#include <argp.h>

const char * argp_program_version = "argp-bug??";
static struct argp_option opts[] = {
    {"good", 'g', "ARG", 0, "This one is good" },
    {"bad", 'b', "ARG", OPTION_ARG_OPTIONAL, "This one is bad" },
    {"cheap-hack", 'h', "ARG", OPTION_ARG_OPTIONAL, "Cheap hack" },
    { NULL, 0, NULL, 0, NULL }
};

struct args {
    char * good;
    char * bad;
    char * cheap_hack;
};

static error_t
parse_opt (int key, char * arg, struct argp_state * state) {
    struct args * args = state->input;

    switch (key) {
        case 'g':
            args->good = arg;
            break;
        case 'b':
            if (arg) args->bad = arg;
            break;
        case 'h':
            if (arg) args->cheap_hack = arg;
            else if (state->next < state->argc) {
                if (state->argv[state->next][0] != '-') {
                    args->cheap_hack = state->argv[state->next];
                    state->next++;
                }
            }
            break;
        default:
            break;
    }
    return (0);
}

int main (int argc, char ** argv) {
    struct args args = { NULL, NULL, NULL };
    struct argp argp = { opts, parse_opt, NULL, NULL };

    argp_parse (&argp, argc, argv, 0, 0, &args);

    printf ("Good:  %s\nBad:  %s\nCheap Hack:  %s\n",
            args.good, args.bad, args.cheap_hack);
    return (0);
}