Report the user's preferred locale.
Defined in SDL_locale.h
void); SDL_Locale * SDL_GetPreferredLocales(
(SDL_Locale *) Return array of locales, terminated with a locale with a NULL language field. Will return NULL on error.
This returns an array of SDL_Locale structs, the final item zeroed out. When the caller is done with this array, it should call SDL_free() on the returned value; all the memory involved is allocated in a single block, so a single SDL_free() will suffice.
Returned language strings are in the format xx, where 'xx' is an ISO-639 language specifier (such as "en" for English, "de" for German, etc). Country strings are in the format YY, where "YY" is an ISO-3166 country code (such as "US" for the United States, "CA" for Canada, etc). Country might be NULL if there's no specific guidance on them (so you might get { "en", "US" } for American English, but { "en", NULL } means "English language, generically"). Language strings are never NULL, except to terminate the array.
Please note that not all of these strings are 2 characters; some are three or more.
The returned list of locales are in the order of the user's preference. For example, a German citizen that is fluent in US English and knows enough Japanese to navigate around Tokyo might have a list like: { "de", "en_US", "jp", NULL }. Someone from England might prefer British English (where "color" is spelled "colour", etc), but will settle for anything like it: { "en_GB", "en", NULL }.
This function returns NULL on error, including when the platform does not supply this information at all.
This might be a "slow" call that has to query the operating system. It's best to ask for this once and save the results. However, this list can change, usually because the user has changed a system preference outside of your program; SDL will send an SDL_LOCALECHANGED event in this case, if possible, and you can call this function again to get an updated copy of preferred locales.
This function is available since SDL 2.0.14.