File-level filesystem change notification in Mac OS X

Question

I want my code to be notified when any file under (either directly or indirectly) a given directory is modified. By \"modified\", I mean I want my code to be notified whenever

Answer 1

I haven't tried this myself, but it seems like FSEvents is able to provide file-level notifications as of 10.7 (Lion). From the description of FSEventStreamCreateFlags:

kFSEventStreamCreateFlagFileEvents

Request file-level notifications. Your stream will receive events about individual files in the hierarchy you're watching instead of only receiving directory level notifications. Use this flag with care as it will generate significantly more events than without it.

Available in OS X v10.7 and later.