> perl -v | head -n2
This is perl 5, version 16, subversion 2 (v5.16.2) built for x86_64-linux

> cat -n program.pl
     1  sub foo {
     2          print join(", ", caller(0)) . "\n";
     3  }
     4
     5  my %hash = (
     6          A => 'foo',
     7          B => {
     8                  C => foo(),
     9          },
    10          D => 'foo',
    11          E => sub { return 1; },
    12          F => 'foo',
    13          G => 'foo',
    14  );
    15
    16  my $foo = 'bar';

> perl program.pl
main, program.pl, 12, main::foo, 1, 1, , , 0, ,

>  perl -MO=Deparse,-p,-l program.pl

#line 3 "program.pl"
sub foo {
#line 2 "program.pl"
    print((join(', ', caller(0)) . "\n"));
}
#line 12 "program.pl"
(my(%hash) = ('A', 'foo', 'B', {'C', foo()}, 'D', 'foo', 'E', sub {
#line 11 "program.pl"
    (return 1);
}
, 'F', 'foo', 'G', 'foo'));
#line 16 "program.pl"
(my $foo = 'bar');
program.pl syntax OK