unless ( GetOptions (
                        "example=s" => \$par_example, # string needed
                                                      # more options and switches..
                        "help"     => \$par_help,     # switch

                        )) { my_show_help(); die "Error in command line arguments: $!"}

if (defined $par_help){my_show_help();exit;}

##</code><code>##

my ($stdout, $stderr, $exit) = capture {
                system( $cmd, @cmdargs );
        };