/**  *  删除非站内链接  *  * @access    public  * @param     string  $body  内容  * @param     array  $allow_urls  允许的超链接  * @return    string  */ function Replace_Links( &$body, $allow_urls=array()  ) {     $host_rule = join('|', $allow_urls);     $host_rule = preg_replace("#[\n\r]#", '', $host_rule);     $host_rule = str_replace('.', "\\.", $host_rule);     $host_rule = str_replace('/', "\\/", $host_rule);     $arr = '';     preg_match_all("#<a([^>]*)>(.*)<\/a>#iU", $body, $arr);     if( is_array($arr[0]) )     {         $rparr = array();         $tgarr = array();         foreach($arr[0] as $i=>$v)         {             if( $host_rule != '' && preg_match('#'.$host_rule.'#i', $arr[1][$i]) )             {                 continue;             } else {                 $rparr[] = $v;                 $tgarr[] = $arr[2][$i];             }         }         if( !empty($rparr) )         {             $body = str_replace($rparr, $tgarr, $body);         }     }     $arr = $rparr = $tgarr = '';     return $body; }