gistfile1.php

<?php

function unchunk($result) {
    return preg_replace_callback(
        '/(?:(?:\r\n|\n)|^)([0-9A-F]+)(?:\r\n|\n){1,2}(.*?)'
        .'((?:\r\n|\n)(?:[0-9A-F]+(?:\r\n|\n))|$)/si',
        create_function(
            '$matches',
            'return hexdec($matches[1]) == strlen($matches[2]) ?
                 $matches[2] :
                 $matches[0];'
        ),
        $result
    );
}