PHP : Trouble developing CURL request for file upload to API - php

Question

I am having this problem from last few days to develop a CURL request in php to post file data to an API.
Here is the CURL request
$ curl --request POST \
--url 'UPLOAD_URL' \
--upload-file 'PATH_TO_FILE' \
--header 'Authorization: Bearer YOUR_ACCESS_TOKEN'
for PATH_TO_FILE I have tried each and every method published over the web and stackoverflow too.
here is my PHP code
<?php
header('Content-Type: application/json');
$sheader = array('Authorization: Bearer '.$_SESSION['access_token']);
$filename = $_FILES['upload-file']['name'];
$filedata = $_FILES['upload-file']['tmp_name'];
$filesize = $_FILES['upload-file']['size'];
$filetype = $_FILES['upload-file']['type'];
if($filename != '')
{
$ch = curl_init();
$cFile = new CURLFile(realpath($filename), $filetype, 'harish.jpg');
//$cFile = '#'. realpath($filename);
$data = array('upload-file' => $cFile);
curl_setopt($ch, CURLOPT_POSTFIELDS, $cFile);
//curl_setopt($ch, CURLOPT_POSTFIELDS, realpath($filename));
curl_setopt($ch, CURLOPT_URL, $_POST['upload_url']);
curl_setopt($ch, CURLOPT_HTTPHEADER, $sheader);
curl_exec($ch);
echo json_encode($ch);
//echo json_encode(array('filename'=>$filename, 'temp_path'=>$filedata, 'basepath'=>realpath($filename)));
} else {
echo 'There is no file selected';
}
Mostly the solution i have found on the web are these two mentioned below
Method 1 (for php < 5.5)
'#'.$filepath
Method 2 (for php > 5.5)
CURLFile($filename, $filetype, 'somefile.jpg');
or
curl_file_create($filedata, 'image/jpeg', $filename);
None of the above worked for me. I have use realpath($filename) too inside CURLFile to fetch absolute path of the file, but sadly that also not worked.

Answer 1

I admit that CURLFile documentation is slightly ambiguous but the first constructor argument, $name, is in fact the physical path to the actual file you want to send, not the "friendly" name (which goes in the optional third argument, $postname). You should note there's something wrong since you never tell Curl about $_FILES['upload-file']['tmp_name']—it has no way to know what file you want to send.
So:
$filename = $_FILES['upload-file']['name'];
$filedata = $_FILES['upload-file']['tmp_name'];
$filesize = $_FILES['upload-file']['size'];
$filetype = $_FILES['upload-file']['type'];
$cFile = new CURLFile($filedata, $filetype, 'harish.jpg')
You aren't being notified about this because you're skipping error checking. You don't check the return value of any function, neither call curl_error() anywhere in your code.
One more error you have is that you pass the CURLFile instance this way:
curl_setopt($ch, CURLOPT_POSTFIELDS, $cFile);
Correct syntax should be like:
curl_setopt($ch, CURLOPT_POSTFIELDS, ['give_a_nice_post_name_here' => $cFile]);