Revision Control System (RCS)

CONCEPTS

• RCS saves all revisions in a space efficient way. Changes do not destroy the original.

• Revisions can be retrieved according to ranges of revision numbers, symbolic names, dates, authors, and states.

• RCS maintains a complete history of changes.

• RCS resolves access conflicts. When two or more programmers wish to modify the same revision, RCS alerts the pro- grammers and prevents one modification from corrupting the other.

• Control releases and configurations. Revisions can be assigned symbolic names and marked as released, stable, experimental, etc. With these facilities, configurations of modules can be described simply and directly.

• RCS needs little extra space for the revisions (only the differences). If intermediate revisions are deleted, the corresponding changes are compresse accordingly.

COMMANDS

• ci filename: Check in a file, filename, under RCS.

• co -l filename: Check out a file, filename, for editing

• co filename: Check out a file, filename, for read-only access

• rcsdiff filename: Show differences between a file, filename, and its reference copy.

• rcs -l filename: Lock changes to a file (if checked out) or lock the file so only you can check it out (if it is not already checked out).

REMARKS

• RCS was developed after SCCS.

• RCS uses fewer commands than SCCS, requiring less memorization by the user.