stream_copy_to_stream() always returns 0 - php

Question

I'm using Fine-Uploader with PHP and something wrong happened. When I use stream_copy_to_stream() in the backend, it always returns 0.
Here's my code in the backend:
private function upload_file($file_name, $tmp_name)
{
$result = array(
'is_successful' => true,
'extra_message' => ''
);
$target_path = $this->get_target_file_path($file_name, $tmp_name);
move_uploaded_file($tmp_name, $target_path);
$result['is_successful'] = $this->handle_upload_request($target_path);
if ( $result['is_successful'] ) {
$result['extra_message'] = $target_path;
} else {
$result['extra_message'] = 'Unknown error occured.<br />';
}
return $result;
}
private function handle_upload_request($path)
{
$input = fopen("php://input", "r");
$temp = tmpfile();
$real_size = stream_copy_to_stream($input, $temp);
fclose($input);
echo $real_size;
if ($real_size != $this->get_size()){
return false;
}
$target = fopen($path, "w");
fseek($temp, 0, SEEK_SET);
stream_copy_to_stream($temp, $target);
fclose($target);
return true;
}
However, the $real_size always equal to 0. Strangely, the file can be uploaded successfully sometimes, but sometimes not.
I think maybe it's due to permission in Linux. Because I found that when I uploaded a file, the mod of the file is 644(But I think 644 is enough). And this problem also exists in Windows.
What's wrong with it?

Answer 1

You should not be using php://input. php://input is used to access the raw request body. It is empty for multipart encoded requests. All upload requests sent by Fine Uploader are multipart encoded by default. Instead, you should grab the file associated with the request using the $_FILES superglobal. There is a functional PHP example which will demonstrate this and more for you in the Fine Uploader server Github repo.
If you insist on writing your own PHP code to handle the requests, you really need to read the traditional server-side documentation for Fine Uploader first, which tells you that all upload requests are multipart encoded by default. This is set to the default in order to make it a bit easier to handle upload requests cross-browser, since we need to send the files in a MPE request from IE9 and older always anyway, since IE9 and older do not support uploading files via ajax requests (XHR2).