Would like to see cp -n to test which files are to be copied

[Larry Alkoff]

I would like to see the  cp utility to have an option (suggesting -n which 
rsync uses)
to show which files would be copied or updated but not actually do the copy.

Many times I would like to do a mass update but am unsure
just which files would be changed and too protective of my system
to let it "just happen".

I believe this feature would be a valuable enhancement to cp
but a search of this list archives came up with no previous discussion.
It should be trivial for someone experienced.

I had the idea that I could change the source myself
and downloaded fileutils-4.1.tar.gz
and looked at the cp source.

Although I used to program in c it's been 20  years.  I don't think
my skills are up to the job.

Particularly I don't understand the "go_copy" function 
which seems to do the actual copy job using the options that are expanded
in the beginning of the source file.

I can't see how to inhibit the actual copy but keep all the other stuff
so that, for example, a
cp -un
will show the files to be updated before doing the actual copy.

If someone was interested enough to do the change that would be wonderful.
Otherwise I'd like some pointers on how to proceed and I'll try it myself.

Larry Alkoff



Larry Alkoff N2LA - Austin TX