Get twitter authorize URL with twitterOAuth

Get twitter authorize URL with twitterOAuth.php

<?php
session_start();

require "twitteroauth/autoload.php";
use Abraham\TwitterOAuth\TwitterOAuth;

define('CONSUMER_KEY', 'hoge');
define('CONSUMER_SECRET','foo');
define('OAUTH_CALLBACK', 'http://localhost');

$connection = new TwitterOAuth(CONSUMER_KEY, CONSUMER_SECRET);

$request_token = $connection->oauth('oauth/request_token', array('oauth_callback' => OAUTH_CALLBACK));

$_SESSION['oauth_token'] = $request_token['oauth_token'];
$_SESSION['oauth_token_secret'] = $request_token['oauth_token_secret'];

$url = $connection->url('oauth/authorize', array('oauth_token' => $request_token['oauth_token']));

print("<a href=\"${url}\">authorize</a>");
?>