title: How can a Rego script call a shell script?
body: <p>I'd like to call a shell script from within a Rego script.
  How can I do it?</p>
  <p>The <a href="https://sangkeon.github.io/opaguide/chap4/builtinfunction.html" rel="nofollow noreferrer">rego built-in functions</a> don't seem to help.</p>