title: Regex to match specific strings without a given prefix
body: <p>I need to match all of its lines that contains a value and that don't have a given prefix.</p>
  
  <p>Example:
  I want all lines that contains <code>word</code> when it's not prefixed by <code>prefix</code></p>
  
  <p>So:</p>
  
  <pre><code>foobar -&gt; no match
  prefix word -&gt; no match
  prefix word suffix -&gt; no match
  word -&gt; MATCH
  something word -&gt; MATCH
  </code></pre>
  
  <p>What I've tried so far:</p>
  
  <pre><code>(?!prefix)word
  </code></pre>
  
  <p>Doesn't seem to do what I want </p>