you can do this two ways
1- Php built-in function (get_meta_tags).
2 - PHP - HTML Dom Parser using Curl.
get_meta_tags - Extracts all meta tag content attributes from a file and returns an array.
Example-
meta tag inside head section
<meta content="Short Tutorials" name="author">
<meta content="Short Tutorials -PHP" name="keywords">
<meta content="Short Tutorials -PHP" name="description">
<meta content="blogger" name="generator">
Note:
Only meta tags with name attributes will be parsed. Quotes are not required.
Php code
<?php
// in my case i want to get 4 meta tags. you can get tag which you want.
$tags = get_meta_tags('pass url"); // pass the url
// it will return all meta tags in array now you can get the value of meta tags which you want.
echo $tags['author'];
echo $tags['keywords'];
echo $tags['description'];
echo $tags['generator'];
?>
For more information check out this link. and get your solution ShortTutorials