## the output:
main.pl = 
foo.pm = I AM BAR.
(they should both print "I AM BAR.")

main.pl:
  use foo;
  require "vars.pl";
  print "main.pl = $bar\n";

foo.pm:
  package foo;
  require "vars.pl";
  print "foo.pm = $bar\n";
  1;

vars.pl:
  $bar="I AM BAR.";