my $x;
my $str = sub { "hello ".${\$x} };
$x = 'kevin';
print $str->();
$x = 'chickenman';
print $str->();

##</code><code>##

{package XYZ;
sub new {
  my $class = shift;
  my $self = {
   homedir => '<empty>'
  };
  return bless $self => $class
}
sub homedir {
  my $self = $_[0];
  if( defined $_[1] ){ $self->{homedir} = $_[1] }
  return $self->{homedir}
}
sub executable { my $self = $_[0]; return $self->homedir()."/xyy/abc" }
1;
}
my $xyz = new XYZ();
$xyz->homedir("ahah");
print "homedir: ".$xyz->homedir()."\n";
print "exec: ".$xyz->executable()."\n";
# note, when dealing with paths use File::Spec->catdir()