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 }