title: How to set breakpoint on a particular file in Perl program?
body: <p>My Perl program looks like:</p>
  <pre><code>foo/
  foo/bar/
  for/bar/test.pm
  foo.pm
  foo/bar.pm
  test.pl
  </code></pre>
  <p>and use <code>perl test.pl</code> to start the program.
  I want to debug a sub in foo/bar/test.pm. How to set a breakpoint on that sub?</p>