package Test;
sub test {
  my $return_value = 1;
  open(FH, '<', 'test.txt') or error_msg(\$return_value) ; #ja, man soll variablen als FH nehmen
  close FH;
  return $return_value;
}

sub error_msg {
  my $r_value = shift;
  $$r_value = 0;
  warn $!;
}
1;