以下代码用于采集页面时，获取网页中所有的链接，并循环输出：

$html = file_get_contents(‘

$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.'<br />’;

}