Check response status code with PHP / cURL (file_get_contents_curl) - php

Question

I use this function (from here) with cURL in PHP:
<?php
function file_get_contents_curl($url) {
$ch = curl_init();
curl_setopt($ch, CURLOPT_AUTOREFERER, TRUE);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);
$data = curl_exec($ch);
curl_close($ch);
return $data;
}
This works quite well - - for example, that way I can get the 'body' of a JSON. Like this:
<?php
$crossrefurl = 'https://api.crossref.org/works/10.1163/1871191X-13020004';
$obj = file_get_contents_curl($crossrefurl);
# convert to json
$obj = json_decode($obj, true);
What I don't know is: how can I get the response status code (given that my ´curl`-commands are in a function)?
Specifically, I want to find out whether the response status code is 429 in which case I would let the script sleep for 5 seconds (to avoid being rate-limited).
According to this post, the code should be something like:
<?php
if(($httpcode == 429)) { sleep(5); }
... but how do I get to $httpcode in the first place?
Thanks for your help!