title: Passing and using arguments to command in Vim script
body: <p>How can I use functions in a user defined command? As a simple specific example:</p>
  <p>How would I write a command that echos the argument passed to it?</p>
  <p>I have this:</p>
  <pre><code>command -nargs=1 FW execute &quot;:echo &quot;.&lt;args&gt;
  </code></pre>
  <p>But when I run:</p>
  <pre><code>:FW something
  </code></pre>
  <p>I get:</p>
  <blockquote>
  <p>E121: Undefined variable: something</p>
  <p>E15: Invalid expression: &quot;:echo&quot;.something</p>
  </blockquote>