Question

i found this question on quora and didn’t know how to resolve it

Scenario —

User is on one.php and clicks a link that points to two.php

Two.php does a header redirect to three.php

If we check the referring URL on three.php $_SERVER shows one.php instead of two.php

How do we find out that two.php was an intermediate page that did a header redirect?

Note that I can not do anything with one.php or two.php that can include any params saying two.php included in the redirect

Answer 1

Save the Record with Sessions

You can save the stack on a session variable. Just keep unshifting values onto $_SESSION["history"], removing items from the end of the array when the collection grows to a certain size.

For instance:

// Need to do this if we wish to store data
session_start();

// Set the history array if it doesn't exist
isset( $_SESSION["history"] ) || $_SESSION["history"] = array();

// Push current URI onto history
array_unshift( $_SESSION["history"], $_SERVER["REQUEST_URI"] );

// Prevent history from exceeding 5 values
array_splice( $_SESSION["history"], 5 );

Load it into all PHP files

This would need to be added to the top of each file, or to a global header template include if you have one. Alternatively, if you dare, you could load it globally using auto_prepend_file:

Specifies the name of a file that is automatically parsed before the main file. The file is included as if it was called with the require function, so include_path is used. – Documentation

Inspect the History

You could show the entire history by accessing $_SESSION["history"]:

// Output history array
var_dump( $_SESSION["history"] );