$re = '/<\s*a\s*[^<]*?>[^>]*>?<\s*\/a\s*>/m';
$str = '<p>This is a test piece of text that contains the keywords in my array like <a>Photos</a>, C.V., CV, <a>Google</a>, <a>Github</a>, <a>Portfolio</a>,</a> Instagram, <a>email</a> and Simon, <a>ign <a oring the keywords if they\'re existing <a href="#>">Simon links</a>.</p>';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php