Directory Sync with a Subdirectory to Ignore
I need to do a directory sync e.g. from `/dir-a/` to `/dir-b/` (always in this direction). However, there are two requirements:

 1. There is a particular subdirectory `/dir-a/.dont-copy/` (yes, started with a `.`) that I should ignore. That is, `/dir-a/.dont-copy/` should always stay in `/dir-a/`, never move.
 2. Files / directories in `/dir-b/` that don't exist in `/dir-a/` should be deleted.

How would I do this using **command-line tools** (ideally, on Mac OSX)? Thanks beforehand for your help!
Directory Sync with a Subdirectory to Ignore
===

I need to do a directory sync e.g. from `/dir-a/` to `/dir-b/` (always in this direction). However, there are two requirements:

 1. There is a particular subdirectory `/dir-a/.dont-copy/` (yes, started with a `.`) that I should ignore. That is, `/dir-a/.dont-copy/` should always stay in `/dir-a/`, never move.
 2. Files / directories in `/dir-b/` that don't exist in `/dir-a/` should be deleted.

How would I do this using **command-line tools** (ideally, on Mac OSX)? Thanks beforehand for your help!