Replace cp -ur with rsync -urvv.

It's not a typo there are two v-s there to increase verbosity to show the files that were skipped.

The skipped files will look like the_filename is newer, so to get the list of skipped files you can use this one-liner:

rsync -urvv source/ target | grep ' is newer$' | sed -e 's/ is newer$//'

Or if you will be using it interactively the --progress flag can be very useful.

Replace cp -ur with rsync -urvv.

The two "v"-s there are not a typo: they are there for increased verbosity, to show the files that were skipped.

The skipped files will look like the_filename is newer, so to get the list of skipped files you can use this one-liner:

rsync -urvv source/ target | grep ' is newer$' | sed -e 's/ is newer$//'

Or if you will be using it interactively the --progress flag can be very useful.