source: BOOK/bootscripts/common/profile.xml@ 3b7bb78

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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 <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 provide global settings.
  If an equivalent file exists in the 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> under the
  <emphasis>Bash Startup Files and Interactive Shells</emphasis> section.</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>The base <filename>/etc/profile</filename> below sets some
  environment variables necessary for native language support. Setting
  them properly results in:</para>

  <itemizedlist>
    <listitem>
      <para>The output of programs translated into the native language</para>
    </listitem>
    <listitem>
      <para>Correct classification of characters into letters, digits and
      other classes. This is necessary for <command>bash</command> to
      properly accept non-ASCII characters in command lines in non-English
      locales</para>
    </listitem>
    <listitem>
      <para>The correct alphabetical sorting order for the country</para>
    </listitem>
    <listitem>
      <para>Appropriate default paper size</para>
    </listitem>
    <listitem>
      <para>Correct formatting of monetary, time, and date values</para>
    </listitem>
  </itemizedlist>

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

  <para>Replace <replaceable>[ll]</replaceable> below with the
  two-letter code for the desired language (e.g., <quote>en</quote>) and
  <replaceable>[CC]</replaceable> with the two-letter code for the
  appropriate country (e.g., <quote>GB</quote>).
  <replaceable>[charmap]</replaceable> should be replaced with the
  canonical charmap for your chosen locale.</para>

  <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>Locales can have a number of synonyms, e.g. <quote>ISO-8859-1</quote>
  is also referred to as <quote>iso8859-1</quote> and <quote>iso88591</quote>.
  Some applications cannot handle the various synonyms correctly, so it is
  safest to choose the canonical name for a particular locale. To determine
  the canonical name, run the following command, where <replaceable>[locale
  name]</replaceable> is the output given by <command>locale -a</command> for
  your preferred locale (<quote>en_GB.iso88591</quote> in our example).</para>

<screen><userinput>LC_ALL=<replaceable>[locale name]</replaceable> locale charmap</userinput></screen>

  <para>For the <quote>en_GB.iso88591</quote> locale, the above command
  will print:</para>

<screen><computeroutput>ISO-8859-1</computeroutput></screen>

  <para>This results in a final locale setting of
  <quote>en_GB.ISO-8859-1</quote>.</para>

  <para>Once the proper locale settings have been determined, create the
  <filename>/etc/profile</filename> file:</para>

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

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

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

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

  <para>Setting the keyboard layout, screen font, and 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 not work properly under such conditions. These steps and patches
  are not included in the LFS book and such locales are not yet supported
  by LFS.</para>

</sect1>