‘tmutil addexclusion’ WTH?!

I have a script where I exclude certain files from the Time Machine backup via xattr -w "com.apple.metadata:com_apple_backup_excludeItem com.apple.backupd". This works fine. 

After reading the tmutil manpage I decided to change that to tmutil addexclusion. Less hardcoding –> better portability.

But somehow that command does not do what I want it to do:

  • it doesn’t accept relative paths (as when you are cd’ing into a directory and run the command there on a file)
  • even with absolute paths it fails if the target file has been created recently or is being opened by an app.

Any ideas?