If you're writing in a Linux box (i cant vouch for the other unixes) you can check out the list of start-up scripts in /etc/init.d.
A few scripts are written to be 're-startable', and will find and restart the process in question when run with the option '-restart'.
These scripts would give you a good idea of how they look for a process already running, in order to stop it, and start it again.
Sam |