Question

I’ve got question to you. I have got two project in PHP that uses captcha, and write it to session. My question is, if I fire first application, that saves captcha to $_SESSION['code'] and then I start second application where I saves captcha to same variable, then the first value will be overwritten by second, or PHP will create two independent sessions?

Answer 1

Normally, each application will override the session variables on the same server.

To avoid this, you can either namespace your sessions or use the session_name function.

You can namespace manually, by setting $_SESSION['app1']['code'] and $_SESSION['app2']['code'] or by using a session abstraction library like the one from Symfony or Zend Framework.

Using session_name in each application could look like this:

//Other init stuff here
define('APPLICATION_ID', "MY_UNIQUE_ID_1");
session_name(APPLICATION_ID);
session_start(); 

You’ll have to change the unique id in some configuration file for each application. I put a define here to show that it doesn’t come out of thin air.