title: Search and replace in bash using regular expressions
body: <p>I've seen this example:</p>
  
  <pre><code>hello=ho02123ware38384you443d34o3434ingtod38384day
  echo ${hello//[0-9]/}
  </code></pre>
  
  <p>Which follows this syntax: <code>${variable//pattern/replacement}</code></p>
  
  <p>Unfortunately the <code>pattern</code> field doesn't seem to support full regex syntax (if I use <code>.</code> or <code>\s</code>, for example, it tries to match the literal characters).</p>
  
  <p>How can I search/replace a string using full regex syntax?</p>