title: Require all characters of a range
body: <p>How can you look for a word which has all characters you need?</p>
  <p>For example I have the following regular expression, how can it match the 1st and the 3rd lines, instead of the 1st and 2nd?</p>
  <pre><code>[abc]+\s
  </code></pre>
  <p>To find:</p>
  <pre><code>abcb # all abc, no other letters
  abab # not all abc, no other letters
  abcd # all abc, other letters
  abdd # not all abc, other letters
  </code></pre>