$re = '/^(http(s)?:\/\/)?([\w]+\.)?linkedin\.com\/(pub|in|profile)/m';
$str = 'es.linkedin.com/pub/francisco-fernandez/30/14/62
https://www.linkedin.com/profile/view?id=107523146&authType=name&authToken=A2nj&trk=nmp_pymk_name
de.linkedin.com/pub/frank-rempp/1/638/7a1
http://uk.linkedin.com/pub/some-name/1/1b3/b45/
http://nl.linkedin.com/pub/other-name/11/223/544
http://www.linkedin.com/in/aname/
http://www.linkedin.com/in/another-name
http://linkedin.com/in/name
http://nl.linkedin.com/in/name
http://nl.linkedin.com/in/name/';
$subst = "";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
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