You have not exported $bbb variable from AAA package, you have exported $b only.Check your code.

our @EXPORT=('$b','$msg');
our $bbb=BBB->new();
[download]

thanks I changed the code.

but $bbb variable is not exported to module BBB

package AAA;
use 5.20.1;
use lib ('.');
use BBB;
use parent('Exporter');
our @EXPORT=('$bbb','$msg');
our $bbb=BBB->new();
return 1;

package BBB;
use 5.20.1;
use lib '.';
use AAA;
sub new{
    my $class=shift;
    my $self=bless {},$class;
    return $self;
}
sub hello{
    my $self=shift;
    say 'hello';
}
sub hello2{
    my $self=shift;
    $bbb->hello();
}
return 1;

package main;
use 5.20.1;
use lib ('.');
use AAA;
$bbb->hello2();


perl test.pl
Global symbol "$bbb" requires explicit package name at BBB.pm line 16.
Compilation failed in require at AAA.pm line 4.
BEGIN failed--compilation aborted at AAA.pm line 4.
Compilation failed in require at test.pl line 4.
BEGIN failed--compilation aborted at test.pl line 4.
[download]

variable $bbb is exported only to package main, not package BBB. I want to make $bbb global to any packages

In your function hello2() you need to call hello() function with $self not with $bbb, as $self already has the BBB package object.

sub hello2{
    my $self=shift;
    #$bbb->hello();
    $self->hello();
}
[download]

---

All is well. I learn by answering your questions...

package AAA;
use lib ('.');
use BBB;
use Exporter 'import';
our @EXPORT = qw /$bbb/;

our $bbb=BBB->new();


1;
[download]

package BBB;
use lib '.';
use AAA;
use feature 'say';
sub new{
    my $class=shift;
    my $self=bless {},$class;
    return $self;
}
sub hello{
    my $self=shift;
    say 'hello';
}
sub hello2{
    my $self=shift;
    $b->hello();
}
[download]

#!/usr/bin/env perl
use strict;
use warnings;
use lib (',');
use AAA;
use BBB;

$bbb->hello;

1;
[download]

package BBB;
use lib '.';
use feature 'say';
sub new{
    my $class=shift;
    my $self=bless {},$class;
    return $self;
}
sub hello{
    my $self=shift;
    say 'hello';
}
sub hello2{
    my $self=shift;
    $b->hello();
}
use AAA;
[download]

package AAA;
use parent('Exporter');
our @EXPORT=('$bbb');
our $bbb=BBB->new();

package BBB;
use AAA;
use feature 'say';
sub new{
    my $class=shift;
    my $self=bless {},$class;
    return $self;
}
sub hello{
    my $self=shift;
    say 'hello';
}
sub hello2{
    my $self=shift;
    #$b->hello(); #what is $b?
    $bbb->hello();
}

package main;
use AAA;
$bbb->hello2();
[download]

not really. 3 files blurs what your goal is.

What's this about not trying to use packages as namespaces? The last time I looked at perlmod, I read this:

Perl provides a mechanism for alternative namespaces to protect packages from stomping on each other's variables. In fact, there's really no such thing as a global variable in Perl. The package statement declares the compilation unit as being in the given namespace.

And perlobj says:

A package is simply a namespace containing variables and subroutines.




Dave

This thinking only works if you can stop any one from using bless and your package. Afterwards your namespace is no longer just a namespace.

yeah... guess you are right.
this article also say to use alias http://www.perl.com/pub/2002/04/23/mod_perl.html