There is no way to make anything work sensibly for typical users without overwriting the whole file. The morass of places that one can set X resources, some of which haven't been commonly used for decades but that still work, makes this problem intractable. The X configuration mechanism is insane. xscreensaver-demo does what it can in an insane world.
If you find the man page incomprehensible, I'm sorry. I will eagerly consider any better words you might suggest. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org