title: What is the difference between $(command) and `command` in shell programming?
body: <p>To store the output of a command as a variable in sh/ksh/bash, you can do either</p>
  
  <pre><code>var=$(command)
  </code></pre>
  
  <p>or</p>
  
  <pre><code>var=`command`
  </code></pre>
  
  <p>What's the difference if any between the two methods?</p>