Just for the record, I am as sick of this part of the book showing up on HN as everyone else. I do not post it here, other people do, and I apologize in advance for it showing up here all the time half-finished.

But, if you have a problem with this I ask that you write code disproving that the copy() function does not terminate for all possible inputs. Or, that you write a function that can check if a C style string is valid. If someone can do that it'd help me with the book.