In my CURL CURLOPT_PROGRESSFUNCTION callback, dltotal is always 0

NOTE: for libcurl older than 7.32.0

the callback function need has the following format

curl_progress_callback($resource,$dltotal, $dlnow, $ultotal, $ulnow)

where as newer curl binary does not require the resource

curl_progress_callback($dltotal, $dlnow, $ultotal, $ulnow)

check your curl version version with

curl -V

Try this with removing the class:

curl_setopt($curl, CURLOPT_PROGRESSFUNCTION, 'curl_progress_callback');

Then remove the first parameter from the callback.

function curl_progress_callback($dltotal, $dlnow, $ultotal, $ulnow){   ...}

UPDATE: A working code: Try to run it from your end.

function getFile(){  $fp = fopen ("output.html", 'w+');  $curl = curl_init();  curl_setopt($curl,CURLOPT_URL,'http://www.mashable.com/');  curl_setopt($curl, CURLOPT_TIMEOUT, 1000);  curl_setopt($curl, CURLOPT_FILE, $fp);  curl_setopt($curl, CURLOPT_FOLLOWLOCATION, true);  curl_setopt($curl, CURLOPT_NOPROGRESS, 0);  curl_setopt($curl, CURLOPT_PROGRESSFUNCTION, 'curl_progress_callback');  $result = curl_exec($curl);  fclose($fp);}function curl_progress_callback($dltotal, $dlnow, $ultotal, $ulnow){    echo "$dltotal\n";    echo "$dlnow\n";}getFile();

The problem seems to be that the website I'm requesting isn't sending an http content-length so dltotal is always empty. Thanks to @Subuj Hassan for correcting my error in my curl_progress_callback which had one too many values and made me originally think that the issue was with the dlnow value.