下面是一个简单的C语言UDP客户端和服务器的示例代码。这个示例演示了如何使用UDP进行数据传输。
UDP 服务器
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#define PORT 8080
#define BUFFER_SIZE 1024
int main() {
int sockfd;
char buffer[BUFFER_SIZE];
struct sockaddr_in server_addr, client_addr;
socklen_t addr_len = sizeof(client_addr);
// 创建socket
if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
perror("Socket creation failed");
exit(EXIT_FAILURE);
}
// 填充服务器信息
memset(&server_addr, 0, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_addr.s_addr = INADDR_ANY; // 接收所有可用的地址
server_addr.sin_port = htons(PORT); // 设置端口号
// 绑定socket到端口
if (bind(sockfd, (const struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
perror("Bind failed");
close(sockfd);
exit(EXIT_FAILURE);
}
printf("UDP Server is listening on port %d...\n", PORT);
while (1) {
ssize_t n = recvfrom(sockfd, buffer, BUFFER_SIZE - 1, MSG_WAITALL,
(struct sockaddr *)&client_addr, &addr_len);
buffer[n] = '\0'; // 添加字符串结束符
printf("Received message: %s\n", buffer);
const char *response = "Message received";
sendto(sockfd, response, strlen(response), MSG_CONFIRM,
(const struct sockaddr *)&client_addr, addr_len);
printf("Response sent.\n");
}
close(sockfd);
return 0;
}
UDP 客户端
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#define PORT 8080
#define SERVER_ADDRESS "127.0.0.1" // 或者你的服务器IP地址
#define BUFFER_SIZE 1024
int main() {
int sockfd;
char *message = "Hello from UDP Client!";
char buffer[BUFFER_SIZE];
struct sockaddr_in server_addr;
// 创建socket
if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
perror("Socket creation failed");
exit(EXIT_FAILURE);
}
memset(&server_addr, 0, sizeof(server_addr));
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(PORT);
// 将IPv4地址从文本转为二进制格式
if (inet_pton(AF_INET, SERVER_ADDRESS, &server_addr.sin_addr) <= 0) {
perror("Invalid address/ Address not supported");
exit(EXIT_FAILURE);
}
sendto(sockfd, message, strlen(message), MSG_CONFIRM,
(const struct sockaddr *) &server_addr,
sizeof(server_addr));
printf("Message sent.\n");
socklen_t len = sizeof(server_addr);
ssize_t n = recvfrom(sockfd, buffer, BUFFER_SIZE - 1,
MSG_WAITALL,
(struct sockaddr *) &server_addr,
&len);
buffer[n] = '\0';
printf("Server response: %s\n", buffer);
close(sockfd);
return 0;
}
编译和运行
要编译并运行这些代码，可以按照以下步骤操作：
- 保存以上两个代码片段分别为
udp_server.c和udp_client.c。 - 打开终端，进入保存文件的目录。
- 编译服务器和客户端：
gcc udp_server.c -o udp_server gcc udp_client.c -o udp_client - 首先运行服务器：
./udp_server & - 然后在另一个终端中运行客户端：
./udp_client
你应该会看到客户端发送的信息被服务器接收，并且服务器向客户端发送确认响应。
内容由零声教学AI助手提供，问题来源于学员提问
![if (item.code === loan'){
for(const loan of item.child){const Index= loan.path.split('.')[1]let contractCode;
me.overDueInfoIndexloan.pathl=Index
const child overduePeriod = loan.child.find(val =>val.code ===](https://linuxcpp.0voice.com/zb_users/upload/2023/05/202305162214111445370.png)
![[E/kernel.sched] thread:tidle0 stack overflow](https://linuxcpp.0voice.com/zb_users/upload/2023/05/202305162232254655144.png)
