addConfigDir() — add a directory to the list of directories where config files are stored
Smarty addConfigDir(string|array config_dir,
                    string key);Example 14.1. addConfigDir()
<?php
// add directory where config files are stored
$smarty->addConigDir('./config_1');
// add directory where config files are stored and specify array-key
$smarty->addConfigDir('./config_1', 'one');
// add multiple directories where config files are stored and specify array-keys
$smarty->addTemplateDir(array(
    'two' => './config_2',
    'three' => './config_3',
));
// view the template dir chain
var_dump($smarty->getConfigDir());
// chaining of method calls
$smarty->setConfigDir('./config')
       ->addConfigDir('./config_1', 'one')
       ->addConfigDir('./config_2', 'two');
?>
   
   See also
   getConfigDir(),
   setConfigDir() and
   $config_dir.