我想尝试弄清楚如何获得
<title>A common title</title>
<meta name="keywords" content="Keywords blabla" />
<meta name="description" content="This is the description" />
即使它以任何顺序排列，我也听说过 PHP Simple HTML DOM Parser，但我并不想使用它。除了使用 PHP Simple HTML DOM Parser 之外，是否有可能提供解决方案。
preg_match如果它是无效的 HTML，将无法做到这一点？
cURL 可以用 preg_match 做这样的事情吗？
Facebook 会做这样的事情，但可以通过以下方式正确使用：
<meta property="og:description" content="Description blabla" />
我想要这样的东西，以便当有人发布链接时，它应该检索标题和元标记。如果没有元标记，则它会被忽略，或者用户可以自己设置（但我稍后会自己设置）。
这是应该的方式：
function file_get_contents_curl($url)
{
$ch = curl_init();
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
$data = curl_exec($ch);
curl_close($ch);
return $data;
}
$html = file_get_contents_curl("http://example.com/");
//parsing begins here:
$doc = new DOMDocument();
@$doc->loadHTML($html);
$nodes = $doc->getElementsByTagName('title');
//get and display what you need:
$title = $nodes->item(0)->nodeValue;
$metas = $doc->getElementsByTagName('meta');
for ($i = 0; $i < $metas->length; $i++)
{
$meta = $metas->item($i);
if($meta->getAttribute('name') == 'description')
$description = $meta->getAttribute('content');
if($meta->getAttribute('name') == 'keywords')
$keywords = $meta->getAttribute('content');
}
echo "Title: $title". '<br/><br/>';
echo "Description: $description". '<br/><br/>';
echo "Keywords: $keywords";
<?php
// Assuming the above tags are at www.example.com
$tags = get_meta_tags('http://www.example.com/');
// Notice how the keys are all lowercase now, and
// how . was replaced by _ in the key.
echo $tags['author']; // name
echo $tags['keywords']; // php documentation
echo $tags['description']; // a php manual
echo $tags['geo_position']; // 49.33;-86.59
?>
get_meta_tags将帮助您解决除标题之外的所有问题。要获得标题，只需使用正则表达式。
$url = 'http://some.url.com';
preg_match("/<title>(.+)<\/title>/siU", file_get_contents($url), $matches);
$title = $matches[1];
希望有帮助。
get_meta_tags不适用于标题。
只有具有名称属性的元标记，例如
<meta name="description" content="the description">
将被解析。
PHP的原生函数：get_meta_tags()
不幸的是，内置的 php 函数 get_meta_tags() 需要 name 参数，而某些网站，例如 twitter 则将其关闭以支持 property 属性。此函数混合使用正则表达式和 dom 文档，将从网页返回一个键控元标记数组。它检查名称参数，然后检查属性参数。这已经在 instragram、pinterest 和 twitter 上进行了测试。
/**
* Extract metatags from a webpage
*/
function extract_tags_from_url($url) {
$tags = array();
$ch = curl_init();
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
$contents = curl_exec($ch);
curl_close($ch);
if (empty($contents)) {
return $tags;
}
if (preg_match_all('/<meta([^>]+)content="([^>]+)>/', $contents, $matches)) {
$doc = new DOMDocument();
$doc->loadHTML('<?xml encoding="utf-8" ?>' . implode($matches[0]));
$tags = array();
foreach($doc->getElementsByTagName('meta') as $metaTag) {
if($metaTag->getAttribute('name') != "") {
$tags[$metaTag->getAttribute('name')] = $metaTag->getAttribute('content');
}
elseif ($metaTag->getAttribute('property') != "") {
$tags[$metaTag->getAttribute('property')] = $metaTag->getAttribute('content');
}
}
}
return $tags;
}
我们不应该使用OG吗？
选择的答案很好，但在重定向站点时不起作用（非常常见！），并且不返回OG 标签，这是新的行业标准。这是一个在 2018 年更有用的小功能。它会尝试获取 OG 标签，如果无法获取，则回退到元标签：
function getSiteOG( $url, $specificTags=0 ){
$doc = new DOMDocument();
@$doc->loadHTML(file_get_contents($url));
$res['title'] = $doc->getElementsByTagName('title')->item(0)->nodeValue;
foreach ($doc->getElementsByTagName('meta') as $m){
$tag = $m->getAttribute('name') ?: $m->getAttribute('property');
if(in_array($tag,['description','keywords']) || strpos($tag,'og:')===0) $res[str_replace('og:','',$tag)] = $m->getAttribute('content');
}
return $specificTags? array_intersect_key( $res, array_flip($specificTags) ) : $res;
}
如何使用它：
/////////////
//SAMPLE USAGE:
print_r(getSiteOG("http://www.stackoverflow.com")); //note the incorrect url
/////////////
//OUTPUT:
Array
(
[title] => Stack Overflow - Where Developers Learn, Share, & Build Careers
[description] => Stack Overflow is the largest, most trusted online community for developers to learn, shareâ âtheir programming âknowledge, and build their careers.
[type] => website
[url] => https://stackoverflow.com/
[site_name] => Stack Overflow
[image] => https://cdn.sstatic.net/Sites/stackoverflow/img/apple-touch-icon@2.png?v=73d79a89bded
)
最好的办法是咬紧牙关使用 DOM 解析器——这是做这件事的“正确方法”。从长远来看，它会为您节省更多的时间，而不是学习如何。众所周知，使用 Regex 解析 HTML 是不可靠的并且不能容忍特殊情况。
一个了解如何检索 og:tags、title 和 description 的简单函数，请自行调整
function read_og_tags_as_json($url){
$ch = curl_init();
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
$HTML_DOCUMENT = curl_exec($ch);
curl_close($ch);
$doc = new DOMDocument();
$doc->loadHTML($HTML_DOCUMENT);
// fecth <title>
$res['title'] = $doc->getElementsByTagName('title')->item(0)->nodeValue;
// fetch og:tags
foreach( $doc->getElementsByTagName('meta') as $m ){
// if had property
if( $m->getAttribute('property') ){
$prop = $m->getAttribute('property');
// here search only og:tags
if( preg_match("/og:/i", $prop) ){
// get results on an array -> nice for templating
$res['og_tags'][] =
array( 'property' => $m->getAttribute('property'),
'content' => $m->getAttribute('content') );
}
}
// end if had property
// fetch <meta name="description" ... >
if( $m->getAttribute('name') == 'description' ){
$res['description'] = $m->getAttribute('content');
}
}
// end foreach
// render JSON
echo json_encode($res, JSON_PRETTY_PRINT |
JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
}
返回此页面（可能有更多信息）：
{
"title": "php - Getting title and meta tags from external website - Stack Overflow",
"og_tags": [
{
"property": "og:type",
"content": "website"
},
{
"property": "og:url",
"content": "https://stackoverflow.com/questions/3711357/getting-title-and-meta-tags-from-external-website"
},
{
"property": "og:site_name",
"content": "Stack Overflow"
},
{
"property": "og:image",
"content": "https://cdn.sstatic.net/Sites/stackoverflow/Img/apple-touch-icon@2.png?v=73d79a89bded"
},
{
"property": "og:title",
"content": "Getting title and meta tags from external website"
},
{
"property": "og:description",
"content": "I want to try figure out how to get the\n\n<title>A common title</title>\n<meta name=\"keywords\" content=\"Keywords blabla\" />\n<meta name=\"description\" content=\"This is the descript..."
}
]
}
我们通过 php（命令行实用程序）使用Apache Tika和 -j for json ：
<?php
shell_exec( 'java -jar tika-app-1.4.jar -j http://www.guardian.co.uk/politics/2013/jul/21/tory-strategist-lynton-crosby-lobbying' );
?>
这是随机监护人文章的示例输出：
{
"Content-Encoding":"UTF-8",
"Content-Length":205599,
"Content-Type":"text/html; charset\u003dUTF-8",
"DC.date.issued":"2013-07-21",
"X-UA-Compatible":"IE\u003dEdge,chrome\u003d1",
"application-name":"The Guardian",
"article:author":"http://www.guardian.co.uk/profile/nicholaswatt",
"article:modified_time":"2013-07-21T22:42:21+01:00",
"article:published_time":"2013-07-21T22:00:03+01:00",
"article:section":"Politics",
"article:tag":[
"Lynton Crosby",
"Health policy",
"NHS",
"Health",
"Healthcare industry",
"Society",
"Public services policy",
"Lobbying",
"Conservatives",
"David Cameron",
"Politics",
"UK news",
"Business"
],
"content-id":"/politics/2013/jul/21/tory-strategist-lynton-crosby-lobbying",
"dc:title":"Tory strategist Lynton Crosby in new lobbying row | Politics | The Guardian",
"description":"Exclusive: Firm he founded, Crosby Textor, advised private healthcare providers how to exploit NHS \u0027failings\u0027",
"fb:app_id":180444840287,
"keywords":"Lynton Crosby,Health policy,NHS,Health,Healthcare industry,Society,Public services policy,Lobbying,Conservatives,David Cameron,Politics,UK news,Business,Politics",
"msapplication-TileColor":"#004983",
"msapplication-TileImage":"http://static.guim.co.uk/static/a314d63c616d4a06f5ec28ab4fa878a11a692a2a/common/images/favicons/windows_tile_144_b.png",
"news_keywords":"Lynton Crosby,Health policy,NHS,Health,Healthcare industry,Society,Public services policy,Lobbying,Conservatives,David Cameron,Politics,UK news,Business,Politics",
"og:description":"Exclusive: Firm he founded, Crosby Textor, advised private healthcare providers how to exploit NHS \u0027failings\u0027",
"og:image":"https://static-secure.guim.co.uk/sys-images/Guardian/Pix/pixies/2013/7/21/1374433351329/Lynton-Crosby-008.jpg",
"og:site_name":"the Guardian",
"og:title":"Tory strategist Lynton Crosby in new lobbying row",
"og:type":"article",
"og:url":"http://www.guardian.co.uk/politics/2013/jul/21/tory-strategist-lynton-crosby-lobbying",
"resourceName":"tory-strategist-lynton-crosby-lobbying",
"title":"Tory strategist Lynton Crosby in new lobbying row | Politics | The Guardian",
"twitter:app:id:googleplay":"com.guardian",
"twitter:app:id:iphone":409128287,
"twitter:app:name:googleplay":"The Guardian",
"twitter:app:name:iphone":"The Guardian",
"twitter:app:url:googleplay":"guardian://www.guardian.co.uk/politics/2013/jul/21/tory-strategist-lynton-crosby-lobbying",
"twitter:card":"summary_large_image",
"twitter:site":"@guardian"
}
从url获取meta标签，php函数示例：
function get_meta_tags ($url){
$html = load_content ($url,false,"");
print_r ($html);
preg_match_all ("/<title>(.*)<\/title>/", $html["content"], $title);
preg_match_all ("/<meta name=\"description\" content=\"(.*)\"\/>/i", $html["content"], $description);
preg_match_all ("/<meta name=\"keywords\" content=\"(.*)\"\/>/i", $html["content"], $keywords);
$res["content"] = @array("title" => $title[1][0], "descritpion" => $description[1][0], "keywords" => $keywords[1][0]);
$res["msg"] = $html["msg"];
return $res;
}
例子：
print_r (get_meta_tags ("bing.com") );
Easy 和 php 的内置函数。
我的解决方案（改编自 cronoklee 和 shamittomar 的部分帖子）所以我可以从任何地方调用它并获得 JSON 返回。可以很容易地解析成任何内容。
<?php
header('Content-type: application/json; charset=UTF-8');
if (!empty($_GET['url']))
{
file_get_contents_curl($_GET['url']);
}
else
{
echo "No Valid URL Provided.";
}
function file_get_contents_curl($url)
{
$ch = curl_init();
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
$data = curl_exec($ch);
curl_close($ch);
echo json_encode(getSiteOG($data), JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
}
function getSiteOG( $OGdata){
$doc = new DOMDocument();
@$doc->loadHTML($OGdata);
$res['title'] = $doc->getElementsByTagName('title')->item(0)->nodeValue;
foreach ($doc->getElementsByTagName('meta') as $m){
$tag = $m->getAttribute('name') ?: $m->getAttribute('property');
if(in_array($tag,['description','keywords']) || strpos($tag,'og:')===0) $res[str_replace('og:','',$tag)] = utf8_decode($m->getAttribute('content'));
}
return $res;
}
?>
如果您正在使用 PHP，请查看pear.php.net上的 Pear 包，看看您是否发现任何对您有用的东西。我已经有效地使用了 RSS 包，它节省了很多时间，前提是您可以通过他们的示例了解他们如何实现他们的代码。
具体看一下Sax 3，看看它是否能满足您的需求。Sax 3 不再更新，但它可能就足够了。
正如已经说过的，这可以解决问题：
$url='http://stackoverflow.com/questions/3711357/get-title-and-meta-tags-of-external-site/4640613';
$meta=get_meta_tags($url);
echo $title=$meta['title'];
//php - Get Title and Meta Tags of External site - Stack Overflow
<?php
// ------------------------------------------------------
function curl_get_contents($url) {
$timeout = 5;
$useragent = 'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:27.0) Gecko/20100101 Firefox/27.0';
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_USERAGENT, $useragent);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, $timeout);
$data = curl_exec($ch);
curl_close($ch);
return $data;
}
// ------------------------------------------------------
function fetch_meta_tags($url) {
$html = curl_get_contents($url);
$mdata = array();
$doc = new DOMDocument();
$doc->loadHTML($html);
$titlenode = $doc->getElementsByTagName('title');
$title = $titlenode->item(0)->nodeValue;
$metanodes = $doc->getElementsByTagName('meta');
foreach($metanodes as $node) {
$key = $node->getAttribute('name');
$val = $node->getAttribute('content');
if (!empty($key)) { $mdata[$key] = $val; }
}
$res = array($url, $title, $mdata);
return $res;
}
// ------------------------------------------------------
?>
我根据最佳答案制作了这个小作曲家包：https ://github.com/diversen/get-meta-tags
composer require diversen/get-meta-tags
进而：
use diversen\meta;
$m = new meta();
// Simple usage, get's title, description, and keywords by default
$ary = $m->getMeta('https://github.com/diversen/get-meta-tags');
print_r($ary);
// With more params
$ary = $m->getMeta('https://github.com/diversen/get-meta-tags', array ('description' ,'keywords'), $timeout = 10);
print_r($ary);
它需要 CURL 和 DOMDocument 作为最佳答案 - 并且内置，但可以选择设置 curl 超时（以及获取各种元标记）。
现在，大多数网站都会在其网站上添加元标记，以提供有关其网站或任何特定文章页面的信息。例如新闻或博客网站。
我创建了一个 Meta API，它为您提供所需的元数据，如 OpenGraph、Schema.Org 等。
我有这个以不同的方式工作，并认为我会分享它。比其他人少的代码，在这里找到了。我添加了一些东西来让它加载你所在的页面元而不是某个页面。我希望它自动将默认页面标题和描述复制到 og 标签中。
但是，出于某种原因，无论我尝试了哪种方式（不同的脚本），页面在线加载速度都非常慢，但在 wamp 上会立即加载。不知道为什么，所以我可能会使用开关盒，因为该站点并不大。
<?php
$url = 'http://sitename.com'.$_SERVER['REQUEST_URI'];
$fp = fopen($url, 'r');
$content = "";
while(!feof($fp)) {
$buffer = trim(fgets($fp, 4096));
$content .= $buffer;
}
$start = '<title>';
$end = '<\/title>';
preg_match("/$start(.*)$end/s", $content, $match);
$title = $match[1];
$metatagarray = get_meta_tags($url);
$description = $metatagarray["description"];
echo "<div><strong>Title:</strong> $title</div>";
echo "<div><strong>Description:</strong> $description</div>";
?>
并在 HTML 标头中
<meta property="og:title" content="<?php echo $title; ?>" />
<meta property="og:description" content="<?php echo $description; ?>" />
改进了上面@shamittomar 的答案以获取元标记（或来自 html 源的指定标记）
可以进一步改进...与 php 的默认 get_meta_tags 的区别在于，即使存在 unicode 字符串，它也可以工作
function getMetaTags($html, $name = null)
{
$doc = new DOMDocument();
try {
@$doc->loadHTML($html);
} catch (Exception $e) {
}
$metas = $doc->getElementsByTagName('meta');
$data = [];
for ($i = 0; $i < $metas->length; $i++)
{
$meta = $metas->item($i);
if (!empty($meta->getAttribute('name'))) {
// will ignore repeating meta tags !!
$data[$meta->getAttribute('name')] = $meta->getAttribute('content');
}
}
if (!empty($name)) {
return !empty($data[$name]) ? $data[$name] : false;
}
return $data;
}
这是获取页面 META 详细信息的 PHP 简单 DOM HTML 类的两行代码。
$html = file_get_html($link);
$meat_description = $html->find('head meta[name=description]', 0)->content;
$meat_keywords = $html->find('head meta[name=keywords]', 0)->content;