Perl getopts example

    use Getopt::Std;
    our %args;
    getopts("?h", \%args) || usage();
    usage() if ($args{'?'} || $args{h});

    sub usage {
        print STDERR "usage: pgm [?h] files \n";
        print STDERR <<EO_HELP if ($args{h});
    -? : print usage message
    -h : print help message
    EO_HELP
    exit(0);
    }

    use Getopt::Std;
    my %args;
    getopts("h?", \%args);

    if ($args{'?'} || $args{h}) {
        print STDERR "usage: pgm args files \n";
        if ($args{'h'}) {
            print STDERR <<EO_HELP;
    EO_HELP
        exit(0);
        }
    }