private fun file_realpath: CString `{
#ifdef _WIN32
		DWORD len = GetFullPathName(self, 0, NULL, NULL);
		char *buf = malloc(len+1); // FIXME don't leak memory
		len = GetFullPathName(self, len+1, buf, NULL);
		return buf;
#else
		return realpath(self, NULL);
#endif
	`}