c# - Validating file types by regular expression

Question

I have a .NET webform that has a file upload control that is tied to a regular expression validator. This validator needs to validate that only certain filetypes should be allowed for upload (jpg,gif,doc,pdf)

The current regular expression that does this is:

^(([a-zA-Z]:)|(\{2}w+)$?)(\(w[w].*))(.jpg|.JPG|.gif|.GIF|.doc|.DOC|.pdf|.PDF)$

However this does not seem to be working... can anyone give me a little reg ex help?

Answer 1

Your regex seems a bit too complex in my opinion. Also, remember that the dot is a special character meaning "any character". The following regex should work (note the escaped dots):

^.*.(jpg|JPG|gif|GIF|doc|DOC|pdf|PDF)$

You can use a tool like Expresso to test your regular expressions.