Comment 37 for bug 64067

(In reply to comment #3)
> Well, consider that some folks want a GUI-oriented progress bar, and some want
> text-only. Some are happy to incur the cost of a curses library, others want
> the minimal footprint and are happy with less eye candy. We've hashed out all
> of this, over the years, and came to the conclusion that if there is to be any
> such thing associated with GNU cp (and mv, and dd, and maybe others, like
> install), then the mechanism must be sufficiently generic to work with an
> independent program that would be in charge of displaying the progress meter.
> Then, the core copying code needn't be polluted with code that some will never
> want or use. Here's a proposed implementation from 2004:
> http://thread.gmane.org/gmane.comp.gnu.coreutils.bugs/1663

And at this point, you have entered well into the realm of over-engineering a
simple problem ;-)

If you're using curses, etc and wanting to show the output of cp, you're already
writing an app at which point the part of cp that are going to be cared about
aren't that hard to implement. The value here is in being able to have a shell
script give some form of progress feedback as it copies a large file.