The PHP class used to parse the.htgroup file

.htgroup file example:
admin: user2
editor: user1 user3
writer: user3

 
class Htgroup { 
private $file = ''; 
private function write($groups = array()) { 
$str = ''; 
foreach ($groups as $group => $users) { 
$users_str = ''; 
foreach ($users as $user) { 
if (!empty($users_str)) { 
$users_str .= ' '; 
} 
$users_str .= $user; 
} 
$str .= "$group: $users_str\n"; 
} 
file_put_contents($this -> file, $str); 
} 
private function read() { 
$groups = array(); 
$groups_str = file($this -> file, FILE_IGNORE_NEW_LINES); 
foreach ($groups_str as $group_str) { 
if (!empty($group_str)) { 
$group_str_array = explode(': ', $group_str); 
if (count($group_str_array) == 2) { 
$users_array = explode(' ', $group_str_array[1]); 
$groups[$group_str_array[0]] = $users_array; 
} 
} 
} 
return $groups; 
} 
public function __construct($file) { 
if (file_exists($file)) { 
$this -> file = $file; 
} else { 
die($file." doesn't exist."); 
return false; 
} 
} 
public function addUserToGroup($username = '', $group = '') { 
if (!empty($username) && !empty($group)) { 
$all = $this -> read(); 
if (isset($all[$group])) { 
if (!in_array($username, $all[$group])) { 
$all[$group][] = $username; 
} 
} else { 
$all[$group][] = $username; 
} 
$this -> write($all); 
} else { 
return false; 
} 
} 
public function deleteUserFromGroup($username = '', $group = '') { 
$all = $this -> read(); 
if (array_key_exists($group, $all)) { 
$user_index = array_search($username, $all[$group]); 
if ($user_index !== false) { 
unset($all[$group][$user_index]); 
if (count($all[$group]) == 0) { 
unset($all[$group]); 
} 
$this -> write($all); 
} 
} else { 
return false; 
} 
} 
} 

 
$groupHandler = new Htgroup('/home/myuser/.htgroup'); 
// Add user 'user1' to group 'admin' in .htgroup. Group will be automatically created if it doesn't exist. 
$groupHandler -> addUserToGroup('user1', 'admin'); 
// Delete user 'user1' from group 'admin' in .htgroup. Group will be automatically removed if it doesn't contain any users. 
$groupHandler -> deleteUserFromGroup('user1', 'admin');