c++实现话题订阅和udp数据转发
时间: 2023-05-28 20:05:43 浏览: 98
话题订阅和UDP数据转发是两个不同的功能,需要分别实现。
1. 实现话题订阅
话题订阅是指客户端订阅某个主题,当主题有更新时,服务器会向客户端发送更新信息。以下是一个简单的话题订阅实现示例:
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#define SERVER_IP "127.0.0.1"
#define SERVER_PORT 8888
int main(int argc, char *argv[]) {
int sockfd;
struct sockaddr_in server_addr;
char topic[256];
// 创建socket
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0) {
perror("socket error");
exit(EXIT_FAILURE);
}
// 设置服务器地址
memset(&server_addr, 0, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = inet_addr(SERVER_IP);
server_addr.sin_port = htons(SERVER_PORT);
// 连接服务器
if (connect(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
perror("connect error");
exit(EXIT_FAILURE);
}
// 输入要订阅的主题
printf("Please enter the topic you want to subscribe: ");
fgets(topic, sizeof(topic), stdin);
topic[strlen(topic) - 1] = '\0'; // 去掉换行符
// 发送订阅请求
if (write(sockfd, topic, strlen(topic)) < 0) {
perror("write error");
exit(EXIT_FAILURE);
}
// 接收更新信息
char buf[1024];
while (1) {
memset(buf, 0, sizeof(buf));
if (read(sockfd, buf, sizeof(buf)) < 0) {
perror("read error");
exit(EXIT_FAILURE);
}
printf("Received update: %s\n", buf);
}
// 关闭socket
close(sockfd);
return 0;
}
```
2. 实现UDP数据转发
UDP数据转发是指客户端将UDP数据包发送给服务器,服务器再将数据包转发给其他客户端。以下是一个简单的UDP数据转发实现示例:
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#define SERVER_IP "127.0.0.1"
#define SERVER_PORT 8888
int main(int argc, char *argv[]) {
int sockfd;
struct sockaddr_in server_addr, client_addr;
char buf[1024];
socklen_t addr_len = sizeof(client_addr);
// 创建socket
sockfd = socket(AF_INET, SOCK_DGRAM, 0);
if (sockfd < 0) {
perror("socket error");
exit(EXIT_FAILURE);
}
// 设置服务器地址
memset(&server_addr, 0, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = inet_addr(SERVER_IP);
server_addr.sin_port = htons(SERVER_PORT);
// 绑定socket到本地地址
if (bind(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
perror("bind error");
exit(EXIT_FAILURE);
}
// 循环接收数据并转发
while (1) {
memset(buf, 0, sizeof(buf));
if (recvfrom(sockfd, buf, sizeof(buf), 0, (struct sockaddr *)&client_addr, &addr_len) < 0) {
perror("recvfrom error");
exit(EXIT_FAILURE);
}
printf("Received data from %s:%d: %s\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port), buf);
// 转发数据给其他客户端
// ...
// 这里只是简单地将数据包原样发送给客户端
if (sendto(sockfd, buf, strlen(buf), 0, (struct sockaddr *)&client_addr, sizeof(client_addr)) < 0) {
perror("sendto error");
exit(EXIT_FAILURE);
}
}
// 关闭socket
close(sockfd);
return 0;
}
```