unexpected T_VARIABLE, expecting T_FUNCTION

You can not put

$connection = sqlite_open("[path]/data/users.sqlite", 0666);

outside the class construction. You have to put that line inside a function or the constructor but you can not place it where you have now.

You cannot use function calls in a class construction, you should initialize that value in the constructor function.

From the PHP Manual on class properties:

This declaration may include an initialization, but this initialization must be a constant value--that is, it must be able to be evaluated at compile time and must not depend on run-time information in order to be evaluated.

A working code sample:

<?php    class UserDatabaseConnection    {        public $connection;        public function __construct()        {            $this->connection = sqlite_open("[path]/data/users.sqlite", 0666);        }        public function lookupUser($username)        {            // rest of my code...            // example usage (procedural way):            $query = sqlite_exec($this->connection, "SELECT ...", $error);            // object oriented way:            $query = $this->connection->queryExec("SELECT ...", $error);        }    }    $udb = new UserDatabaseConnection;?>

Depending on your needs, protected or private might be a better choice for $connection. That protects you from accidentally closing or messing with the connection.

Use access modifier before the member definition:

    private $connection;

As you cannot use function call in member definition in PHP, do it in constructor:

 public function __construct() {      $this->connection = sqlite_open("[path]/data/users.sqlite", 0666); }