site_archiver@lists.apple.com Delivered-To: darwin-kernel@lists.apple.com Amanda Walker _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.a... On Jun 15, 2007, at 4:05 AM, Yogesh Kulkarni wrote: The application i am currently working on needs to do simple Copy- On-Write mechanism by which i will be able to take the backup of those files which are going to be modified. So, i am more interested in getting the event before the read/write operation on particular file or before the data gets modified for the file. But currently KAuth is giving event to my user space application after the file data gets modified because of this i am not able to get the previous state of that file for achieving Copy-On- Write mechanism. My main aim is to keep the previous state of the file to some other location before modified data gets written to that file. This is not going to be possible with Kauth, since a Kauth module gets notified after the I/O operation is already underway. You can deny the operation, but you can't interpose user space processing in between seeing the request and either denying it or letting it proceed. This email sent to site_archiver@lists.apple.com