source: postlfs/config/skel.xml@ 78b3cd61

<sect1 id="postlfs-config-skel">
<?dbhtml filename="skel.html" dir="postlfs"?>
<title>Configuring for Adding Users</title>

<para>Together, the <command>/usr/sbin/useradd</command> command and
<filename>/etc/skel</filename> directory (both are easy to setup and use)
provide a way to assure new users are added on your <acronym>LFS</acronym> 
system with the same beginning settings for things like <envar>PATH</envar>, 
keyboard processing and environmental variables.  Using these two facilities 
makes it easier to assure this initial state for each new user.</para>

<para>The <filename>/etc/skel</filename> directory holds copies of various
initialization and other files that may be copied to the new user's home
directory when the <command>/usr/sbin/useradd</command> program adds the new 
user.</para>

<para><emphasis>Useradd<</emphasis></para>

<para>The <command>useradd</command> program uses a collection of
default values kept in <filename>/etc/default/useradd</filename>,
if it exists.  If the file does not exist, then it uses some internal
defaults.  You can see the default values by running <command>/usr/sbin/useradd 
-D</command>.</para>

<para>To change these values to something new, create a base <filename>
/etc/default/useradd</filename> file with the same values as the output of 
<command>/usr/sbin/useradd -D</command>.  Here is a sample.</para>

<screen># Begin /etc/default/useradd

GROUP=100
HOME=/home
INACTIVE=-1
EXPIRE=
SHELL=
SKEL=/etc/skel

# End /etc/default/useradd</screen>

<para>The only thing missing from the file is a default shell.  Add that
by running:</para>

<screen><userinput><command>/usr/sbin/useradd -D -s/bin/bash</command></userinput></screen>

<para>This will set the <envar>SHELL</envar>= line to 
<envar>SHELL</envar>=/bin/bash.</para>

<para><command>Useradd</command> has many parameters that
can be set in the <filename>/etc/default/useradd</filename> file.</para>

<para>For more information see <command>man useradd</command>.</para>

<para><emphasis><filename>/etc/skel</filename></emphasis></para>

<para>To get started create an <filename>/etc/skel</filename> directory
and make sure it is writable only by the system administrator, usually
root. Creating the directory as root is the best way to go.</para>

<para>The mode of any files from this part of the book that you put in
<filename>/etc/skel</filename> should be writable only by the owner.
Also, since there is no telling what kind of sensitive information a
user may eventually place in their copy of these files, you should
make them unreadable by "group" and "other".</para>

<para>You can also put other files in <filename>/etc/skel</filename> and
different permissions may be needed for them.</para>

<para>Decide which initialization files should be provided in every (or most)
new user's home directory. The decisions you make will affect what you
do in the next three sections, <xref linkend="postlfs-config-inputrc"/>, 
<xref linkend="postlfs-config-profile"/> and 
<xref linkend="postlfs-config-vimrc"/>. Some or all of those files will be
useful for root, any already-existing users, and new users.</para>

<para>The files from those sections that you might want to place in
<filename>/etc/skel</filename> include
<filename>.inputrc</filename>, <filename>.bash_profile</filename>,
<filename>.bashrc</filename>, <filename>.bash_logout</filename>,
<filename>.dircolors</filename>, and <filename>.vimrc</filename>. If
you are unsure which of these should be placed there, just continue to
the following sections, read each section and any references provided,
and then make your decision.</para>

<para>You will run a slightly modified set of commands for files which
are placed in <filename>/etc/skel</filename>. Each section will remind
you of this. In brief, the book's commands have been written for files
<emphasis>not</emphasis> added to <filename>/etc/skel</filename> and
just send the results to the user's home directory. If the file is going
to be in <filename>/etc/skel</filename>, change the book's command(s) to
send output there instead and then just copy the file from
<filename>/etc/skel</filename> to the appropriate directories, like
<filename>/etc</filename>, <filename>~</filename> or the home directoriy
of any other user already in the system.</para>

<para><emphasis>When Adding a User</emphasis></para>

<para>When adding a new user with <command>useradd</command> use
the <userinput>-m</userinput> parameter, which tells
<command>useradd</command> to create the user's home directory and
copy files from <filename>/etc/skel</filename> (can be overridden) to
the new user's home directory.  For example:</para>

<screen><command>useradd -m -s/bin/bash jwrober</command></screen>

</sect1>