package MyModule; use vars qw(@ISA @EXPORT_OK $name $street $city $zip); BEGIN { @ISA = qw(Exporter); @EXPORT_OK = qw($name $street $city $zip); require Exporter; } my $callback; sub set_callback(&) { $callback = shift } sub exec_callback { local(($name, $street, $city, $zip) = @_); $callback->(); } package Main; BEGIN { import MyModule qw($name $street $city $zip) } MyModule::set_callback { $name =~ /^[a-zA-Z\s]+$/ and $zip =~/^\d+$/ }; MyModule::exec_callback('Bob', '600 1st St.', 'Beverly Hills', '90210') and print "Record is valid.\n";