Question

I have the following function:

if (isset($_REQUEST["f"]))
{
  //get file details from database
  $fileID=$_REQUEST["f"];
  $sql = "select * from sds_files where file_id = " .fquery_sanitize($fileID);
  $result = fquery_db($sql);

  //$file_extension = strtolower(substr(strrchr($filename,"."),1));
  if(mysql_num_rows($result) >0)
  {
    $row = mysql_fetch_assoc($result);
    $filename = $row['file_name'];
    $file = file_GetPath($fileID); 

    header ("Cache-Control: must-revalidate, post-check=0, pre-check=0");
    header('Content-Type: application/octetstream');
    header("Content-Transfer-Encoding: Binary");
    header("Content-length: ".filesize($file));
    header("Content-disposition: attachment; filename=\"".basename($filename)."\"");
    readfile("$file");                
  }
  else
  {
    echo "File cannot be found";
  }
}
else
{
    echo "No file selected";
}

this gets a file, which could be any type, .xls, .doc .dox, .pdf etc…

For most pdfs this code works, but in isolated cases, I get users claiming they recieve an error like “file not found”. But, if I give them a direct link to a file it works fine.

I’m at a loss to understand what the problem is, I’ve forced the attachment type so that their forced to save it rather than it come up in a browser, as in ie6 it tends to crash if you use the adobe plugin rather than the program.

EDIT:

The error comes as part of an adobe acrobat error, nothing to do with the PHP or apache error codes. More client related. I’m showing the code as the user’s behaviour is different.

I’ve looked into it a little more and it seems the direct link has a MIME type of PDF, which adobe tells the browser belongs to adobe reader, I’m wondering whether save as will force the same behaviour to cause the error.

Any help would be appreciated!

Answer 1

Ok it seems to be isolated to:

header(“Content-disposition: attachment;….

This forces the browser to download to content and not use the browser plugin, which leads to permissions problems on some user setups.