fwprintf
int fwprintf(FILE * __restrict, const wchar_t * __restrict, ...);
PROTO_NORMAL(fwprintf);
DEF_STRONG(fwprintf);
TEST_WIDE(fwprintf(f, L"%s\n", L"foo"));
nums = fwprintf(f, L"%lc", *s);
nums = fwprintf(f, L"%ls", s);
fwprintf(f, L"%lc", eols);