Question

I would like to know how can we identify the Nofollow relation in the URL through PHP REGEX.

<a href="abc.html" rel="NOFOLLOW">How to check NOFOLLOW<a>

Please give me the solution to findout this things

Answer 1

You could try with something such as…

preg_match('/<a.+?rel="nofollow".*?>[\s\S]*?<\/a>/i', $html);

CodePad.

But you are better off using a HTML parser which deals with things that a regex can not.

$dom = new DOMDocument;

$dom->loadHTML($html);

$anchors = $dom->getElementsByTagName('a');

foreach($anchors as $anchor) {
   if ($anchor->hasAttribute('rel')) {
      $rel = preg_split('/\s+/', strtolower($anchor->getAttribute('rel')));

      if (in_array('nofollow', $rel)) {
         echo 'This anchor is "nofollow"\'d.';
      }
   }
}

CodePad.