How can I remove invalid querystring using php header location

Question

I have this invalid link hard coded in software which I cannot modify.

http://www.16start.com/results.php?cof=GALT:#FFFFFF;GL:1;DIV:#FFFFFF;FORID:1&q=search

I would like to use php header location to redirect it to a valid URL which does not contain the querystring. I'd like to pass just the parameter q=.

I've tried

$q = $_GET['q'];
header ("Location: http://www.newURL.com/results.php?" . $q . ""); 

But it's just passing the invalid querystring to the new location in addition to modifying it in a strange way

This is the destination location I get, which is also invalid

http://www.newURL.com/results.php?#FFFFFF;GL:1;DIV:#FFFFFF;FORID:1&q=search

Answer 1

That's because # is seen as the start of a fragment identifier and confuses the parser.

You can take the easy-way as Stretch suggested but you should be aware that q is the last query parameter in your URL. Therefore, it might be better to fix the URL and extract the query parameters in a safer way:

<?php
$url = "http://www.16start.com/results.php?cof=GALT:#FFFFFF;GL:1;DIV:#FFFFFF;FORID:1&q=search";

// Replace # with its HTML entity:
$url = str_replace('#', "%23", $url);

// Extract the query part from the URL
$query = parse_url($url, PHP_URL_QUERY);

// From here on you could prepend the new url
$newUrl = "http://www.newURL.com/results.php?" . $query;
var_dump($newUrl);

// Or you can even go further and convert the query part into an array
parse_str($query, $params);
var_dump($params);
?>

Output

string 'http://www.newURL.com/results.php?cof=GALT:%23FFFFFF;GL:1;DIV:%23FFFFFF;FORID:1&q=search' (length=88)

array
  'cof' => string 'GALT:#FFFFFF;GL:1;DIV:#FFFFFF;FORID:1' (length=37)
  'q' => string 'search' (length=6)

Update

After your comments, it seems that the URL is not available as a string in your script and you want to get it from the browser.

The bad news is that PHP will not receive the fragment part (everything after the #), because it is not sent to the server. You can verify this if you check the network tab in the Development tools of your browser F12 .

In this case, you'll have to host a page at http://www.16start.com/results.php that contains some client-side JavaScript for parsing the fragment and redirecting the user.

Answer 2

one way could be to use strstr() to get everything after (and including q= ) in the string.

So:

$q=strstr($_GET['q'],'q=');

Give that a whirl