title: How do I specify "the word under the cursor" on VIM's commandline?
body: <p>I want to write a command that specifies "the word under the cursor" in VIM.  For instance, let's say I have the cursor on a word and I make it appear twice.  For instance, if the word is "abc" and I want "abcabc" then I could type:  </p>
  
  <pre><code>:s/\(abc\)/\1\1/
  </code></pre>
  
  <p>But then I'd like to be able to move the cursor to "def" and use the same command to change it to "defdef":  </p>
  
  <pre><code>:s/\(def\)/\1\1/
  </code></pre>
  
  <p>How can I write the command in the commandline so that it does this?</p>
  
  <pre><code>:s/\(*whatever is under the commandline*\)/\1\1
  </code></pre>