__fputwc_unlock
wint_t __fputwc_unlock(wchar_t wc, FILE *stream);
r = __fputwc_unlock(wc, fp);
if (__fputwc_unlock(*ws++, fp) == WEOF) {
extern wint_t __fputwc_unlock(wchar_t, FILE *);
return __fputwc_unlock(wc, fp);