Module Link: http://drupal.org/project/url_alter
The URL Alter module allows module authors to easily re-write both incoming and outgoing URLs without having to resort to writing their own custom_url_rewrite.
- Who: Module authors only
- When: Use this module when you need to change how links are going to be displayed (example: http://example.com/sites/default/files/example.jpg to be http://example.s3.amazonaws.com/example.jpg) and how Drupal reads incoming links.
- Where: 99.9% of the interface of this module is done through PHP but it does offer an admin panel at admin/settings/url-alter so you can try out your own re-writes.
- Why: Most modules that require custom url rewriting ask the user to modify their settings.php which is pretty bad. This module makes it so you can modify those paths in your module without having the user do anything other than enable your module.