linux curl网络库的使用方法

struct V3MemoryStruct {
      char *memory;
      size_t size;
};
static size_t WriteMemoryCallback(void *contents, size_t size, size_t nmemb, void *userp)
{
  size_t realsize = size * nmemb;
  struct V3MemoryStruct *mem = (struct V3MemoryStruct *)userp;
 
  char *ptr = (char *)realloc(mem->memory, mem->size + realsize + 1);
  if(ptr == NULL) {
    /* out of memory! */ 
    printf("not enough memory (realloc returned NULL)\n");
    return 0;
  }
 
  mem->memory = ptr;
  memcpy(&(mem->memory[mem->size]), contents, realsize);
  mem->size += realsize;
  mem->memory[mem->size] = 0;
 
  return realsize;
}

void EW_HandleV3Url(APIV3_REQUEST_TYPE type,char *url,Json::Value &resultjson)
{

    struct V3MemoryStruct chunk;
    
    chunk.memory = (char *)malloc(sizeof(char));  /* will be grown as needed by the realloc above */ 
    chunk.size = 0;   /* no data at this point */ 

    //if(type == APIV3_SEARCH_TYPE)
    {
        curl_global_init(CURL_GLOBAL_ALL);
        
        CURL *curl = NULL;
        
            curl  = curl_easy_init();
            
        if(curl == NULL)
        {
            printf("curl is NULL.\n");
            curl_global_cleanup();        
            return ;
        }
        curl_easy_setopt(curl, CURLOPT_URL,url);
        curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER,0);//跳过ssl证书 从机
        curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0);//跳过ssl 证书 主机
        curl_easy_setopt(curl, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4);//使用IPV4地址
        curl_easy_setopt(curl, CURLOPT_VERBOSE, 1);//将一些请求参数输出到控制台 类似如打印
        curl_easy_setopt(curl,CURLOPT_WRITEFUNCTION,WriteMemoryCallback);//请求 返回的数据回调函数指针
        curl_easy_setopt(curl,CURLOPT_WRITEDATA,(void *)&chunk);//请求 返回数据的buffer
        curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT_MS,15000);
        CURLcode res = CURLE_FAILED_INIT;
        res = curl_easy_perform(curl);
        if(res != CURLE_OK)
                  printf("curl_easy_perform() failed: %s\n",curl_easy_strerror(res));
        else
            printf("%lu bytes retrieved\n",(unsigned long)chunk.size);
        if(chunk.size <=0)
        {
            printf("recv data have problem.please check curl flow.\n ");
            return;
        }
        //json parse start
        if(type == APIV3_SEARCH_TYPE)
        {
           //
        }
        else
        {//most popular part
        }



        //json parse end
            /* always cleanup */ 
            curl_easy_cleanup(curl);
        free(chunk.memory);    
        curl_global_cleanup();            
    }
    
}