source: clfs-sysroot/BOOK/bootscripts/common/locale.xml @ 676d923

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE sect1 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="ch-scripts-locale">
  <title>Setting Up Locale Information</title>
  <?dbhtml filename="locale.html"?>

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

  <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 role="nodump"><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_US.utf8</quote> in our example).</para>

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

  <para>For the <quote>en_US.utf8</quote> locale, the above command
  will print:</para>

<screen><computeroutput>UTF-8</computeroutput></screen>

  <para>This results in a final locale setting of <quote>en_US.UTF-8</quote>.
  It is important that the locale found using the heuristic above is tested prior
  to it being added to the Bash startup files:</para>

<screen role="nodump"><userinput>LC_ALL=[locale name] locale country
LC_ALL=[locale name] locale language
LC_ALL=[locale name] locale charmap
LC_ALL=[locale name] locale int_curr_symbol
LC_ALL=[locale name] locale int_prefix</userinput></screen>

  <para>The above commands should print the language name, the character
  encoding used by the locale, the local currency, and the prefix to dial
  before the telephone number in order to get into the country. If any of the
  commands above fail with a message similar to the one shown below, this means
  that your locale was either not installed in Chapter 10 or is not supported by
  the default installation of Glibc.</para>

<screen><computeroutput>locale: Cannot set LC_* to default locale: No such file or directory</computeroutput></screen>

  <para>If this happens, you should either install the desired locale using
  the <command>localedef</command> command, or consider choosing a different
  locale. Further instructions assume that there are no such error messages
  from Glibc.</para>

  <para>Some packages beyond CLFS may also lack support for your chosen locale.
  One example is the X library (part of the X Window System), which outputs
  the following error message:</para>

<screen><computeroutput>Warning: locale not supported by Xlib, locale set to C</computeroutput></screen>

  <para>Sometimes it is possible to fix this by removing the charmap part of
  the locale specification, as long as that does not change the character map
  that Glibc associates with the locale (this can be checked by running the
  <command>locale charmap</command> command in both locales). For example,
  one would have to change &quot;de_DE.ISO-8859-15@euro&quot; to
  &quot;de_DE@euro&quot; in order to get this locale recognized by Xlib.</para>

  <para>Other packages can also function incorrectly (but may not necessarily
  display any error messages) if the locale name does not meet their expectations.
  In those cases, investigating how other Linux distributions support your locale
  might provide some useful information.</para>

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

<screen><userinput>cat &gt; ${CLFS}/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>

  <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. UTF-8 has been testing on the English, French, German,
  Italian, and Spanish locales. All other locales are untested. If you discover
  issues with any other locale please open a ticket in our trac system.</para>

  <para>Some locales need addtional programs and support. CLFS will not be supporting
  these locales via the book. We welcome the support for these other locales via the
  <ulink url="&cblfs-root;"/>.</para>

</sect1>