MacOS – Recover an overwritten Mac note

Unfortunately there is no way of recovering notes generally. If you don't have a backup and did not sync notes to other devices, I see no way of recovering it. If the note had a very high value, perhaps a data forensics company might be able to recover something. But that would cost money.

OS X maintains deleted files in the local time machine storage area if you have enabled (or the system has enabled) a local store.

tmutil snapshot

If you can make a snapshot, you can enter Time Machine and recover these files. If you get an error like **Local snapshots are not enabled. ** then you don't have the ability to recover the files from the OS level. Since there is no other undelete mechanism in the filesystem, you have a good survey of recovery tools (I use Data Rescue pretty much exclusively) and your only third option would be to locate a viable backup of the system or the files in question.

I make a habit of enabling the local store and forcing a snapshot before doing anything as root or anything I might regret from the terminal. Having made mistakes like this over the years, I've learned to have that "premonition" to check backup and double check the syntax. In general, I try to make a list of files to delete and save it to a file so I have a pause and a second script that does the removal rather than piping them together. It's not going to help, but it's my experience and way to mitigate when I can't ensure a good backup.

sudo tmutil enablelocal
sleep 8 && tmutil snapshot