getlocalename_l
extern const char *getlocalename_l(int, locale_t);
if (setlocale(LC_ALL, getlocalename_l(LC_ALL, loc)) == NULL) {
if (getlocalename_l(LC_ALL, NULL) != NULL) {
if (getlocalename_l(12345, LC_GLOBAL_LOCALE) != NULL) {
if (getlocalename_l(0x7777, uselocale(NULL)) != NULL) {
const char *name = getlocalename_l(lc_cats[i].lc_cat, loc);
name = getlocalename_l(LC_ALL, loc);
name = getlocalename_l(LC_ALL, loc);
name = getlocalename_l(LC_ALL, LC_GLOBAL_LOCALE);