Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uwm.edu!csd4.csd.uwm.edu
From: jgd@csd4.csd.uwm.edu (John G Dobnick)
Newsgroups: comp.unix.wizards
Subject: Re: Question about RCS check-in
Message-ID: <4720@uwm.edu>
Date: 27 Jun 90 06:19:55 GMT
References: <1990Jun22.212249.6130@sq.sq.com>
Sender: news@uwm.edu
Reply-To: jgd@csd4.csd.uwm.edu
Lines: 54

From article <1990Jun22.212249.6130@sq.sq.com>, by lee@sq.sq.com (Liam R. E. Quin):
> shaw@hpihoah.HP.COM (Joy-lim Shaw) and others suggest:
>> [...]
>> You can use:
>> $(SRCS): $(RCSDIR)/$$@,v
>> 	@$(CO) $(COFLAGS) $@
>>in your makefiles to checkout files only if their corresponding RCS file
>>is newer
> The obvious problem is that a change to the date of the ,v file does not
> necessarily reflect a change to the actual source file.
> 
> One way round this is to have a shell script "cocmp", say, that does a
> co followed by a cmp, and only overwrites the source file if the version
> checked out was different. [...]
> 
> Has anyone done this?

Strangely enough, yes.  In the copy of RCS I obtained (Version 4, from
Purdue or from uunet), there is an 'rcsclean' program that does exactly
this. Manpage extract follows:

^->RCSCLEAN(L)         UNIX Programmer's Manual          RCSCLEAN(L)
^->
^->NAME
^->     rcsclean - clean up working files
^->
   [...]
^->
^->DESCRIPTION
^->     Rcsclean removes working files that were checked out and
^->     never modified.  For each file given, rcsclean compares the
^->     working file and a revision in the corresponding RCS file.
^->     If it finds no difference, it removes the working file, and,
^->     if the revision was locked by the caller, unlocks the revi-
^->     sion.
^->
   [...]
^->
^->EXAMPLES
^->     The command
^->
^->          rcsclean *.c *.h
^->
^->     removes all working files ending in ".c" or ".h" that were
^->     not changed since their checkout.
   [...]
-- 
John G Dobnick  (JGD2)
Computing Services Division @ University of Wisconsin - Milwaukee
INTERNET: jgd@csd4.csd.uwm.edu             ATTnet: (414) 229-5727
UUCP: uunet!uwm!csd4.csd.uwm.edu!jgd

"Knowing how things work is the basis for appreciation,
and is thus a source of civilized delight."  -- William Safire