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

sub print_calling_line {
  my $actual_line = $_[0];
  my $caller_line = (caller)[2];
  printf "Called from line %2d; caller() reports line %2d\n",
    $actual_line, $caller_line;
}

print_calling_line( __LINE__,
  { A => 1, B => 2, C => 3 }
);

print_calling_line( __LINE__,
  %{{ A => 1, B => 2, C => 3 }}
);


##</code><code>##

Called from line 11; caller() reports line 11
Called from line 15; caller() reports line 16

##</code><code>##

#!/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";

##</code><code>##

    Called from line 22; caller() reports line 22 [args: A 1 D 4 C 3 E 5 B 2]
    Called from line 23; caller() reports line 23 [args: HASH(0x974070)]
    Called from line 24; caller() reports line 24 [args: A 1 D 4 C 3 E 5 B 2]
    Called from line 25; caller() reports line 25 [args: 1]
    Called from line 26; caller() reports line 26 [args: 1]
    Called from line 27; caller() reports line 27 [args: 2 3 4]
    Called from line 28; caller() reports line 28 [args: 2 3 4]

    Called from line 31; caller() reports line 31 [args: A 1 D 4 C 3 E 5 B 2]
    Called from line 34; caller() reports line 34 [args: HASH(0x974070)]
*** Called from line 37; caller() reports line 38 [args: A 1 D 4 C 3 E 5 B 2]
    Called from line 40; caller() reports line 40 [args: 1]
    Called from line 43; caller() reports line 43 [args: 1]
    Called from line 46; caller() reports line 46 [args: 1]
*** Called from line 49; caller() reports line 50 [args: 1]

    Called from line 54; caller() reports line 54 [args: 1 2 3 4 5]
    Called from line 55; caller() reports line 55 [args: ARRAY(0x999730)]
    Called from line 56; caller() reports line 56 [args: 1 2 3 4 5]
    Called from line 57; caller() reports line 57 [args: 1]
    Called from line 58; caller() reports line 58 [args: 1]
    Called from line 59; caller() reports line 59 [args: 3 4 5]
    Called from line 60; caller() reports line 60 [args: 3 4 5]

    Called from line 63; caller() reports line 63 [args: 1 2 3 4 5]
    Called from line 66; caller() reports line 66 [args: ARRAY(0x999730)]
*** Called from line 69; caller() reports line 70 [args: 1 2 3 4 5]
    Called from line 72; caller() reports line 72 [args: 1]
    Called from line 75; caller() reports line 75 [args: 1]
    Called from line 78; caller() reports line 78 [args: 3 4 5]
*** Called from line 81; caller() reports line 82 [args: 3 4 5]

    Called from line 86; caller() reports line 86 [args: strings_are_scalar]
    Called from line 87; caller() reports line 87 [args: SCALAR(0x9999e0)]
    Called from line 88; caller() reports line 88 [args: strings_are_scalar]

    Called from line 91; caller() reports line 91 [args: strings_are_scalar]
    Called from line 94; caller() reports line 94 [args: SCALAR(0x9999e0)]
*** Called from line 97; caller() reports line 98 [args: strings_are_scalar]

    Called from line 102; caller() reports line 102 [args: 0.728356104883463]
    Called from line 103; caller() reports line 103 [args: CODE(0x999a50)]
    Called from line 104; caller() reports line 104 [args: 0.996905960000248]

    Called from line 107; caller() reports line 107 [args: 0.690901509291631]
    Called from line 110; caller() reports line 110 [args: CODE(0x999a50)]
*** Called from line 113; caller() reports line 114 [args: 0.898765947759735]

    Called from line 118; caller() reports line 118 [args: strings_are_scalar]
*** Called from line 119; caller() reports line 120 [args: strings_are_scalar]
*** Called from line 122; caller() reports line 124 [args: space_1 strings_are_scalar]
*** Called from line 126; caller() reports line 129 [args: space_1 space_2 strings_are_scalar]
*** Called from line 131; caller() reports line 134 [args: space_1 space_2 strings_are_scalar space_3 space_4]