如何定义支持HTTPS和HTTP的路径？

Question

I have a redirect character strip script, that takes the original URL, strips the requested strings out of it (foo , bar) and then redirects to the same URL only without these strings.

It's currently set up to work with HTTP Only, as users always requests the HTTP page. But now I'm adding HTTPS, so some users will land on HTTPS. in that case, I'd like the redirect to be to the HTTPS.

How Can I do it?

I've tried simply changing:

$url = "http://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";

Into:

$url = "://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";

But it created an invalid request (mydomain.com//mydomain.com....)

CODE:

function unparse_url($parsed_url) {
  $scheme   = isset($parsed_url['scheme']) ? $parsed_url['scheme'] . '://' : '';
  $host     = isset($parsed_url['host']) ? $parsed_url['host'] : '';
  $port     = isset($parsed_url['port']) ? ':' . $parsed_url['port'] : '';
  $user     = isset($parsed_url['user']) ? $parsed_url['user'] : '';
  $pass     = isset($parsed_url['pass']) ? ':' . $parsed_url['pass']  : '';
  $pass     = ($user || $pass) ? "$pass@" : '';
  $path     = isset($parsed_url['path']) ? $parsed_url['path'] : '';
  $query    = !empty($parsed_url['query']) ? '?' . trim($parsed_url['query'], '&') : '';
  $fragment = isset($parsed_url['fragment']) ? '#' . $parsed_url['fragment'] : '';
  return "$scheme$user$pass$host$port$path$query$fragment";
}

function strip_query($url, $query_to_strip) {
  $parsed = parse_url($url);
  $parsed['query'] = preg_replace('/(^|&)'.$query_to_strip.'[^&]*/', '', $parsed['query']);
  return unparse_url($parsed);
}

$url = "http://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";

$url2 = (strip_query($url, 'foo')); # query to strip  - foo
$new_url = (strip_query($url2, 'bar')); # strip also - bar


$filtered = array_filter(array_keys($_GET), function($k) {
    return strpos($k, 'foo') === 0;
});

if ( !empty($filtered) ) {
    $_SESSION['trackParam'] = $_GET; // #### Save original request data and url before redirection
    $_SESSION['REQUEST_URI'] = $_SERVER[REQUEST_URI]; 
    $_SESSION['redirected'] = true;
    header ("Location: $new_url");
}

Answer 1

You can use $_SERVER['HTTPS'] to decide whether to use https in your $url:

function check_https() {
    return    (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off')
           || $_SERVER['SERVER_PORT'] == 443;
}

$url = (check_https() ? "https" : "http")
       ."://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";