Predefined Constants
 
The constants below are defined by this extension, and
will only be available when the extension has either
been compiled into PHP or dynamically loaded at runtime.
 
  
   - 
    SID(string)
- 
    
     Constant containing either the session name and session ID in
     the form of "name=ID" or empty string
     if session ID was set in an appropriate session cookie. This is
     the same id as the one returned by session_id().
    
   
- 
    PHP_SESSION_DISABLED(int)
- 
    
     Since PHP 5.4.0. Return value of session_status() if sessions are disabled.
    
   
- 
    PHP_SESSION_NONE(int)
- 
    
     Since PHP 5.4.0. Return value of session_status() if sessions are enabled,
     but no session exists.
    
   
- 
    PHP_SESSION_ACTIVE(int)
- 
    
     Since PHP 5.4.0. Return value of session_status() if sessions are enabled,
     and a session exists.