c:\@Work\Perl>perl -wMstrict -le
"my $template = 'i2 f3';
 ;;
 sub template_len {
   my ($template) = @_;
   ;;
   my $s = pack $template;
   return length $s;
   }
 ;;
 my $buf_size = template_len($template);
 print $buf_size;
 ;;
 print template_len('i i f f f');
 print template_len('i f3 i');
"
20
20
20