It is correct, because when you press Ctrl+D on an empty line, the OS will return an EOF. It's not a complete answer, but neither's yours, because you didn't co

It is correct, because when you press Ctrl+D on an empty line, the OS will return an EOF. It's not a complete answer, but neither's yours, because you didn't consider what happens when the OOM killer reaps cat. However, it's not intended to be a complete description, because it's describing a UI convention.