title: using ruby to test if a directory is writable?
body: <p>Using ruby how can i test if a directory is writable?</p>
  
  <p>There is a command:
   <code>FileUtils.writable?(file_name)</code> </p>
  
  <p>That test if a file is writable.</p>
  
  <p>Does it do it for directories as well?</p>