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diff --git a/chapter07/locale.xml b/chapter07/locale.xml new file mode 100644 index 000000000..76dbb7251 --- /dev/null +++ b/chapter07/locale.xml @@ -0,0 +1,152 @@ +<?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"> + <?dbhtml filename="locale.html"?> + + <title>Configuring the System Locale</title> + + <indexterm zone="ch-scripts-locale"> + <primary sortas="e-etc-locale-conf">/etc/locale.conf</primary> + </indexterm> + + <para>The <filename>/etc/locale.conf</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>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. Optional + modifiers such as <quote>@euro</quote> may also be present.</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>Charmaps can have a number of aliases, 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 (e.g., require + that <quote>UTF-8</quote> is written as <quote>UTF-8</quote>, not + <quote>utf8</quote>), so it is safest in most + cases 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 role="nodump"><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>. + 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 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 6 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> + + <!-- FIXME: the xlib example will became obsolete real soon --> + <para>Some packages beyond LFS 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 if the locale does not exactly match one of the character + map names in its internal files:</para> + +<screen><computeroutput>Warning: locale not supported by Xlib, locale set to C</computeroutput></screen> + + <para>In several cases Xlib expects that the character map will be listed in + uppercase notation with canonical dashes. For instance, "ISO-8859-1" rather + than "iso88591". It is also possible to find an appropriate specification by + removing the charmap part of the locale specification. This can be checked + by running the <command>locale charmap</command> command in both locales. + For example, one would have to change "de_DE.ISO-8859-15@euro" to + "de_DE@euro" 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/locale.conf</filename> file:</para> + +<screen><userinput>cat > /etc/locale.conf << "EOF" +<literal>LANG=<replaceable><ll>_<CC>.<charmap><@modifiers></replaceable></literal> +EOF</userinput></screen> + + <para>Note that you can modify <filename>/etc/locale.conf</filename> with + systemd <command>localectl</command> utility. To use <command>localectl</command> + for the example above, run:</para> + +<screen role="nodump"><userinput>localectl set-locale LANG="<replaceable><ll>_<CC>.<charmap><@modifiers></replaceable>"</userinput></screen> + + <para>You can also specify other language specific environment variables such + as <envar>LANG</envar>, <envar>LC_CTYPE</envar>, <envar>LC_NUMERIC</envar> or + any other environment variable from <command>locale</command> output. Just + separate them with a space. An example where <envar>LANG</envar> is set as + en_US.UTF-8 but <envar>LC_CTYPE</envar> is set as just en_US is:</para> + +<screen role="nodump"><userinput>localectl set-locale LANG="en_US.UTF-8" LC_CTYPE="en_US"</userinput></screen> + + <note><para>Please note that <command>localectl</command> command can + be used only on a system booted with systemd.</para></note> + + <para>The <quote>C</quote> (default) and <quote>en_US</quote> (the recommended + one for United States English users) locales are different. <quote>C</quote> + uses the US-ASCII 7-bit character set, and treats bytes with the high bit set + as invalid characters. That's why, e.g., the <command>ls</command> command + substitutes them with question marks in that locale. Also, an attempt to send + mail with such characters from Mutt or Pine results in non-RFC-conforming + messages being sent (the charset in the outgoing mail is indicated as <quote>unknown + 8-bit</quote>). So you can use the <quote>C</quote> locale only if you are sure that + you will never need 8-bit characters.</para> + + <para>UTF-8 based locales are not supported well by many programs. + Work is in progress to document and, if possible, fix such problems, see + <ulink url="&blfs-book;introduction/locale-issues.html"/>.</para> + +</sect1> |