Once called the FILE * should I<ONLY> be closed by calling
C<PerlIO_close()> on the returned PerlIO *.
+The PerlIO is set to textmode. Use PerlIO_binmode if this is
+not the desired mode.
+
=item B<PerlIO_exportFILE(f,flags)>
Given a PerlIO * create a 'native' FILE * suitable for passing to code