function file_transfer

7.x file.inc file_transfer($uri, $headers)
6.x file.inc file_transfer($source, $headers)

Transfer file using http to client. Pipes a file through Drupal to the client.

Parameters

$source File to transfer.:

$headers An array of http headers to send along with file.:

Related topics

File interface
Common file handling functions.
1 call to file_transfer()
file_download in drupal-6.x/includes/file.inc
Call modules that implement hook_file_download() to find out if a file is accessible and what headers it should be transferred with. If a module returns -1 drupal_access_denied() will be returned. If one or more modules returned headers the download…

File

drupal-6.x/includes/file.inc, line 923
API for handling file uploads and server file management.

Code

function file_transfer($source, $headers) {
  if (ob_get_level()) {
    ob_end_clean();
  }

  // IE cannot download private files because it cannot store files downloaded
  // over HTTPS in the browser cache. The problem can be solved by sending
  // custom headers to IE. See http://support.microsoft.com/kb/323308/en-us
  if (isset($_SERVER['HTTPS']) && ($_SERVER['HTTPS'] == 'on')) {
    drupal_set_header('Cache-Control: private');
    drupal_set_header('Pragma: private');
  }

  foreach ($headers as $header) {
    // To prevent HTTP header injection, we delete new lines that are
    // not followed by a space or a tab.
    // See http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.2
    $header = preg_replace('/\r?\n(?!\t| )/', '', $header);
    drupal_set_header($header);
  }

  $source = file_create_path($source);

  // Transfer file in 1024 byte chunks to save memory usage.
  if ($fd = fopen($source, 'rb')) {
    while (!feof($fd)) {
      print fread($fd, 1024);
    }
    fclose($fd);
  }
  else {
    drupal_not_found();
  }
  exit();
}