( [string path] )
session_save_path() returns the path of the current
directory used to save session data. If path
is specified, the path to which data is saved will be changed.
session_save_path() needs to be called before
session_start() for that purpose.
On some operating systems, you may want to specify a path on a
filesystem that handles lots of small files efficiently. For
example, on Linux, reiserfs may provide better performance than
See also the session.save_path