title: How to convert a string to lower case in Bash
body: <p>Is there a way in <a href="/questions/tagged/bash" class="post-tag" title="show questions tagged &#39;bash&#39;" rel="tag">bash</a> to convert a string into a lower case string?</p>
  
  <p>For example, if I have:</p>
  
  <pre><code>a="Hi all"
  </code></pre>
  
  <p>I want to convert it to:</p>
  
  <pre><code>"hi all"
  </code></pre>