卷曲：多次下载进度的回调

Question

我有两个线程调用相同的例程来使用curl下载文件。如何使用curl同时打印正在下载的每个文件的进度？我认为curl指针是唯一可以区分正在进行的两次下载回调的变量。每次调用进程回调时，如何使用它来打印每个文件的进度？请建议。谢谢.Below是片段。

struct myprog
{
   char filename[10];
}

static int txfrprogress(void *p,
                curl_off_t  dltotal, curl_off_t  dlnow,
                curl_off_t  ultotal, curl_off_t  ulnow)
{
   static L7_uint32 cnt=0;
   L7_uchar8 buf[32] = {0};
   struct myprog *mp = (struct myprog*)p;

   cnt++;
   if(!(cnt%15000)) {
     sprintf(buf,"%3d%%",(int)((dlnow/dltotal)*100));
     printf("Completed %s download for %s\n",buf,mp->filename);
   }

   return 0;
}

int mymain(char *str) 
{
 struct myprog prog= {0};
 char filename[10]={0};
 CURL *curl;
 /*copy namestring received as arguement into filename*/
 curl_global_init(CURL_GLOBAL_DEFAULT);
 strcpy(prog.filename,filename);
 curl = curl_easy_init();
 curl_easy_setopt(curl, CURLOPT_XFERINFOFUNCTION, txfrprogress);
 curl_easy_setopt(curl, CURLOPT_XFERINFODATA, &prog);
 curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 0L);
 /*some code**/
 return 0;
}