How to return data using cURL call - php

Question

This returns a token, like: {"token":"260e5b8adf74af6be5dfa250c5ad93c8"}
And I want just want the content part: 260e... Which I think I can get it by using $getInfo['token'], right?
$user="admin";
$password="Moodle15!";
$services="moodle_mobile_app";
$url = "https://localhost/moodle/login/token.php?username=".$user."&password=".$password."&service=".$services."";
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURL_RETURNTRANSFER, true);
$getURL = curl_exec($ch);
$getInfo = json_decode($getURL, true);
$displayToken = $getInfo['token'];
echo $displayToken;
curl_close($ch);
And I don't know what's going on with the CURL_RETURNTRANSFER.
And the error:
Notice: Use of undefined constant CURL_RETURNTRANSFER - assumed 'CURL_RETURNTRANSFER' in C:\xampp\htdocs\moodle\cURL_script.php on line 12
Warning: curl_setopt() expects parameter 2 to be long, string given in C:\xampp\htdocs\moodle\cURL_script.php on line 12
{"token":"260e5b8adf74af6be5dfa250c5ad93c8"}
EDITED:
And if I had:
{"id":4,"username":"Jhon","firstname":"smith","lastname":"Reches","fullname":"Jhon smith","email":"Jhon.smith#example.com","department":"","firstaccess":0,"lastaccess":0,"description":"","descriptionformat":1,"profileimageurlsmall":"http:\/\/localhost\/moodle\/pluginfile.php\/25\/user\/icon\/f2","profileimageurl":"http:\/\/localhost\/moodle\/pluginfile.php\/25\/user\/icon\/f1","groups":[],"roles":[{"roleid":5,"name":"","shortname":"student","sortorder":0}],"enrolledcourses":[{"id":3,"fullname":"Game Design","shortname":"Game Design"},{"id":2,"fullname":"Grup de Recerca","shortname":"Grp. Recerca"}]}
How can I acces to 'username'? or 'fullname' when you know there are many 'fullname' in it?
EDITED2:
New code I have now:
$token = "260e5b8adf74af6be5dfa250c5ad93c8";
$funcion="core_enrol_get_enrolled_users";
$courseid="3";
$format="json";
$url= "https://localhost/moodle/webservice/rest/server.php?wstoken=".$token."&wsfunction=".$funcion."&courseid=".$courseid."&moodlewsrestformat=".$format."";
$ch = curl_init($url);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$getURL = curl_exec($ch);
$getInfo = json_decode($getURL, true);
$email = $getInfo[2]['email'];
echo $email."</br>";
curl_close($ch);
Now $email contains jhon.smith#example.com but I have many results, how can I manage to display all of them with a foreach? Because it is a multidimentional array. See below.
[{"id":4,"username":"jhon1.smith1","firstname":"Jhon1","lastname":"Smith1","fullname":"jhon1 smith1","email":"jhon1.smith1#example.cat","department":"","firstaccess":0,"lastaccess":0,"description":"","descriptionformat":1,"profileimageurlsmall":"http:\/\/localhost\/moodle\/pluginfile.php\/25\/user\/icon\/f2","profileimageurl":"http:\/\/localhost\/moodle\/pluginfile.php\/25\/user\/icon\/f1","groups":[],"roles":[{"roleid":5,"name":"","shortname":"student","sortorder":0}],"enrolledcourses":[{"id":3,"fullname":"Game Design","shortname":"Game Design"},{"id":2,"fullname":"Grup de Recerca","shortname":"Grp. Recerca"}]},{"id":5,"username":"jhon1.smith1","firstname":"Josep","lastname":"jhon1 ","fullname":"jhon1 smith1","email":"jhon1.smith1#example.cat","department":"","firstaccess":0,"lastaccess":0,"description":"","descriptionformat":1,"profileimageurlsmall":"http:\/\/localhost\/moodle\/pluginfile.php\/26\/user\/icon\/f2","profileimageurl":"http:\/\/localhost\/moodle\/pluginfile.php\/26\/user\/icon\/f1","groups":[],"roles":[{"roleid":5,"name":"","shortname":"student","sortorder":0}],"enrolledcourses":[{"id":3,"fullname":"Game Design","shortname":"Game Design"},{"id":2,"fullname":"Grup de Recerca","shortname":"Grp. Recerca"}]},{"id":6,"username":"jhon1.smith1","firstname":"jhon1","lastname":"smith1","fullname":"jhon1 smith1","email":"jhon1.smith1#example.cat","department":"","firstaccess":0,"lastaccess":0,"description":"","descriptionformat":1,"profileimageurlsmall":"http:\/\/localhost\/moodle\/pluginfile.php\/32\/user\/icon\/f2","profileimageurl":"http:\/\/localhost\/moodle\/pluginfile.php\/32\/user\/icon\/f1","groups":[],"roles":[{"roleid":1,"name":"","shortname":"manager","sortorder":0}],"enrolledcourses":[{"id":3,"fullname":"Game Design","shortname":"Game Design"},{"id":2,"fullname":"Grup de Recerca","shortname":"Grp. Recerca"}]},{"id":7,"username":"jhon1.jhon1","firstname":"jhon1","lastname":"jhon1","fullname":"jhon1 smith1","email":"jhon1.smith1#example.cat","department":"","firstaccess":0,"lastaccess":0,"description":"","descriptionformat":1,"profileimageurlsmall":"http:\/\/localhost\/moodle\/pluginfile.php\/35\/user\/icon\/f2","profileimageurl":"http:\/\/localhost\/moodle\/pluginfile.php\/35\/user\/icon\/f1","groups":[],"roles":[{"roleid":5,"name":"","shortname":"student","sortorder":0}],"enrolledcourses":[{"id":3,"fullname":"Game Design","shortname":"Game Design"}]},{"id":8,"username":"jhon1.smith1","firstname":"jhon","lastname":"smith1","fullname":"jhon1 smith1","email":"jhon1.smith1#example.cat","department":"","firstaccess":0,"lastaccess":0,"description":"","descriptionformat":1,"profileimageurlsmall":"http:\/\/localhost\/moodle\/pluginfile.php\/41\/user\/icon\/f2","profileimageurl":"http:\/\/localhost\/moodle\/pluginfile.php\/41\/user\/icon\/f1","groups":[],"roles":[{"roleid":3,"name":"","shortname":"editingteacher","sortorder":0}],"enrolledcourses":[{"id":3,"fullname":"Game Design","shortname":"Game Design"}]}]
and I wish:
foo#example.com
bar#example.com
foo2#..

Answer 1

CURL_RETURNTRANSFER needs to be changed to CURLOPT_RETURNTRANSFER.
That is affecting what is returned by curl_exec() so you aren't getting the JSON string in $getURL.
Once the constant is corrected, the rest of your code is correct.
EDIT (added):
When dealing with JSON, it helps to format it so it's easier to read, I use jsonlint.com.
Then looking at the structure, if you had:
$data = json_decode($response, true);
Accessing the fullnames from enrolledcourses would be:
echo $data['enrolledcourses'][0]['fullname'];
Or if you were using object notation, rather than associative array:
echo $data->enrolledcourses[0]->fullname;