title: Get bash read command to understand spaces only
body: <p>I need to have the following work:</p>
  
  <pre><code>$ read -r -p 'input: ' foo
  input: &lt;space&gt;&lt;space&gt;&lt;space&gt;
  $ echo "text""$foo""more text"
  text   more text
  </code></pre>
  
  <p>Where <code>&lt;space&gt;&lt;space&gt;&lt;space&gt;</code> is replaced with actual spaces.</p>
  
  <p>However this is only possible if I set the variable manually:</p>
  
  <pre><code>$ foo='   '
  $ echo "text""$foo""more text"
  text   more text
  </code></pre>
  
  <p>I thought using <code>-r</code>, aka raw, would not mess with input like this. How can I perform such a task?</p>
  
  <p>Using bash 3.2.57(1)-release under El Capitan, but am willing to install 3rd party tools if needed.</p>