int pkeyparam_main(int argc, char **argv)
{
    BIO *in = NULL, *out = NULL;
    EVP_PKEY *pkey = NULL;
    int text = 0, noout = 0, ret = 1;
    OPTION_CHOICE o;
    char *infile = NULL, *outfile = NULL, *prog;

    prog = opt_init(argc, argv, pkeyparam_options);
    while ((o = opt_next()) != OPT_EOF) {
        switch (o) {
        case OPT_EOF:
        case OPT_ERR:
            BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
            goto end;
        case OPT_HELP:
            opt_help(pkeyparam_options);
            ret = 0;
            goto end;
        case OPT_IN:
            infile = opt_arg();
            break;
        case OPT_OUT:
            outfile = opt_arg();
            break;
        case OPT_ENGINE:
            (void)setup_engine(opt_arg(), 0);
            break;
        case OPT_TEXT:
            text = 1;
            break;
        case OPT_NOOUT:
            noout = 1;
            break;
        }
    }
    argc = opt_num_rest();
    argv = opt_rest();

    if (!app_load_modules(NULL))
        goto end;

    in = bio_open_default(infile, 'r', FORMAT_PEM);
    if (in == NULL)
        goto end;
    out = bio_open_default(outfile, 'w', FORMAT_PEM);
    if (out == NULL)
        goto end;
    pkey = PEM_read_bio_Parameters(in, NULL);
    if (!pkey) {
        BIO_printf(bio_err, "Error reading parameters\n");
        ERR_print_errors(bio_err);
        goto end;
    }

    if (!noout)
        PEM_write_bio_Parameters(out, pkey);

    if (text)
        EVP_PKEY_print_params(out, pkey, 0, NULL);

    ret = 0;

 end:
    EVP_PKEY_free(pkey);
    BIO_free_all(out);
    BIO_free(in);

    return ret;
}