source: archive/etcshells.xml

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE part PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
  <!ENTITY % general-entities SYSTEM "../../general.ent">
  %general-entities;
]>

<sect1 id="postlfs-config-shells" xreflabel="The /etc/shells File">
  <?dbhtml filename="etcshells.html"?>


  <title>The /etc/shells File</title>

  <indexterm zone="postlfs-config-shells">
    <primary sortas="e-etc-shells">/etc/shells</primary>
  </indexterm>

  <para>The <filename>shells</filename> file contains a list of
  login shells on the system. Applications use this file to determine
  whether a shell is valid. For each shell a single line should be
  present, consisting of the shell's path, relative to the root of the
  directory structure (/).</para>

  <para>For example, this file is consulted by <command>chsh</command>
  to determine whether an unprivileged user may change the login shell for her
  own account. If the command name is not listed, the user will be denied of
  change.</para>

  <para>It is a requirement for applications such as
  <application>GDM</application> which does not populate the
  face browser if it can't find <filename>/etc/shells</filename>, or
  FTP daemons which traditionally disallow access to users
  with shells not included in this file.</para>

<screen role="root"><userinput>cat &gt; /etc/shells &lt;&lt; "EOF"
<literal># Begin /etc/shells

/bin/sh
/bin/bash

# End /etc/shells</literal>
EOF</userinput></screen>

</sect1>