title: How can I tell if a Perl module is core or part of the standard install?
body: <p>How can I check if a Perl module is part of the core - i.e. it is part of the standard installation?</p>
  
  <p>I'm looking for:</p>
  
  <ul>
  <li>a command-line command:</li>
  <li>a Perl subroutine/function to check within code</li>
  </ul>
  
  <p>Perhaps the question should be: How can I tell what modules were originally provided with the <em>specific</em> Perl installation on a machine? (Actually, it is now asked as <em><a href="https://stackoverflow.com/questions/2085516/how-can-i-tell-what-modules-were-originally-provided-with-the-specific-perl-insta">How can I tell what modules were originally provided with the specific Perl installation on a machine?</a></em>.)</p>
  
  <p>Given that there now appears to not to be an overall Perl standard installation, at least the answer to this new question will tell me what I originally had in the installation when it was first installed.</p>
  
  <p>With that knowledge and if I keep the original installer image/package OR know how to get the exact thing again online, then I have a repeatable Perl installation for several machines with the knowledge of what modules will be present and what modules will not. </p>
  
  <p>To clarify further: I am looking at what <em>came</em> with the installation originally, what modules were provided as part of that installation, and what was built-in. <em>NOT</em> what has been installed since then.</p>
  
  <p>And I want to be able to do this <em>on the machine that has the installation</em>. So for this I would be relying upon the installation to have a record in some form as to what it has originally.</p>
  
  <p>I asked spin-off question:
  <em><a href="https://stackoverflow.com/questions/2085516/how-can-i-tell-what-modules-were-originally-provided-with-the-specific-perl-insta">How can I tell what modules were originally provided with the specific Perl installation on a machine?</a></em> (How can I tell what modules were originally provided with the specific Perl installation on a machine?)</p>