linux下c语言的udp

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>

#define PORT 8888
#define BUFFER_SIZE 1024

int main() {
    int sockfd;
    struct sockaddr_in server_addr, client_addr;
    socklen_t addr_len = sizeof(client_addr);
    char buffer[BUFFER_SIZE];

    // 创建UDP套接字
    if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
        perror("socket");
        exit(1);
    }

    // 绑定地址和端口
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(PORT);
    server_addr.sin_addr.s_addr = htonl(INADDR_ANY);

    if (bind(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) == -1) {
        perror("bind");
        close(sockfd);
        exit(1);
    }

    printf("Server listening on port %d\n", PORT);

    while (1) {
        // 接收数据
        int recv_len = recvfrom(sockfd, buffer, BUFFER_SIZE, 0, (struct sockaddr *)&client_addr, &addr_len);
        if (recv_len == -1) {
            perror("recvfrom");
            continue;
        }

        buffer[recv_len] = '\0';
        printf("Received message: %s\n", buffer);

        // 发送响应
        sendto(sockfd, "Message received", strlen("Message received"), 0, (struct sockaddr *)&client_addr, addr_len);
    }

    close(sockfd);
    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>

#define SERVER_IP "127.0.0.1"
#define SERVER_PORT 8888
#define BUFFER_SIZE 1024

int main() {
    int sockfd;
    struct sockaddr_in server_addr;
    char buffer[BUFFER_SIZE];

    // 创建UDP套接字
    if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
        perror("socket");
        exit(1);
    }

    // 设置服务器地址
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_port = htons(SERVER_PORT);
    inet_pton(AF_INET, SERVER_IP, &server_addr.sin_addr);

    // 发送数据
    const char *message = "Hello, UDP Server!";
    sendto(sockfd, message, strlen(message), 0, (struct sockaddr *)&server_addr, sizeof(server_addr));

    // 接收响应
    int recv_len = recvfrom(sockfd, buffer, BUFFER_SIZE, 0, NULL, NULL);
    if (recv_len == -1) {
        perror("recvfrom");
    } else {
        buffer[recv_len] = '\0';
        printf("Server response: %s\n", buffer);
    }

    close(sockfd);
    return 0;
}