use Test::Simple tests => 3;
ok !open(my $fh, '|-', 'nonexistent program'), 'string form of open fails';
ok open(my $prince, '|-', 'nonexistent program 2>/dev/null'), 'but succeeds if shell uses redirection';
ok !open(my $none, '|-', 'nonexistent', 'program'), 'list form of open fails, as it should';
__END__
1..3
ok 1 - string form of open fails
ok 2 - but succeeds if shell uses redirection
ok 3 - list form of open fails, as it should