It should print `after fork` two times, they just wrote it wrong. They clearly wrote the whole thing manually, since they used `vim` and not `cat` to display the contents of the file, and they show it printing `After fork` and not `after fork`. I think they just forgot to put the line twice. The fact that they have `Int` and not `int` means their example doesn't actually compile, so I don't think they tested this one.