网络文件传输 自定义协议二进制传输C语言

您好！对于网络文件传输，您可以使用自定义协议进行二进制传输。使用C语言可以实现这一功能。以下是一个简单的示例代码，用于在客户端和服务器之间传输文件的二进制数据：

服务器端代码（server.c）：

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

#define PORT 8080
#define BUFFER_SIZE 1024

int main() {
    int server_fd, new_socket, valread;
    struct sockaddr_in address;
    int addrlen = sizeof(address);
    char buffer[BUFFER_SIZE] = {0};
    FILE *file;

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

    address.sin_family = AF_INET;
    address.sin_addr.s_addr = INADDR_ANY;
    address.sin_port = htons(PORT);

    // 绑定套接字到指定端口
    if (bind(server_fd, (struct sockaddr *)&address, sizeof(address)) < 0) {
        perror("bind failed");
        exit(EXIT_FAILURE);
    }

    // 监听连接
    if (listen(server_fd, 3) < 0) {
        perror("listen failed");
        exit(EXIT_FAILURE);
    }

    // 接受连接
    if ((new_socket = accept(server_fd, (struct sockaddr *)&address, (socklen_t *)&addrlen)) < 0) {
        perror("accept failed");
        exit(EXIT_FAILURE);
    }

    // 接收文件名
    valread = read(new_socket, buffer, BUFFER_SIZE);
    printf("Received file name: %s\n", buffer);

    // 打开文件
    file = fopen(buffer, "wb");
    if (file == NULL) {
        perror("failed to open file");
        exit(EXIT_FAILURE);
    }

    // 接收并写入文件内容
    while ((valread = read(new_socket, buffer, BUFFER_SIZE)) > 0) {
        fwrite(buffer, 1, valread, file);
    }

    printf("File received successfully.\n");

    fclose(file);
    close(new_socket);
    close(server_fd);

    return 0;
}

客户端代码（client.c）：

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

#define PORT 8080
#define BUFFER_SIZE 1024

int main() {
    int sock = 0, valread;
    struct sockaddr_in serv_addr;
    char buffer[BUFFER_SIZE] = {0};
    FILE *file;

    // 创建套接字
    if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
        printf("\n Socket creation error \n");
        return -1;
    }

    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(PORT);

    // 将IP地址从字符串转换为网络地址
    if (inet_pton(AF_INET, "127.0.0.1", &serv_addr.sin_addr) <= 0) {
        printf("\nInvalid address/ Address not supported \n");
        return -1;
    }

    // 连接到服务器
    if (connect(sock, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) {
        printf("\nConnection Failed \n");
        return -1;
    }

    // 发送文件名
    char *filename = "file.txt";
    send(sock, filename, strlen(filename), 0);

    // 打开文件
    file = fopen(filename, "rb");
    if (file == NULL) {
        perror("failed to open file");
        exit(EXIT_FAILURE);
    }

    // 读取文件内容并发送
    while ((valread = fread(buffer, 1, BUFFER_SIZE, file)) > 0) {
        send(sock, buffer, valread, 0);
    }

    printf("File sent successfully.\n");

    fclose(file);
    close(sock);

    return 0;
}

请注意，这只是一个简单的示例代码，仅用于演示如何使用C语言进行网络文件传输。在实际应用中，您可能需要添加错误处理、完整性校验等功能来提高安全性和可靠性。