$ perl -MGetopt::Long -e " my $help; GetOptions( q!help|h|?! => \$help ); warn $help; " -- --help
1 at -e line 1.

$ perl -MGetopt::Long -e " my $help; GetOptions( q!help|h|?! => \$help ); warn $help; " -- -h
1 at -e line 1.

$ perl -MGetopt::Long -e " my $help; GetOptions( q!help|h|?! => \$help ); warn $help; " -- -?
1 at -e line 1.

$ perl -MGetopt::Long -e " my $help; GetOptions( q!help|h|?! => \$help ); warn $help; " -- -f
Unknown option: f
Warning: something's wrong at -e line 1.