"Unauthorized"]); exit; } $usersFile = USERS_DIR . USERS_FILE; $users = []; if (file_exists($usersFile)) { $lines = file($usersFile, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES); foreach ($lines as $line) { $parts = explode(':', trim($line)); if (count($parts) >= 3) { // Validate username format: if (preg_match(REGEX_USER, $parts[0])) { $users[] = [ "username" => $parts[0], "role" => trim($parts[2]) ]; } } } } echo json_encode($users); ?>