“>

 80) {

    echo "Too long.";

   return FALSE;

  }

  //echo '$ whois ' . htmlentities($domain) . "\r\n";

  $whois = shell_exec("whois '" . addslashes($domain) . "'");

  print_r($whois);

}
function is_valid_domain_name($domain_name) {

  // Thanks to http://stackoverflow.com/a/4694816

  return (preg_match("/^([a-z\d](-*[a-z\d])*)(\.([a-z\d](-*[a-z\d])*))*$/i", $domain_name) //valid chars check

    && preg_match("/^.{1,253}$/", $domain_name) //overall length check

    && preg_match("/^[^\.]{1,63}(\.[^\.]{1,63})*$/", $domain_name)   ); //length of each label

}