$cache_dir
This is the name of the directory where template caches are
stored. By default this is
"./cache", meaning that
Smarty will look for the cache directory in the same directory
as the executing php script.
This directory must
be writeable by the web server
(see install).
You can also use your own
custom cache handler
function to control cache files, which will ignore this
setting.
See also
$use_sub_dirs.
Technical Note:
This setting must be either a relative or
absolute path. include_path is not used for writing files.
Technical Note:
It is not recommended to put this directory under
the web server document root.
See also
$caching,
$use_sub_dirs,
$cache_lifetime,
$cache_handler_func,
$cache_modified_check
and
Caching section.