How to prevent every malicious file upload on my server? (check file type)?

Question

my proble is to avoid that users upload some malicious file on my web-server. Im working on linux environment (debian).

Actually the uploads are handled via php by t

Answer 1

Typically you use the 'file' command to find out what a file contains. I'm not sure, however, if it will detect .exe files:

http://unixhelp.ed.ac.uk/CGI/man-cgi?file