amir@pilat.Israel.Silvaco.COM (Amir J. Katz (Xpert)) (03/14/91)
There is an alternative to SCCS, called RCS (Revision Control System).
Questions:
1. Is this a commercial product or public domain ?
2. Where can I get more information about RCS ?
3. Is it better than SCCS ? If so, why ?
-- TIA,
--
Amir J. Katz, System Manager
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19 Maskit St., Herzelia, Israeljik@athena.mit.edu (Jonathan I. Kamens) (03/16/91)
In article <AMIR.91Mar14144117@pilat.Israel.Silvaco.COM>, amir@pilat.Israel.Silvaco.COM (Amir J. Katz (Xpert)) writes: |> There is an alternative to SCCS, called RCS (Revision Control System). |> Questions: |> 1. Is this a commercial product or public domain ? It is distributed by the Free Software Foundation under the GNU Public License, which means that it is not public domain, but it is freely redistributable as long as long as you meet the conditions of the GPL (which is, basically, that you give the sources for it to anyone who asks and that you send any changes you make back to the authors; but don't take my word for it, read the GPL). |> 2. Where can I get more information about RCS ? Anonymous ftp to prep.ai.mit.edu and grab the file /pub/gnu/rcs-5.5.tar.Z. |> 3. Is it better than SCCS ? If so, why ? This is a recurring debate on the net. Which one is better is pretty much a matter of personal opinion, so your best bet is to grab the RCS sources and take a look at them and decide for yourself. One of the biggest differences between the two (in my opinion) is that the basic SCCS commands are very primitive and almost impossible for the user to "just use" -- you almost certainly need some sort of front-end in order to use SCCS effectively. RCS, on the other hand, has useful utilities that can be used by the user without any front-end (which isn't to say that front-ends for RCS don't exist; they do, for example CVS, which is also distributed by the FSF). -- Jonathan Kamens USnail: MIT Project Athena 11 Ashford Terrace jik@Athena.MIT.EDU Allston, MA 02134 Office: 617-253-8085 Home: 617-782-0710
gwyn@smoke.brl.mil (Doug Gwyn) (03/16/91)
In article <1991Mar15.175701.17723@athena.mit.edu> jik@athena.mit.edu (Jonathan I. Kamens) writes: > One of the biggest differences between the two (in my opinion) is that the >basic SCCS commands are very primitive and almost impossible for the user to >"just use" -- you almost certainly need some sort of front-end in order to use >SCCS effectively. I disagree -- the BRL MUVES project (over 100,000 lines of code in numerous files in dozens of directories, with a half dozen developers) uses SCCS to maintain the source code, documentation, etc. and it is pretty easy to use for routine purposes: admin -ifoo s.foo # to create the initial archive get s.foo # to check out the latest version get -e s.foo # to check out for editing delta s.foo # to check back in after editing The main need for any sort of "front end" program occurs on Berkeley-based systems where it is desired to strictly enforce access controls, due to lack of kernel support for the sort of UID manipulation that SCCS relies upon to support such usage. However, if you simply rely on the normal user/group permissions, as we do for the MUVES project use of SCCS, it works adequately. It also helps if you have an "augmented make" that knows how to deal with the s. prefixes, and if your Makefiles for documentation etc. contain .DEFAULT: $(GET) $(GFLAGS) -p s.$@ > $@
mjf@mjm.mjm.com (Mark Fresolone) (03/17/91)
One significant advantage that RCS has over SCCS is the ability to tag any version of a file with a "symbolic version" string. By tagging, say, all current versions of a set of files with the same "symbolic version" string one can essentially identify a "release". SCCS has no such feature, and thus is often accompanied by locally written scripts to extract all of the file versions which make up a configuration, store them away, and if they're good (and not so simple), retrieve them. There is also another similar feature in RCS that we use to identify internal configurations such as "last stable version", or "current unit test", called the RCS "state". While these two features alone don't qualify RCS as a full "configuration management" package, they are very useful, and are perhaps the most significant RCS advantage over SCCS. Mark Fresolone mjf@mjm.com, rutgers!mjm!mjf Melillo Consulting/MJM Software 908 873-0075/Fax 908 873-2250
runyan@hpcuhc.cup.hp.com (Mark Runyan) (03/19/91)
>/ amir@pilat.Israel.Silvaco.COM (Amir J. Katz (Xpert)) >There is an alternative to SCCS, called RCS (Revision Control System). >Questions: >1. Is this a commercial product or public domain ? It comes from GNU >2. Where can I get more information about RCS ? "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) >3. Is it better than SCCS ? If so, why ? --- Repost of a previous response I made on the subject: 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. (While you *may* edit an SCCS file, you will have to recalculate the checksum using the admin program. Also, editing either RCS or SCCS files is a bad idea just because mistakes are so easy to make and so fatal to the history of the file). 5. RCS keeps history in files with a ",v" suffix. SCCS keeps history in files with a "s." prefix. Some Make programs recognize the "s." prefix while having trouble with ",v" suffix. Your mileage will vary. 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. (RCS uses backward deltas. SCCS uses a "merged delta" concept. SCCS does *NOT* use forward deltas). 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 that 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.