The first thing you must do is to get your own working copy of the
source for ‘tc’. For this, you use the
$ cvs checkout tc
This will create a new directory called tc and populate it with the source files.
$ cd tc $ ls CVS Makefile backend.c driver.c frontend.c parser.c
The CVS directory is used internally by CVS. Normally, you should not modify or remove any of the files in it.
You start your favorite editor, hack away at backend.c, and a couple of hours later you have added an optimization pass to the compiler. A note to RCS and SCCS users: There is no need to lock the files that you want to edit. See Multiple developers, for an explanation.