<?xml version="1.0" encoding="UTF-8"?>
<refentry id='grpck.8'>
  <!-- $Id$ -->
  <refmeta>
    <refentrytitle>grpck</refentrytitle>
    <manvolnum>8</manvolnum>
    <refmiscinfo class="sectdesc">System Management Commands</refmiscinfo>
  </refmeta>
  <refnamediv id='name'>
    <refname>grpck</refname>
    <refpurpose>verify integrity of group files</refpurpose>
  </refnamediv>

  <refsynopsisdiv id='synopsis'>
    <cmdsynopsis>
      <command>grpck</command>    <arg choice='opt'>-r </arg>
      <arg choice='opt'>
	<arg choice='plain'><replaceable>group</replaceable></arg>
	<arg choice='plain'><replaceable>shadow</replaceable></arg>
      </arg>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1 id='description'>
    <title>DESCRIPTION</title>
    <para>
      The <command>grpck</command> command verifies the integrity of the
      system authentication information. All entries in the
      <filename>/etc/group</filename> and <filename>/etc/gshadow</filename>
      are checked to see that the entry has the proper format and valid data
      in each field. The user is prompted to delete entries that are
      improperly formatted or which have other uncorrectable errors.
    </para>

    <para>Checks are made to verify that each entry has:</para>

    <itemizedlist mark='bullet'>
      <listitem>
	<para>the correct number of fields</para>
      </listitem>
      <listitem>
	<para>a unique group name</para>
      </listitem>
      <listitem>
	<para>a valid list of members and administrators</para>
      </listitem>
    </itemizedlist>

    <para>
      The checks for correct number of fields and unique group name are
      fatal. If the entry has the wrong number of fields, the user will be
      prompted to delete the entire line. If the user does not answer
      affirmatively, all further checks are bypassed. An entry with a
      duplicated group name is prompted for deletion, but the remaining
      checks will still be made. All other errors are warnings and the user
      is encouraged to run the <command>groupmod</command> command to
      correct the error.
    </para>

    <para>
      The commands which operate on the <filename>/etc/group</filename> file
      are not able to alter corrupted or duplicated entries. 
      <command>grpck</command> should be used in those circumstances to
      remove the offending entry.
    </para>
  </refsect1>

  <refsect1 id='options'>
    <title>OPTIONS</title>
    <para>
      By default, <command>grpck</command> operates on the files
      <filename>/etc/group</filename> and <filename>/etc/gshadow</filename>. 
      The user may select alternate files with the <emphasis
      remap='I'>group</emphasis> and <emphasis remap='I'>shadow</emphasis>
      parameters. Additionally, the user may execute the command in
      read-only mode by specifying the <option>-r</option> flag. This causes
      all questions regarding changes to be answered <emphasis>no</emphasis>
      without user intervention. <command>grpck</command> can also sort
      entries in <filename>/etc/group</filename> and
      <filename>/etc/gshadow</filename> by GID. To run it in sort mode pass
      it <option>-s</option> flag. No checks are performed then, it just
      sorts.
    </para>
  </refsect1>

  <refsect1 id='files'>
    <title>FILES</title>
    <variablelist>
      <varlistentry>
	<term><filename>/etc/group</filename></term>
	<listitem>
	  <para>Group account information.</para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><filename>/etc/gshadow</filename></term>
	<listitem>
	  <para>Secure group account information.</para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><filename>/etc/passwd</filename></term>
	<listitem>
	  <para>User account information.</para>
	</listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1 id='see_also'>
    <title>SEE ALSO</title>
    <para>
      <citerefentry>
	<refentrytitle>group</refentrytitle><manvolnum>5</manvolnum>
      </citerefentry>,
      <citerefentry>
	<refentrytitle>passwd</refentrytitle><manvolnum>5</manvolnum>
      </citerefentry>,
      <citerefentry>
	<refentrytitle>shadow</refentrytitle><manvolnum>5</manvolnum>
      </citerefentry>,
      <citerefentry>
	<refentrytitle>groupmod</refentrytitle><manvolnum>8</manvolnum>
      </citerefentry>.
    </para>
  </refsect1>

  <refsect1 id='exit_values'>
    <title>EXIT VALUES</title>
    <para>
      The <command>grpck</command> command exits with the following values:
      <variablelist>
	<varlistentry>
	  <term><replaceable>0</replaceable></term>
	  <listitem>
	    <para>success</para>
	  </listitem>
	</varlistentry>
	<varlistentry>
	  <term><replaceable>1</replaceable></term>
	  <listitem>
	    <para>invalid command syntax</para>
	  </listitem>
	</varlistentry>
	<varlistentry>
	  <term><replaceable>2</replaceable></term>
	  <listitem>
	    <para>one or more bad group entries</para>
	  </listitem>
	</varlistentry>
	<varlistentry>
	  <term><replaceable>3</replaceable></term>
	  <listitem>
	    <para>can't open group files</para>
	  </listitem>
	</varlistentry>
	<varlistentry>
	  <term><replaceable>4</replaceable></term>
	  <listitem>
	    <para>can't lock group files</para>
	  </listitem>
	</varlistentry>
	<varlistentry>
	  <term><replaceable>5</replaceable></term>
	  <listitem>
	    <para>can't update group files</para>
	  </listitem>
	</varlistentry>
      </variablelist>
    </para>
  </refsect1>
</refentry>
