求教：my $items=shift \@skipper;如何理解？【看错了】

QUOTE:

sub check_required_items {
  my $who   = shift;
  my $items = shift;

  my @required = qw(preserver sunscreen water_bottle jacket);
  for my $item (@required) {
    unless (grep $item eq $_, @{$items}) { # not found in list?
      print "$who is missing $item.\n";
    }
  }
}

my @skipper = qw(blue_shirt hat jacket preserver sunscreen);
check_required_items('The Skipper', \@skipper);