title: How to remove untracked files in SVN
body: <p>How can I remove all untracked files from an SVN checkout with the <code>svn</code> command line tool? Git and Hg offer <code>clean</code> and <code>purge</code> commands for this purpose, but I can't find the corresponding command in SVN.</p>
  
  <p>I don't care if I have to revert all my local modifications in the process (in which case I'd essentially want to restore my checkout to a pristine state) or whether local modifications to tracked files can remain intact; either situation is acceptable.</p>