title: How to use non-capturing groups in grep?
body: <p><a href="https://stackoverflow.com/a/4825089/266309">This answer</a> suggests that <code>grep -P</code> supports the <code>(?:pattern)</code> syntax, but it doesn't seem to work for me (the group is still captured and displayed as part of the match). Am I missing something?</p>
  
  <p>I am trying <code>grep -oP "(?:syntaxHighlighterConfig\.)[a-zA-Z]+Color" SyntaxHighlighter.js</code> on <a href="http://www.mediawiki.org/wiki/User:Remember_the_dot/Syntax_highlighter.js" rel="noreferrer">this code</a>, and expect the results to be:</p>
  
  <pre><code>wikilinkColor
  externalLinkColor
  parameterColor
  ...
  </code></pre>
  
  <p>but instead I get:</p>
  
  <pre><code>syntaxHighlighterConfig.wikilinkColor
  syntaxHighlighterConfig.externalLinkColor
  syntaxHighlighterConfig.parameterColor
  ...
  </code></pre>