Is there something like filter driver for Mac OS X?

Question

Windows lets you develop a filter driver to catch file I/O's on VFS. But I can't seem to find something similar for Mac. It does have something called Filter Schemes, but those are for HFS+. Anyone know if there is a way for me to intercept file I/O's on Mac without using programs like MacFUSE?

Answer 1

I'm not at all familier with the Windows technologies that you mention, but it sounds like you might be looking for FSEvents.

http://developer.apple.com/mac/library/documentation/Darwin/Conceptual/FSEvents_ProgGuide/Introduction/Introduction.html

The file system events API provides a way for your application to ask for notification when the contents of a directory hierarchy are modified. For example, your application can use this to quickly detect when the user modifies a file within a project bundle using another application.

It also provides a lightweight way to determine whether the contents of a directory hierarchy have changed since your application last examined them. For example, a backup application can use this to determine what files have changed since a given time stamp or a given event ID.

You should read this document if your application works with a large number of files—particularly if your application works with large hierarchies of files.

Answer 2

I found out that Mac OS X does not allow filter drivers at all.

“A stacking file system (sometimes called a filter file system) sits on top of another file system and modifies its behavior in some way. The canonical example of a stacking file system is an encryption file system. You could stack this file system on top of any existing file system to provide encryption support. Apple does not support the development of stacking VFS plug-ins on Mac OS X” (http://developer.apple.com/mac/library/qa/qa2001/qa1242.html)