http://search.cpan.org/dist/HTML-Parser/lib/HTML/Entities.pm

decode_entities( $string, ... )

This routine replaces HTML entities found in the $string with the corresponding Unicode character. Unrecognized entities are left alone.

  use HTML::Entities qw/decode_entities/;

  my $ok=decode_entities($orig);
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Im not sure this would work on "chunks", $orig has to be the entire string to decode at once for with chunks an entity could be split across them.