76         int len = recv(conn, buffer, sizeof(buffer), 0);  in tcp_server()  local
77         if (len <= 0)  in tcp_server()
79             printf("Receive data failed! len=%d\n", len);  in tcp_server()
88         send(conn, buffer, len, 0);  in tcp_server()
119 …int len = recvfrom(server_sockfd, buffer, sizeof(buffer), 0, (struct sockaddr *)&client_addr, &cli…  in udp_server()  local
120         if (len <= 0)  in udp_server()
122             printf("Receive data failed! len=%d", len);  in udp_server()
131         sendto(server_sockfd, buffer, len, 0, (struct sockaddr *)&client_addr, client_length);  in udp_server()
195     int sockfd, len = 0;  in udp_client()  local
222         len = read(STDIN_FILENO, buffer, sizeof(buffer));  in udp_client()
223         printf("to send: %d\n", len);  in udp_client()
225         sendto(sockfd, buffer, len, 0, (struct sockaddr *)&addr, addr_len);  in udp_client()
228         len = recvfrom(sockfd, buffer, sizeof(buffer), 0, (struct sockaddr *)&addr, &addr_len);  in udp_client()