C/C++网络编程6——实现基于UDP的服务器端/客户端

服务器端：

 1 #include <iostream>
 2 #include <arpa/inet.h>
 3 #include <sys/socket.h>
 4 #include <unistd.h>
 5 #include <cstring>
 6 
 7 const unsigned int BUFFER_SIZE = 1024;
 8 
 9 int main()
10 {
11     // step1：创建UDP套接字
12     int ser_socket = socket(PF_INET, SOCK_DGRAM, 0);
13     if (ser_socket == -1) {
14         std::cout << "socket failed" << std::endl;
15         return 0;
16     }
17 
18     // step2：绑定ip地址和端口号
19     sockaddr_in ser_addr;
20     memset(&ser_addr, 0, sizeof(ser_addr));
21     ser_addr.sin_family = AF_INET;
22     ser_addr.sin_addr.s_addr = htonl(INADDR_ANY);
23     ser_addr.sin_port = htons(9999);
24     if (bind(ser_socket, (sockaddr *)(&ser_addr), sizeof(ser_addr)) == -1) {
25         std::cout << "bind failed" << std::endl;
26         close(ser_socket);
27         return 0;
28     }
29 
30     char message[BUFFER_SIZE];
31     sockaddr_in client_addr;
32     socklen_t client_addr_len = sizeof(client_addr_len);
33     int message_len = recvfrom(ser_socket, message, BUFFER_SIZE, 0, 
34         (sockaddr*)(&client_addr), &client_addr_len);
35     std::cout << message << std::endl;
36 
37     sendto(ser_socket, message, message_len, 0, 
38         (sockaddr *)(&client_addr), client_addr_len);
39     close(ser_socket);
40     return 0;
41 }

客户端：

 1 #include <iostream>
 2 #include <arpa/inet.h>
 3 #include <sys/socket.h>
 4 #include <unistd.h>
 5 #include <cstring>
 6 
 7 const unsigned int BUFFER_SIZE = 1024;
 8 
 9 int main()
10 {
11     // 创建UDP套接字
12     int client_sock = socket(PF_INET, SOCK_DGRAM, 0);
13     if (client_sock == -1) {
14         std::cout << "socket failed" << std::endl;
15         return 0;
16     }
17 
18     sockaddr_in ser_addr;
19     memset(&ser_addr, 0, sizeof(ser_addr));
20     ser_addr.sin_family = AF_INET;
21     ser_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
22     ser_addr.sin_port = htons(9999);
23     
24     char info[] = "i love china";
25     sendto(client_sock, info, sizeof(info), 0, 
26         (sockaddr *)(&ser_addr), sizeof(ser_addr));
27 
28     char message[BUFFER_SIZE];
29     sockaddr_in from_addr;
30     socklen_t from_addr_len = sizeof(from_addr);
31     recvfrom(client_sock, message, BUFFER_SIZE, 0, 
32         (sockaddr*)(&from_addr), &from_addr_len);
33 
34     std::cout << message << std::endl;
35     close(client_sock);
36     return 0;
37 }