Sharing SESSION Variables Between Multiple Subdomains

php subdomain session-variables
Kevin Oluseun Karimu picture Kevin Oluseun Karimu · Feb 5, 2012 · Viewed 39.8k times · Source

I have a website www.example.com. That will have multiple subdomains that work with a single application or program. For an example, login.example.com will allow the user to log in to the site while system.example.com will allow the user to access an information system, while forums.example.com will allow the user to access forums.

We may need to pass information between the subdomains such as a user id, or a user preference, etc. How do we go about passing information between the sudomains using SESSION variables?

EDIT: I like this idea:

As the first thing in your script:

ini_set('session.cookie_domain', '.example.com' );

Answer

Shiplu Mokaddim picture Shiplu Mokaddim · Feb 5, 2012

PHP session ids are saved in Cookies. To make a cookie available in all the sub-domains you need to assign it to the root domain. Then all the sub-domains will get the session id from cookie and PHP can find the session using passed session id.

As it turns out, You just need to set the session.cookie_domain to the root domain in php.ini file

session.cookie_domain = ".example.com"

Also check manual for different approaches used to set an ini entry.

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