1)	Internationalization environment variables
	------------------------------------------

	LANG

	LC_COLLATE

	LC_CTYPE

	LC_MONETARY

	LC_NUMERIC

	LC_TIME

	LC_MESSAGES

	LC_ALL

2)	Globale locale examples
	-----------------------

	en_US	English (United States)
	it_IT	Italian (Italy)
	fr_FR	French (France)
	fr_CA	French (Canada)

3)	Using gettext
        -------------

3.1)	Example

	#include <stdio.h>
	#include <libintl.h>

	int main() {

	  textdomain("hello-world");
	  printf(gettext("Hello, world !\n"));
	  return 0;

	}

	The following macro is often used :

	#define _(x) gettext(x)

3.2)	Message translation :

	Use xgettext to produce a .po (portable object) file; for example:

	xgettext -a -d hello-world -k_ -s hello.c

	The hello-world.po file can than be edited, without any other
	knowledge of the source code.

	To be used, a portable object must be compiled to a machine object
	(.mo) file; this is done with:

	msgfmt -o hello-world.mo -v hello-world.po

3.3)	Special cases

	When a string must be initialized with variables, it cannot be
	translated directly. One may use gettext_noop as a marker to
	make a string recognizable by xgettext.

	See the following example:

	#define gettext_noop(x) (x)

	char *item_names[] {
	  gettext_noop("files"),
	  gettext_noop("messages")
	} ;

	...

	if ((index >= 0) && (index >= 1))
	  strcpy(items, gettext(item_names[index]));
	else
	  strcpy(items, gettext("unknown_items"));

	printf(gettext("You have %d %s\n"), quantity, items);