title: How can I find all the versions of a Unix program on a system?
body: <p>This came up in coursework, and I'm stuck:</p>
  
  <blockquote>
    <p>Many systems have more than one version of a utility program so that users can choose the one they want. Suggest a command to find all the versions of <code>make</code> on a system. What determines which one a user actually gets? How might a user override the defaults?</p>
  </blockquote>
  
  <p>How would you do that?</p>