bug#61105: cp/mv: want a fatal --no-clobber

[Pádraig Brady]

On 30/01/2023 20:12, Paul Eggert wrote:
> Better, I think, would be to change cp -n to be compatible with FreeBSD,
> where 'cp -n A B' exits with status 1 if B exists. This matches what
> FreeBSD 'cp -i A B' does when you say "no". This would be more useful
> than what GNU cp does, and the FreeBSD cp -i behavior conforms to POSIX
> whereas GNU cp -i (I think accidentally) does not. This would be simpler
> than adding a fatal --no-clobber, and would encourage portability a bit.
>
> The reason it's a POSIX conformance issue is that POSIX says exit status
> zero means "All files were copied successfully." which "cp -n A B" does
> not do when B exists.
>
> Similarly for 'mv' (though FreeBSD mv -i does not conform to POSIX here,
> unfortunately).

This is a good observation.
Also the current "skip" functionality of coreutils cp -n
is already catered for with the --update option.

cheers,
Pádraig