__vfprintf
extern int __vfprintf(FILE *, locale_t, int, const char *, __va_list);
ret = __vfprintf(&f, locale, serrno, fmt, ap);
ret = __vfprintf(&f, __get_locale(), serrno, fmt, ap);
ret = __vfprintf(&f, locale, serrno, fmt, ap);
if ((ret = __vfprintf(&f, __get_locale(), serrno, fmt, ap)) < 0)
ret = __vfprintf(&fake, locale, serrno, fmt, ap);
ret = __vfprintf(fp, locale, serrno, fmt0, ap);
ret = __vfprintf(&f, locale, serrno, fmt, ap);
ret = __vfprintf(&f, locale, serrno, fmt, ap);