Parser html code without libraries, how?

Question

HTML

Hello! I need an html parser of someone else's site so that I get all the values ​​of a specific tag (span, div), class, id
They are displayed in the form of an array
There is something like this:

$url = 'ссылка на сайт';
// НАЧАЛО
$ch = curl_init($url);
$html = curl_exec($ch);
curl_close($ch);
var_dump($html);
?>

But it displays the whole site

Answer 1

Well, he does the right thing by displaying the entire site. You request the entire html by reference and then display it in its entirety.
And the process of writing a parser "without libraries" will lead to the fact that you write self-made libraries. Moreover, the chances that they will be better than competitors tend to zero.
And I'll tell you a secret: cURL is also a library. Can you rewrite it on sockets from scratch?