通过从外部文件提取URL进行动态PHP重定向

Question

As a precaution I am wanting to use PHP to create an easily reusable/modifiable means to redirect users to a specified URL.

I have the usual php header redirect:

<?php

   header( 'Location: http://www.stackoverflow.com/' ) ;

?>

What I'd prefer to do however, as this file will be placed across a lot of directories, to make life easier, and have the url extracted from an external file, eg

http://www.stackoverflow.com/url.xml

This would of course contain the URL of the website in question, unless there is another way to capture the domain itself automatically? This I'm not sure.

Could anyone be kind enough to show how this would be done or provide the best approach?

Thank you.

Answer 1

I was thinking in the same approach as @adam , i don't recommend you to extract urls from a file because it can be read from an attacker. It's better to include them in a php file as variables, an array or any other data structure.

Store the urls once in a file called config.inc.php:

<?php

define('USER_PATH', '/redirect/user/path');
define('ADMIN_PATH', '/redirect/admin/path');

?>

Then in your php file:

<?php
include 'config.inc.php';
header( "Location: http://{$_SERVER['HTTP_HOST']} . USER_PATH ) ; //or whatever variable you want to use to redirect.
?>

If you want to redirect some folders due to security issues you can do it with an Apache's htaccess. Just put this at root folder then add the last line as many as you want for each redirection. Each folder mentioned here can only be accessed by scripts running on the server.
Using this every access request using HTTP gets redirected. So this only works for directories containing scripts to be included. It doesn't work for ie image directories whose index shouldn't be shown, but the images should stay accessible.

RewriteEngine on
RewriteBase /
RewriteRule ^includes/(.*) http://www.stackoverflow.com/ [R=301,L]
RewriteRule ^includes/(.*) http://www.stackoverflow.com/ [R=301,L]

If you aren't familiar with this you can use http://www.htaccessredirect.net/

Answer 2

If the file containing the url is on a domain you don't control, there are security risks.

Instead, store the url once in a file called config.inc.php :

<?php

define('REDIRECT_URL', '/redirect/path');

?>

Then include it in your project:

<?php

include 'config.inc.php';

echo REDIRECT_URL;

// /redirect/path

?>