How to check for the presence of directories and remove the missing ones from the array?

Question

PHP

Hello, the structure is as follows:
/index.php - among other things, controls the redirect to the desired localization
/langs.php - contains an array with all languages

<?PHP
return array(
  array(
    'name'		=> 'Russia',
    'sysname'	=> 'ru',
  ),
  array(
    'name'		=> 'Germany',
    'sysname'	=> 'de',
  ),
  array(
    'name'		=> 'European-union',
    'sysname'	=> 'en',
  ),
  array(
    'name'		=> 'Australia',
    'sysname'	=> 'au',
  ),
);

/langs/en, ru, de - the folder contains existing localizations
. The next idea is to the index file, the langs array gets there, then it is necessary by 'sysname', check for the presence of directories and overwrite the array with only the existing ones.

Answer 1

foreach ($langs as $key => $value) {
  if (file_exists($_SERVER['DOCUMENT_ROOT'] . '/lib/langs/'. $value['sysname'] .'/index.php')) {
  }else{
    unset($langs[$key]);
  };
};

Answer 2

file_exists