Author: Naveen Kumar
Internationalization (i18n) refers to an application's/package's support for multiple languages. This support comes from a kind of generalization on part of application/package that helps Localize it in different languages.
Localization or (l10n) here refers to the process of adapting, translating or customising that application/package for a particular locale.
Locale is a term used to define a set of information corresponding to a given language & country. A locale information is used by a software application (or operating system) to exhibit a localised behaviour. This localised behaviour is in the form of displaying Application's/package's text in local language or other things pertaining to a locale convention such as localized date, currency format, color conventions, etc.
In this tutorial we will cover i18n & l10n only with respect to text i18n/l10n.
Gettext framework is one such approach to do text i18n. It refers to a collection of tools which are used to internationalize and localize an application/package. Apart from internationalization of applications/packages these tools assist in translating the strings on menus, messages boxes or icons on the applications in the language that the user is interested in.
For a detailed information on text internationalization you can refer to Gettext manual
We assume that you use emacs. Do the following:
- Run emacs
- type ALT+x
- type
ansi-termin the lower window - press return key twice one after the other
Development Environment
To internationalize an application we need a set of development tools. This is a one-time-only setup,
installed by running those commands from a system administration (root) account:
yum install @development-tools yum groupinstall <langname>-support
The <langname> above refers to the name of your language. For hindi I would write something like:
yum groupinstall hindi-support
Hello World
Let us write our first Hello World program:
#include<stdio.h>
int main()
{
printf("Hello World\n");
return 0;
}
The output generated by this program is entirely in English. Now in order
Internationalized Hello World
#include<libintl.h>
#include<locale.h>
#include<stdio.h>
#define _(String) gettext (String)
#define _t(String1,String2,n) ngettext (String1,String2,n)
int main()
{
setlocale(LC_ALL,"");
bindtextdomain("helloworld","/usr/share/locale");
textdomain("helloworld");
printf(_("Hello World\n"));
return 0;
}
Create a new directory named po/
mkdir po/hi/
Extract the strings in a POT (helloworld.pot) file using the following command
xgettext -d helloworld -o po/helloworld.pot --keyword=_t:1,2 -k_ -s helloworld.c
A new file helloworld.pot will be created inside directory po/
PO(T) files
helloworld.pot
# SOME DESCRIPTIVE TITLE. # Copyright (C) YEAR THE PACKAGE'S COPYRIGHT HOLDER # This file is distributed under the same license as the PACKAGE package. # FIRST AUTHOR <EMAIL@ADDRESS>, YEAR. # #, fuzzy msgid "" msgstr "" "Project-Id-Version: PACKAGE VERSION\n" "Report-Msgid-Bugs-To: \n" "POT-Creation-Date: 2010-04-27 17:42+0530\n" "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" "Language-Team: LANGUAGE <LL@li.org>\n" "MIME-Version: 1.0\n" "Content-Type: text/plain; charset=CHARSET\n" "Content-Transfer-Encoding: 8bit\n" #: helloworld.c:13 #, c-format msgid "Hello World\n" msgstr ""
create a directory with the name of your language. This language name should be probably a 2-digit/3-digit code listed for your language in ISO 639-1. Use http://www.loc.gov/standards/iso639-2/php/code_list.php for reference. A directory with the same name should also be listed at /usr/share/locale. For hindi I would do this:
mkdir hi/ cp helloworld.pot hi/helloworld.po
Open an Editor of your choice and translate your file in the following manner:
# Hello World Localization. # Copyright (C) 2010 Naveen Kumar # This file is distributed under the same license as the PACKAGE package. # Naveen Kumar <nkumar@redhat.com>, 2010. # msgid "" msgstr "" "Project-Id-Version: helloworld 1.0\n" "Report-Msgid-Bugs-To: \n" "POT-Creation-Date: 2010-04-27 18:31+0530\n" "PO-Revision-Date: 2010-04-27 18:53+0530\n" "Last-Translator: Naveen Kumar <nkumar@redhat.com>\n" "Language-Team: Hindi <LL@li.org>\n" "MIME-Version: 1.0\n" "Content-Type: text/plain; charset=UTF-8\n" "Content-Transfer-Encoding: 8bit\n" #: helloworld.c:13 #, c-format msgid "Hello World" msgstr "नमस्कार दुनिया\n"
In root mode copy the po file to your <lang>/LC_MESSAGES directory at /usr/share/locale/hi/LC_MESSAGES. For Hindi I would do something like this:
cp helloworld.mo /usr/share/locale/hi/LC_MESSAGES/
Compile your C file
gcc -o helloworld helloworld.c
Run something like
LANG=hi_IN ./helloworld
You should see message (Hello World) appear in your local language:
[nkumar@localhost]$ LANG=hi_IN [nkumar@localhost]$ ./helloworld नमस्कार दुनिया
.....editing on-----