Re: Suggested new feature for rcsdiff

[Keith Thompson]

On Tue 10-11-09 08:01, Keith Thompson wrote:
> On Tue 10-11-09 09:24, Thien-Thi Nguyen wrote:
> [...]
> > On the other hand, since RCS is a GNU program, it would be fine IMO
> > if RCS were to explicitly require a GNU diff workalike diff for
> > proper operation.
> > 
> > Overall, do you have a specific case in mind for using another diff?
> 
> Not really.

Let me amend that statement.

I've worked on systems (Solaris, for example) where the GNU utilities
aren't necessary pre-installed and/or aren't installed in consistent
locations.  Installing GNU diffutils (from source or otherwise) is
easy enough, but configuring RCS so it knows where to find "diff"
is another matter.  For example:

    Install diffutils version X
    Install RCS, configuring it to use /usr/local/apps/diffutils-X/bin/diff
    Install diffutils version Y
    Nuke diffutils version X because it's obsolete
    RCS stops working

Most modern systems use package management systems that avoid
this kind of problem, and I haven't actually run into it myself in
some time.  The question is, is this worth addressing?

If so, there could be a mechanism (perhaps a config file whose
location is set when RCS is installed) that tells RCS where to
find the "diff" command.  It needn't be flexible enough to allow
for something that doesn't act like GNU diff.

If I'm inventing problems that nobody will ever run into, or that
are so rare that reinstalling RCS is an acceptable solution,
then it's probably not worth the effort.

-- 
Keith Thompson (The_Other_Keith) address@hidden  <http://www.ghoti.net/~kst>
Nokia
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"