static void signal_handler(int signum) {
	char cmd[1024];
	if (!crash_handler_cmd) {
		return;
	}
	snprintf (cmd, sizeof(cmd) - 1, crash_handler_cmd, getpid ());
	r_sys_backtrace ();
	exit (r_sys_cmd (cmd));
}
static void signal_handler(int signum) {
	char cmd[1024];
	if (!crash_handler_cmd) {
		return;
	}
	snprintf (cmd, sizeof(cmd) - 1, crash_handler_cmd, getpid ());
	r_sys_backtrace ();
	exit (r_sys_cmd (cmd));
}