Plugin management

I'm writing dynamic loading of classes which is for a plug-in architecture, but a bit confused on how they are generally used. The main executable is a daemon I plan on running in the background, but somehow during runtime, the user needs to be able to command it to load a certain library, or unload it. How exactly is this done? Is there some sort of command line way where a user just types "$ mydaemon load this_module"? Just looking for the most common practices of doing module management for a current process during runtime.

Thanks,

http://www.freebsd.org/doc/en/books...cs-daemons.html
Send it a signal, and have it re-read a config file.