php - 如何获取完整的url？

Question

$html = file_get_contents("any site");
$dom = new domDocument;
@$dom->loadHTML($html);
$dom->preserveWhiteSpace = false;
$images = $dom->getElementsByTagName('img');

foreach ($images as $image) {
   echo $image->src;
}

不给我任何返回

$html = file_get_contents("any site");
$dom = new domDocument;
@$dom->loadHTML($html);
$dom->preserveWhiteSpace = false;
$images = $dom->getElementsByTagName('img');

foreach ($images as $image) {
   echo $image->getAttribute('src');
}

返回相对网址，如“/images/example.jpg

$html = file_get_contents("any site");
$dom = new domDocument;
@$dom->loadHTML($html);
$dom->preserveWhiteSpace = false;
$images = $dom->getElementsByTagName('img');

foreach ($images as $image) {
   echo $image.src;
}

返回给我:

Fatal error: Call to undefined function getElementsByTagName()

那么，如何获得绝对路径呢？

Answer 1

您可以使用parse_url查找基本 URL:

$url = 'http://www.example.com/path?opt=234';
$parts = parse_url($url);
if (isset($parts['scheme'])){
    $base_url = $parts['scheme'].'://';
} else {
    $base_url = 'http://';
    $parts = parse_url($base_url.$url);
}
$base_url .= $parts['host'];
if (isset($parts['path'])){
    $base_url .= $parts['path'];
}

然后将其与您的代码结合起来，如下所示:

$html = file_get_contents("any site");
$dom = new domDocument;
@$dom->loadHTML($html);
$dom->preserveWhiteSpace = false;
$images = $dom->getElementsByTagName('img');

foreach ($images as $image) {
   echo $base_url.$image->getAttribute('src');
}