PHP 获取网页的所有超链接 [ 新手入门 ]

<?php
$html = file_get_contents('http://www.baidu.com'); 
  
$dom = new DOMDocument(); 
@$dom->loadHTML($html); 

$xpath = new DOMXPath($dom); 
$hrefs = $xpath->evaluate("/html/body//a"); 

for ($i = 0; $i < $hrefs->length; $i++) { 
    $href = $hrefs->item($i); 
    $url = $href->getAttribute('href'); 
    echo $url . '<br />'; 
}
?>