学习笔记5 截图+代码

一、苏格拉底挑战

二、遇见的困难

三、实践截图和代码

课堂笔记：

man 3 printf

man -k sort   //会找到含有sort功能的命令或函数
man -k sort | grep 3 //缩小查找范围到C语言命令

课本练习：

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

#define BLOCK_SIZE 1024  

// 读取位图数据的函数
void read_bitmap(FILE *file, uint32_t block_number, uint8_t *bitmap_data) {
    fseek(file, block_number * BLOCK_SIZE, SEEK_SET);
    fread(bitmap_data, 1, BLOCK_SIZE, file);
}

int main() {
    FILE *ext2_image = fopen("your_ext2_image.img", "rb"); // 请替换为你的文件系统镜像文件

    if (ext2_image == NULL) {
        perror("Error opening the EXT2 image file");
        return 1;
    }

    // 读取超级块
    fseek(ext2_image, BLOCK_SIZE, SEEK_SET);
    uint8_t superblock_data[BLOCK_SIZE];
    fread(superblock_data, 1, BLOCK_SIZE, ext2_image);

    // 从超级块中获取块位图和索引节点位图的块号
    uint32_t block_bitmap_block = *(uint32_t*)(superblock_data + 0x20);
    uint32_t inode_bitmap_block = *(uint32_t*)(superblock_data + 0x24);

    // 读取块位图和索引节点位图数据
    uint8_t block_bitmap_data[BLOCK_SIZE];
    uint8_t inode_bitmap_data[BLOCK_SIZE];
    read_bitmap(ext2_image, block_bitmap_block, block_bitmap_data);
    read_bitmap(ext2_image, inode_bitmap_block, inode_bitmap_data);

    // 打印块位图数据
    printf("Block Bitmap:\n");
    for (int i = 0; i < BLOCK_SIZE; i++) {
        for (int j = 0; j < 8; j++) {
            uint8_t byte = block_bitmap_data[i];
            printf("%d", (byte >> j) & 1);
        }
        printf(" ");
    }

    // 打印索引节点位图数据
    printf("\n\nInode Bitmap:\n");
    for (int i = 0; i < BLOCK_SIZE; i++) {
        for (int j = 0; j < 8; j++) {
            uint8_t byte = inode_bitmap_data[i];
            printf("%d", (byte >> j) & 1);
        }
        printf(" ");
    }

    fclose(ext2_image);

    return 0;
}