linux下简单模拟文件系统
来源：互联网 发布：如何补充胶原蛋白知乎 编辑：程序博客网 时间：2024/05/17 02:56
整体思路：
文件系统基于一个大文件实现
大文件数据分为几个区域来模拟简单的文件系统
1.User:username and password
2.SuperBlock:blockSize,blockNum,inodeNum,blockFree
3.blockBitmap:the use state of block area
4.inodeBitmap:the use state of inode area
5.Inode area:inode * inodeMax(blockNum)
6.Block area:block * blockNum
系统评估：
系统的实现只是很基础的，许多实现细节还有优化的空间，还有一些功能可继续扩展。
待优化：
文件读写具体实现写法；
文件写入的方式；
可扩展：
cd命令任意性；
文件移动；
文件复制；
多用户；
图形化支持；
已实现：
基于标准输入输出流读写；
大文件存储，最多支持二级索引，文件大小上限为64M;
子目录和父目录跳转；
文件重命名；
文件，目录删除；
文件，目录读写权限控制；
code:
FileSystem.h 文件系统定义
#ifndef FILESYSTEM_H#define FILESYSTEM_H#include <time.h>#include <stdio.h>#include <string.h>#include <string>#include <stdlib.h>#include <malloc.h>#include <signal.h>#include <unistd.h>#include <sys/types.h>#define BLOCK_SIZE 1024#define BLOCK_NUM 102400#define SYSTEM_NAME "FileSystem.tzh"#define SUDO 0#define HELP 1#define LS 2#define CD 3#define MKDIR 4#define TOUCH 5#define CAT 6#define WRITE 7#define RM 8#define MV 9#define CP 10#define CHMOD 11#define LOGOUT 12#define EXIT 13#define SYSINFO 14#define CLEAR 15#define ACCOUNT 16using namespace std;/**文件系统块结构*/typedef struct{ unsigned short blockSize;//2B,文件块大小 unsigned int blockNum;//4B,文件块数量 unsigned int inodeNum;//4B,i节点数量,即文件数量 unsigned int blockFree;//4B,空闲块数量}SuperBlock;/**文件i节点结构100Ｂ*/typedef struct{ unsigned int id; //4B,i节点索引 char name[30]; //30B,文件名，最大长度29 unsigned char isDir; //1B,文件类型 0-file 1-dir unsigned int parent; //4B,父目录i节点索引 unsigned int length; //4B,文件长度,unsigned int最大2^32-1(4GB-1B),目录文件则为子文件项数量 unsigned char type; //1B,文件权限,0-read-only,1-read-write time_t time; //8B,文件最后修改时间，从1970年1月1日00时00分00秒至今所经过的秒数 unsigned int addr[12];//12*4B,文件内容索引,文件前10项为直接索引，目录前11项为直接索引 unsigned int blockId; //文件项所在的目录数据块的id，便于删除时定位}Inode,*PInode;/**文件部分信息节点，用于简要显示文件信息文件名 文件／目录 文件长度 文件权限 修改时间*/typedef struct { unsigned int id; //4B char name[30]; //30B unsigned char isDir; //1B unsigned int blockId; //4B,在目录数据块中的位置0-255}Fcb,*PFcb;typedef struct FCB_LINK_NODE{ Fcb fcb; struct FCB_LINK_NODE* next;}FcbLinkNode, *FcbLink;/**文件系统用户结构*/typedef struct{ char username[10];//用户名，最大长度9 char password[10];//密码，最大长度9}User;class FileSystem{ public: FileSystem(char* name); virtual ~FileSystem(); int init(); //system init void createFileSystem(); void openFileSystem(); //command void help(); void ls(); void ls_l(); int cd(char* name); //file operation int createFile(char* name, unsigned char isDir); int read(char* name); int write(char* name); int del(char* name); int mv(char* name, char* newName); int cp(char* src, char* dst); int chmod(char* name, unsigned char type); //system void login(); void logout(); void exit(); void systemInfo(); void clr(); int account(); void command(void); protected: private: const int blockSize;//文件块大小 const int blockNum; //文件块数量 unsigned char* blockBitmap;//文件块使用图 unsigned char* inodeBitmap;//i节点使用图 //大小 unsigned short userSize; unsigned short superBlockSize; unsigned short blockBitmapSize; unsigned short inodeBitmapSize; unsigned short inodeSize; unsigned short fcbSize; unsigned short itemSize; //偏移 unsigned long sOffset; //superBlock偏移 unsigned long bbOffset; //blockBitmap偏移 unsigned long ibOffset; //inodeBitmap偏移 unsigned long iOffset; //i节点区偏移 unsigned long bOffset; //数据区偏移 unsigned char isAlive; //系统是否在运行 char name[30];//文件系统名 FILE* fp;//文件系统文件指针 SuperBlock superBlock;//文件系统块信息 string curPath;//当前目录字符串 Inode curInode;//当前目录i节点 FcbLink curLink;//当前目录子文件链指针 User user;//用户 char cmd[5][20];//命令行输入 char* SYS_CMD[17];//系统支持的命令 //user区域操作 void getUser(User* pUser); void setUser(User user); //superBlock区域操作 void getSuperBlock(SuperBlock* pSuper); void updateSuperBlock(SuperBlock super); //blockBitmap区域操作 unsigned int getAvailableBlockId(); void getBlockBitmap(unsigned char* bitmap); void updateBlockBitmap(unsigned char* bitmap, unsigned int index); void updateBlockBitmap(unsigned char* bitmap, unsigned int start, unsigned int count); //inodeBitmap区域操作 unsigned int getAvailableInodeId(); void getInodeBitmap(unsigned char* bitmap); void updateInodeBitmap(unsigned char* bitmap, unsigned int index); void updateInodeBitmap(unsigned char* bitmap, unsigned int start, unsigned int count); //inode block区域操作 void getInode(PInode pInode, unsigned int id); void updateInode(Inode inode); void releaseInode(unsigned int id); //data block区域操作 //地址或文件项 unsigned int getAvailableFileItem(Inode& inode, unsigned int* availableIndex); unsigned int getItem(unsigned int blockId, unsigned int index); void updateItem(unsigned int blockId, unsigned int index, unsigned int value); void releaseItem(unsigned int blockId, unsigned int id); //文件内容 int getData(unsigned int blockId, char* buff, unsigned int size, unsigned int offset); int writeData(unsigned int blockId, char* buff, unsigned int size, unsigned int offset); void releaseBlock(unsigned int blockId); //定位操作 unsigned int findChildInode(FcbLink curLink, char* name); //目录信息链操作 void getFcbLinkNode(FcbLink pNode, Inode inode); void getFcbLink(FcbLink& curLink, Inode inode); void appendFcbLinkNode(FcbLink curLink, Inode inode); void removeFcbLinkNode(FcbLink curLink, Inode inode); void removeFcbLinkNode(FcbLink curLink, char* name); void releaseFcbLink(FcbLink& curLink); //system command int analyse(char* str); void stopHandle(int sig); void updateResource(); void showPath(); //util void showFileDigest(FcbLink pNode); void showFileDetail(PInode pInode); unsigned int waitForInput(char* buff, unsigned int limit);};#endif // FILESYSTEM_HFileSystem.cpp 文件系统实现
#include "FileSystem.h"/**初始化常量，文件系统名和命令集合finish*/FileSystem::FileSystem(char* name):blockSize(BLOCK_SIZE),blockNum(BLOCK_NUM),blockBitmap(new unsigned char[BLOCK_NUM+1]),inodeBitmap(new unsigned char[BLOCK_NUM+1]),isAlive(0),fp(NULL),curLink(NULL){ userSize = sizeof(User); superBlockSize = sizeof(SuperBlock); blockBitmapSize = blockNum; inodeBitmapSize = blockNum; inodeSize = sizeof(Inode); fcbSize = sizeof(Fcb); itemSize = sizeof(unsigned int); sOffset = userSize; bbOffset = sOffset+sizeof(SuperBlock); ibOffset = bbOffset+blockBitmapSize; iOffset = ibOffset+inodeBitmapSize; bOffset = iOffset+sizeof(Inode)*blockNum; if(name == NULL || strcmp(name, "") == 0) strcpy(this->name, SYSTEM_NAME); else strcpy(this->name, name); SYS_CMD[0] = new char[5]; strcpy(SYS_CMD[0], "sudo"); SYS_CMD[1] = new char[5]; strcpy(SYS_CMD[1], "help"); SYS_CMD[2] = new char[3]; strcpy(SYS_CMD[2], "ls"); SYS_CMD[3] = new char[3]; strcpy(SYS_CMD[3], "cd"); SYS_CMD[4] = new char[6]; strcpy(SYS_CMD[4], "mkdir"); SYS_CMD[5] = new char[6]; strcpy(SYS_CMD[5], "touch"); SYS_CMD[6] = new char[4]; strcpy(SYS_CMD[6], "cat"); SYS_CMD[7] = new char[6]; strcpy(SYS_CMD[7], "write"); SYS_CMD[8] = new char[3]; strcpy(SYS_CMD[8], "rm"); SYS_CMD[9] = new char[3]; strcpy(SYS_CMD[9], "mv"); SYS_CMD[10] = new char[3]; strcpy(SYS_CMD[10], "cp"); SYS_CMD[11] = new char[6]; strcpy(SYS_CMD[11], "chmod"); SYS_CMD[12] = new char[7]; strcpy(SYS_CMD[12], "logout"); SYS_CMD[13] = new char[5]; strcpy(SYS_CMD[13], "exit"); SYS_CMD[14] = new char[8]; strcpy(SYS_CMD[14], "sysinfo"); SYS_CMD[15] = new char[6]; strcpy(SYS_CMD[15], "clear"); SYS_CMD[16] = new char[8]; strcpy(SYS_CMD[16], "account");}/**释放动态分配的控件finish*/FileSystem::~FileSystem(){ if(blockBitmap != NULL) { delete blockBitmap; blockBitmap = NULL; } if(inodeBitmap != NULL) { delete inodeBitmap; inodeBitmap = NULL; } if(SYS_CMD[0] != NULL) { delete []SYS_CMD; SYS_CMD[0] = NULL; } if(curLink != NULL) { releaseFcbLink(curLink); }}/**系统初始化,启动系统时调用finish*/int FileSystem::init(){ if(isAlive) return -1; //signal(SIGINT,stopHandle); openFileSystem(); login(); command(); return 0;}/**创建文件系统finish*/void FileSystem::createFileSystem(){ printf("create file system...\n"); if ((fp = fopen(name,"wb+"))==NULL) { printf("open file %s error...\n",name); ::exit(-1); } //init user printf("username:"); fgets(user.username, sizeof(user.username), stdin); if(user.username[strlen(user.username)-1] == '\n') user.username[strlen(user.username)-1] = '\0'; system("stty -echo"); printf("password:"); fgets(user.password, sizeof(user.password), stdin); if(user.password[strlen(user.password)-1] == '\n') user.password[strlen(user.password)-1] = '\0'; system("stty echo"); printf("\n"); printf("username:%s\npassword:%s\n", user.username, user.password); setUser(user); //init superBlock superBlock.blockSize = blockSize; superBlock.blockNum = blockNum; //分配一个给root superBlock.inodeNum = 1; superBlock.blockFree = blockNum-1; updateSuperBlock(superBlock); //init two bitmaps unsigned long i; //分配一个给root blockBitmap[0] = 1; inodeBitmap[0] = 1; for(i = 1; i < blockNum; i++) { blockBitmap[i] = 0; inodeBitmap[i] = 0; } updateBlockBitmap(blockBitmap, 0, blockBitmapSize); updateInodeBitmap(inodeBitmap, 0, inodeBitmapSize); //init inode and block long len = 0; len += (inodeSize+ blockSize) * blockNum; for (i = 0; i < len; i++) { fputc(0, fp); } //init root dir //set root inode info curInode.id = 0; strcpy(curInode.name, "/"); curInode.isDir = 1; curInode.parent = inodeSize; curInode.length = 0; curInode.type = 0; time(&(curInode.time)); for(i = 0; i < 12; i++) curInode.addr[i] = 0; curInode.blockId = 0; //write root inode updateInode(curInode); fflush(fp); //get curLink info getFcbLink(curLink, curInode); //get current path curPath = "/"; printf("create file system %s finish.\n", this->name);}/**打开文件系统，若不存在，则创建finish*/void FileSystem::openFileSystem(){ if((fp = fopen(this->name,"rb"))==NULL) { createFileSystem(); } else { printf("open file system...\n"); if ((fp=fopen(this->name,"rb+"))==NULL) { printf("open file %s error...\n", name); ::exit(1); } rewind(fp); //read header getUser(&user); getSuperBlock(&superBlock); getBlockBitmap(blockBitmap); getInodeBitmap(inodeBitmap); //get current inode getInode(&curInode, 0); //get curLink info getFcbLink(curLink, curInode); //get current path curPath = "/"; printf("open file system %s success\n", this->name); }}/**显示帮助信息finish*/void FileSystem::help(){ printf("command: \n\ help --- show help menu \n\ sysinfo --- show system base information \n\ logout --- exit user \n\ account --- modify username and password \n\ clear --- clear the screen \n\ ls --- list the digest of the directory's children \n\ ls -l --- list the detail of the directory's children \n\ cd --- change directory \n\ mkdir --- make directory \n\ touch --- create a new file \n\ cat --- read a file \n\ write --- write something to a file \n\ rm --- delete a directory or a file \n\ cp --- cp a directory file to another directory or file (not finish)\n\ mv --- rename a file or directory \n\ chmod --- change the authorizatino of a directory or a file \n\ exit --- exit this system\n");}/**列出目录下所有文件(目录)名finish*/void FileSystem::ls(){ //printf("ls %s\n", curInode.name); FcbLink link = curLink->next; while(link != NULL) { showFileDigest(link); link = link->next; }}/**列出目录下所有文件(目录)的详细信息finish*/void FileSystem::ls_l(){ //printf("ls -l %s\n", curInode.name); FcbLink link = curLink->next; PInode pInode = new Inode(); while(link != NULL) { pInode->id = link->fcb.id; getInode(pInode, pInode->id); showFileDetail(pInode); link = link->next; }}/**进入目录,暂时只支持进入子目录和返回父目录finish*/int FileSystem::cd(char* name){ //printf("cd from %s to child %s\n", curInode.name, name); unsigned int id; //回到父目录 if(strcmp(name, "..") == 0) { id = curInode.parent; if(curInode.id > 0) { getInode(&curInode, id); getFcbLink(curLink, curInode); int pos = curPath.rfind('/', curPath.length()-2); curPath.erase(pos+1, curPath.length()-1-pos); } return 0; } id = findChildInode(curLink, name); if(id > 0) { getInode(&curInode, id); getFcbLink(curLink, curInode); curPath.append(name); curPath.append(1, '/'); return 0; } else { printf("no such file or directory:%s\n", name); return -1; }}/**创建文件或目录flag:0-file,1-dirfinish*/int FileSystem::createFile(char * name, unsigned char isDir){ if(name == NULL || strcmp(name, "") == 0 || findChildInode(curLink, name) > 0) { printf("invalid file name:the name is empty,or the file has existed\n"); return -1; } //printf("create file %s (isDir=%d) in %s\n", name, isDir, curInode.name); unsigned int index; unsigned int dirBlockId = getAvailableFileItem(curInode, &index); //找到一个可用文件项 if(dirBlockId > 0 || curInode.id == 0) { unsigned int blockId = getAvailableBlockId(); //找到一个空闲数据块 if(blockId > 0) { //更新superBlock superBlock.blockFree--; superBlock.inodeNum++; //更新blockBitmap blockBitmap[blockId] = 1; updateBlockBitmap(blockBitmap, blockId); unsigned int id = getAvailableInodeId(); //创建i节点 PInode pInode = new Inode(); pInode->id = id; strcpy(pInode->name, name); pInode->isDir = isDir; pInode->parent = curInode.id; pInode->length = 0; pInode->type = 1; time(&(pInode->time)); int i; pInode->addr[0] = blockId; for(i = 1; i < 12; i++) pInode->addr[i] = 0; pInode->blockId = dirBlockId; //写入i节点 updateInode(*pInode); //更新inodeBitmap inodeBitmap[id] = 1; updateInodeBitmap(inodeBitmap, id); //将文件id(i节点索引)写入目录文件 //printf("%d register in dir %d [%d]\n", id, dirBlockId, index); updateItem(dirBlockId, index, id); //printf("%d [%d] = %d\n", dirBlockId, index, id); //更新目录i节点 curInode.length++; time(&(curInode.time)); updateInode(curInode); //更新curLink appendFcbLinkNode(curLink, *pInode); delete pInode; //printf("create file %s success:id=%d\n", pInode->name, pInode->id); return 0; } else { printf("storage space is not enough, %d\n", blockId); return -1; } } else { printf("the directory can't append file item, %d\n", dirBlockId); return -1; }}/**读取文件finish*/int FileSystem::read(char *name){ //printf("read file %s in %s\n", name, curInode.name); unsigned int id = findChildInode(curLink, name); if(id > 0) { //读取i节点 PInode pInode = new Inode(); getInode(pInode, id); if(pInode->isDir == 0) { unsigned long len = pInode->length; //remember to delete it char* buff = new char[blockSize+1]; int i; unsigned int blockId; //遍历10个直接索引，读取数据块 for(i = 0; i < 10; i++) { blockId = pInode->addr[i]; if(blockId > 0) { if(len > blockSize) { len -= getData(blockId, buff, blockSize, 0); printf("%s", buff); } else { len -= getData(blockId, buff, len, 0); printf("%s\n", buff); //read finish delete buff; return 0; } } else { //read finish printf("\n"); delete buff; return 0; } } if(len <= 0) { //read finish printf("\n"); delete buff; return 0; } //遍历１个一级索引 unsigned int addrBlockId = pInode->addr[10]; int totalItem = blockSize/itemSize; if(addrBlockId > 0) { //遍历totalItem个直接索引 for(i = 0; i < totalItem; i++) { blockId = getItem(addrBlockId, i); if(blockId > 0) { if(len > blockSize) { len -= getData(blockId, buff, blockSize, 0); printf("%s", buff); } else { len -= getData(blockId, buff, len, 0); printf("%s\n", buff); //read finish delete buff; return 0; } } else { //read finish printf("\n"); delete buff; return 0; } } } else { //read finish printf("\n"); delete buff; return 0; } if(len <= 0) { //read finish printf("\n"); delete buff; return 0; } //遍历一个二级索引 unsigned int addrBlockId2 = pInode->addr[11]; if(addrBlockId2 > 0) { //遍历totalItem个一级索引 unsigned j; for(j = 0; j < totalItem; j++) { addrBlockId = getItem(addrBlockId2, j); if(addrBlockId > 0) { //遍历totalItem个直接索引 for(i = 0; i < totalItem; i++) { blockId = getItem(addrBlockId, i); if(blockId > 0) { if(len > blockSize) { len -= getData(blockId, buff, blockSize, 0); printf("%s", buff); } else { len -= getData(blockId, buff, len, 0); printf("%s\n", buff); //read finish delete buff; return 0; } } else { //read finish printf("\n"); delete buff; return 0; } } } else { //read finish printf("\n"); delete buff; return 0; } } } else { //read finish printf("\n"); delete buff; return 0; } return 0; } else { printf("%s is a directory\n", name); return -1; } } else { printf("no such file or directory\n"); return -1; } return 0;}/**写入文件未完成大文件一级、二级索引时写入finish*/int FileSystem::write(char *name){ //printf("write file %s in %s\n", name, curInode.name); unsigned int id = findChildInode(curLink, name); unsigned long len = 0; unsigned int num; char ch; if(id > 0) { //读取i节点 PInode pInode = new Inode(); getInode(pInode, id); if(pInode->isDir == 0) { if(pInode->type == 0) { printf("file %s is Read-Only file\n", name); return -1; } printf("write %s: use flag \"</>\" to end\n", name); //remember to delete it char* buff = new char[blockSize+1]; //写入10个直接索引对应数据块 int i; unsigned int blockId; for(i = 0; i < 10; i++) { blockId = pInode->addr[i]; if(blockId > 0) { num = waitForInput(buff, blockSize); writeData(blockId, buff, num, 0); len += num; if(num < blockSize) { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } else { printf("You have input %ld Byte dat, continue?[Y/N]", len); ch = getchar(); if(ch != 'Y' && ch != 'y') { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } else { blockId = getAvailableBlockId(); if(blockId > 0) { superBlock.blockFree--; updateSuperBlock(superBlock); blockBitmap[blockId] = 1; updateBlockBitmap(blockBitmap, blockId); pInode->addr[i] = blockId; time(&(pInode->time)); updateInode(*pInode); num = waitForInput(buff, blockSize); writeData(blockId, buff, num, 0); len += num; if(num < blockSize) { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } else { printf("You have input %ld Byte dat, continue?[Y/N]", len); ch = getchar(); if(ch != 'Y' && ch != 'y') { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } else { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } //写入1个一级索引 unsigned addrBlockId = pInode->addr[10]; int itemTotal = blockSize/itemSize; //写入itemTotal个直接索引对应的数据块 if(addrBlockId > 0) { for(i = 0; i < itemTotal; i++) { blockId = getItem(addrBlockId, i); if(blockId > 0) { num = waitForInput(buff, blockSize); writeData(blockId, buff, num, 0); len += num; if(num < blockSize) { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } else { printf("You have input %ld Byte dat, continue?[Y/N]", len); ch = getchar(); if(ch != 'Y' && ch != 'y') { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } else { blockId = getAvailableBlockId(); if(blockId > 0) { superBlock.blockFree--; updateSuperBlock(superBlock); blockBitmap[blockId] = 1; updateBlockBitmap(blockBitmap, blockId); updateItem(addrBlockId, i, blockId); time(&(pInode->time)); updateInode(*pInode); num = waitForInput(buff, blockSize); writeData(blockId, buff, num, 0); len += num; if(num < blockSize) { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } else { printf("You have input %ld Byte dat, continue?[Y/N]", len); ch = getchar(); if(ch != 'Y' && ch != 'y') { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } else { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } } else { addrBlockId = getAvailableBlockId(); if(addrBlockId > 0) { superBlock.blockFree--; updateSuperBlock(superBlock); blockBitmap[addrBlockId] = 1; updateBlockBitmap(blockBitmap, addrBlockId); pInode->addr[10] = addrBlockId; time(&(pInode->time)); updateInode(*pInode); // for(i = 0; i < itemTotal; i++) { blockId = getItem(addrBlockId, i); if(blockId > 0) { num = waitForInput(buff, blockSize); writeData(blockId, buff, num, 0); len += num; if(num < blockSize) { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } else { printf("You have input %ld Byte dat, continue?[Y/N]", len); ch = getchar(); if(ch != 'Y' && ch != 'y') { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } else { blockId = getAvailableBlockId(); if(blockId > 0) { superBlock.blockFree--; updateSuperBlock(superBlock); blockBitmap[blockId] = 1; updateBlockBitmap(blockBitmap, blockId); updateItem(addrBlockId, i, blockId); time(&(pInode->time)); updateInode(*pInode); num = waitForInput(buff, blockSize); writeData(blockId, buff, num, 0); len += num; if(num < blockSize) { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } else { printf("You have input %ld Byte dat, continue?[Y/N]", len); ch = getchar(); if(ch != 'Y' && ch != 'y') { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } else { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } } else { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } //写入1个二级索引 unsigned int addrBlockId2 = pInode->addr[11]; int j; if(addrBlockId2 > 0) { //遍历itemTotal个一级索引 for(j = 0; j < itemTotal; j++) { addrBlockId = getItem(addrBlockId2, j); if(addrBlockId > 0) { //遍历itemTotal个直接索引 for(i = 0; i < itemTotal; i++) { blockId = getItem(addrBlockId, i); if(blockId > 0) { num = waitForInput(buff, blockSize); writeData(blockId, buff, num, 0); len += num; if(num < blockSize) { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } else { printf("You have input %ld Byte dat, continue?[Y/N]", len); ch = getchar(); if(ch != 'Y' && ch != 'y') { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } else { blockId = getAvailableBlockId(); if(blockId > 0) { superBlock.blockFree--; updateSuperBlock(superBlock); blockBitmap[blockId] = 1; updateBlockBitmap(blockBitmap, blockId); updateItem(addrBlockId, i, blockId); time(&(pInode->time)); updateInode(*pInode); num = waitForInput(buff, blockSize); writeData(blockId, buff, num, 0); len += num; if(num < blockSize) { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } else { printf("You have input %ld Byte dat, continue?[Y/N]", len); ch = getchar(); if(ch != 'Y' && ch != 'y') { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } else { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } } else { addrBlockId = getAvailableBlockId(); if(addrBlockId > 0) { superBlock.blockFree--; updateSuperBlock(superBlock); blockBitmap[addrBlockId] = 1; updateBlockBitmap(blockBitmap, addrBlockId); updateItem(addrBlockId2, j, addrBlockId); time(&(pInode->time)); updateInode(*pInode); // for(i = 0; i < itemTotal; i++) { blockId = getItem(addrBlockId, i); if(blockId > 0) { num = waitForInput(buff, blockSize); writeData(blockId, buff, num, 0); len += num; if(num < blockSize) { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } else { printf("You have input %ld Byte dat, continue?[Y/N]", len); ch = getchar(); if(ch != 'Y' && ch != 'y') { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } else { blockId = getAvailableBlockId(); if(blockId > 0) { superBlock.blockFree--; updateSuperBlock(superBlock); blockBitmap[blockId] = 1; updateBlockBitmap(blockBitmap, blockId); updateItem(addrBlockId, i, blockId); time(&(pInode->time)); updateInode(*pInode); num = waitForInput(buff, blockSize); writeData(blockId, buff, num, 0); len += num; if(num < blockSize) { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } else { printf("You have input %ld Byte dat, continue?[Y/N]", len); ch = getchar(); if(ch != 'Y' && ch != 'y') { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } else { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } } else { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } } else { addrBlockId2 = getAvailableBlockId(); if(addrBlockId2 > 0) { superBlock.blockFree--; updateSuperBlock(superBlock); blockBitmap[addrBlockId2] = 1; updateBlockBitmap(blockBitmap, addrBlockId2); pInode->addr[11] = addrBlockId2; time(&(pInode->time)); updateInode(*pInode); //遍历itemTotal一级索引 for(j = 0; j < itemTotal; j++) { addrBlockId = getItem(addrBlockId2, j); if(addrBlockId > 0) { //遍历itemTotal个直接索引 for(i = 0; i < itemTotal; i++) { blockId = getItem(addrBlockId, i); if(blockId > 0) { num = waitForInput(buff, blockSize); writeData(blockId, buff, num, 0); len += num; if(num < blockSize) { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } else { printf("You have input %ld Byte dat, continue?[Y/N]", len); ch = getchar(); if(ch != 'Y' && ch != 'y') { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } else { blockId = getAvailableBlockId(); if(blockId > 0) { superBlock.blockFree--; updateSuperBlock(superBlock); blockBitmap[blockId] = 1; updateBlockBitmap(blockBitmap, blockId); updateItem(addrBlockId, i, blockId); time(&(pInode->time)); updateInode(*pInode); num = waitForInput(buff, blockSize); writeData(blockId, buff, num, 0); len += num; if(num < blockSize) { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } else { printf("You have input %ld Byte dat, continue?[Y/N]", len); ch = getchar(); if(ch != 'Y' && ch != 'y') { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } else { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } } else { addrBlockId = getAvailableBlockId(); if(addrBlockId > 0) { superBlock.blockFree--; updateSuperBlock(superBlock); blockBitmap[addrBlockId] = 1; updateBlockBitmap(blockBitmap, addrBlockId); updateItem(addrBlockId2, j, addrBlockId); time(&(pInode->time)); updateInode(*pInode); // for(i = 0; i < itemTotal; i++) { blockId = getItem(addrBlockId, i); if(blockId > 0) { num = waitForInput(buff, blockSize); writeData(blockId, buff, num, 0); len += num; if(num < blockSize) { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } else { printf("You have input %ld Byte dat, continue?[Y/N]", len); ch = getchar(); if(ch != 'Y' && ch != 'y') { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } else { blockId = getAvailableBlockId(); if(blockId > 0) { superBlock.blockFree--; updateSuperBlock(superBlock); blockBitmap[blockId] = 1; updateBlockBitmap(blockBitmap, blockId); updateItem(addrBlockId, i, blockId); time(&(pInode->time)); updateInode(*pInode); num = waitForInput(buff, blockSize); writeData(blockId, buff, num, 0); len += num; if(num < blockSize) { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } else { printf("You have input %ld Byte dat, continue?[Y/N]", len); ch = getchar(); if(ch != 'Y' && ch != 'y') { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } else { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } } else { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } } } else { pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } } pInode->length = len; time(&(pInode->time)); updateInode(*pInode); delete buff; return 0; } else { printf("%s is a directory\n", name); return -1; } } else { printf("no such file or directory\n"); return -1; }}/**删除文件finish*/int FileSystem::del(char* name){ //printf("delete file %s in %s\n", name, curInode.name); unsigned int id = findChildInode(curLink, name); if(id > 0) { //读取i节点 PInode pInode = new Inode(); getInode(pInode, id); //删除文件 if(pInode->isDir == 0) { if(pInode->type == 0) { printf("file %s is Read-Only file\n", name); return -1; } //释放文件内容数据块 int i; unsigned int blockId; //遍历10个直接索引，释放数据块 for(i = 0; i < 10; i++) { blockId = pInode->addr[i]; //printf("direct addr:%d\n", blockId); if(blockId > 0) { //更新superBlock superBlock.blockFree++; updateSuperBlock(superBlock); //释放block releaseBlock(blockId); //更新blockBitmap blockBitmap[blockId] = 0; updateBlockBitmap(blockBitmap, blockId); } } //遍历１个一级索引 unsigned int addrBlockId = pInode->addr[10]; int totalItem = blockSize/itemSize; if(addrBlockId > 0) { //遍历totalItem个直接索引 for(i = 0; i < totalItem; i++) { blockId = getItem(addrBlockId, i); if(blockId > 0) { //更新superBlock superBlock.blockFree++; updateSuperBlock(superBlock); //释放block releaseBlock(blockId); //更新blockBitmap blockBitmap[blockId] = 0; updateBlockBitmap(blockBitmap, blockId); } } //释放一级索引块 //更新superBlock superBlock.blockFree++; updateSuperBlock(superBlock); //释放block releaseBlock(addrBlockId); //更新blockBitmap blockBitmap[addrBlockId] = 0; updateBlockBitmap(blockBitmap, addrBlockId); } //遍历一个二级索引 unsigned int addrBlockId2 = pInode->addr[11]; if(addrBlockId2 > 0) { //遍历totalItem个一级索引 unsigned j; for(j = 0; j < totalItem; j++) { addrBlockId = getItem(addrBlockId2, j); if(addrBlockId > 0) { //遍历totalItem个直接索引 for(i = 0; i < totalItem; i++) { blockId = getItem(addrBlockId, i); if(blockId > 0) { //更新superBlock superBlock.blockFree++; updateSuperBlock(superBlock); //释放block releaseBlock(blockId); //更新blockBitmap blockBitmap[blockId] = 0; updateBlockBitmap(blockBitmap, blockId); } } //释放一级索引块 //更新superBlock superBlock.blockFree++; updateSuperBlock(superBlock); //释放block releaseBlock(addrBlockId); //更新blockBitmap blockBitmap[addrBlockId] = 0; updateBlockBitmap(blockBitmap, addrBlockId); } } //释放二级索引块 //更新superBlock superBlock.blockFree++; updateSuperBlock(superBlock); //释放block releaseBlock(addrBlockId2); //更新blockBitmap blockBitmap[addrBlockId2] = 0; updateBlockBitmap(blockBitmap, addrBlockId2); } //释放i节点 releaseInode(pInode->id); //更新superBlock superBlock.inodeNum--; updateSuperBlock(superBlock); //更新inodeBitmap inodeBitmap[pInode->id] = 0; updateInodeBitmap(inodeBitmap, pInode->id); //释放目录文件项 releaseItem(pInode->blockId, pInode->id); //printf("delete file %s\n", pInode->name); } //删除目录 else { //删除子文件... cd(name); FcbLink link = curLink->next; while(link != NULL) { del(link->fcb.name); link = link->next; } cd(".."); if(pInode->type == 0) { printf("file %s is Read-Only file\n", name); return -1; } //删除目录文件本身 //释放文件内容数据块 int i; unsigned int blockId; //遍历11个直接索引，释放数据块 for(i = 0; i < 11; i++) { blockId = pInode->addr[i]; if(blockId > 0) { //更新superBlock superBlock.blockFree++; updateSuperBlock(superBlock); //释放block releaseBlock(blockId); //更新blockBitmap blockBitmap[blockId] = 0; updateBlockBitmap(blockBitmap, blockId); } } //遍历１个一级索引 unsigned int addrBlockId = pInode->addr[11]; int totalItem = blockSize/itemSize; if(addrBlockId > 0) { //遍历totalItem个直接索引 for(i = 0; i < totalItem; i++) { blockId = getItem(addrBlockId, i); if(blockId > 0) { //更新superBlock superBlock.blockFree++; updateSuperBlock(superBlock); //释放block releaseBlock(blockId); //更新blockBitmap blockBitmap[blockId] = 0; updateBlockBitmap(blockBitmap, blockId); } } //释放一级索引块 //更新superBlock superBlock.blockFree++; updateSuperBlock(superBlock); //释放block releaseBlock(addrBlockId); //更新blockBitmap blockBitmap[addrBlockId] = 0; updateBlockBitmap(blockBitmap, addrBlockId); } //释放i节点 releaseInode(pInode->id); //更新superBlock superBlock.inodeNum--; updateSuperBlock(superBlock); //更新inodeBitmap inodeBitmap[pInode->id] = 0; updateInodeBitmap(inodeBitmap, pInode->id); //释放目录文件项 releaseItem(pInode->blockId, pInode->id); //printf("delete dir %s\n", pInode->name); } //更新目录i节点 curInode.length--; time(&(curInode.time)); updateInode(curInode); //更新curLink removeFcbLinkNode(curLink, *pInode); delete pInode; return 0; } else { printf("no such file or directory\n"); return -1; }}/**重命名文件finish*/int FileSystem::mv(char* name, char* newName){ //printf("rename file %s in %s to %s\n", name, curInode.name, newName); unsigned int id = findChildInode(curLink, name); if(id > 0) { Inode inode; getInode(&inode, id); if(inode.type == 0) { printf("file %s is Read-Only file\n", name); return -1; } strcpy(inode.name, newName); time(&(inode.time)); updateInode(inode); //update curLink FcbLink link = curLink->next; while(link != NULL) { if(strcmp(link->fcb.name, name) == 0) { strcpy(link->fcb.name, newName); return 0; } link = link->next; } } else { printf("no such file or directory:%s\n", name); return -1; }}/**复制文件unsurpport because input and output control is difficult*/int FileSystem::cp(char* src, char* dst){ printf("unsurpport command\n"); return 0;}/**修改文件权限:只读/可写finish*/int FileSystem::chmod(char* name, unsigned char type){ //printf("chmod file %s (isDir=%d) in %s to value %d\n", name, isDir, curInode.name, type); unsigned int id = findChildInode(curLink, name); if(id > 0) { Inode inode; getInode(&inode, id); //目录 if(inode.isDir == 1) { cd(name); FcbLink link = curLink->next; while(link != NULL) { chmod(link->fcb.name, type); link = link->next; } cd(".."); } inode.type = type; time(&(inode.time)); updateInode(inode); return 0; } else { printf("no such file or directory:%s\n", name); return -1; }}/**登录文件系统验证finish*/void FileSystem::login(){ char username[10]; char password[10]; while(1) { printf("username:"); fgets(username, sizeof(username), stdin); if(username[strlen(username)-1] == '\n') username[strlen(username)-1] = '\0'; system("stty -echo"); printf("password:"); fgets(password, sizeof(password), stdin); if(password[strlen(password)-1] == '\n') password[strlen(password)-1] = '\0'; system("stty echo"); printf("\n"); if(strcmp(username,user.username)==0 && strcmp(password,user.password)==0) break; else { printf("username or password is not correct,please try again.\n"); } }}/**退出账户finish*/void FileSystem::logout(){ //保存数据 updateResource(); printf("%s has logout\n", user.username); //重新打开系统并进行登录验证，由于命令循环未退出，故会继续接受命令 openFileSystem(); login();}/**退出finish*/void FileSystem::exit(){ //保存数据并彻底退出 printf("Bye!\n"); stopHandle(0);}/**查看文件系统信息finish*/void FileSystem::systemInfo(){ printf("Sum of block number:%d\n",superBlock.blockNum); printf("Each block size:%d\n",superBlock.blockSize); printf("Free of block number:%d\n",superBlock.blockFree); printf("Sum of inode number:%d\n",superBlock.inodeNum);}/**清屏finish*/void FileSystem::clr(){ system("clear");}/**修改账户信息:用户名和密码*/int FileSystem::account(){ char username[10]; char password[10]; system("stty -echo"); printf("old password:"); fgets(password, 10, stdin); if(password[strlen(password)-1] == '\n') password[strlen(password)-1] = '\0'; system("stty echo"); printf("\n"); if(strcmp(password,user.password)==0) { while(1) { printf("new username:"); fgets(username, 10, stdin); if(username[strlen(username)-1] == '\n') username[strlen(username)-1] = '\0'; system("stty -echo"); printf("new password:"); fgets(password, 10, stdin); if(password[strlen(password)-1] == '\n') password[strlen(password)-1] = '\0'; system("stty echo"); printf("\n"); if(strlen(username) < 2 || strlen(password) < 4) { printf("your username or password is too long or too short,please try again\n"); } else { break; } } strcpy(user.username, username); strcpy(user.password, password); setUser(user); printf("modify account info success.\n"); return 0; } else { printf("password is not correct, you are not permitted to modify account info.\n"); return -1; }}/**运行文件系统，处理用户命令finish*/void FileSystem::command(){ char input[128]; do { showPath(); fgets(input, 128, stdin); switch(analyse(input)) { case HELP: help(); break; case LS://执行ls或ls-l if(strcmp(cmd[1], "-l") == 0) ls_l(); else ls(); break; case CD: cd(cmd[1]); break; case MKDIR: createFile(cmd[1],1); break; case TOUCH: createFile(cmd[1],0); break; case CAT: read(cmd[1]); break; case WRITE: write(cmd[1]); break; case RM: if(strcmp(cmd[1], "-r") == 0) del(cmd[2]); else del(cmd[1]); break; case MV: mv(cmd[1], cmd[2]); break; case CP: if(strcmp(cmd[1], "-r") == 0) cp(cmd[2], cmd[3]); else cp(cmd[1], cmd[2]); break; case CHMOD: if(strcmp(cmd[1], "-r") == 0) chmod(cmd[3], cmd[2][0]-'0'); else chmod(cmd[2], cmd[1][0]-'0'); break; case LOGOUT: logout(); break; case EXIT: exit(); break; case SYSINFO: systemInfo(); break; case CLEAR: clr(); break; case ACCOUNT: account(); break; default: printf("unsurpport command\n"); break; } }while(1);}/**private methods*///user区域操作/**取出user数据finish*/void FileSystem::getUser(User* pUser){ if(fp == NULL || pUser == NULL) { return; } rewind(fp); fread(pUser, userSize, 1, fp);}/**更新user数据finish*/void FileSystem::setUser(User user){ if(fp == NULL) { return; } rewind(fp); fwrite(&user, userSize, 1, fp);}//superBlock区域操作/**取出superBlock数据finish*/void FileSystem::getSuperBlock(SuperBlock* pSuper){ if(fp == NULL || pSuper == NULL) { return; } fseek(fp, sOffset, SEEK_SET); fread(pSuper, superBlockSize, 1, fp);}/**更新superBlock数据finish*/void FileSystem::updateSuperBlock(SuperBlock super){ if(fp == NULL) { return; } fseek(fp, sOffset, SEEK_SET); fwrite(&super, superBlockSize, 1, fp);}//blockImage区域操作/**寻找一个空闲的数据块,０号已被分配给根目录，返回值大于0表示找到finish*/unsigned int FileSystem::getAvailableBlockId(){ if(superBlock.blockFree <= 0) { printf("no free block\n"); return 0; } int i; for(i = 0; i < blockNum; i++) { if(blockBitmap[i] == 0) { //printf("find block %d\n", i); releaseBlock(i); return i; } } printf("no free block\n"); return 0;}/**取出blockBitmapfinish*/void FileSystem::getBlockBitmap(unsigned char* bitmap){ if(fp == NULL || bitmap == NULL) { return; } fseek(fp, bbOffset, SEEK_SET); fread(bitmap, blockBitmapSize, 1, fp);}/**更新blockBitmapfinish*/void FileSystem::updateBlockBitmap(unsigned char* bitmap, unsigned int index){ this->updateBlockBitmap(bitmap, index, 1); //printf("update blockBitmap index=%d, value=%d\n", index, bitmap[index]);}/**更新blockBitmapfinish*/void FileSystem::updateBlockBitmap(unsigned char* bitmap, unsigned int start, unsigned int count){ if(fp == NULL) { return; } fseek(fp, bbOffset+start, SEEK_SET); fwrite(bitmap+start, count, 1, fp);}//inodeImage区域操作/**寻找一个空闲的i节点块,０号已被分配给根目录，返回值大于0表示找到finish*/unsigned int FileSystem::getAvailableInodeId(){ unsigned int i; for(i = 0; i < blockNum; i++) { if(inodeBitmap[i] == 0) { //printf("find inode %d\n", i); return i; } } return 0;}/**取出inodeBitmapfinish*/void FileSystem::getInodeBitmap(unsigned char* bitmap){ if(fp == NULL || bitmap == NULL) { return; } fseek(fp, ibOffset, SEEK_SET); fread(bitmap, inodeBitmapSize, 1, fp);}/**更新inodeBitmapfinish*/void FileSystem::updateInodeBitmap(unsigned char* bitmap, unsigned int index){ this->updateInodeBitmap(bitmap, index, 1);}/**更新inodeBitmapfinish*/void FileSystem::updateInodeBitmap(unsigned char* bitmap, unsigned int start, unsigned int count){ if(fp == NULL) { return; } fseek(fp, ibOffset+start, SEEK_SET); fwrite(bitmap+start, count, 1, fp);}//inode block区域操作/**取出一条inodefinish*/void FileSystem::getInode(PInode pInode, unsigned int id){ if(fp == NULL || pInode == NULL) { return; } fseek(fp, iOffset+inodeSize*id, SEEK_SET); fread(pInode, inodeSize, 1, fp);}/**更新一条inodefinish*/void FileSystem::updateInode(Inode inode){ if(fp == NULL ) { return; } fseek(fp, iOffset+inodeSize*inode.id, SEEK_SET); fwrite(&inode, inodeSize, 1, fp);}/**释放一条inodefinish*/void FileSystem::releaseInode(unsigned int id){ if(fp == NULL ) { return; } fseek(fp, iOffset+inodeSize*id, SEEK_SET); int i; for(i = 0; i < inodeSize; i++) { fputc(0, fp); }}//data block区域操作//地址或文件项/**寻找一个当前目录文件中可用的文件项，返回数据块地址和文件项索引,大于0表示找到finish*/unsigned int FileSystem::getAvailableFileItem(Inode& inode, unsigned int* availableIndex){ //遍历建立子文件或子目录节点 int i; unsigned int index; unsigned int blockId; unsigned int fileItem; Inode fileInode; const int itemTotal = blockSize/itemSize; //遍历11个直接索引 for(i = 0; i < 11; i++) { blockId = inode.addr[i]; //直接索引数据块已分配，直接查找 if(blockId > 0 || inode.id == 0) { //遍历直接索引下itemTotal个fileItem项(文件i节点索引),查找 for(index = 0; index < itemTotal; index++) { fileItem = getItem(blockId, index); //printf("%d [%d] = %d\n", blockId, index, fileItem); //读取i子文件或子目录i节点 if(fileItem == 0) { *availableIndex = index; return blockId; } } } //直接索引数据块未分配，分配成功后立即返回， else { blockId = getAvailableBlockId(); //分配成功 if(blockId > 0) { //更新superBlock superBlock.blockFree--; updateSuperBlock(superBlock); //更新blockBitmap blockBitmap[blockId] = 1; updateBlockBitmap(blockBitmap, blockId); //更新i节点 inode.addr[i] = blockId; updateInode(inode); //直接返回第0个 *availableIndex = 0; return blockId; } //分配失败 else { return 0; } } } //遍历一级索引1个 unsigned int addrBlockId = inode.addr[11]; //一级索引数据块已分配 if(addrBlockId > 0) { //遍历一级索引下itemTotal个直接索引 for(i = 0; i < itemTotal; i++) { //直接索引数据块已分配，直接查找 if(blockId > 0) { //遍历直接索引下itemTotal个fileItem项(文件i节点索引),查找 for(index = 0; index < itemTotal; index++) { fileItem = getItem(blockId, index); //读取i子文件或子目录i节点 if(fileItem == 0) { *availableIndex = index; return blockId; } } } //直接索引数据块未分配，分配成功后立即返回， else { blockId = getAvailableBlockId(); //分配成功 if(blockId > 0) { //更新superBlock superBlock.blockFree--; updateSuperBlock(superBlock); //更新blockBitmap blockBitmap[blockId] = 1; updateBlockBitmap(blockBitmap, blockId); //更新i节点 inode.addr[i] = blockId; updateInode(inode); //直接返回第0个 *availableIndex = 0; return blockId; } //分配失败 else { return 0; } } } } //一级索引数据块未分配 else { addrBlockId = getAvailableBlockId(); //一级索引数据块分配成功 if(addrBlockId > 0) { //更新superBlock superBlock.blockFree--; updateSuperBlock(superBlock); //更新blockBitmap blockBitmap[addrBlockId] = 1; updateBlockBitmap(blockBitmap, addrBlockId); //更新i节点 inode.addr[11] = addrBlockId; updateInode(inode); //一级索引数据块第一项直接索引分配数据块 blockId = getAvailableBlockId(); //分配成功 if(blockId > 0) { //更新superBlock superBlock.blockFree--; updateSuperBlock(superBlock); //更新blockBitmap blockBitmap[blockId] = 1; updateBlockBitmap(blockBitmap, blockId); //更新一级索引第一项直接索引数据块 updateItem(addrBlockId, 0, blockId); //直接返回第0个 *availableIndex = 0; return blockId; } } //一级索引数据块分配失败 else { return 0; } }}/**取出一个地址项或文件项,针对目录的操作finish*/unsigned int FileSystem::getItem(unsigned int blockId, unsigned int index){ unsigned int value = 0; if(fp == NULL) { return value; } fseek(fp, bOffset+blockSize*blockId+itemSize*index, SEEK_SET); fread(&value, itemSize, 1, fp); return value;}/**更新一个地址项或文件项finish*/void FileSystem::updateItem(unsigned int blockId, unsigned int index, unsigned int value){ if(fp == NULL) { return; } fseek(fp, bOffset+blockSize*blockId+itemSize*index, SEEK_SET); fwrite(&value, itemSize, 1, fp);}/**释放一个地址项或文件项finish*/void FileSystem::releaseItem(unsigned int blockId, unsigned int id){ int itemTotal = blockSize/itemSize; int i; unsigned int itemId; fseek(fp, bOffset+blockSize*blockId, SEEK_SET); for(i = 0; i < itemTotal; i++) { fread(&itemId, itemSize, 1, fp); if(itemId == id) { //printf("release item id=%d in %d\n", id, blockId); fseek(fp, -itemSize, SEEK_CUR); itemId = 0; fwrite(&itemId, itemSize, 1, fp); return; } }}//文件内容/**取出一个数据块的全部或部分,针对文件的操作finish*/int FileSystem::getData(unsigned int blockId, char* buff, unsigned int size, unsigned int offset){ int len = 0; if(fp == NULL || buff == NULL || offset >= blockSize) { return len; } fseek(fp, bOffset+blockSize*blockId, SEEK_SET); if(size > blockSize-offset) size = blockSize-offset; len = fread(buff, size, 1, fp); return len;}/**写入一个数据块的全部或部分,针对文件的操作finish*/int FileSystem::writeData(unsigned int blockId, char* buff, unsigned int size, unsigned int offset){ int len = 0; if(fp == NULL || buff == NULL || offset >= blockSize) { return len; } fseek(fp, bOffset+blockSize*blockId, SEEK_SET); if(size > blockSize-offset) size = blockSize-offset; len = fwrite(buff, size, 1, fp); return len;}/**释放一个数据块finish*/void FileSystem::releaseBlock(unsigned int blockId){ if(fp == NULL) { return; } fseek(fp, bOffset+blockSize*blockId, SEEK_SET); int i; for (i = 0; i < blockSize; i++) { fputc(0, fp); } //printf("release block %d\n", blockId);}//定位操作/**寻找目录下的文件或子目录,返回i节点索引,大于０表示找到finish*/unsigned int FileSystem::findChildInode(FcbLink curLink, char* name){ if(curLink == NULL || name == NULL) { return 0; } FcbLink link = curLink->next; while(link != NULL) { if(strcmp(link->fcb.name, name) == 0) { return link->fcb.id; } link = link->next; } return 0;}//目录信息链操作/**构建一个FcbLinkNodefinish*/void FileSystem::getFcbLinkNode(FcbLink pNode, Inode inode){ if(pNode == NULL) { return; } pNode->fcb.id = inode.id; strcpy(pNode->fcb.name, inode.name); pNode->fcb.isDir = inode.isDir; pNode->fcb.blockId = inode.blockId; pNode->next = NULL;}/**建立目录的信息链finish*/void FileSystem::getFcbLink(FcbLink& curLink, Inode inode){ if(curLink != NULL) { releaseFcbLink(curLink); } //目录本身节点 //printf("start read dir self inode\n"); curLink = new FcbLinkNode(); getFcbLinkNode(curLink, inode); //printf("end read dir self inode\n"); if(inode.length <= 0) return; //遍历建立子文件或子目录节点 int i; unsigned int index; unsigned int blockId; unsigned int fileItem; Inode fileInode; FcbLink pNode; FcbLink link = curLink; unsigned long len = inode.length;//子文件或子目录数 const int itemTotal = blockSize/itemSize; //遍历11个直接索引 for(i = 0; i < 11; i++) { blockId = inode.addr[i]; if(blockId > 0 || curInode.id == 0) { //遍历直接索引下itemTotal个fileItem项(文件i节点索引) for(index = 0; index < itemTotal; index++) { fileItem = getItem(blockId, index); //读取i子文件或子目录i节点 if(fileItem > 0) { getInode(&fileInode, fileItem); pNode = new FcbLinkNode(); getFcbLinkNode(pNode, fileInode); link->next = pNode; link = pNode; len--; //printf("read dir item inode: id=%d, name=%s, index=%d\n", fileItem, fileInode.name, index); if(len <= 0) { return; } } } } } //遍历一级索引1个 unsigned int addrBlockId = inode.addr[11]; if(addrBlockId > 0) { //遍历一级索引下itemTotal个直接索引 for(i = 0; i < itemTotal; i++) { blockId = inode.addr[i]; if(blockId > 0) { //遍历直接索引下itemTotal个fileItem项(文件i节点索引) for(index = 0; index < itemTotal; index++) { fileItem = getItem(blockId, index); //读取i子文件或子目录i节点 if(fileItem > 0) { getInode(&fileInode, fileItem); pNode = new FcbLinkNode(); getFcbLinkNode(pNode, fileInode); link->next = pNode; link = pNode; len--; //printf("read dir item inode: id=%d, name=%s, index=%d\n", fileItem, fileInode.name, index); if(len <= 0) return; } } } } }}/**目录信息链增加一个节点,不能增加根节点finish*/void FileSystem::appendFcbLinkNode(FcbLink curLink, Inode inode){ if(curLink == NULL || inode.id <= 0) { return; } FcbLink link = curLink; while(link->next != NULL) { link = link->next; } FcbLink pNode = new FcbLinkNode(); getFcbLinkNode(pNode, inode); link->next = pNode;}/**目录信息链删除一个节点，不能删除根节点finish*/void FileSystem::removeFcbLinkNode(FcbLink curLink, Inode inode){ if(curLink == NULL || inode.id <= 0) { return; } FcbLink link = curLink->next; FcbLink last = curLink; while(link != NULL) { if(link->fcb.id == inode.id) { last->next = link->next; delete link; break; } last = link; link = link->next; }}/**目录信息链删除一个节点，不能删除根节点finish*/void FileSystem::removeFcbLinkNode(FcbLink curLink, char* name){ if(curLink == NULL || name == NULL) { return; } FcbLink link = curLink->next; FcbLink last = curLink; while(link != NULL) { if(strcmp(link->fcb.name, name) == 0) { last->next = link->next; delete link; break; } last = link; link = link->next; }}/**清空并释放目录信息链finish*/void FileSystem::releaseFcbLink(FcbLink& curLink){ FcbLink link = curLink; FcbLink tmp; while(link != NULL) { tmp = link->next; delete link; link = tmp; } curLink = NULL;}//private system methods/**分析命令finish*/int FileSystem::analyse(char* str){ int i; for(i = 0; i < 5; i++) cmd[i][0] = '\0'; sscanf(str, "%s %s %s %s %s",cmd[0], cmd[1], cmd[2], cmd[3], cmd[4]); for(i = 1; i < 17; i++) { if(strcmp(cmd[0], SYS_CMD[i]) == 0) { return i; } } return 0;}/**停止控制输入捕获,更新并关闭文件,最后直接退出finish*/void FileSystem::stopHandle(int sig){ //printf("\nUpdating resource, please wait...\n"); updateResource(); ::exit(0);}/**更新文件系统头部信息,关闭文件finish*/void FileSystem::updateResource(){ rewind(fp); fwrite(&user, userSize, 1, fp); fwrite(&superBlock, superBlockSize, 1, fp); fwrite(blockBitmap, blockBitmapSize, 1, fp); fwrite(inodeBitmap, inodeBitmapSize, 1, fp); fclose(fp);}/**输出当前路径作为命令提示符号finish*/void FileSystem::showPath(){ printf("%s@localhost %s>",user.username, curPath.data());}//util/**显示文件摘要finish*/void FileSystem::showFileDigest(FcbLink pNode){ if(pNode == NULL) return; printf("%s",pNode->fcb.name); if(pNode->fcb.isDir==1) { printf("/"); } printf("\n");}/**显示文件详情finish*/void FileSystem::showFileDetail(PInode pInode){ if(pInode == NULL) return; //format output if(pInode->isDir == 1) { printf("%c", 'd'); } else { printf("%c", '-'); } printf("%c", 'r'); if(pInode->type == 1) { printf("%c", 'w'); } else { printf("%c", '-'); } printf(" %10d", pInode->length); printf(" %.12s", 4 + ctime(&(pInode->time))); printf(" %s", pInode->name); printf("\n");}/**等待数据输入*/unsigned int FileSystem::waitForInput(char* buff, unsigned int limit){ unsigned int len = 0; char ch[3]; ch[0] = 0; ch[1] = 0; while(len < limit) { ch[2] = getchar(); if(ch[0] == '<' && ch[1] == '/' && ch[2] == '>') { len -= 2; buff[len] = '\0'; return len; } else { ch[0] = ch[1]; ch[1] = ch[2]; buff[len] = ch[2]; len++; } } buff[len] = '\0'; return len;}main.cpp 文件系统调用
#include <iostream>#include "FileSystem.h"using namespace std;int main(int argc, char* argv[]){ FileSystem file(argv[1]); file.init(); cout << "Hello world!" << endl; return 0;}test.c 附:文件系统用户名和密码找回
#include <stdio.h>#include <stdlib.h>int main(int argc, char* argv[]){ FILE* fp = fopen(argv[1], "rb"); char username[10]; char password[10]; fread(username, sizeof(username), 1, fp); fread(password, sizeof(password), 1, fp); fclose(fp); printf("username:%s\npassword:%s\n", username, password); return 0;}编译方法：
生成可执行文件system
$ g++ -o system main.cpp FileSystem.cpp运行方法：
打开或创建systemFile，并以此为基础启动文件系统
$ ./system systemFile附：
用于忘记文件系统用户名和密码时找回
$ gcc -o test test.c$ ./test systemFile使用方法(类似于linux终端命令):
帮助(会提示命令操作)
> help 系统信息
> sysinfo 退出账户
> logout修改账户(username,password)
> account 清屏
> clear 列出目录下所有文件摘要
> ls 列出目录下所有文件详情
> ls -l 进入子目录dir或父目录,暂不支持进入任意层次目录
> cd dir(..) 创建目录dir
> mkdir dir 创建文件file
> touch file 查看文件
> cat file 写入文件，暂时只支持标准输入，以
> write file 删除文件file或删除目录dir及其子文件
> rm file(dir) 暂不支持文件复制
> cp src dst 重命名文件oldFileName为newFileName
> mv oldFileName newFileName 修改文件file或目录dir及其子文件读写权限为只读(0)或读写(1)
> chmod 0(1) file(dir) 退出文件系统
> exit 0 0
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