How to log login attempts directly on a log file

I need to see all the failed login attempts to wordpress admin panel. I see there is a plugin "Simple Login Log" in wordpress doing exactly same. The only problem is that it shows me failed (and successful) attempts on it's page (http://localhost/wp-admin/users.php?page=login_log), but I need them on a log file. Again there is an option to export these logs, but I need to "auto export" them to some log file whenever some failed attempt is done.

Thanks.

via Chebli Mohamed