title: extract middle of string with pure bash
body: <p>Say I have... 
  string='first/second/third'</p>
  
  <p>how can I extract 'second' from string using pure bash only (not awk/sed etc.) and in 1 line?</p>
  
  <p>I know I can do ${string#*/} to get 'second/third' but what about just 'second'</p>
  
  <p>Thanks!</p>