织梦DedeCMS关键词怎么替换

//高亮专用, 替换多次是可能不能达到最多次
function _highlight($string, $words, $result, $pre)
{
    global $cfg_replace_num;
    $string = str_replace('"', '"', $string);
    uasort($words,create_function('$a, $b','return strlen($a)>strlen($b);'));