title: How can I switch from forward to backward in Interactive search/replace regex in Vim?
body: <p>For example I have some text:</p>
  
  <pre><code>    'y'     to substitute this match
      'l'     to substitute this match and then quit ("last")
      'n'     to skip this match
      &lt;Esc&gt;   to quit substituting
      'a'     to substitute this and all remaining matches {not in Vi}
      'q'     to quit substituting {not in Vi}
  </code></pre>
  
  <p>and by <code>:%s/substitute/sub/gc</code> I can interactively search/replace. If I press 'n' it goes to the next matched pattern, how can I undo 'n'? or search backwards?</p>
  
  <p>In usual search mode <code>/search_word</code> we can skip by 'n' and 'N' is there something similar for substitute - <code>:%s/substitute/sub/gc</code> ?</p>