Blog : How to Upload a File using PHP cURL

How to Upload a File using PHP cURL

Here's how to upload a file to a server using PHP cURL. It took me a little longer than planned to sort this one out, as the API I was communicating with required the top level key in the post data array to be 'file'. See my note below.

// Helper function courtesy of https://github.com/guzzle/guzzle/blob/3a0787217e6c0246b457e637ddd33332efea1d2a/src/Guzzle/Http/Message/PostFile.php#L90
function getCurlValue($filename, $contentType, $postname)
{
  // PHP 5.5 introduced a CurlFile object that deprecates the old @filename syntax
  // See: https://wiki.php.net/rfc/curl-file-upload
  if (function_exists('curl_file_create')) {
  return curl_file_create($filename, $contentType, $postname);
  }
 
  // Use the old style if using an older version of PHP
  $value = "@{$this->filename};filename=" . $postname;
  if ($contentType) {
  $value .= ';type=' . $contentType;
  }
 
  return $value;
}
 
$filename = '/path/to/file.jpg';
$cfile = getCurlValue($filename,'image/jpeg','cattle-01.jpg');
 
//NOTE: The top level key in the array is important, as some apis will insist that it is 'file'.
$data = array('file' => $cfile);
 
$ch = curl_init();
$options = array(CURLOPT_URL => 'http://your/server/api/upload',
  CURLOPT_RETURNTRANSFER => true,
  CURLINFO_HEADER_OUT => true, //Request header
  CURLOPT_HEADER => true, //Return header
  CURLOPT_SSL_VERIFYPEER => false, //Don't veryify server certificate
  CURLOPT_POST => true,
  CURLOPT_POSTFIELDS => $data
  );
 
curl_setopt_array($ch, $options);
$result = curl_exec($ch);
$header_info = curl_getinfo($ch,CURLINFO_HEADER_OUT);
$header_size = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
$header = substr($result, 0, $header_size);
$body = substr($result, $header_size);
curl_close($ch);
 
?>
 



 
 
 

Raw Result:
 

Header Sent:

Header Received:

 

Body: