CURL call works in terminal, but it won't in PHP - php

Question

I've been searching through extensively, but couldn't find any topics which are really related to my problem, so I decided to ask a new question...
I'm trying to issue a batch request to the Facebook Graph API using CURL, which works fine in Terminal, but it simply won't in PHP...
Steps to reproduce:
1.) Obtain an access token for yourself from the Graph API Explorer (no permissions needed, just a valid token) Link: http://developers.facebook.com/tools/explorer
2.) Paste it in the following terminal command: (PLEASE be careful, you need to paste it in 4 placeholders in total to work correctly!)
curl \
-F 'access_token=PASTE_ACCESS_TOKEN_HERE' \
-F 'batch=[{"method":"GET","relative_url":"fql?q=SELECT+name+FROM+user+WHERE+uid%3Dme%28%29&access_token=PASTE_ACCESS_TOKEN_HERE"},{"method":"GET","relative_url":"fql?q=SELECT+name+FROM+user+WHERE+uid%3Dme%28%29&access_token=PASTE_ACCESS_TOKEN_HERE"},{"method":"GET","relative_url":"fql?q=SELECT+name+FROM+user+WHERE+uid%3Dme%28%29&access_token=PASTE_ACCESS_TOKEN_HERE"}]' \
https://graph.facebook.com
3.) Execute it in terminal, it should return lots of headers, and your name 4 times in the body section (JSON encoded).
4.) Until now, everything should be working. Here comes the bad part, paste your token again in the 4 placeholders in the following PHP script:
<?php
$url = 'https://graph.facebook.com';
$fields = array(
'access_token' => 'PASTE_ACCESS_TOKEN_HERE',
'batch' =>
'[{"method":"GET","relative_url":"fql?q=SELECT+name+FROM+user+WHERE+uid%3Dme%28%29&access_token=PASTE_ACCESS_TOKEN_HERE"},{"method":"GET","relative_url":"fql?q=SELECT+name+FROM+user+WHERE+uid%3Dme%28%29&access_token=PASTE_ACCESS_TOKEN_HERE"},{"method":"GET","relative_url":"fql?q=SELECT+name+FROM+user+WHERE+uid%3Dme%28%29&access_token=PASTE_ACCESS_TOKEN_HERE"}]'
);
//url-ify the data for the POST
foreach($fields as $key=>$value) { $fields_string .= $key.'='.$value.'&'; }
$fields_string = rtrim($fields_string, '&');
//open connection
$ch = curl_init();
//set the url, number of POST vars, POST data
curl_setopt($ch,CURLOPT_URL, $url);
curl_setopt($ch,CURLOPT_POST, count($fields));
curl_setopt($ch,CURLOPT_POSTFIELDS, $fields_string);
//execute post
$result = curl_exec($ch);
//close connection
curl_close($ch);
print_r($result);
?>
6.) Run the code, and you should (at least I do...) get the following error message from Facebook: '{"error":{"message":"Malformed access token ACCESS_TOKEN_HERE....\"}]","type":"OAuthException","code":190}}1'
I guess that Facebook thinks that the JSON closing braces are part of the access token, and because of that it will return this error. I tried removing the escaped double quote and braces from the end of $fields['batch'] , but then it throws another error stating that the batch parameter must be a JSON string (obviously...)
Am I missing something or is this Facebook's fault (if so, I don't understand why the Terminal solution works...)?
Here are the official Facebook Docs BTW:
http://developers.facebook.com/docs/reference/api/batch
Thanks in advance!
EDIT:
I found a (temporary) workaround, this will work (of course, since it uses a shell script):
<?php
$result = shell_exec('curl \
-F \'access_token=PASTE_ACCESS_TOKEN_HERE\' \
-F \'batch=[{"method":"GET","relative_url":"fql?q=SELECT+name+FROM+user+WHERE+uid%3Dme%28%29&access_token=PASTE_ACCESS_TOKEN_HERE"},{"method":"GET","relative_url":"fql?q=SELECT+name+FROM+user+WHERE+uid%3Dme%28%29&access_token=PASTE_ACCESS_TOKEN_HERE"},{"method":"GET","relative_url":"fql?q=SELECT+name+FROM+user+WHERE+uid%3Dme%28%29&access_token=PASTE_ACCESS_TOKEN_HERE"}]\' \
https://graph.facebook.com');
print_r(json_decode($result),true);
?>
Does somebody know why this is a worse solution (I suppose it is) than using PHP-cURL?
I read somewhere that you shouldn't use shell scripts in PHP, I don't know why though...
Thanks!

Answer 1

I ran the first half of your code just to see what the contents of $fields_string would be before starting any of the curl commands. For some reason rtrim is not removing the last ampersand in the string for me. Perhaps use this instead to remove the last character:
$fields_string = substr($fields_string, 0, -1);