php 正则表达式提取网页超级链接url的函数

function match_links($document) { preg_match_all("'<\s*a\s.*?href\s*=\s*([\"\'])?(?(1)(.*?)\\1|([^\s\>]+))[^>]*>?(.*?)</a>'isx",$document,$links); while(list($key,$val) = each($links[2])) { if(!empty($val)) $match['link'][] = $val; } while(list($key,$val) = each($links[3])) { if(!empty($val)) $match['link'][] = $val; } while(list($key,$val) = each($links[4])) { if(!empty($val)) $match['content'][] = $val; } while(list($key,$val) = each($links[0])) { if(!empty($val)) $match['all'][] = $val; } return $match; }