Mac OS X - detect file system read

Mac OS X - detect file system read

I want to know what files a specific application is trying to access on my disk. I know that you can use fs_usage, but this outputs events from all applications. I know that you can target a single application, but only one that is already running. I want to detect all readfile-events an application is trying to do, ever since it is started. I don't want to miss out on any event.