use warnings;
use strict;

Main( @ARGV );
exit( 0 );

my %hash;
BEGIN {
    %hash = ( bar => 'value' );
}
sub Foo { print $hash{shift(@_)} }

sub Main
{
    Foo('bar');
}

##</code><code>##

sub Foo
{
    my %hash = ( bar => 'value' ) BEGIN;
    print $hash{shift(@_)};
}