RCS vs SCCS: Whats in a Revision File?
RCS keeps history in files with a “,v” suffix. SCCS keeps history in files with a “s.” prefix. RCS looks for RCS files automatically in the current directory or in a RCS subdirectory, or you can specify an alternate RCS file. The sccs front end to SCCS always uses the SCCS directory. If you don’t use the sccs front end, you must specify the full SCCS filename. RCS stores its revisions by holding a copy of the latest version and storing backward deltas. SCCS uses a “merged delta” concept. All RCS activity takes place within a single RCS file. SCCS maintains several files. This can be messy and confusing. Editing either RCS or SCCS files is a bad idea because mistakes are so easy to make and so fatal to the history of the file. Revision information is easy to edit in both types, whereas one would not want to edit the actual text of a version in RCS. If you edit an SCCS file, you will have to recalculate the checksum using the admin program.