opensnoop(1m) on macOS
The text a0156693ea35, as Mac OS X 10.5.8, Mac OS X 10.5.7, Mac OS X 10.5.6, Mac OS X 10.5.5, Mac OS X 10.5.4, Mac OS X 10.5.3, Mac OS X 10.5.2, Mac OS X 10.5.1, Mac OS X 10.5 shipped it.
snoop file opens as they occur. Uses DTrace.
Flags it lists
-
-A -
-Z -
-a -
-c -
-e -
-f -
-g -
-n -
-p -
-s -
-v -
-x