# MyTools.pm

package MyTools;

use warnings;
use strict;

sub import {

    my ($importing_package,
        $string_for_export,
        ) = @_;

    $string_for_export = '[default]' if ! defined $string_for_export;

    { no strict 'refs';  # turn off in narrowest scope
        # use a symbolic reference (gasp)
        ${ $importing_package . '::var' } = $string_for_export;
        }

    }

1;