I'm updating my Drupal environment by comparing the currently live file structure with the latest patch level of Drupal core (official tarball).
On Windows I used to use WinMerge for the job, but that tool is unavailable on MacOS.
So I'm looking for a way to compare the contents of the live folder structure with the one from the latest Drupal core release, and remove identical files from the Drupal core release folder structure.
So, if live/file.txt and drupal-x.y/file.txt are identical, I want to delete drupal-x.y/file.txt.
This way I only need to review the files remaining in drupal-x.y and eventually upload them to update the changes.
I'm pretty sure that this can be achieved with diff but I have some difficulties finding the right recipe.