Here's an example using HTML::Parser

use strict;
use HTML::Parser;
use Data::Dumper;

my $input = q{<tag ref=1>Start<tag ref=2>and more</tag>and end</tag>};

print "Input: [$input]\n";


my $p = HTML::Parser->new(api_version=>3,
               start_h=>[
                    \&startTokenHandler, 
                    "self,tokens"
                   ],
               end_h=>[
                   \&endTokenHandler,
                   "self,tokens"
                   ],
               text_h =>[
                     \&textHandler,
                     "self,dtext"
                    ],
              );

$p->parse($input);

sub startTokenHandler
  {
    my $self = shift;
    my $token = shift;
    printf("<%s %s=%d>\n", @$token); 
    
  }

sub endTokenHandler
  {
    my $self = shift;
    my $token = shift;
    printf("</%s>\n", $token->[0]);
    
  }

sub textHandler
  {
    my $self = shift;
    my $text = shift;
    print "$text\n";
  }
[download]

sample output:

$perl sample2.pl
Input: [<tag ref=1>Start<tag ref=2>and more</tag>and end</tag>]
<tag ref=1>
Start
<tag ref=2>
and more
</tag>
and end
</tag>
[download]