title: Regex expression to exclude both prefix and suffix
body: <p>I'm trying to build an expression which will match all text <strong>EXCLUDING</strong> text with prefix <code>'abc'</code> <strong>AND</strong> suffix <code>'def'</code> (text which only has the prefix <strong>OR</strong> the suffix is ok).</p>
  
  <p>I've tried the following:
  <code>^(?!([a][b][c]])).*(?!([d][e][f])$)</code>, but it doesn't match text which only has one of the criterias (i.e. abc.xxx fails, as well as xxx.pdf, though they should pass)</p>
  
  <p>I understand the answer is related to 'look behind' but i'm still not quite sure how to achieve this behavior</p>
  
  <p>I've also tried the following:
  <code>^(?&lt;!([a][b][c])).*(?!([d][e][f])$)</code>, but again, with no luck</p>