PHP完美的提取链接正则

function match_links($document) {    
preg_match_all("']+))[^>]*>?(.*?)'isx",$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;
}