package config;
use strict;

our $configvariable = 1;
return 1;

sub setconfigvariable {
    $configvariable = shift;
}
sub getconfigvariable {
    return $configvariable;
}

##</code><code>##

package functions;
use strict;
use config;
return 1;
sub printconfigvariable {
    print config::getconfigvariable;
}

##</code><code>##

use strict;
use config;
use functions;

print config::getconfigvariable; # 1
functions::printconfigvariable;  # 1

config::setconfigvariable(2);

print config::getconfigvariable; # 2
functions::printconfigvariable;  # 1