title: xor conditional in bash
body: <p>I want to see if any of two variables are set, but not both in bash.</p>
  
  <p>I have something like this, but I am not sure about the syntax. I know xor operator does are not logical and should be use as bitwise, but how can i parse [ -z "$tag" ]  into 1 or 0 instead of true or false</p>
  
  <pre class="lang-sh prettyprint-override"><code>if [ -z "$tag" ] ^ [ -z "$flag" ]; then
    echo yes
  else 
    echo no
  fi
  </code></pre>