#!/usr/bin/perl -w
use strict;

my %HASH      = ( A => 1, B => 2, C => 3, D => 4, E => 5 );
my $HASHREF   = \%HASH;
my @ARRAY     = ( 1 .. 5 );
my $ARRAYREF  = \@ARRAY;
my $SCALAR    = "strings_are_scalar";
my $SCALARREF = \$SCALAR;
sub CODE { rand }
my $CODEREF   = \&CODE;

sub print_calling_line {
  my $actual_line = shift;
  my $caller_line = (caller)[2];
  my $different = $actual_line != $caller_line ? "***" : "";
  printf "%3s Called from line %2d; caller() reports line %2d [args: @_]\n",
    $different, $actual_line, $caller_line;
}

print "\n";
print_calling_line( __LINE__, %HASH                    );
print_calling_line( __LINE__, $HASHREF                 );
print_calling_line( __LINE__, %{$HASHREF}              );
print_calling_line( __LINE__, $HASH{A}                 );
print_calling_line( __LINE__, $HASHREF->{A}            );
print_calling_line( __LINE__, @HASH{qw(B C D)}         );
print_calling_line( __LINE__, @{$HASHREF}{qw(B C D)}   );

print "\n";
print_calling_line( __LINE__,
  %HASH
);
print_calling_line( __LINE__,
  $HASHREF
);
print_calling_line( __LINE__,
  %{$HASHREF}
);
print_calling_line( __LINE__,
  $HASH{A}
);
print_calling_line( __LINE__,
  $HASHREF->{A}
);
print_calling_line( __LINE__,
  @HASH{qw(A)}
);
print_calling_line( __LINE__,
  @{$HASHREF}{qw(A)}
);

print "\n";
print_calling_line( __LINE__, @ARRAY                   );
print_calling_line( __LINE__, $ARRAYREF                );
print_calling_line( __LINE__, @{$ARRAYREF}             );
print_calling_line( __LINE__, $ARRAY[0]                );
print_calling_line( __LINE__, $ARRAYREF->[0]           );
print_calling_line( __LINE__, @ARRAY[2 .. 4]           );
print_calling_line( __LINE__, @{$ARRAYREF}[2 .. 4]     );

print "\n";
print_calling_line( __LINE__,
  @ARRAY
);
print_calling_line( __LINE__,
  $ARRAYREF
);
print_calling_line( __LINE__,
  @{$ARRAYREF}
);
print_calling_line( __LINE__,
  $ARRAY[0]
);
print_calling_line( __LINE__,
  $ARRAYREF->[0]
);
print_calling_line( __LINE__,
  @ARRAY[2 .. 4]
);
print_calling_line( __LINE__,
  @{$ARRAYREF}[2 .. 4]
);

print "\n";
print_calling_line( __LINE__, $SCALAR                  );
print_calling_line( __LINE__, $SCALARREF               );
print_calling_line( __LINE__, ${$SCALARREF}            );

print "\n";
print_calling_line( __LINE__,
  $SCALAR
);
print_calling_line( __LINE__,
  $SCALARREF
);
print_calling_line( __LINE__,
  ${$SCALARREF}
);

print "\n";
print_calling_line( __LINE__, &CODE                   );
print_calling_line( __LINE__, $CODEREF                );
print_calling_line( __LINE__, &{$CODEREF}             );

print "\n";
print_calling_line( __LINE__,
  &CODE
);
print_calling_line( __LINE__,
  $CODEREF
);
print_calling_line( __LINE__,
  &{$CODEREF}
);

print "\n";
print_calling_line( __LINE__, ${$SCALARREF}           );
print_calling_line( __LINE__,
  ${$SCALARREF}
);
print_calling_line( __LINE__,
  "space_1",
  ${$SCALARREF}
);
print_calling_line( __LINE__,
  "space_1",
  "space_2",
  ${$SCALARREF}
);
print_calling_line( __LINE__,
  "space_1",
  "space_2",
  ${$SCALARREF},
  "space_3",
  "space_4",
);

print "\n";