PHP取得一个页面中的所有链接

    $html = file_get_contents('http://www.example.com');  
      
    $dom = new DOMDocument();  
    @$dom->loadHTML($html);  
      
    // grab all the on the page  
    $xpath = new DOMXPath($dom);  
    $hrefs = $xpath->evaluate("/html/body//a");  
      
    for ($i = 0; $i < $hrefs->length; $i++) {  
           $href = $hrefs->item($i);  
           $url = $href->getAttribute('href');  
           echo $url.'  
    ';  
    }