As Apple's Official Doc said:
-viewDidUnloadis deprecated in iOS 6.0. Views are no longer purged under low-memory conditions and so this method is never called.
Meanwhile, it's better to remove all -viewDidUnload implements from projects that the deployment target is iOS 6.0 or later. But removing it one by one is boring, especially you've hundreds of controllers & several projects.
So, is there any script or command can do this batch job?