title: How can I check if a file exists in Perl?
body: <p>I have a relative path </p>
  
  <pre><code>   $base_path = "input/myMock.TGZ";
  </code></pre>
  
  <p><code>myMock.TGZ</code> is the file name located in input folder.
  The filename can change. But the path is always stored in <code>$base_path</code>.</p>
  
  <p>I need to check if the file exists in <code>$base_path</code>.</p>