# Copied from node 265898 by valdez. Cut and modified slightly.

use HTML::TokeParser::Simple;
use HTML::Entities;

my $parser = HTML::TokeParser::Simple->new( 'filename' );
my $in_body = 0;

while ( my $token = $parser->get_token ) {
  if ($in_body) {
    # we are inside BODY
    if ($token->is_text) {
      # it's text, convert it
      print HTML::Entities::encode_entities($token->as_is);
    } else {
      if ($token->is_end_tag( 'body' )) {
        # we've found the end of the BODY
        $in_body = 0;
      }
      print $token->as_is;
    }
  } else {
    if ($token->is_start_tag( 'body' )) {
      # we've found the beginning of the BODY
      $in_body = 1;
    }
    print $token->as_is;
  }
}