Initial support of UTF-8. Thanks Alexander Patrakov.

git-svn-id: http://svn.linuxfromscratch.org/LFS/trunk/BOOK@7245 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

1 files changed, 31 insertions, 17 deletions

diff --git a/chapter07/profile.xml b/chapter07/profile.xml
index dd53a5141..e2748d9df 100644
--- a/chapter07/profile.xml
+++ b/chapter07/profile.xml
@@ -69,17 +69,20 @@
   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>
+  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>Locales can have a number of synonyms, e.g. <quote>ISO-8859-1</quote>
+  <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, so it is
-  safest to choose the canonical name for a particular locale. To determine
+  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>
@@ -115,6 +118,7 @@ LC_ALL=[locale name] locale int_prefix</userinput></screen>
   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:</para>
@@ -139,23 +143,33 @@ LC_ALL=[locale name] locale int_prefix</userinput></screen>
 <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 LANG=<replaceable>[ll]</replaceable>_<replaceable>[CC]</replaceable>.<replaceable>[charmap]</replaceable><replaceable>[@modifiers]</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>
+  <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. E.g., the
+  <command>watch</command> program displays only ASCII characters in UTF-8
+  locales and has no such restriction in traditional 8-bit locales like en_US.
+  Without patches and/or installing software beyond BLFS, in UTF-8 based locales
+  you will not be able to do such basic tasks as printing plain-text files from
+  the command line, recording Windows-readable CDs with filenames containing
+  non-ASCII characters, viewing ID3v1 tags in MP3 files and so on. Work is in
+  progress to document and, if possible, fix such problems, see
+  <ulink url="&blfs-root;view/svn/introduction/locale-issues.html"/>.
+  It is, however, safe to use UTF-8 based locales if you are going to use only
+  KDE or GNOME and never open the terminal.</para>
+  <!-- All abovementioned problems except "watch" have a known fix beyond BLFS -->
 
 </sect1>