FileCopyrightText: 1992       , Phillip Street
   SPDX-FileCopyrightText: 2007 - 2011, Nicolas François
   SPDX-License-Identifier: BSD-3-Clause
-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook V4.5//EN"
  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
<!ENTITY LASTLOG_UID_MAX       SYSTEM "login.defs.d/LASTLOG_UID_MAX.xml">
<!-- SHADOW-CONFIG-HERE -->
]>
<refentry id='lastlog.8'>
  <!-- $Id$ -->
  <refentryinfo>
    <author>
      <firstname>Julianne Frances</firstname>
      <surname>Haugh</surname>
      <contrib>Creation, 1992</contrib>
    </author>
    <author>
      <firstname>Thomas</firstname>
      <surname>Kłoczko</surname>
      <email>kloczek@pld.org.pl</email>
      <contrib>shadow-utils maintainer, 2000 - 2007</contrib>
    </author>
    <author>
      <firstname>Nicolas</firstname>
      <surname>François</surname>
      <email>nicolas.francois@centraliens.net</email>
      <contrib>shadow-utils maintainer, 2007 - now</contrib>
    </author>
  </refentryinfo>
  <refmeta>
    <refentrytitle>lastlog</refentrytitle>
    <manvolnum>8</manvolnum>
    <refmiscinfo class="sectdesc">System Management Commands</refmiscinfo>
    <refmiscinfo class="source">shadow-utils</refmiscinfo>
    <refmiscinfo class="version">&SHADOW_UTILS_VERSION;</refmiscinfo>
  </refmeta>
  <refnamediv id='name'>
    <refname>lastlog</refname>
    <refpurpose>reports the most recent login of all users or of a given user</refpurpose>
  </refnamediv>
  <!-- body begins here -->
  <refsynopsisdiv id='synopsis'>
    <cmdsynopsis>
      <command>lastlog</command>
      <arg choice='opt'>
	<replaceable>options</replaceable>
      </arg>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1 id='description'>
    <title>DESCRIPTION</title>
    <para>
      <command>lastlog</command> formats and prints the contents of the last
      login log <filename>/var/log/lastlog</filename> file. The
      <emphasis>login-name</emphasis>, <emphasis>port</emphasis>, and
      <emphasis>last login time</emphasis> will be printed.  The default (no
      flags) causes lastlog entries to be printed, sorted by their order in
      <filename>/etc/passwd</filename>.
    </para>
  </refsect1>

  <refsect1 id='options'>
    <title>OPTIONS</title>
    <para>
      The options which apply to the <command>lastlog</command> command are:
    </para>
    <variablelist remap='IP'>
      <varlistentry>
	<term>
	  <option>-b</option>, <option>--before</option>&nbsp;<replaceable>DAYS</replaceable>
	</term>
	<listitem>
	  <para>
	    Print only lastlog records older than <replaceable>DAYS</replaceable>.
	  </para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>
	  <option>-C</option>, <option>--clear</option>
	</term>
	<listitem>
	  <para>
	    Clear lastlog record of a user. This option can be used only together
	    with <option>-u</option> (<option>--user</option>)).
	  </para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>
	  <option>-h</option>, <option>--help</option>
	</term>
	<listitem>
	  <para>Display help message and exit.</para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>
	  <option>-R</option>, <option>--root</option>&nbsp;<replaceable>CHROOT_DIR</replaceable>
	</term>
	<listitem>
	  <para>
	    Apply changes in the <replaceable>CHROOT_DIR</replaceable>
	    directory and use the configuration files from the
	    <replaceable>CHROOT_DIR</replaceable> directory.
	  </para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>
	  <option>-S</option>, <option>--set</option>
	</term>
	<listitem>
	  <para>
	    Set lastlog record of a user to the current time. This option can be
	    used only together with <option>-u</option> (<option>--user</option>)).
	  </para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>
	  <option>-t</option>, <option>--time</option>&nbsp;<replaceable>DAYS</replaceable>
	</term>
	<listitem>
	  <para>
	    Print the lastlog records more recent than
	    <replaceable>DAYS</replaceable>.
	  </para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>
	  <option>-u</option>, <option>--user</option>&nbsp;<replaceable>LOGIN</replaceable>|<replaceable>RANGE</replaceable>
	</term>
	<listitem>
	  <para>
	    Print the lastlog record of the specified user(s).
	  </para>
	  <para>
	    The users can be specified by a login name, a numerical user ID,
	    or a <replaceable>RANGE</replaceable> of users. This
	    <replaceable>RANGE</replaceable> of users can be specified with a
	    min and max values (<replaceable>UID_MIN-UID_MAX</replaceable>), a
	    max value (<replaceable>-UID_MAX</replaceable>), or a min value
	    (<replaceable>UID_MIN-</replaceable>).
	  </para>
	</listitem>
      </varlistentry>
    </variablelist>

    <para>
      If the user has never logged in the message <emphasis>** Never logged
      in**</emphasis> will be displayed instead of the port and time.
    </para>

    <para>
      Only the entries for the current users of the system will be
      displayed.  Other entries may exist for users that were deleted
      previously.
    </para>
  </refsect1>

  <refsect1 id='note'>
    <title>NOTE</title>
    <para>
      The <filename>lastlog</filename> file is a database which contains info
      on the last login of each user. You should not rotate it. It is a sparse
      file, so its size on the disk is usually much smaller than the one shown
      by "<command>ls -l</command>" (which can indicate a really big file if
      you have in <filename>passwd</filename> users with a high UID). You can
      display its real size with "<command>ls -s</command>".
    </para>
  </refsect1>

  <refsect1 id='configuration'>
    <title>CONFIGURATION</title>
    <para>
      The following configuration variables in
      <filename>/etc/login.defs</filename> change the behavior of this
      tool:
    </para>
    <variablelist>
      &LASTLOG_UID_MAX;
    </variablelist>
  </refsect1>

  <refsect1 id='files'>
    <title>FILES</title>
    <variablelist>
      <varlistentry>
	<term><filename>/var/log/lastlog</filename></term>
	<listitem>
	  <para>Database times of previous user logins.</para>
	</listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1 id='caveats'>
    <title>CAVEATS</title>
    <para>
      Large gaps in UID numbers will cause the lastlog program to run
      longer with no output to the screen (i.e. if in lastlog database there
      is no entries for users with UID between 170 and 800 lastlog will appear
      to hang as it processes entries with UIDs 171-799).
    </para>
    <para>
      Having high UIDs can create problems when handling the <term><filename>
      /var/log/lastlog</filename></term> with external tools. Although the
      actual file is sparse and does not use too much space, certain
      applications are not designed to identify sparse files by default and may
      require a specific option to handle them.
    </para>
  </refsect1>
</refentry>