You can use inotify to figure out what files are opened, closed or when they are written too. Can be used for example to indicate active file downloads in the f

You can use inotify to figure out what files are opened, closed or when they are written too. Can be used for example to indicate active file downloads in the file manager. However I don't think that's quite enough, as most apps will close the files again after they have read them. There is no need to keep them open, as you are working on their in-memory representation, not on the file on the disk until you hit 'Save'. So this seems more like a desktop level feature similar to "Recent Files", where the apps has to manually announce what it is doing instead of relying on low level file operations to figure it out.