How to get the interest categories ids of list in mailchimp using api

Simples curl call that can pull all the interest categories ids from a list of mailchimp.

$apiKey = [YOUR-API-KEY];
$url = 'https://us18.api.mailchimp.com/3.0/lists/[YOUR-LIST-ID]/interest-categories';
$ch = curl_init($url);

curl_setopt($ch, CURLOPT_USERPWD, 'user:' . $apiKey);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_TIMEOUT, 10);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);

$result = curl_exec($ch);
$err = curl_error($ch);
curl_close($ch);

if ($err) {
    echo "cURL Error #:" . $err;
} else {
    $response = json_decode($result);
}