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   1 <?xml version="1.0" encoding="UTF-8"?>
   2 <!--
   3    Copyright (c) 1989 - 1990, Julianne Frances Haugh
   4    Copyright (c) 2007 - 2008, Nicolas François
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  16       endorse or promote products derived from this software without
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  31 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook V4.5//EN"
  32   "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
  33 <!-- SHADOW-CONFIG-HERE -->
  34 ]>
  35 <refentry id='passwd.5'>
  36   <!-- $Id$ -->
  37   <refentryinfo>
  38     <author>
  39       <firstname>Julianne Frances</firstname>
  40       <surname>Haugh</surname>
  41       <contrib>Creation, 1989</contrib>
  42     </author>
  43     <author>
  44       <firstname>Thomas</firstname>
  45       <surname>Kłoczko</surname>
  46       <email>kloczek@pld.org.pl</email>
  47       <contrib>shadow-utils maintainer, 2000 - 2007</contrib>
  48     </author>
  49     <author>
  50       <firstname>Nicolas</firstname>
  51       <surname>François</surname>
  52       <email>nicolas.francois@centraliens.net</email>
  53       <contrib>shadow-utils maintainer, 2007 - now</contrib>
  54     </author>
  55   </refentryinfo>
  56   <refmeta>
  57     <refentrytitle>passwd</refentrytitle>
  58     <manvolnum>5</manvolnum>
  59     <refmiscinfo class="sectdesc">File Formats and Conversions</refmiscinfo>
  60     <refmiscinfo class="source">shadow-utils</refmiscinfo>
  61     <refmiscinfo class="version">&SHADOW_UTILS_VERSION;</refmiscinfo>
  62   </refmeta>
  63   <refnamediv id='name'>
  64     <refname>passwd</refname>
  65     <refpurpose>the password file</refpurpose>
  66   </refnamediv>
  67
  68   <refsect1 id='description'>
  69     <title>DESCRIPTION</title>
  70     <para>
  71       <filename>/etc/passwd</filename> contains one line for each
  72       user account, with seven fields delimited by colons
  73       (<quote>:</quote>).
  74       These fields are:
  75     </para>
  76     <itemizedlist mark='bullet'>
  77       <listitem>
  78         <para>login name</para>
  79       </listitem>
  80       <listitem>
  81         <para>optional encrypted password</para>
  82       </listitem>
  83       <listitem>
  84         <para>numerical user ID</para>
  85       </listitem>
  86       <listitem>
  87         <para>numerical group ID</para>
  88       </listitem>
  89       <listitem>
  90         <para>user name or comment field</para>
  91       </listitem>
  92       <listitem>
  93         <para>user home directory</para>
  94       </listitem>
  95       <listitem>
  96         <para>optional user command interpreter</para>
  97       </listitem>
  98     </itemizedlist>
  99
 100     <para>
 101       The encrypted password field may be blank, in which case no password
 102       is required to authenticate as the specified login name. However,
 103       some applications which read the <filename>/etc/passwd</filename> file
 104       may decide not to permit <emphasis>any</emphasis> access at all if the
 105       <emphasis>password</emphasis> field is blank. If the
 106       <emphasis>password</emphasis> field is a lower-case <quote>x</quote>,
 107       then the encrypted password is actually stored in the
 108       <citerefentry><refentrytitle>shadow</refentrytitle>
 109       <manvolnum>5</manvolnum></citerefentry> file instead; there
 110       <emphasis>must</emphasis> be a corresponding line in the
 111       <filename>/etc/shadow</filename> file, or else the user account is invalid.
 112       If the <emphasis>password</emphasis> field is any other string, then
 113       it will be treated as an encrypted password, as specified by
 114       <citerefentry><refentrytitle>crypt</refentrytitle>
 115       <manvolnum>3</manvolnum></citerefentry>.
 116
 117     </para>
 118
 119     <para>
 120       The comment field is used by various system utilities, such as
 121       <citerefentry><refentrytitle>finger</refentrytitle>
 122       <manvolnum>1</manvolnum></citerefentry>.
 123     </para>
 124
 125     <para>
 126       The home directory field provides the name of the initial working
 127       directory. The <command>login</command> program uses this information
 128       to set the value of the <envar>$HOME</envar> environmental variable.
 129     </para>
 130
 131     <para>
 132       The command interpreter field provides the name of the user's command
 133       language interpreter, or the name of the initial program to execute.
 134       The <command>login</command> program uses this information to set the
 135       value of the <envar>$SHELL</envar> environmental variable. If this
 136       field is empty, it defaults to the value <filename>/bin/sh</filename>.
 137     </para>
 138   </refsect1>
 139
 140   <refsect1 id='files'>
 141     <title>FILES</title>
 142     <variablelist>
 143       <varlistentry>
 144         <term><filename>/etc/passwd</filename></term>
 145         <listitem>
 146           <para>User account information.</para>
 147         </listitem>
 148       </varlistentry>
 149       <varlistentry>
 150         <term><filename>/etc/shadow</filename></term>
 151         <listitem>
 152           <para>optional encrypted password file</para>
 153         </listitem>
 154       </varlistentry>
 155       <varlistentry>
 156         <term><filename>/etc/passwd-</filename></term>
 157         <listitem>
 158           <para>Backup file for /etc/passwd.</para>
 159           <para>
 160             Note that this file is used by the tools of the shadow
 161             toolsuite, but not by all user and password management tools.
 162           </para>
 163         </listitem>
 164       </varlistentry>
 165     </variablelist>
 166   </refsect1>
 167
 168   <refsect1 id='see_also'>
 169     <title>SEE ALSO</title>
 170     <para>
 171       <citerefentry>
 172         <refentrytitle>crypt</refentrytitle><manvolnum>3</manvolnum>
 173       </citerefentry>,
 174       <citerefentry>
 175         <refentrytitle>getent</refentrytitle><manvolnum>1</manvolnum>
 176       </citerefentry>,
 177       <citerefentry>
 178         <refentrytitle>getpwnam</refentrytitle><manvolnum>3</manvolnum>
 179       </citerefentry>,
 180       <citerefentry>
 181         <refentrytitle>login</refentrytitle><manvolnum>1</manvolnum>
 182       </citerefentry>,
 183       <citerefentry>
 184         <refentrytitle>passwd</refentrytitle><manvolnum>1</manvolnum>
 185       </citerefentry>,
 186       <citerefentry>
 187         <refentrytitle>pwck</refentrytitle><manvolnum>8</manvolnum>
 188       </citerefentry>,
 189       <citerefentry>
 190         <refentrytitle>pwconv</refentrytitle><manvolnum>8</manvolnum>
 191       </citerefentry>,
 192       <citerefentry>
 193         <refentrytitle>pwunconv</refentrytitle><manvolnum>8</manvolnum>
 194       </citerefentry>,
 195       <citerefentry>
 196         <refentrytitle>shadow</refentrytitle><manvolnum>5</manvolnum>
 197       </citerefentry>,
 198       <citerefentry>
 199         <refentrytitle>su</refentrytitle><manvolnum>1</manvolnum>
 200       </citerefentry>,
 201       <citerefentry>
 202         <refentrytitle>sulogin</refentrytitle><manvolnum>8</manvolnum>
 203       </citerefentry>.
 204     </para>
 205   </refsect1>
 206 </refentry>