file uploads - exclude file types vs including file types?

[eluser]gstjohn[/eluser]
This post is a bit old, but I figured I would post my solution here in case others came across it. This is an extended version of the existing Upload library in CodeIgniter 1.7.1 to allow you to set the types of files you wish to disallow OR allow depending on your needs. Hope this will be a help to someone.

Modified version of the Upload library to disallow file types