PHP - easiest way to get $_GET parameters string as written in the URL

Question

I'm trying to redirect from one page to another while retaining the parameters.

e.g. if I have a page page.php?param1=1&param2=2, what's the easiest way to extract "param1=1&param2=2"?

Answer 1

Use $_SERVER['QUERY_STRING'] to access everything after the question mark.

So if you have the url:

http://www.sample.com/page.php?param1=1&param2=2

then this:

$url = "http://www.sample.com/page2.php?".$_SERVER['QUERY_STRING'];
echo $url;

will return:

http://www.sample.com/page2.php?param1=1&param2=2

Answer 2

In addition to Robs answer:

You can use http_build_query and $_GET.
This is build-in and can deal with arrays.
Also you can easily manipulate the GET params this way, befor you put them together again.

unset($_GET['unsetthis']);
$query = http_build_query($_GET);