title: Check if bash variable equals 0
body: <p>I have a bash variable depth and I would like to test if it equals 0. In case yes, I want to stop executing of script. So far I have:</p>
  
  <pre><code>zero=0;
  
  if [ $depth -eq $zero ]; then
      echo "false";
      exit;
  fi
  </code></pre>
  
  <p>Unfortunately, this leads to:</p>
  
  <pre><code> [: -eq: unary operator expected
  </code></pre>
  
  <p>(might be a bit inaccurate due to translation)</p>
  
  <p>Please, how can I modify my script to get it working?</p>