Links Spider

We need a spider to periodically browse posted links otherwise our links base will rot.

If page has been modified : screenshot retake.

If a mark is to be removed, should we remove it without notifying users who own it ?

Code idea : 

foreach ( $links as $link ) {
 $code = $http_client->getResponseCode( $link->href );
 $func = 'do_' . $code;
 $spider->$func( $link );
}

// $spider->$func
// w/ do_* funcs behaving like http://www.fiftyfoureleven.com/weblog/blogging/link-blogs-and-link-validation
function do_404( $link ) {
 $link->delete();
}

-- TristanRivoallan

See also : DeveloperDiscussions