UDP Socket，第一次没有工作，第二次工作

Question

尝试为从udp套接字接收数据的简单程序构建框架。然而，我会收到一条收到的消息，消息永远不会弹出，如果我尝试重新发送消息，则会弹出消息但反复出现同样的问题。我确信我错过了一些愚蠢的东西，但不能放置它。

#include <sys/socket.h>
#include <strings.h>
#include <string.h>
#include <netinet/in.h>
#include <stdio.h>


int shared_sock,n, received, receivelen;
struct sockaddr_in receivesocket;
socklen_t len;
char mesg[100];
unsigned char assist_id[] = {0x18, 0xDE, 0x1B};



int main()
{

   shared_sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
   /* my address */
   memset(&receivesocket, 0, sizeof(receivesocket));
   receivesocket.sin_family = AF_INET;
   receivesocket.sin_addr.s_addr = htonl(INADDR_ANY);
   receivesocket.sin_port = htons(11000);

   receivelen = sizeof(receivesocket);
   if (bind(shared_sock, (struct sockaddr *) &receivesocket, receivelen) < 0) {
      perror("bind");
      return 1;
   }
   memset(mesg, 0, 100);
   while(true){
      if ((received = recvfrom(shared_sock, mesg, 100, 0, NULL, NULL)) < 0){
         perror("recvfrom");
         return 1;
      }
      printf("Received the following %d:\n", received);
      printf("%s",mesg);
   }
   return 0;
}