string session_save_path(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.
Note: 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 ext2fs.
Note: This function was added in PHP 4.0.