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');