title: Setting variables with executing a command with exec
body: <p>You can set a variable for a single command like this:</p>
  
  <pre><code>MY_VARIABLE=my_value ./my_script.sh
  </code></pre>
  
  <p>You can hand off to another script like this:</p>
  
  <pre><code>exec ./my_script.sh
  </code></pre>
  
  <p>But when I try to do both like this:</p>
  
  <pre><code>exec MY_VARIABLE=my_value ./my_script.sh
  </code></pre>
  
  <p>I get an error:</p>
  
  <pre><code>exec: MY_VARIABLE=my_value: not found
  </code></pre>
  
  <p>Why is that?<br>
  Is there any way to do this?</p>