title: Powershell core - regular expression
body: <p>Is there a problem with regular expressions in powershell. Running on Linux.
  So, as an example.</p>
  
  <pre><code>PS&gt; "Does this get found" | select-string -Pattern "^[A-Z ]*$"
  
  Does this get found
  </code></pre>
  
  <p>But on bash shell</p>
  
  <pre><code>$ echo "Does this get found" | grep "^[A-Z ]*$"
  $ echo "DOES THIS GET FOUND" | grep "^[A-Z ]*$"
  DOES THIS GET FOUND
  </code></pre>
  
  <p>So regex acts differently. Is this a bug in powershell?</p>