title: Regular expression in bash s character
body: <p>I have very strange issue with s character. 
  This works: </p>
  
  <pre><code>[[ "import scala" =~ ^import\s*.+cala$ ]] &amp;&amp; echo "yes"
  </code></pre>
  
  <p>but this doesn't work: </p>
  
  <pre><code>[[ "import scala" =~ ^import\s*scala$ ]] &amp;&amp; echo "yes"
  </code></pre>
  
  <p>I tried to escape s and but it didn't works. 
  How to solve this issue? </p>