use warnings;
use strict;
use Data::Dumper;

"<div></div>" =~ /(?<start>.*?)((?!\< *\/[\w\d\-]+\>).)*/;
print Dumper(\%+);

__END__

$VAR1 = {
          'start' => ''
        };

##</code><code>##

----------------------------------------------------------------------
  .*?                      any character except \n (0 or more times
                           (matching the least amount possible))
----------------------------------------------------------------------