lfs-book/chapter07/profile.xml

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<sect1 id="ch-scripts-profile">
<title>The Bash Shell Startup Files</title>
<?dbhtml filename="profile.html"?>

<indexterm zone="ch-scripts-profile"><primary sortas="e-/etc/profile">/etc/profile</primary></indexterm>

<para>The shell program <command>/bin/bash</command> (hereafter
referred to as just <quote>the shell</quote>) uses a collection of startup files to
help create an environment to run in.  Each file has a specific use and
may affect login and interactive environments differently.  The files in
the <filename class="directory">/etc</filename> directory generally provide global
settings. If an equivalent file exists in your home directory it may
override the global settings.
</para>

<para>An interactive login shell is started after a successful login, using
<command>/bin/login</command>, by reading the
<filename>/etc/passwd</filename> file.  An
interactive non-login shell is started at the command-line (e.g.,
<prompt>[prompt]$</prompt><command>/bin/bash</command>).  A non-interactive 
shell is usually present when a shell script is running.  It is non-interactive
because it is processing a script and not waiting for user input between
commands.</para>

<para>For more information see <command>info bash</command> -- 
<emphasis role="strong">Nodes: Bash Startup Files and Interactive
Shells.</emphasis></para>

<para>The files <filename>/etc/profile</filename> and
<filename>~/.bash_profile</filename> are read when the shell is invoked
as an interactive login shell.</para>

<para>A base <filename>/etc/profile</filename> created below sets some
environment variables necessary for native language support. By setting them
properly, you get:
</para>
<itemizedlist>
<listitem><para>the output of programs translated into your native
language;</para></listitem>
<listitem><para>correct classification of characters into letters, digits and
other classes - this is necessary for Bash to accept non-ASCII characters
in command lines properly in non-English locales;</para></listitem>
<listitem><para>the alphabetical sorting order correct for your
country;</para></listitem>
<listitem><para>good default paper size;</para></listitem>
<listitem><para>correct formatting of monetary, time and date
values.</para></listitem>
</itemizedlist>

<para>This script also sets the INPUTRC environment variable that makes
<application>Bash</application> and <application>Readline</application> use
the <filename>/etc/inputrc</filename> file we created earlier.</para>

<para>Replace <replaceable>[ll]</replaceable> below with the
two-letter code for your language (e.g., <quote>en</quote>) and
<replaceable>[CC]</replaceable> with the two-letter code for your country
(e.g., <quote>GB</quote>). Also you may need to specify
(and this is actually the preferred form) your
character encoding (e.g. <quote>iso8859-1</quote>) after a dot
(so that the result is <quote>en_GB.iso8859-1</quote>).
Issue the following command for more information:</para>

<screen><userinput>man 3 setlocale</userinput></screen>

<para>The list of all locales supported by Glibc can be obtained by running
the following command:</para>

<screen><userinput>locale -a</userinput></screen>

<para>Now, when you are sure about your locale settings, create the
<filename>/etc/profile</filename> file:</para>

<screen><userinput>cat &gt; /etc/profile &lt;&lt; "EOF"
# Begin /etc/profile

export LC_ALL=<replaceable>[ll]</replaceable>_<replaceable>[CC]</replaceable>
export LANG=<replaceable>[ll]</replaceable>_<replaceable>[CC]</replaceable>
export INPUTRC=/etc/inputrc

# End /etc/profile
EOF</userinput></screen>

<note><para>The <quote>C</quote> (default) and <quote>en_US</quote>
(the recommended one for US English users) locales are
different.</para></note>

<para>Setting the keyboard layout,
the screen font and the locale-related environment variables
are the only internationalization steps needed to support
locales that use ordinary single-byte encodings and left-to-right
writing direction. More complex cases (including UTF-8 based locales)
require additional steps and additional patches because many applications
tend to break in such conditions. Because of too little educational
value for a typical reader, these steps and patches are not included
in the LFS book and such locales are not supported by LFS in any way.
</para>
</sect1>