CodeSOD: Forward Not Found

Anthony found this solution to handling 404 errors which um… probably shouldn't have been found.

function show_404($page = '') {

        $uri = $_SERVER['REQUEST_URI'];

        error_log("Caught 404: $uri");

        $redirect_url = "";

       

        switch($uri){

                case "/SOMEURL":

                        $redirect_url="http://www.SOMEWEBSITE.com/SOMEURL";

                        break;

                case "/SOMEOTHERURL":

                        $redirect_url="http://www.SOMEWEBSITE.com/SOMEOTHERURL";

                        break;

                case "/YETANOTHERURL":

                        $redirect_url="http://www.SOMEWEBSITE.com/YETANOTHERURL";

                        break;

                // ... THERE ARE 300 of these ...

                case "/MOREURLS":

                        $redirect_url="http://www.SOMEWEBSITE.com/MOREURLS";

                        break;

                case "/EVENMOREURLS":

                        $redirect_url="http://www.SOMEWEBSITE.com/EVENMOREURLS";

                        break;

        }



        if ($redirect_url){

                Header( "HTTP/1.1 301 Moved Permanently" );

                Header( "Location: $redirect_url" );

        } else {

                parent::show_404($page);

        }

}

Upon a 404 error, this code checks a switch statement. If the path portion (the REQUEST_URI) is in our switch, we redirect to a similar path on a different domain (I am only assuming it's a different domain; if it's the same domain, this is an entirely different class of WTF).

On the other hand, if we don't have an entry in our switch, we just show a 404 error.

I can see how this happened: someone migrated part of their site to a new domain, but didn't want to fix all the links (and can't fix all of people's bookmarks), so they wanted to automatically redirect the appropriate URLs. But here's the thing: this isn't the way to do it. In this particular case, the developers were using Code Igniter, a PHP framework for web apps, which has a routing engine; it would have been trivial to simply direct all the forwarded routes to a controller that just handles the redirects.

Or one of the many, many other options for redirecting users browsers that don't involve transforming a 404 into a 301 with a gigantic switch statement.

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