title: How to find all <meta> tags which are NOT in the HTML comment (<!-- -->) from a file?
body: <p>I am trying to find all <code>&lt;meta&gt;</code> tags which are not in the HTML comment (<code>&lt;!-- --&gt;</code>) from a file and fetch(extract) the contents by using PHP function - <code>get_meta_tags</code>. But there are two problems when using this function:</p>
  
  <ol>
  <li><p>Though the <code>&lt;meta&gt;</code> tags are in the comment, like:</p>
  
  <pre><code>&lt;!--
  &lt;meta name="title" content="Title name"&gt;
  &lt;mata name="keywords" content="keyword 1, keyword 2, keyword 3"&gt;
  &lt;meta name="description" content="Hello world!"&gt;
  &lt;meta name="author" content="Author name"&gt;
  &lt;meta name="copyright" CONTENT="All rights reserved."&gt;
  &lt;meta property="og:title" content="Title name" /&gt;
  &lt;meta property="og:image" content="http://www.example.com/img/logo.gif" /&gt;
  &lt;meta property="og:description" content="Hello world!" /&gt;
  --&gt;
  </code></pre>
  
  <p>, the <code>get_meta_tags</code> function still extracts all <code>&lt;meta&gt;</code> tags whether they are in the comment or not into an array. But what I need is to extract the <code>&lt;meta&gt;</code> tags which are outside the HTML comment(s). That is, I just want the <code>&lt;meta&gt;</code> tags that is REALLY AVAILABLE in this page.</p></li>
  <li><p>If the <code>&lt;meta&gt;</code> tags have no name, for example, there are some <code>&lt;meta&gt;</code> tags which only have “property” or “http-equiv”, like <code>property="og:title"</code>, <code>http-equiv="refresh"</code>, the <code>get_meta_tags</code> function will not extract these <code>&lt;meta&gt;</code> tags into the array.</p></li>
  </ol>
  
  <p>In order to solve these two problems, how can I do? Thanks.</p>