file_transfer

5 file.inc	`file_transfer($source, $headers)`
6 file.inc	`file_transfer($source, $headers)`
7 file.inc	`file_transfer($uri, $headers)`
8 file.inc	`file_transfer($uri, $headers)`

Transfer file using HTTP to client.

Pipes a file through Drupal to the client.

Parameters

$uri: String specifying the file URI to transfer.

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

▸ 2 functions call file_transfer()

▾ 2 functions call file_transfer()

file_download in includes/file.inc: Menu handler for private file transfers.
image_style_deliver in modules/image/image.module: Menu callback; Given a style and image path, generate a derivative.

File

includes/file.inc, line 1923: API for handling file uploads and server file management.

Code

<?php
function file_transfer($uri, $headers) {
  if (ob_get_level()) {
    ob_end_clean();
  }

  foreach ($headers as $name => $value) {
    drupal_add_http_header($name, $value);
  }
  drupal_send_headers();
  $scheme = file_uri_scheme($uri);
  // Transfer file in 1024 byte chunks to save memory usage.
  if ($scheme && file_stream_wrapper_valid_scheme($scheme) && $fd = fopen($uri, 'rb')) {
    while (!feof($fd)) {
      print fread($fd, 1024);
    }
    fclose($fd);
  }
  else {
    drupal_not_found();
  }
  drupal_exit();
}
?>

Comments

Note about the headers

Posted by joe casey on February 7, 2011 at 11:21pm

Note that the comment by jpwarren00 for the Drupal 6 version of this call does not apply to Drupal 7. Use an associative array, as in:
'Content-Type' => 'application/octet-stream'
Also, for public files, the uri should be relative to the public file system path, which is sites/default/files by default.

After file_transfer() inside form submit no code is executed

Posted by rgutierrezc on December 20, 2011 at 12:34pm

<?php
function my_form_submit($form, $form_state) {

    $headers = array(...);
    $path_to_file = "/bla/bla/blabla";
    file_transfer($path_to_file, $headers);
    
     //Any code here won't be executed
     //I guess it's due to drupal_exit() inside file_transfer()
     //Help someone?

}
?>

Sub

Posted by gilzero on January 17, 2012 at 4:08pm

+1. Also wondering.

Yes, either drupal_exit or

Posted by patchrobe on January 30, 2012 at 12:06pm

Yes, either drupal_exit or drupal_not_found is called by file_transfer dependent on the success or failure of transferring the file (you can find the function defined in includes/file.inc). I'm no authority on this, but I'm supposing the thinking is that calling file_transfer is quite a final action to take. You have to send headers followed by file content to the browser and once that's done there's nothing more you can do in terms of loading the page. Can you achieve the results you want by running your code before calling file_transfer?