For the [hopefully very infrequent] times when you still need to deal with CVS, in 2010, and [god forbid] fix something you messed up there, here's how you can revert an accidental commit back to the previous version.

First find the revision you need to revert back to by running:

cvs log screwed_up.code

Once you have the revision number you want to switch to (say,, run:

cvs -Q update -p -r screwed_up.code > screwed_up.code