Why not just re-open STDOUT such as:

open(STDOUT,">tempfile.html",") or die $!;
[download]

in the case(s) where you need to redirect to a file?

If for some reason you want to preseve STDOUT you can also do the following:

use FileHandle;

my $fh=new FileHandle;
if ($use_a_file) {
   $fh=open(">tempfile.html","w") or die !:
} else {
    $fh->fdopen(STDOUT,"w");
}


print $fh "blahblahblahblah\n";
[download]

One last thought of a cautionary nature, make sure your CGI environment has permissions to open a file for writing in the directory you are attempting to do so.

I'm sure there are more ways of doing this...

---

Peter L. Berghold -- Unix Professional Peter at Berghold dot Net
	Dog trainer, dog agility exhibitor, brewer of fine Belgian style ales. Happiness is a warm, tired, contented dog curled up at your side and a good Belgian ale in your chalice.