#### Globals.pm

package Globals;
use Exporter;
our @ISA = 'Exporter';
our @EXPORT_OK = qw( %tn %ti %bn);

#### Main.pm

use Globals qw(%tn %ti %bn);
*tn = \%Track::by_name;
*ti = \%Track::by_index;
*bn = \%Bus::by_name;


#### ChainSetup.pm

package ChainSetup;
use Globals qw(%tn %ti %bn);
print $tn{Master}->name; # can't do method 'name' on undef