to \code{'hard'} or \code{'sym'}; if it is \code{None} (the default),
files are copied. Don't set \var{link} on systems that don't support
it: \function{copy_file()} doesn't check if hard or symbolic linking is
-available.
-
-Under Mac OS 9, uses the native file copy function in \module{macostools};
-on other systems, uses \var{_copy_file_contents()} to copy file contents.
+available. It uses \var{_copy_file_contents()} to copy file contents.
Return a tuple \samp{(dest_name, copied)}: \var{dest_name} is the actual
name of the output file, and \var{copied} is true if the file was copied