PHP：如何获取href属性的绝对链接

Question

I'm trying to fetch favicon image path of a site and I'm doing something like:

$favicon_img_url = $link->getAttribute('href');
echo $favicon_img_url;

But it only returns the relative url (/favicon.ico) and NOT the absolute link ( http://www.anysite.com/favicon.ico ) that I want.

EDIT: For more clarity, here's a bigger chunk of the code:

function file_get_contents_curl($url)
{
    //Some code here to get contents from a website....
}

$html = file_get_contents_curl($target_website);
$doc = new DOMDocument();
@$doc->loadHTML($html);

// GET FAVICON PATH
$links = $doc->getElementsByTagName('link');
for ($i = 0; $i < $links->length; $i++)
{
$link = $links->item($i);
$rel = $link->getAttribute('rel');
if($rel == 'shortcut icon')
    $favicon = $link->getAttribute('href');
}
echo $favicon; 

It only returns "/favicon.ico" not " http://www.website.com/favicon.ico "

Answer 1

try add to relative path, domain url $_SERVER['SERVER_NAME']

edit: it give you domain without http or https. To add it, you can check if it is https or http: if(isset($_SERVER['HTTPS'])){..}else{...}

Answer 2

The href attribute is defined as an (absolute/relative) path and stays that way. When the browser processes the HTML markup, it will do one of two things with that attribute:

• If it considers the attribute a valid absolute path, that will become that elements href property.
• If it considers the attribute a relative path, it will pop it on the end of the base URL and use that as the href property.

Take this page title for example, if you inspect the markup, the attribute is

/questions/26441184/php-how-to-get-absolute-link-of-href-attribute

It is not an absolute path, but because the browser knows that the base URL is http://stackoverflow.com , clicking it will take you to the property value, which is:

http://stackoverflow.com/questions/26441184/php-how-to-get-absolute-link-of-href-attribute

tl;dr : You can't, not without knowing the base URL for the page on which your <a> falls.