use strict;
   use warnings;

   open my $fh,'>','foo' or die $!;
   print $fh 'foo';
   close $fh or die $!;
   
   symlink 'foo','bar';         # ln -s foo bar

   BEGIN {
       *::_ = sub {
            return \*_ unless @_; 
       };
   }
   

   { 
    no warnings;   
    print lstat 'bar' && -l _;   # '' (incorrect)
    print "\n";
   }

   print lstat 'bar' && -l _;   # Use of -l on filehandle _
   print "\n";

   local *_;
   print lstat 'bar' && -l _;   # Undefined subroutine &main::_ 
   print "\n";