Highlight PHP

[code]
<?php

    $phpcode = '<?php echo "hallo wereld!"; ?>';

    echo highlight_php($phpcode);

    // Highlight PHP code
    function highlight_php($string, $bAddDefaultCss = false)
    {
        $sPhpManual = 'http://nl2.php.net/';
        $aKeywords = array();

        // Keywords
        $aKeywords[] = array("<?"); // array("match", "css-class");
        $aKeywords[] = array("<?php");
        $aKeywords[] = array("?>");
        $aKeywords[] = array("array");
        $aKeywords[] = array("as");
        $aKeywords[] = array("break");
        $aKeywords[] = array("class");
        $aKeywords[] = array("die");
        $aKeywords[] = array("do");
        $aKeywords[] = array("else");
        $aKeywords[] = array("elseif");
        $aKeywords[] = array("exit");
        $aKeywords[] = array("extends");
        $aKeywords[] = array("false");
        $aKeywords[] = array("for");
        $aKeywords[] = array("foreach");
        $aKeywords[] = array("function");
        $aKeywords[] = array("if");
        $aKeywords[] = array("in");
        $aKeywords[] = array("include");
        $aKeywords[] = array("include_once");
        $aKeywords[] = array("new");
        $aKeywords[] = array("null");
        $aKeywords[] = array("or");
        $aKeywords[] = array("private");
        $aKeywords[] = array("public");
        $aKeywords[] = array("require");
        $aKeywords[] = array("require_once");
        $aKeywords[] = array("return");
        $aKeywords[] = array("static");
        $aKeywords[] = array("true");
        $aKeywords[] = array("unknown");
        $aKeywords[] = array("var");
        $aKeywords[] = array("while");

        $result = '';

        if($bAddDefaultCss)
        {
            $result .= '<style type="text/css">'
            . 'code.php { background: #FCFCFC; border: #E8E8E8 solid 1px; color: #000000; display: block; overflow: auto; padding: 20px; white-space: nowrap; }'
            . 'code.php .keyword { color: #0000FF; }'
            . 'code.php .comment { color: #00A000; }'
            . 'code.php .quoted { color: #FF00FF; }'
            . 'code.php .variable { color: #009999; }'
            . 'code.php .function { color: #FF0000; }'
            . '</style>';
        }

        if(strlen($string) > 0)
        {
            $expr = '/(\'((\\\\.)|[^\\\\\\\'])*\')|("((\\\\.)|[^\\\\\\\"])*")|(\/\*(\n|.)*?\*\/)|(\/\/[^\\n]+\\n)|(\$[a-z0-9_]+)|([a-z0-9_]+)|(<\?php|<\?|\?>)|([\n|\s]+)|(.)/i';
            $matches = array();

            preg_match_all($expr, $string, $matches);
            // print_r($matches[0]);

            for($i = 0; $i < sizeof($matches[0]); $i++)
            {
                if(strcasecmp($match = $matches[0][$i], "") !== 0)
                {
                    if(preg_match("/^(\/\*((\n|.)*?)\*\/)$/i", $match)) // comment
                    {
                        $result .= '<span class="comment">' . stringToHtml($match) . '</span>';
                    }
                    elseif(preg_match("/^(\/\/[^\\n]+\\n)$/i", $match)) // comment
                    {
                        $result .= '<span class="comment">' . stringToHtml($match) . '</span>';
                    }
                    elseif(function_exists($match)) // Quoted text
                    {
                        $result .= '<a class="function" href="' . $sPhpManual . stringToHtml($match) . '" target="_blank">' . stringToHtml($match) . '</a>';
                    }
                    elseif(preg_match("/^(\\\$[a-z0-9_]+)$/i", $match)) // variable
                    {
                        $result .= '<span class="keyword">$</span><span class="variable">' . stringToHtml(substr($match, 1)) . '</span>';
                    }
                    elseif(strcasecmp(substr($match, 0, 1), "\"") === 0) // Quoted text
                    {
                        $result .= '<span class="quoted">' . stringToHtml($match) . '</span>';
                    }
                    elseif(strcasecmp(substr($match, 0, 1), "'") === 0) // Quoted text
                    {
                        $result .= '<span class="quoted">' . stringToHtml($match) . '</span>';
                    }
                    else
                    {
                        $aKeyword = false;

                        for($j = 0; $j < sizeof($aKeywords); $j++)
                        {
                            if(strcasecmp($match, $aKeywords[$j][0]) === 0)
                            {
                                $aKeyword = $aKeywords[$j];
                                break;
                            }
                        }

                        if($aKeyword)
                        {
                            $result .= '<span class="' . (isset($aKeyword[1]) ? $aKeyword[1] : 'keyword') . '">' . stringToHtml($match) . '</span>';
                        }
                        elseif(is_numeric($match))
                        {
                            $result .= '<span class="quoted">' . stringToHtml($match) . '</span>';
                        }
                        else
                        {
                            $result .= stringToHtml($match);
                        }
                    }
                }
            }
        }

        return '<code class="php">' . $result . '</code>';
    }

?>
[/code]