WatchFS is a file event monitoring utility for Mac OS. Ever wondered which process deleted a file? You can watch all kind of file events with WatchFS.
In simplest form:
sudo ./watchfs myfile
Filter with a specifif event:
sudo ./watchfs -e 6 myfile
where -e for event filtering and 6 means unlink event. To list all events use -l:
./watchfs -l
Also use -p for process filtering.
WatchFS uses audit pipe under the hood. Since audit pipe is also available in FreeBSD, WatchFS should be usable there!