title: how to remove the file when "permisson denied" in R?
body: <p>My system is "win7", and I want to delete the file "workspace".</p>
  
  <pre><code>file.remove("c:\\workspace")
  # [1] FALSE
  # Warning message:
  # In file.remove("c:\\workspace") :
  # cannot remove file 'c:\workspace', reason 'Permission denied'
  </code></pre>
  
  <p>How can I give the R the power to delete it?</p>
  
  <pre><code>file.info("c:\\workspace")
  #               size isdir mode               mtime               ctime
  # c:\\workspace    0  TRUE  777 2014-01-01 14:42:51 2014-01-01 14:33:27
  #                             atime exe
  # c:\\workspace 2014-02-25 09:39:08  no
  </code></pre>