Virus scanning an uploaded file

The uploading part is elementary, however I wonder how I would go about implementing a virus scan of the file?

A lot of peeps seem to frown on it, but I am probably going to store the file in a database as a blob. I'd prefer handling it this way since any file that is uploaded will be a text file or small batch file. I wouldn't do it this way if I were handling images or other larger files.

The trick is how to I scan it prior to inserting into the db?

Or, I guess the better question is how do I insert a file into mysql db from a linux command prompt?

I can upload the file, run my virus scan with a system command, and abort if virus is found, or return an 'ok' if the file is ok. If ok, do the MySQL insert statement and finish the operation.

I don't really see why you'd want to insert it from a linux shell. Can't you just do

from your PHP script after you scanned it?