Internationalization

Internationalization — gettext support macros.

Synopsis


#include <glib.h>
#include <glib/gi18n.h>


#define             _                                   (String)
#define             Q_                                  (String)
#define             N_                                  (String)
const gchar*        g_strip_context                     (const gchar *msgid,
                                                         const gchar *msgval);

const gchar* const * g_get_language_names               (void);

Description

GLib doesn't force any particular localization method upon its users. But since GLib itself is localized using the gettext() mechanism, it seems natural to offer the de-facto standard gettext() support macros in an easy-to-use form.

In order to use these macros in an application, you must include glib/gi18n.h. For use in a library, must include glib/gi18n-lib.h after defining the GETTEXT_PACKAGE macro suitably for your library: 

#define GETTEXT_PACKAGE "gtk20"
#include <glib/gi18n-lib.h>

The gettext manual covers details of how to set up message extraction with xgettext.

Details

_()

#define             _(String)

Marks a string for translation, gets replaced with the translated string at runtime.

String : the string to be translated

Since 2.4

Q_()

#define             Q_(String)

Like _(), but applies g_strip_context() to the translation. This has the advantage that the string can be adorned with a prefix to guarantee uniqueness and provide context to the translator.

One use case given in the gettext manual is GUI translation, where one could e.g. disambiguate two "Open" menu entries as "File|Open" and "Printer|Open". Another use case is the string "Russian" which may have to be translated differently depending on whether it's the name of a character set or a language. This could be solved by using "charset|Russian" and "language|Russian".

Note

If you are using the Q_() macro, you need to make sure that you pass --keyword=Q_ to xgettext when extracting messages.

String : the string to be translated, with a '|'-separated prefix which must not be translated

Since 2.4

N_()

#define             N_(String)

Marks a string for translation, gets replaced with the untranslated string at runtime. This is useful in situations where the translated strings can't be directly used, e.g. in string array initializers. 

     {
       static const char *messages[] = {
         N_("some very meaningful message"),
         N_("and another one")
       };
       const char *string;
       ...
       string
         = index > 1 ? _("a default message") : gettext (messages[index]);
     
       fputs (string);
       ...
     }
String : the string to be translated

Since 2.4

g_strip_context ()

const gchar*        g_strip_context                     (const gchar *msgid,
                                                         const gchar *msgval);

An auxiliary function for gettext() support (see Q_()).

msgid : a string
msgval : another string
Returns : msgval, unless msgval is identical to msgid and contains a '|' character, in which case a pointer to the substring of msgid after the first '|' character is returned.

Since 2.4

g_get_language_names ()

const gchar* const * g_get_language_names               (void);

Computes a list of applicable locale names, which can be used to e.g. construct locale-dependent filenames or search paths. The returned list is sorted from most desirable to least desirable and always contains the default locale "C".

For example, if LANGUAGE=de:en_US, then the returned list is "de", "en_US", "en", "C".

This function consults the environment variables LANGUAGE, LC_ALL, LC_MESSAGES and LANG to find the list of locales specified by the user.

Returns : a NULL-terminated array of strings owned by GLib that must not be modified or freed.

Since 2.6

See Also

The gettext manual.