example of using the Facebook PHP SDK

sample_fb.php

<?php
require '../facebook-php-sdk/src/facebook.php';

$facebook = new Facebook(array(
	'appId'  => 'YOUR_APP_ID',
	'secret' => 'YOUR_APP_SECRET',
));

$redirecturl = "REDIRECT_URL_AFTER_LOGIN_(THIS_FILE_FOR_THIS_EXAMPLE)";

//GET THE USER DATA
$user = $facebook->getUser();

//ADD THE SCOPE publish_stream SO WE CAN WRITE ON WALLS
$loginUrl = $facebook->getLoginUrl( array('scope'=>'email,publish_stream', 'redirect_uri' => $redirecturl) );

//CHECK IS USER IS LOGGED IN
if($user){
	try {
		$user_profile = $facebook->api('/me');
	} catch (FacebookApiException $e) {
		error_log($e);
		$user = null;
	}
	//LOGOUT URL (IF YOU NEED AN URL FOR THE LOGOUT BUTTON)
	$logoutUrl = $facebook->getLogoutUrl();
}else{
	//REDIRECT TO LOGIN/ADD APP URL
	echo "<script type='text/javascript'>top.location.href='$loginUrl';</script>";
	exit;
}

//GET THE ACCESS TOKEN
$access_token = $facebook->getAccessToken();

//example: SHOW AVATAR
echo "<img src='https://graph.facebook.com/".$user_profile['id']."/picture'><br/>";

//example: WRITE ON USER'S WALL
$url = "https://graph.facebook.com/".$user_profile["id"]."/feed";
$fields = "access_token=".$access_token."&message=publish to wall using Facebook PHP SDK";

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_POST, 2);
curl_setopt($ch, CURLOPT_POSTFIELDS,$fields);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1); 
curl_setopt($ch, CURLOPT_HEADER, 0);  // DO NOT RETURN HTTP HEADERS 
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);  // RETURN THE CONTENTS OF THE CALL
$rst_data = curl_exec($ch);
curl_close($ch);

if(!is_null($rst_data)) echo "<h3>WRITIN ON WALL SUCCESFUL.</h3>";

//DISPLAY THE user_profile ARRAY 
echo "<pre>";
var_dump($user_profile);
echo "</pre>";
?>