Linux – Why does locale es_MX work but not es

linuxlocale

Wikipedia entry for GNU gettext shows an example where the locale is just the lanuage, "fr". Whereas the 'i18n gettext() “hello world” example' in SO has the locale value with both the language and country, "es_MX".

I have modified the "es_MX" example to use just the lanuage, "es". This covers making an "es" rather than "'es_MX'" message catalog and invoking the program with environment variable LANG set to "es".But this produces the English text rather the expected Spanish. 

cat >hellogt.cxx <<EOF
// hellogt.cxx
#include <libintl.h>
#include <locale.h>
#include <iostream>
int main (){
    setlocale(LC_ALL, "");
    bindtextdomain("hellogt", ".");
    textdomain( "hellogt");
    std::cout << gettext("hello, world!") << std::endl;
}
EOF
g++ -ohellogt hellogt.cxx
xgettext -d hellogt -o hellogt.pot hellogt.cxx
msginit --no-translator -l es -o hellogt_spanish.po -i hellogt.pot
sed --in-place hellogt_spanish.po --expression='/#: /,$ s/""/"hola mundo"/'
sed --in-place hellogt_spanish.po --expression='s/PACKAGE VERSION/hellogt 1.0/'
mkdir -p ./es.utf8/LC_MESSAGES
msgfmt -c -v -o ./es.utf8/LC_MESSAGES/hellogt.mo hellogt_spanish.po
LANG=es.utf8 ./hellogt

According to Controlling your locale with environment variables:

environment variable, LANGUAGE, which
is used only by GNU gettext … If
defined, LANGUAGE takes precedence
over LC_ALL, LC_MESSAGES, and LANG.

LANGUAGE=es.utf8 ./hellogt

produces the expected Spanish text rather than English.

But this does not explain why "LANG=es" does not work.

Best Answer

Wikipedia is probably not the best reference for stuff like this. It usually has very simple examples that may not be widely applicable, constructed for understanding concepts more than for practical considerations.

Why not use gnu's own documentation?

http://www.gnu.org/software/gettext/manual/gettext.html#Setting-the-POSIX-Locale

You can set LANGUAGE to "es" (or even "es:fr:en" for a priority list), but LANG would still need to be set to es_MX or something like that. The docs explain it fairly clearly.

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