Testing php / mysqli connection

mysqli_connect() always returns a MySQLi object. To check for connection errors, use:

$mysqli_connection = new MySQLi('localhost', 'user', 'pass', 'db');
if ($mysqli_connection->connect_error) {
   echo "Not connected, error: " . $mysqli_connection->connect_error;
}
else {
   echo "Connected.";
}

For test php connection in you terminal execute:

$ php -r 'var_dump(mysqli_connect("localhost:/tmp/mysql.sock", "MYSQL_USER", "MYSQL_PASS",
     "DBNAME));'