R_API int r_sys_cmdf(const char *fmt, ...) {
	int ret;
	char cmd[4096];
	va_list ap;
	va_start(ap, fmt);
	vsnprintf (cmd, sizeof (cmd), fmt, ap);
	ret = r_sys_cmd (cmd);
	va_end (ap);
	return ret;
}
R_API int r_sys_cmdf(const char *fmt, ...) {
	int ret;
	char cmd[4096];
	va_list ap;
	va_start(ap, fmt);
	vsnprintf (cmd, sizeof (cmd), fmt, ap);
	ret = r_sys_cmd (cmd);
	va_end (ap);
	return ret;
}