Sending a HTTP DELETE to the Atom representation of a folder or file will purge it completely. Please note: there is no undo and this is a single-step process; once files are deleted they are deleted for good - if you delete a folder, all files beneath it will also be deleted. We do not need to send any extra content with the DELETE.

mat@augustus:~$ curl -i -X DELETE -u cuscav
   "https://files.warwick.ac.uk/files/api/atom/node?account=mmannion&path=mmannion%2FFiles%2Frenamed+folder%2Fmountains.jpg"
Enter host password for user 'cuscav':

HTTP/1.1 200 OK
Date: Tue, 05 Mar 2013 16:09:03 GMT
Content-Length: 0
  

No content is returned in the response body for a DELETE.