title: How to tell if a file was corrupted through a form-based web page file upload (input type="file")
body: <p>Is it possible for file corruption to occur during a form-based web page file upload?  I'm talking about when an input of type "file" is submitted as part of a form and a file is saved somewhere on the server (usually in a server-app-defined temporary upload directory).  If corruption is possible during this transfer, is there any way to tell without knowing a file's checksum before performing the upload and confirming that the checksum has not changed after the upload?</p>
  
  <p>We all upload files to various sites on a regular basis without calculating checksums in advance.  If there isn't some kind of check, are we risking corruption every time?</p>