use CGI;                             

   my $q = new CGI;     
   open(SAVE, ">&STDOUT");                    
   open(STDOUT, '/tmp/out.html') or die "Couldn't open out file: !$"; 
   print $q->header,                    
         $q->start_html('hello world'), 
         $q->h1('hello world'),         
         $q->end_html;                  
   open(STDOUT, ">&SAVE");