Running a program with sudo

Hi: I have a program that must be run as root, to access directly the parallel port of my server. This is done using sudo. When I try to see who is running the program, ps or top show that user root is running it. Is there a way I can find the real user who called sudo to run that particular instance of the program? Thank you. -- Alfredo J. Cole http://www.acyc.com http://www.clshonduras.com linux@acyc.com