switch statement for header redirection - php

Question

if (isset($_GET['ssl'])) {
switch ($_GET['ssl']) {
case 1:
{
header("Location: https://site.com");
exit;
}
default:
{
header("Location: http://site.com");
exit;
}
}
}
Should I be using exit; because I'm using header? Or should I use break like the switch requires?

Answer 1

As I still feel bad about that whole exchange yesterday, I figured I'd offer an answer and explain some things to do with break and exit().
As amosrivera points out, using a break is not required within a switch statement; it is also valid within other loop structures.
From the manual:
break ends execution of the current
for, foreach, while, do-while or
switch structure.
What this means is that for each one of these loop types, it will stop execution of the current loop, but not the execution of the calling script itself. Note also:
break accepts an optional numeric
argument which tells it how many
nested enclosing structures are to be
broken out of.
The purpose is to stop executing the loop; in a switch, it prevents fall-through. For example:
function mySwitch($var) {
$return = '';
switch ($var) {
case 1:
$return .= 'a';
case 2:
$return .= 'b';
break;
case 3:
$return .= 'c';
}
return $return;
}
echo mySwitch(1); // outputs 'ab'
echo mySwitch(2); // outputs 'b'
echo mySwitch(3); // outputs 'c'
See live example: http://codepad.org/8EMvYt7V
switch will match the first case then run each case following until it reaches a break or return.
Concerning return, if called in a function within a loop, it will end the function execution and, possibly confusingly, return() will also end the current script execution if called in the global scope, but in a different way from exit() (for instance, for include'd or require'd files, it will not affect the main script).
How exit() (or die()) differ from break and return is that is ends execution of the entire script, not just the current loop (break), function (return), or script (return()).
Now, I happen to agree with coreyward that it's probable you don't need a switch for this; I use a different method under a potentially different scenario:
if (strtolower($_SERVER['HTTPS']) != 'on') {
exit(header("location: https://{$_SERVER['SERVER_NAME']}{$_SERVER['REQUEST_URI']}"));
}
Which could be rewritten to be:
if (strtolower($_SERVER['HTTPS']) != 'on' && $_GET['ssl']) {
exit(header("location: https://{$_SERVER['SERVER_NAME']}{$_SERVER['REQUEST_URI']}"));
}
Or you could create a lookup list of actions/pages that require ssl and call that in the redirect:
function requireSSL($page) {
$req = array('login.php','myaccount.php','updateaccount.php');
return in_array($page, $req);
}
function doSSLRedirect($page) {
if (strtolower($_SERVER['HTTPS']) != 'on' && requireSSL($page)) {
exit(header("location: https://{$_SERVER['SERVER_NAME']}{$_SERVER['REQUEST_URI']}"));
}
}
Then you can call this when you need to enforce a redirect (and you don't need $_GET['ssl'] in the URL):
doSSLRedirect($_SERVER['SCRIPT_NAME']);
This would be more handy if you're using some kind of MVC pattern and were checking for actions in the URL; otherwise, you could just use an include checkssl.php at the head of your script.
Since I don't know how you're actually implementing your SSL check, these are just suggestions. Looking at the code you have above, if that were simply plugged in at the top of a page, you might end up with an infinite loop if you inadvertently add the ssl variable back to the redirected URL.
As far as calling exit() (or die()), you don't have to pair the two, but they typically do occur at the same time or near each other, since any output that follows should not be seen by the user's browser.
For instance, if you separated them, you might create a check for the redirect in case you have other things you want to happen before exit (maybe some logging or something).
For example:
$sslredirected = false;
if (isset($_GET['ssl'])) {
switch ($_GET['ssl']) {
case 1:
header("Location: https://site.com");
$sslredirected = true;
default:
header("Location: http://site.com");
$sslredirected = false;
}
}
if ($sslredirected === true) {
$otherstuff = youNeedToDoBeforeRedirection();
exit;
}
However, in this case you could probably just as easily put that in an include'd file and just call that in your switch and let it do the exit() call. There's a number of different ways this could go.
One other note about using header(), you need to call it before anything is outputted (including whitespace). See http://codepad.org/nJ4aght4 for an example of what I mean. Note in this case, the header is not sent, so the redirect will not occur.
Hopefully this helps. :)

Answer 2

I think you mean switch requires break, and the point is, it doesn't requires it, break should be used when needed to after a condition, in this case you are already doing that with exit the way you have it is fine.

Answer 3

the whole code block is pointless in my opinion, you can achieve the exact same results like so:
$protocol = empty($_GET['ssl']) ? 'http' : 'https';
header("Location: " . $protocol . "://site.com");
exit;
the function empty will be true if the value the index is not defined as well as being empty or 0.

Answer 4

Use exit at the end if u need :
if (isset($_GET['ssl'])) {
switch ($_GET['ssl']) {
case 1:
{
header("Location: https://site.com");
break;
}
default:
{
header("Location: http://site.com");
}
}
}
exit;

Answer 5

switch isn't really appropriate here — it's making things more complicated, not less.
if (isset($_GET['ssl']) {
header('Location: ' . ($_GET['ssl'] ? 'https' : 'http') . '://example.com/');
exit();
}