Here are 3 ways of getting Time Machines exclusions:
Firstly, every backup includes its own exclusion list. At the top level of each backup there is a hidden file called
.exclusions.plist, for example
/Volumes/<TM volume name>/2022-05-03-124500/.exclusions.plist. You can see this in Finder so long as you are showing hidden files by pressing Shift and Command and then the dot (or >) key.
The file has exclusions of 4 types:
- Standard exclusion paths,
- Sticky exclusion paths set on particular files (lots of these),
- System files excluded - there are none (I suspect it is a relic from older versions of TM), and
- User exclusion paths - those set in Time Machine's System Preferences.
So the list you want is at the end of the file.
Howard Oakley's blog has the best reference for the above What doesn't Time Machine back up?
Secondly, Time Machines preference file contains the list of locations added in Time Machine's System Preferences. This is
This preference file does not include individual files with exclusion set or the standard exclusions.
Thirdly, and thanks to @Gordon Davisson, here is a simple one-liner for the exclusions added in the GUI:
defaults read /Library/Preferences/com.apple.TimeMachine SkipPaths