class Program{static void Main(string[] args){string file = "weidiao";if (File.Exists(file)) File.Delete(file);File.Create(file);FileStream s = new FileStream(file, FileMode.Truncate);s.Write(Encoding.Default.GetBytes("weidiao"),0,"weidiao".Length);}}

struct Leader{short blockCnt;short nextLeader;short member[30];
};

struct Dir
{short blockCnt;//本目录所占的块数short itemCnt;//子项的个数short data[30];//30个块号
};

struct Item{char name[8];short block;bool isFile;char ext[5];//扩展
};

 1 #include<string>
 2 using namespace std;
 3 #pragma once
 4 struct Scanner
 5 {
 6     int si;
 7     char s[1000];
 8     Scanner(char ss[]){
 9         int i;
10         for (i = 0; ss[i]; i++)s[i] = ss[i];
11         s[i] = 0;
12         si = 0;
13         while (s[si] == ' ')si++;
14     }
15     bool hasNext(){
16         return s[si] != 0;
17     }
18     string next(){
19         string ans = "";
20         while (s[si] != ' '&&s[si])ans += s[si++];
21         while (s[si] == ' ')si++;
22         return ans;
23     }
24 };
25  

#include"disk.h"
#include<string>
#include<string.h>
using namespace std;
#pragma once
struct Path{Item a[100];int ai;Path(){ai = 1;a[0].block = 2;a[0].isFile = false; strcpy(a[0].name, "root");}void push(Item it){a[ai++] = it;}Item pop(){ if (ai == 1){Item it; it.block = -1;return it;}return a[--ai];}Item peek(){return a[ai - 1];}string gets(){string s = "";extern string str(char*);for (int i = 0; i < ai; i++){s +=string(a[i].name)+"\\";}return s;}void home(){ai = 1;}
};

#pragma once
//组长块
struct Leader{short blockCnt;short nextLeader;short member[30];
};
struct Dir
{short blockCnt;short itemCnt;short data[30];
};
struct Item{char name[8];short block;bool isFile;char ext[5];
};struct Block{char a[64];
};

#include<iostream>
#include<math.h>
#include<string>
#include<string.h>
#include"scanner.h"
#include"disk.h"
#include"path.h"
using namespace std;const char disk[] = "disk.txt";
const int BlockCount = 1024;
const int BlockCapacity = 64;
const int BlocksPerGroup = 31;
const int ItemsPerBlock = 4;
const int BytesPerItem = 4;
Leader super;string replace(string src, string olds, string news){string ans = "";for (int i = 0; i < src.length();){int j;for (j = 0; j < olds.length() && i + j < src.length(); j++){if (src[j + i] != olds[j]){break;}}if (j == olds.length()){ans += news;i += j;}else{ans += src[i];i++;}}return ans;
}
void readBlock(short x, void *block){FILE*file = fopen(disk, "rb");fseek(file, x*BlockCapacity, 0);fread(block, sizeof(Block), 1, file);fclose(file);
}
void writeBlock(short x, void* block){FILE *file = fopen(disk, "rb+");fseek(file, x*BlockCapacity, 0);fwrite(block, sizeof(Block), 1, file);fclose(file);
}Item getItem(short folder, const char name[8]){Dir dir; readBlock(folder, &dir);Item it; it.block = -1;int k = 0;for (int i = 0; i < dir.blockCnt; i++){Item a[4];readBlock(dir.data[i], a);for (int j = 0; j < 4 && k++ < dir.itemCnt; j++){if (strcmp(name, a[j].name) == 0){it = a[j];return it;}}}return it;
}bool exist(short x, const char name[8]){Item it = getItem(x, name);if (it.block == -1)return false;else return true;
}
void format(){//删除旧磁盘,创建新磁盘,设置新磁盘长度
    remove(disk);FILE*file = fopen(disk, "w");//write会覆盖,没有文件就创建文件fseek(file, BlockCapacity*BlockCount - 1, 0);char c = 'a';fwrite(&c, 1, 1, file);fclose(file);//第0块char userName[8] = "root";char password[8] = "haha";Block b0;strcpy(b0.a, userName);strcpy(b0.a + 8, password);b0.a[16] = 0;//0个用户writeBlock(0, &b0);//初始化所有组长块int leader = BlockCount - BlocksPerGroup;for (; leader >= 3; leader -= BlocksPerGroup){Leader l;l.blockCnt = BlocksPerGroup - 1;l.nextLeader = leader + BlocksPerGroup;for (int i = 0; i < l.blockCnt; i++){l.member[i] = i + 1 + leader;}writeBlock(leader, &l);}//初始化超级块leader += BlocksPerGroup;Leader super;super.blockCnt = leader - 3;super.nextLeader = leader;for (int i = 0; i < super.blockCnt; i++)super.member[i] = 3 + i;writeBlock(1, &super);//根目录
    Dir root;root.blockCnt = 0;root.itemCnt = 0;writeBlock(2, &root);
}
int allocBlock(){if (super.blockCnt == 0){int ans = super.nextLeader;if (ans == BlockCount)return -1;readBlock(ans, &super);return ans;}else{return super.member[--super.blockCnt];}
}
void freeBlock(short x){if (super.blockCnt == BlocksPerGroup - 1){writeBlock(x, &super);super.blockCnt = 0;super.nextLeader = x;}else{super.member[super.blockCnt++] = x;}
}
void readFile(short x, char s[]){Dir dir;readBlock(x, &dir);int k = 0;for (int i = 0; i < dir.blockCnt; i++){Block data;readBlock(dir.data[i], &data);for (int j = 0; j < BlockCapacity&&k < dir.itemCnt; j++)s[k++] = data.a[j];}s[k] = 0;
}
void writeFile(short x, char s[]){Dir dir;readBlock(x, &dir);int itemCnt = 1 + strlen(s);int blockCnt = ceil(1.0*itemCnt / BlockCapacity);if (blockCnt>dir.blockCnt){for (int i = dir.blockCnt; i < blockCnt; i++){dir.data[i] = allocBlock();}}else if (blockCnt < dir.blockCnt){for (int i = blockCnt; i < dir.blockCnt; i++){freeBlock(dir.data[i]);}}dir.itemCnt = itemCnt;dir.blockCnt = blockCnt;int k = 0;for (int i = 0; i < dir.blockCnt; i++){Block data;for (int j = 0; j < BlockCapacity&&k < dir.itemCnt; j++)data.a[j] = s[k++];writeBlock(dir.data[i], &data);}writeBlock(x, &dir);
}
int addItem(short x, const char *name, bool isFile){Dir dir;readBlock(x, &dir);if (exist(x, name)){cout << "此文件夹中已经包含同名文件或文件夹" << endl;return -1;}int pos = dir.itemCnt % 4;if (pos == 0){dir.blockCnt++;dir.data[dir.blockCnt - 1] = allocBlock();}Item t[4];readBlock(dir.data[dir.blockCnt - 1], t);strcpy(t[pos].name, name);t[pos].isFile = isFile;t[pos].block = allocBlock();writeBlock(dir.data[dir.blockCnt - 1], t);Dir it; it.blockCnt = 0; it.itemCnt = 0;writeBlock(t[pos].block, &it);dir.itemCnt++;writeBlock(x, &dir);return t[pos].block;
}
void deleteFile(short x){Dir dir;readBlock(x, &dir);for (int i = 0; i < dir.blockCnt; i++){freeBlock(dir.data[i]);}freeBlock(x);
}
void deleteFolder(short x){Dir dir;readBlock(x, &dir);int k = 0;for (int i = 0; i < dir.blockCnt; i++){Item a[4];readBlock(dir.data[i], a);for (int j = 0; j < 4 && k++ < dir.itemCnt; j++){if (a[j].isFile){deleteFile(a[j].block);}else {deleteFolder(a[j].block);}}freeBlock(dir.data[i]);}freeBlock(x);
}
void deleteItem(short folder, const char name[8]){Dir dir;readBlock(folder, &dir);int k = 0;for (int i = 0; i < dir.blockCnt; i++){Item a[4];readBlock(dir.data[i], a);for (int j = 0; j < 4 && k++ < dir.itemCnt; j++){if (strcmp(name, a[j].name) == 0){if (a[j].isFile){deleteFile(a[j].block);}else{deleteFolder(a[j].block);}Item last[4];readBlock(dir.data[dir.blockCnt - 1], last);a[j] = last[(dir.itemCnt - 1) % 4];writeBlock(dir.data[i], a);if (dir.itemCnt % 4 == 1){dir.blockCnt--;freeBlock(dir.data[dir.blockCnt]);}dir.itemCnt--;writeBlock(folder, &dir);return;}}}
}
void start(){FILE*file = fopen(disk, "r");if (file == 0){cout << "磁盘不存在,将要进行新建磁盘并格式化" << endl;format();}readBlock(1, &super);
}
void exit(){writeBlock(1, &super);
}
void debugGroup(){writeBlock(1, &super);int k = 0;for (int leader = 1; leader < BlockCount&&k++ < 6;){Leader l;readBlock(leader, &l);cout << "leader " << leader << " " << l.blockCnt << ":";for (int i = 0; i < l.blockCnt; i++){cout << l.member[i] << " ";}cout << endl;leader = l.nextLeader;}
}
void ls(short x){Dir dir;readBlock(x, &dir);int k = 0;const int len = 28;char table[len];for (int i = 0; i < len; i++)table[i] = '-';table[len - 1] = 0;cout << table << endl;for (int i = 0; i < dir.blockCnt; i++){Item a[4];readBlock(dir.data[i], a);for (int j = 0; j < 4 && k++ < dir.itemCnt; j++){printf("| %-10s | %-10s |\n", a[j].name, a[j].isFile ? "文件" : "文件夹");}}cout << table << endl;
}
int filelen(FILE*file){fseek(file, 0, 2);return ftell(file);
}
//a little difficult
void tree(short x, const char*name, bool isFile,string prefix, string &treeString){treeString += prefix + name + "\n"; if (isFile)return;string temp =replace(prefix,"┣", "┃");temp = replace(temp,"━", "  ");temp = replace(temp,"┗", "  "); // 一定要注意，一个这个符号是两个空格Dir dir; readBlock(x, &dir);int k = 0;for (int i = 0; i < dir.blockCnt; i++){Item a[4]; readBlock(dir.data[i], a);for (int j = 0; j < 4 && k++ < dir.itemCnt; j++){if (k == dir.itemCnt)tree(a[j].block,a[j].name,a[j].isFile,temp + "┗━", treeString);else tree(a[j].block, a[j].name,a[j].isFile ,temp + "┣━", treeString);}}
}
char cmds[100][100] = {"newfile  fileName", "创建新文件","newfolder folderName ", "创建新文件夹","cd 文件夹名 ", "进入子文件夹","show 文件名", "显示子文件内容","ls", "显示当前目录下的全部子项","tree", "显示以当前目录为根的树形结构","home ", "返回根目录","back ", "返回上级目录","del  文件名或者文件夹名 ", "删除当前目录下的文件或文件夹","writefile 文件名  文本文件名", "写入文件","format", "格式化磁盘","exit", "退出系统","help", "帮助","debug", "显示磁盘使用情况","#"
};
void help(){char table[64];for (int i = 0; i < 64; i++)table[i] = '-';table[63] = 0;for (int i = 0; strcmp(cmds[i], "#"); i += 2){if (i == 0)printf("\t\t%s\n", table);printf("\t\t|%-30s|%-30s|\n", cmds[i], cmds[i + 1]);printf("\t\t%s\n", table);}
}
void run(){char cmd[100];Path p;cout << "请您一定要注意,退出时要使用exit指令退出,不要关闭控制台" << endl;cout << "因为程序需要用exit()做一些善后工作" << endl;cout << "请使用help命令查看帮助" << endl;while (cout << p.gets() << ">" , gets(cmd)){Scanner s(cmd);string one = s.next();if (one == "")continue;else if (one == "format"){cout << "格式化将会清空全部文件及文件夹" << endl;cout << "您真的要清空吗?(Y/N)" << endl;gets(cmd); Scanner ss = Scanner(cmd);string c = ss.next();if (c == "y" || c == "Y")format(), start(),p.home(), cout << "格式化成功" << endl;else cout << "取消格式化" << endl;start();}else if (one == "help"){cout << "您可以使用以下指令" << endl;help();}else if (one == "ls"){cout << p.gets() << endl;ls(p.peek().block);}else if (one == "home"){p.home();}else if (one == "back"){p.pop();}else if (one == "exit"){ break;}else if (one == "tree"){Item it = p.peek();string tr = "";cout << "---------------------------" << endl;tree(it.block, it.name, 0, "", tr);cout << "---------------------------" << endl;cout << tr << endl;}else if (one == "del"){if (s.hasNext() == false){cout << "命令格式错误,缺少文件名" << endl;continue;}string file = s.next();const char *name = file.c_str();if (file.length() > 8 || !exist(p.peek().block, name)){cout << "不存在这样的文件" << endl;continue;}Item it = getItem(p.peek().block, name);deleteItem(p.peek().block, name);}else if (one == "newfile" || one == "newfolder"){if (s.hasNext() == false){cout << "命令格式错误,缺少文件名" << endl;continue;}string file = s.next();const char *name = file.c_str();if (file.length() > 8){cout << "文件名太长" << endl;continue;}if (exist(p.peek().block, name)){cout << "已经存在名为" << file << "的文件了" << endl;continue;}bool isFile = (one == "newfile");addItem(p.peek().block, name, isFile);}else if (one == "cd"){if (s.hasNext() == false){cout << "命令格式错误" << endl;continue;}string son = s.next();const char* name = son.c_str();if (son.length() > 8 || !exist(p.peek().block, name)){cout << "不存在这样的文件" << endl;continue;}Item it = getItem(p.peek().block, name);if (it.isFile){cout << "不能进入文件,请输入文件夹" << endl;continue;}p.push(it);}else if (one == "show"){if (s.hasNext() == false){cout << "命令格式错误" << endl;continue;}string son = s.next();const char* name = son.c_str();if (son.length() > 8 || exist(p.peek().block, name) == 0){cout << "不存在这样的文件" << endl;continue;}Item it = getItem(p.peek().block, name);if (it.isFile == 0){cout << son << "不是文件,而是文件夹" << endl;continue;}char content[BlockCapacity * 30];readFile(it.block, content);cout << content << endl;}else if (one == "del"){if (s.hasNext() == false){cout << "命令格式错误" << endl;continue;}string son = s.next();const char*name = son.c_str();if (son.length() > 8 || exist(p.peek().block, name) == 0){cout << "不存在这样的文件" << endl;continue;}Item it = getItem(p.peek().block, name);deleteItem(p.peek().block, it.name);}else if (one == "writefile"){if (s.hasNext() == false){cout << "命令格式错误" << endl;continue;}string son = s.next();const char*name = son.c_str();if (son.length() > 8 || exist(p.peek().block, name) == 0){cout << "不存在这样的文件" << endl;continue;}Item it = getItem(p.peek().block, name);if (it.isFile==0){cout << "不能往文件夹中写内容" << endl;continue;}if (s.hasNext() == false){cout << "命令格式错误" << endl;continue;}string fin = s.next();FILE*ff = fopen(fin.c_str(), "r");if (ff == 0){cout << "不存在名为" << fin << "的子文件" << endl;continue;}int len = filelen(ff);if (len > BlockCapacity * 30 - 1){cout << fin << "文件太长" << endl;continue;}char *content = new char[len + 1];fseek(ff, 0, 0);fread(content, len, 1, ff);content[len] = 0;writeFile(it.block, content);fclose(ff);delete content;}else if (one == "debug"){cout << "------------" << endl;debugGroup();cout << endl;}else {cout << "没有这样的命令,请输入help查看可用命令" << endl;}//这句话本来该省略,之所以加在这里是为了防止不用exit命令退出,那样会破坏系统.writeBlock(1, &super);}
}
int main(){  start();run();exit();return 0;
}