问C/C libcurl如何发布表单提交，只是普通的web表单提交数据

EN

#define HADES "Content-Type:application/x-www-form-urlencoded;charset=utf-8"

int SendPacket(char *packet, const char *server)
{
    curl_global_init(CURL_GLOBAL_ALL);
    CURL *curl = curl_easy_init();
    if (!curl) {
        return -1;
    }
    CURLcode ret;
    struct curl_slist *haderlist = NULL;
    struct curl_httppost *post = NULL;
    struct curl_httppost *last = NULL;
    haderlist = curl_slist_append(haderlist, HADES);

    curl_formadd(&post, &last, CURLFORM_COPYNAME, "username",
             CURLFORM_COPYCONTENTS,
             "11111111111", CURLFORM_END);
    curl_formadd(&post, &last, CURLFORM_COPYNAME, "password",
             CURLFORM_COPYCONTENTS,
             "111111", CURLFORM_END);
    curl_formadd(&post, &last, CURLFORM_COPYNAME, "client", CURLFORM_FILE,
             "wap", CURLFORM_END);


    curl_easy_setopt(curl, CURLOPT_HTTPHEADER, haderlist);
    curl_easy_setopt(curl, CURLOPT_URL, server);
    curl_easy_setopt(curl, CURLOPT_POST, 1);
    curl_easy_setopt(curl, CURLOPT_POSTFIELDS, post); 
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_callback);

    //SendData
    ret = curl_easy_perform(curl);
    if (ret != CURLE_OK ) {
        curl_easy_strerror(ret);

        return -1;
    }
    return 0;
}