holtz@csmil.umich.edu (03/16/90)
What are the differences between RCS and SCCS?
runyan@hpcuhc.HP.COM (Mark Runyan) (03/17/90)
>/ hpcuhc:comp.unix.questions / holtz@csmil.umich.edu / 12:41 pm Mar 15, 1990 / > >What are the differences between RCS and SCCS? >---------- A simple questions that has a complicated and long answer. Possible short answers. 1. SCCS is supported by AT&T. RCS isn't. 2. RCS allows you treat a set of files as a family of files while SCCS is meant primarily for keeping the revision history of files. RCS has the ability to use symbolic names to point to sets of revisions. 3. [religious argument] RCS has an easier interface for first time users. SCCS has more options for determining when a specific line of code was added to a system. 4. RCS files are directly editable. SCCS files should only be acted on by the SCCS tools. 5. RCS keeps history in files with a ",v" suffix. SCCS keeps history in files with a "s." prefix. 6. Locks are kept in separate files for SCCS. A lock on an RCS file is kept in the RCS file. 7. RCS stores its revisions so retrieval of the latest revision is quick and easy, but early revisions take longer. SCCS stores revisions so that recovering any given revision takes a constant amount of time which increases with the number of revisions stored. 8. You can translate SCCS to RCS, but not the other way. 9. They use different keywords that are expanded in the text. For SCCS the keyword "%R%" is replaced with the revision number if the file is checked out for reading. In RCS, the keyword $Revision$ has the revision number added to it when the file is checked out (either locked or not). Other than that (and a few more others may throw in) they are essentially the same. As a comparison of the commands: SCCS Command RCS Command Explanation admin -i -nfile s.file ci file,v Checks in the file for the first time, creating the revision history file. get s.file co file,v Check out a file for reading. get -e s.file co -l file,v Check out a file for modification delta s.file ci file,v Check in a file previously locked prs s.file rlog file,v Print a history of the file. sccsdiff -rx -ry s.file rcsdiff -rx -ry file,v Compare two revisions. ??? rcs -l file,v Lock the latest revision ??? rcs -u file,v Unlock the latest revision. Possible to break another's lock, but mail is sent to the other person to explain why. For more details, read "RCS - A system for Version Control", Walter Tichy, _Software_Practice_and_ Experience_, Vol 15(7), 637-654 (July 1985) "Design, Implementation, and Evaluation of a Revision Control System", Walter Tichy, _IEEE_, 58-67, (??? 1982)
fischer@utower.gopas.sub.org (Axel Fischer) (03/19/90)
Another difference is that RCS has a good (and easy to use) interface for GNU emacs. There is also a SCCS interface for GNU emacs, but I have lots of trouble using it. (Pointed out only as a sidenote) -Axel -- fischer@utower.gopas.sub.org / fischer@db0tui6.BITNET / fischer@tmpmbx.UUCP
segel@tellab5.tellabs.com (Mike Segel) (03/20/90)
In article <1990Mar15.204111.4923@csmil.umich.edu> holtz@csmil.umich.edu () writes: > >What are the differences between RCS and SCCS?
segel@tellab5.tellabs.com (Mike Segel) (03/20/90)
In article <1990Mar15.204111.4923@csmil.umich.edu> holtz@csmil.umich.edu () writes: > >What are the differences between RCS and SCCS? Sorry about that, my News hiccuped .... The difference is two fold. 1) RCS uses backwards Deltas. This means that the latest version contains the actual code and the earlier versions are actually the delta, or changes made over the course of development. SCCS uses forward deltas. This means that when you "check in" a piece of code, the original is stored, and the later copies are really deltas based on the original. Backward deltas actually make the retrieval of a stored file faster. (Especially as time goes on and many revisions are made) 2) SCCS comes standard with BSD and SYS V Unix. RCS is public domain and has to be installed by an individual. I personally feel that RCS is easier and better, but some people object to the fact that since it is not std, don't use it. Which ever you choose, use it. It can save a lot of headaches. -Mike Segel Consultant, BALR Oakbrook, Illinois segel@balr.com segel@tellabs.com segel@quanta.eng.ohio-state.edu
rfinch@caldwr.UUCP (Ralph Finch) (03/21/90)
In article <U1=*UZH@utower.gopas.sub.org>, fischer@utower.gopas.sub.org (Axel Fischer) writes: > Another difference is that RCS has a good (and easy to use) interface > for GNU emacs. There are a number of GNU elisp interfaces for RCS...the best I think is from snow.white.toronto.edu, pub/emacs/rcs-cks.el. Last update apparently March 1. I've modified it quite extensively to do tag file checkin-checkouts, checkin of all checked-out files in a directory, and automatic creation of branches for naive users who don't want to learn rcs commands. I would consider it not quite beta ready, but if anybody wants it send mail. Since I modified a version prior to March 1, I'll have to merge my changes in with the new ones. Sigh. Anyway an interface does make things easier for users. -- Ralph Finch The opinions expressed herein are mine... rfinch@water.ca.gov ...ucbvax!ucdavis!caldwr!rfinch 916-445-0088
scjones@sdrc.UUCP (Larry Jones) (03/21/90)
In article <2265@tellab5.tellabs.com>, segel@tellab5.tellabs.com (Mike Segel) writes: > 1) RCS uses backwards Deltas. This means that the latest > version contains the actual code and the earlier versions > are actually the delta, or changes made over the course of > development. This is mostly correct -- thus, the older the version of the file you want, the longer it takes to get it. It's not completely correct because RCS uses forward deltas to handle branches. So, if you want a branch version, you do backward deltas to the common ancestor, then forward deltas along the branch to the version you want. Thus, variant versions take even longer to get. > SCCS uses forward deltas. This means that when you "check in" > a piece of code, the original is stored, and the later copies > are really deltas based on the original. Not strictly true -- SCCS uses merged deltas. That is, all of the different versions are merged into a single file so that any version can be retrieved in one pass over the file. Bottom line is RCS can get the most recent version(s) quicker than SCCS, SCCS can get older version much quicker than RCS. Which is better depends, of course, on how often you do which. I would expect the file sizes to be similar, but I've never really done any actual comparisons. ---- Larry Jones UUCP: uunet!sdrc!scjones SDRC scjones@SDRC.UU.NET 2000 Eastman Dr. BIX: ltl Milford, OH 45150-2789 AT&T: (513) 576-2070 "You know how Einstein got bad grades as a kid? Well MINE are even WORSE!" -Calvin
guy@auspex.auspex.com (Guy Harris) (03/21/90)
> SCCS uses forward deltas. This means that when you "check in" > a piece of code, the original is stored, and the later copies > are really deltas based on the original. This is not correct. SCCS does not use forward deltas. As Mark Runyan stated in his posting: 7. RCS stores its revisions so retrieval of the latest revision is quick and easy, but early revisions take longer. SCCS stores revisions so that recovering any given revision takes a constant amount of time which increases with the number of revisions stored. >2) SCCS comes standard with BSD and SYS V Unix. This is also not correct. SCCS does not come standard with BSD. The "sccs" *front end* to SCCS does, but the SCCS code doesn't.
gwyn@smoke.BRL.MIL (Doug Gwyn) (03/22/90)
In article <2265@tellab5.tellabs.com> segel@tellab5.UUCP (Mike Segel) writes: > SCCS uses forward deltas. This means that when you "check in" > a piece of code, the original is stored, and the later copies > are really deltas based on the original. This is another "urban myth". In fact SCCS does stores deltas in such a fashion that any revision can be extracted from the archive in a single sequential pass.
paj@hic.uucp (Paul Johnson) (10/02/90)
I am setting up a common directory for a group project. We want some kind of source code control a la SCCS and RCS. We already have SCCS (via SunOS 4) and can get RCS if there is sufficient reason (via FTP). Is RCS better than SunOS? Is it worth the work of setting it up and learning a new system? Mail me and I will summarise. Thanks in advance. Paul. Paul Johnson UUCP: <world>!mcvax!ukc!gec-mrc!paj --------------------------------!-------------------------|------------------- GEC-Marconi Research is not | Telex: 995016 GECRES G | Tel: +44 245 73331 responsible for my opinions. | Inet: paj@uk.co.gec-mrc | Fax: +44 245 75244
gwyn@smoke.BRL.MIL (Doug Gwyn) (10/04/90)
In article <648@hic.mrcu> paj@uk.co.gec-mrc (Paul Johnson) writes: >Is RCS better than SunOS? Hmm, interesting question...
gene@bellahs.UUCP (Gene Rondenet) (05/22/91)
We are currently evaluating a configuration management system and are trying to decide between sccs and rcs. What are the advantages or disadvantages of each of these? Is rcs easily obtainable/available on a wide range of systems? Is either one more flexible or configurable? Please email responses to me and I will try to post a summary of responses if any other people are interested. Gene Rondenet = Gene Rondenet UUCP: ...!uunet!bellahs!gene = = Bell Atlantic Healthcare Systems UUCP: ...!pacbell!bellahs!gene = = Greenbrae, California PHONE: (415) 925-0121 = = ***** All opinions expressed are my own and not those of Bell Atlantic ***** =