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

Get the file headers of the "safe" file types - executables always have their own types of headers, and you can probably detect those. You'd have to be familiar with every format that you intend to accept, however.