RCS

The Revision Control System

To Be Covered…

• An RCS overview• The RCS command set• Some useful things• Where it can be used• Alternatives to RCS

RCS Overview• RCS is for version management.• RCS allows you to manage and

maintain files/documents as they develop.

• RCS can maintain binary files as well as text files.

• Files can be developed by multiple users.

• All versions are stored as a single file.

RCS Overview

RCS is…

• Open Source• Available for all

Linux/UNIX distros• Bundled with

most Linux distros• Free!

RCS is not…

• The be-all end-all version management tool

• Available for Windows (see WinRCS)

RCS Commands

• Primary Commands:– ci # Check In– co # Check Out– rcs # set/change attributes of RCS

file

Example• The RCS file is

$ /home/fred/RCS/colours,v

• Working from /home/fred/$ co –l colours # Check out and lock a copy # of colours from the RCS file

• When done editing, check it back in$ ci colours

Example (cont’d)

• Add access for another user$ rcs –abarney colours#Now “barney” can check out, modify

and check in colours.#See the rcs and rcsintro man pages

for all rcs options.

Other RCS Commands• rlog # Summary header info from the

RCS file• ident # Extract keywords from RCS file

or working file• rcsdiff # Compare checked out file with

latest revision in RCS file• rcsmerge #Like merge, only using RCS

files (not checked out copies)• rcsclean #Removes all working copies

that have not been changed.

Useful RCS commands

Borrowing from the /home/fred/RCS/colours,v example (working in fred):

$ rcsdiff colours # compare# your working copy to the most# recent revision in the RCS# file

Useful RCS commands

rlog colours | more# View all revision header info# in the RCS file

ci -l colours# Check in and then check out# and lock your working version.# Handy for quickly setting a# checkpoint in development.

Useful RCS commandsident colours# View keyword values from your# working version.ident RCS/colours,v# View keyword values from your# entire RCS file.rcsclean colours# Remove all working files that # have not changed from the RCS # file’s latest revision.

Where To Use RCS

Small to Medium sized projects such as:• Script development for admins,

developers and users.• Document and documentation

development (how many versions of your resume do you have?)

• Program development• http://www.cs.purdue.edu/homes/

trinkle/RCS

Alternatives to RCS

• CVS – Concurrent Versions System– A superset of RCS– Concurrent multi-user– Can be used over a network– Manages entire directory hierarchies– Commonly preferred for large-scale

development– http://cvshome.org

• Pay-tools (‘nuff said)

Summary

• RCS is free software• RCS is conveniently bundled for

Linux• RCS is easy to learn and use• RCS is a fully functional version

management system