获取正确网址的魔术技巧？

Question

I am about to make a system that automaticly puts &pni=something behind an URL. It would be easy if the url just was http://t.co/something.php with "?pni=...." but users can also have http://t.co/something.php?myown=paramater and then the system should add & instead of ?

How can I put the pni parameter behind the URL and to be valid every time? I've tried this without luck.

<?php
function nice($in){
  $out = parse_url($in);
  return $out['scheme'] . "://" . $out['host'] . $out['path'] . "?" . $out['query'];
}

$urls = array(
  "http://t.co/something.php?w=23&",
  "http://t.co/something.php?w=23&dfdf=",
  "http://t.co/something.php?",
  "http://t.co/something.php",
  "http://t.co/something",
  "http://t.co/something.php?w=23&dfdf=34&hvem",
);

foreach ( $urls as $url):
  echo print_r(nice($url)) . "<br/>";
endforeach;
?>

Answer 1

function nice($in) {
    $out = parse_url($in);
    if ($out['query'] != "") {
        $out['query'] = "pni=something&".$out['query'];
    }
    else { 
      $out['query'] = "pni=something";
    }

    return $out['scheme'] . "://" . $out['host'] . $out['path'] . "?" . $out['query'];
}