open (REPORT,">$filename") || die "error";
...
$^ = "NEWPAGE";
...
foreach [outer loop]
   $~ = "FIRST_FORMAT";
   write (REPORT);

   foreach [inner loop]
      $~ = "SECOND_FORMAT";
      write (REPORT);

   [end inner loop]

[end outer loop]

close (REPORT) || die ...

##</code><code>##

$oldHandle = select (REPORT);
$~ = [format reference]
select $oldHandle;

##</code><code>##

write() on closed filehandle REPORT at script line xxx
[repeated several times]
Cannot close <filename> (Bad file descriptor)