#!/usr/bin/perl
# File: demo.pl

use strict;
use warnings;
$|=1; # turn off buffering

use Demo qw(example);

# test() is not exported by Demo.pl
# this the error produced...
# Undefined subroutine &main::test called at C:\Projects_Perl\testing\demo.pl line 7.
# my $x = test();


my $y = Demo::test();  #this is ok , Fully qualified name
print "test() returned $y\n";

__END__
Prints:
top level in Demo.pm
this is the test subroutine!
test() returned 1