同一会话的不同内容？

Question

I have 2 php pages in the same domain. One is in the root, other one is 3 folder below. A also have the following code in both files:

[...]
session_start();
var_dump(array('id' => session_id(), 'name' => session_name(), 'content' => $_SESSION));
die();
[...]

id is the same, name is the same, content differs...

If I execute session_regenerate_id() in any of them, both pages will have the new session id, but content still differs. Cleaning up browser cache and wiping out all existing cookies won't help.

what have I missed?

Answer 1

All kinds of session settings can differ per-dir. Note that these can be set in php configuration, host configuration, per-dir configuration (in apache: .htaccess), but also in code .

To determine what differs, inspecting the output of ini_get_all('session') at the point in the code you use the session probably shows the difference in settings.

With the described symptoms (session id is the same for the different dirs, but the stored content varies), the most likely reasons are that either save_handler is different (another mechanism is used to store the session, eg files vs. memcached), or save_path is different (another location is used for storing the sessions). In this case it was the save_path according to the comments.

Note that if the session-id is different in the 2 directories, the most likely cause is an incorrect cookie_path setting, if it differs between subdomains, look at the cookie_domain setting.