bug#20094: cp --dry-run

[Bob Proulx]

積丹尼 Dan Jacobson wrote:
> Proposal:
> add a new "cp --dry-run"
> Reason: we want to know what the verbose output of e.g.,
> $ cp -i -av /mnt/usb/thumb/ tmp/androidBackup/SDCard
> will be without actually running the command first.
> We are about to commit to a megabyte copy and we want to be sure where
> all those files are exactly going even after understanding all the
> documentation, and without needing to do partial "wet" runs
> etc. etc. etc. etc.

For this functionality I suggest using rsync which already implements
this capability.

  rsync -n -av /mnt/usb/thumb/ tmp/androidBackup/SDCard/thumb/

I see you using cp -i but if you are going to be copying megabytes and
many files I assert that cp -i isn't a good practical way to ensure a
good result.  But rsync --ignore-existing and --update options are
available for data merging.

Bob