This procedure closes the file that is currently associated
with the given
stream. The file preceding the closed file (in the order
of opening) is then assigned to the corresponding stream.
A file that is closed with this procedure must previously have been
opened with
fopen.
This function has no effect if the corresponding stream is not
associated with any explicitly opened file (
i.e. it is not possible to close the default input or output stream). All open streams are automatically closed when the program
terminates.