Find out the real file type

Question

I am working on an ASP web page that handles file uploads. Only certain types of files are allowed to be uploaded, like .XLS, .XML, .CSV, .TXT, .PDF, .PPT, etc.

I

Answer 1

I know you said C#, but this could maybe be ported. Also, it has an XML file already containing many descriptors for common file types.

It's a Java library called JMimeMagic. It's here: http://jmimemagic.sourceforge.net/