session_id

(PHP 4 , PHP 5)

session_id -- Get and/or set the current session id

Description

string session_id ( [string id])

session_id() returns the session id for the current session.

If id is specified, it will replace the current session id. session_id() needs to be called before session_start() for that purpose. Depending on the session handler, not all characters are allowed within the session id. For example, the file session handler only allows characters in the range a-z, A-Z and 0-9!

Note: When using session cookies, specifying an id for session_id() will always send a new cookie when session_start() is called, regardless if the current session id is identical to the one being set.

The constant SID can also be used to retrieve the current name and session id as a string suitable for adding to URLs. Note that SID is only defined if the client didn't send the right cookie. See also Session handling.

See also session_start(), session_set_save_handler(), and session.save_handler.