Some additional notes for curlopt_writefunction. I struggled with this at first because it really isn't documented very well.
When you write a callback function and use it with curlopt_writefunction it will be called MULTIPLE times. Your function MUST return the ammount of data written to it each time. It is very picky about this. Here is a snippet from my code that may help you
<?php
curl_setopt($this->curl_handle, CURLOPT_WRITEFUNCTION, array($this, "receiveResponse"));
private function receiveResponse($curlHandle,$xmldata)
{
$this->responseString = $xmldata;
$this->responseXML .= $this->responseString;
$this->length = strlen($xmldata);
$this->size += $this->length;
return $this->length;
}
?>
Now I did this for a class. If you aren't doing OOP then you will obviously need to modify this for your own use.
CURL calls your script MULTIPLE times because the data will not always be sent all at once. Were talking internet here so its broken up into packets. You need to take your data and concatenate it all together until it is all written. I was about to pull my damn hair out because I would get broken chunks of XML back from the server and at random lengths. I finally figured out what was going on. Hope this helps