<?xml version="1.0" encoding="UTF-8"?>
<!--
   SPDX-FileCopyrightText: 1990       , Julianne Frances Haugh
   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 CHSH_AUTH             SYSTEM "login.defs.d/CHSH_AUTH.xml">
<!ENTITY LOGIN_STRING          SYSTEM "login.defs.d/LOGIN_STRING.xml">
<!-- SHADOW-CONFIG-HERE -->
]>

<refentry id='chsh.1'>
  <!-- $Id$ -->
  <refentryinfo>
    <author>
      <firstname>Julianne Frances</firstname>
      <surname>Haugh</surname>
      <contrib>Creation, 1990</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>chsh</refentrytitle>
    <manvolnum>1</manvolnum>
    <refmiscinfo class="sectdesc">User Commands</refmiscinfo>
    <refmiscinfo class="source">shadow-utils</refmiscinfo>
    <refmiscinfo class="version">&SHADOW_UTILS_VERSION;</refmiscinfo>
  </refmeta>
  <refnamediv id='name'>
    <refname>chsh</refname>
    <refpurpose>change login shell</refpurpose>
  </refnamediv>

  <refsynopsisdiv id='synopsis'>
    <cmdsynopsis>
      <command>chsh</command>
      <arg choice='opt'>
	<replaceable>options</replaceable>
      </arg>
      <arg choice='opt'>
        <replaceable>LOGIN</replaceable>
      </arg>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1 id='description'>
    <title>DESCRIPTION</title>
    <para>
      The <command>chsh</command> command changes the user login shell.
      This determines the name of the user's initial login command. A normal
      user may only change the login shell for her own account; the
      superuser may change the login shell for any account.
    </para>

  </refsect1>

  <refsect1 id='options'>
    <title>OPTIONS</title>
    <para>
      The options which apply to the <command>chsh</command> command are:
    </para>
    <variablelist remap='IP'>
      <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.
	    Only absolute paths are supported.
	  </para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>
	  <option>-s</option>, <option>--shell</option>&nbsp;<replaceable>SHELL</replaceable>
	</term>
        <listitem>                                                                                                                   
	  <para>
	    The name of the user's new login shell. Setting this field to
	    blank causes the system to select the default login shell.
	  </para>
	</listitem>
      </varlistentry>
    </variablelist>
    <para>
      If the <option>-s</option> option is not selected,
      <command>chsh</command> operates in an interactive fashion, prompting
      the user with the current login shell. Enter the new value to change
      the shell, or leave the line blank to use the current one. The current
      shell is displayed between a pair of <emphasis>[ ]</emphasis> marks.
    </para>
  </refsect1>

  <refsect1 id='note'>
    <title>NOTE</title>
    <para condition="without_vendordir">
      The only restriction placed on the login shell is that the command
      name must be listed in <filename>/etc/shells</filename>, unless the
      invoker is the superuser, and then any value may be added. An
      account with a restricted login shell may not change her login shell.
      For this reason, placing <filename>/bin/rsh</filename> in
      <filename>/etc/shells</filename> is discouraged since accidentally
      changing to a restricted shell would prevent the user from ever
      changing her login shell back to its original value.
    </para>
    <para condition="with_vendordir">
      The only restriction placed on the login shell is that the command
      name must be listed in <filename>/etc/shells</filename>.
      If this file does not exist, the definitions are taken from the files
      <filename>%vendordir%/shells</filename>,
      <filename>%vendordir%/shells.d/*</filename> and
      <filename>/etc/shells.d/*</filename> in that order.
      If <filename>/etc/shells.d/@filename@</filename> exists, then
      <filename>%vendordir%/shells.d/@filename@</filename> will not be used.
      If the invoker is the superuser any value may be added regardless what is
      defined in the configuration files.
      An account with a restricted login shell may not change her login shell.
    </para>
    <para>
      For this reason, placing <filename>/bin/rsh</filename> in
      <filename>/etc/shells</filename> is discouraged since accidentally
      changing to a restricted shell would prevent the user from ever
      changing her login shell back to its original value.
    </para>
  </refsect1>

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

  <refsect1 id='files'>
    <title>FILES</title>
    <variablelist>
      <varlistentry>
	<term><filename>/etc/passwd</filename></term>
	<listitem>
	  <para>User account information.</para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><filename>/etc/shells</filename></term>
	<listitem condition="without_vendordir">
	  <para>List of valid login shells.</para>
	</listitem>
	<listitem condition="with_vendordir">
	  <para>User defined list of valid login shells.</para>
	</listitem>
      </varlistentry>
      <varlistentry condition="with_vendordir">
       <term><filename>%vendordir%/shells</filename></term>
        <listitem>
          <para>Default configuration file if
	  <filename>/etc/shells</filename> does not exist.</para>
        </listitem>
      </varlistentry>
      <varlistentry condition="with_vendordir">
        <term><filename>%vendordir%/shells.d</filename></term>
        <listitem>
          <para>Directory for additional vendor specific configuration files.</para>
        </listitem>
      </varlistentry>
      <varlistentry condition="with_vendordir">
        <term><filename>/etc/shells.d</filename></term>
        <listitem>
          <para>Directory for additional user defined configuration files.</para>
        </listitem>
      </varlistentry>
      <varlistentry>
	<term><filename>/etc/login.defs</filename></term>
	<listitem>
	  <para>Shadow password suite configuration.</para>
	</listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1 id='see_also'>
    <title>SEE ALSO</title>
    <para>
      <citerefentry>
	<refentrytitle>chfn</refentrytitle><manvolnum>1</manvolnum>
      </citerefentry>,
      <citerefentry>
	<refentrytitle>login.defs</refentrytitle><manvolnum>5</manvolnum>
      </citerefentry>,
      <citerefentry>
	<refentrytitle>passwd</refentrytitle><manvolnum>5</manvolnum>
      </citerefentry>.
    </para>
  </refsect1>
</refentry>
