use v5.20;
use warnings;
use autodie qw/:all/;
use File::Glob qw/:bsd_glob/;
use File::Spec;
use File::Basename;


sub showtree {
  my ($dir,$indent) = @_;
  $indent .= '  ';
  my @list = bsd_glob(File::Spec->catfile($dir,'*'));
  foreach my $f (@list) {
    if (-d $f) {
      say $indent,'+-',basename($f);
      showtree($f,$indent . '|');
    }
    if (-l $f) {
      say $indent,'+-',basename($f),' --> ',readlink($f);
    }
  }
}

showtree($ARGV[0] // '.');