package MySTDOUT;
    use Tie::Handle;
    @ISA = qw/Tie::Handle/;

    sub TIEHANDLE {
        my $class = shift;
        bless {}, $class;
    }

    package main;
    tie *STDOUT, 'MySTDOUT';

##</code><code>##

    package MySTDOUT;
    use Tie::Handle;
    @ISA = qw/Tie::Handle/;

    sub TIEHANDLE {
        my $class = shift;
        bless {}, $class;
    }

    sub PRINT {
        my $self = shift;
        my $caller = caller;
        print STDERR map "$caller: $_", @_;
    }

    package main;
    tie *STDOUT, 'MySTDOUT';

    print "Foo";

##</code><code>##

    main: Foo