gistfile1.txt

$square_url = 'https://connect.squareup.com/v1/me/items/27/image';

$cfile = new CURLFile('sites/default/files/styles/artists_page/public/artists/grant.png', 'image/png', 'image_data');
$image_data = array('image_data' => $cfile);

$curl = curl_init();
curl_setopt($curl, CURLOPT_HTTPHEADER, array(
  'Authorization: Bearer ' . $access_token,
  'Content-Type: multipart/form-data; boundary=BOUNDARY',
  'Accept: application/json'
));
curl_setopt($curl, CURLOPT_POSTFIELDS, $image_data);
curl_setopt($curl, CURLOPT_URL, $square_url);
curl_setopt($curl, CURLOPT_POST, TRUE);
curl_setopt($curl, CURLOPT_SAFE_UPLOAD, TRUE);
curl_setopt($curl, CURLOPT_BINARYTRANSFER, TRUE);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, TRUE);
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, FALSE);
curl_setopt($curl, CURLINFO_HEADER_OUT, TRUE);
curl_setopt($curl, CURLOPT_VERBOSE, TRUE);
$json = curl_exec($curl);



echo("curl result:");
if (!$json) {
	die('Error: "' . curl_error($curl) . '" - Code: ' . curl_errno($curl));
 
}
else {
	echo $json;	
}
curl_close($curl);