Feature-beg: --dry-run

[Ed Avis]

I have submitted a bug (feature request) to savannah
(<https://savannah.gnu.org/bugs/?func=detailbug&bug_id=4771&group_id=2613>)
but I don't think that is set up to gateway to the mailing list so I
thought I would also send a message to the list in case people want to
discuss it.

It would be handy if some of the coreutils (particularly cp and
mv) had a --dry-run option that tries to do everything short of
actually copying or moving the files.  The output of --dry-run
--verbose would be the same as the output of --verbose, as far as
possible.

The suggested name of the option is chosen for consistency with GNU
patch.

Myself I would find such an option useful for a wrapper program I am
writing around mv, which looks at the files being moved and writes a
.htaccess file for Apache to set up http redirects.  I would like it
to check for redirection loops before trying to move any files, and
the simplest way to do that would be to ask mv: if I did run you, what
files would you move?

Of course if --dry-run succeeds it would not be guaranteed that a
following real run of mv or cp would produce the same results, but it
would be good enough.

-- 
Ed Avis <address@hidden>