PHP class used to parse .htpasswd files_PHP tutorial

class Htpasswd {
private $file = '';
private $salt = 'AynlJ2H.74VEfI^BZElc-Vb6G0ezE9a55-Wj';
private function write($pairs = array()) {
$str = '';
foreach ($pairs as $username => $password) {
$str .= "$username:{SHA}$passwordn";
}
file_put_contents($this -> file, $str);
}
private function read() {
$pairs = array();
$fh = fopen($this -> file, 'r');
while (!feof($fh)) {
$pair_str = str_replace("n", '', fgets($fh));
$pair_array = explode(':{SHA}', $pair_str);
if (count($pair_array) == 2) {
$pairs[$pair_array[0]] = $pair_array[1];
}
}
return $pairs;
}
private function getHash($clear_password = '') {
if (!empty($clear_password)) {
return base64_encode(sha1($clear_password, true));
} else {
return false;
}
}
public function __construct($file) {
if (file_exists($file)) {
$this -> file = $file;
} else {
die($file." doesn't exist.");
return false;
}
}
public function addUser($username = '', $clear_password = '') {
if (!empty($username) && !empty($clear_password)) {
$all = $this -> read();
if (!array_key_exists($username, $all)) {
$all[$username] = $this -> getHash($clear_password);
$this -> write($all);
}
} else {
return false;
}
}
public function deleteUser($username = '') {
$all = $this -> read();
if (array_key_exists($username, $all)) {
unset($all[$username]);
$this -> write($all);
} else {
return false;
}
}
public function doesUserExist($username = '') {
$all = $this -> read();
if (array_key_exists($username, $all)) {
return true;
} else {
return false;
}
}
public function getClearPassword($username) {
return strtolower(substr(sha1($username.$this -> salt), 4, 12));
}
}

$passwdHandler = new Htpasswd('/home/myuser/.htpasswd');
// Add a user with name 'user1' and password 'I prefer to use passphrase rather than password.' if it doesn't exist in .htpasswd.
$passwdHandler -> addUser('user1', 'I prefer to use passphrase rather than password.');
// Delete the user 'user1' if it exists in .htpasswd.
$passwdHandler -> deleteUser('user1');
// Check if user 'user1' exists in .htpasswd.
if ($passwdHandler -> doesUserExist('user1')) {
// User 'user1' exists.
}