linux udp和tcp代码

以下是 Linux 上使用 C 语言编写 UDP 和 TCP 服务器和客户端的示例代码：

UDP 服务器端代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#define PORT 8080
#define BUFFER_SIZE 1024

int main() {
    int sockfd;
    struct sockaddr_in server_addr, client_addr;
    socklen_t client_len;
    char buffer[BUFFER_SIZE];
    int n;

    // 创建套接字
    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sockfd < 0) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    // 初始化服务器地址
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    server_addr.sin_port = htons(PORT);

    // 绑定套接字
    if (bind(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
        perror("bind");
        exit(EXIT_FAILURE);
    }

    // 接收数据
    while (1) {
        client_len = sizeof(client_addr);
        n = recvfrom(sockfd, buffer, BUFFER_SIZE, 0, (struct sockaddr *)&client_addr, &client_len);
        if (n < 0) {
            perror("recvfrom");
            exit(EXIT_FAILURE);
        }
        printf("Received packet from %s:%d\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));
        printf("Data: %s\n", buffer);
    }

    // 关闭套接字
    close(sockfd);

    return 0;
}

UDP 客户端代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#define PORT 8080
#define BUFFER_SIZE 1024

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

    // 创建套接字
    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sockfd < 0) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    // 初始化服务器地址
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
    server_addr.sin_port = htons(PORT);

    // 发送数据
    while (1) {
        printf("Enter message: ");
        fgets(buffer, BUFFER_SIZE, stdin);
        n = sendto(sockfd, buffer, strlen(buffer), 0, (struct sockaddr *)&server_addr, sizeof(server_addr));
        if (n < 0) {
            perror("sendto");
            exit(EXIT_FAILURE);
        }
    }

    // 关闭套接字
    close(sockfd);

    return 0;
}

TCP 服务器端代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>

#define PORT 8080
#define BUFFER_SIZE 1024

int main() {
    int sockfd, newsockfd;
    struct sockaddr_in server_addr, client_addr;
    socklen_t client_len;
    char buffer[BUFFER_SIZE];
    int n;

    // 创建套接字
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    // 初始化服务器地址
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = htonl(INADDR_ANY);
    server_addr.sin_port = htons(PORT);

    // 绑定套接字
    if (bind(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
        perror("bind");
        exit(EXIT_FAILURE);
    }

    // 监听套接字
    if (listen(sockfd, 5) < 0) {
        perror("listen");
        exit(EXIT_FAILURE);
    }

    // 接受连接
    while (1) {
        client_len = sizeof(client_addr);
        newsockfd = accept(sockfd, (struct sockaddr *)&client_addr, &client_len);
        if (newsockfd < 0) {
            perror("accept");
            exit(EXIT_FAILURE);
        }
        printf("Accepted connection from %s:%d\n", inet_ntoa(client_addr.sin_addr), ntohs(client_addr.sin_port));

        // 接收数据
        while ((n = read(newsockfd, buffer, BUFFER_SIZE)) > 0) {
            printf("Data: %s\n", buffer);
            write(newsockfd, buffer, n);
        }

        // 关闭连接
        close(newsockfd);
    }

    // 关闭套接字
    close(sockfd);

    return 0;
}

TCP 客户端代码：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>

#define PORT 8080
#define BUFFER_SIZE 1024

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

    // 创建套接字
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) {
        perror("socket");
        exit(EXIT_FAILURE);
    }

    // 初始化服务器地址
    memset(&server_addr, 0, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
    server_addr.sin_port = htons(PORT);

    // 连接服务器
    if (connect(sockfd, (struct sockaddr *)&server_addr, sizeof(server_addr)) < 0) {
        perror("connect");
        exit(EXIT_FAILURE);
    }

    // 发送数据
    while (1) {
        printf("Enter message: ");
        fgets(buffer, BUFFER_SIZE, stdin);
        n = write(sockfd, buffer, strlen(buffer));
        if (n < 0) {
            perror("write");
            exit(EXIT_FAILURE);
        }
        n = read(sockfd, buffer, BUFFER_SIZE);
        if (n < 0) {
            perror("read");
            exit(EXIT_FAILURE);
        }
        printf("Received data: %s\n", buffer);
    }

    // 关闭套接字
    close(sockfd);

    return 0;
}