You can recognise most of the high-level input/output functions that
operate on files because they begin with the letter f; for
example, the high-level function for opening a file called fopen,
as opposed to the low-level file-opening function open. Some of
them are more generalized versions of functions with which you may
already be familiar; for example, the function fprintf behaves
like the familiar printf, but takes an additional parameter -- a
stream -- and sends all its output to that stream instead of simply
sending its output to stdout, as printf does.
