http://www.phpbuilder.com/snippet/detail.php?type=snippet&id=597
core highlighting syntax:
//highlighting attribute characters
$patterns = array(
"/</", //html special char '>' => '>';
"/>/", //html special char '<' => '&lg';
"/_".chr(8)."(.)".chr(8)."./", // _^H?^H? => <b>?</b>
"/_".chr(8)."(.)/", //_^H? => <u>?</u>
"/.".chr(8)."(.)/", //^H? => <b>?</b>
"/<b>.<\/b>".chr(8)."(<b>.<\/b>)/", //duplacted <b>?</b>^H<b>?</b>
"/".chr(173)."/" //end line mark
);
$replace = array(
"<",
">",
"<b>\\1</b>",
"<u>\\1</u>",
"<b>\\1</b>",
"\\1",
""
);