C 如何获取本地IP地址

string GetLocalIpAddress()
 {
  WORD wVersionRequested = MAKEWORD(2, 2);

  WSADATA wsaData;
  if (WSAStartup(wVersionRequested, &wsaData) != 0)
   return "";

  char local[255] = {0};
  gethostname(local, sizeof(local));
  hostent* ph = gethostbyname(local);
  if (ph == NULL)
   return "";

  in_addr addr;
  memcpy(&addr, ph->h_addr_list[0], sizeof(in_addr)); // 这里仅获取第一个ip

  string localIP;
  localIP.assign(inet_ntoa(addr));

  WSACleanup();
  return localIP;
 }