title: Posix regular expression non capturing group
body: <p>I'm writing a simple shell in C under linux. I'm trying to parse user input with POSIX regex with group capturing. My problem is I dont want to capture all the groups, but the ?: symbol desnt seem to work for me.</p>
  
  <pre><code>"^(?:[A-Za-z0-9]+)( [A-Za-z0-9]*(?:\"[^\"]*\")*(?:\'[^\']*\')*[A-Za-z0-9]*)*&amp;?$"
  </code></pre>