操作系统课程设计（二）简单文件系统实现
- #include<stdio.h>
- #include<string.h>
- #include<stdlib.h>
- #define DIR_LENGTH 1024 /*路径最长可达100字节*/
- #define MAX_WRITE 1024*128 /*写入文字可达128k字节*/
- #define MEM_D_SIZE 1024*1024 /*1M磁盘空间*/
- #define DISKSIZE 1024 /*磁盘快的大小 1K*/
- #define MSD 5 /*最大子目录数 5 (类似五叉树)*/
- #define DISK_NUM MEM_D_SIZE/DISKSIZE /*磁盘快数目 1024=1M/1K*/
- #define FATSIZE DISK_NUM*sizeof(struct fatitem) /*FAT表大小 8K=8192B (理想应该是 1.5K)*/
- #define MOFN 5 /*最大文件打开数 5 (即除根以外最大深度为5)*/
- #define ROOT_DISK_NO FATSIZE/DISKSIZE+1 /*根目录起始盘快号 9*/
- #define ROOT_DISK_SIZE sizeof(struct direct)/*根目录大小 196*/
- /*---------------FAT表项结构-----------------------*/
- struct fatitem /* size 8*/
- {
- int item; /*存放文件下一个磁盘的指针*/
- char em_disk; /*磁盘块是否空闲标志位 0 空闲*/
- };
- /*-------------------目录项结构------------------------*/
- struct direct /* size 196*/
- {
- /*-----文件控制快信息-----*/
- struct FCB
- {
- char name[9]; /*文件/目录名 8位*/
- char property; /*属性 1位目录 0位普通文件*/
- int size; /*文件/目录字节数(原注释位盘块数)*/
- int firstdisk; /*文件/目录 起始盘块号*/
- int next; /*子目录起始盘块号*/
- int sign; /*1是根目录 0不是根目录*/
- }directitem[MSD+2];
- };
- /*------------------文件打开表项结构--------------------------*/
- struct opentable /* size 104*/
- {
- struct openttableitem /* size 20*/
- {
- char name[9]; /*文件名*/
- int firstdisk; /*起始盘块号*/
- int size; /*文件的大小*/
- }openitem[MOFN];
- int cur_size; /*当前打文件的数目*/
- };
- /*-------------------------------------------------------------------*/
- struct fatitem *fat; /*FAT表*/
- struct direct *root; /*根目录*/
- struct direct *cur_dir; /*当前目录*/
- struct opentable u_opentable; /*文件打开表*/
- int fd=-1; /*文件打开表的序号*/
- char *bufferdir; /*记录当前路径的名称*/
- char *fdisk; /*虚拟磁盘起始地址*/
- void initfile();
- void format();
- void enter();
- void halt();
- int create(char *name);
- int open(char *name);
- int close(char *name);
- int write(int fd,char *buf,int len);
- int read(int fd,char *buf);
- int del(char *name);
- int mkdir(char *name);
- int rmdir(char *name);
- void dir();
- int cd(char *name);
- void print();
- void show();
- /*----------------------------------------------------------------------------------------------*/
- /*------------------------------------------初始化文件系统--------------------------------------*/
- void initfile()
- {
- fdisk = (char *)malloc(MEM_D_SIZE*sizeof(char)); /*申请 1M空间*/
- format();
- free(fdisk);
- }
- /*----------------------------------------------------------------------------------------------*/
- /*------------------------------------------格式化----------------------------------------------*/
- void format()
- {
- int i;
- FILE *fp;
- fat = (struct fatitem *)(fdisk+DISKSIZE); /*计算FAT表地址(为什么向后偏移 1k)*/
- /*-----初始化FAT表------------*/
- fat[0].item=-1; /*引导块*/
- fat[0].em_disk='1';
- for(i=1;i<ROOT_DISK_NO-1;i++) /*存放 FAT表的磁盘块号*/
- {
- fat[i].item=i+1;
- fat[i].em_disk='1';
- }
- fat[ROOT_DISK_NO-1].item=-1;
- fat[ROOT_DISK_NO-1].em_disk='1';
- fat[ROOT_DISK_NO].item=-1; /*存放根目录的磁盘块号*/
- fat[ROOT_DISK_NO].em_disk='1';
- for(i=ROOT_DISK_NO+1;i<DISK_NUM;i++)
- {
- fat[i].item = -1;
- fat[i].em_disk = '0';
- }
- /*-----------------------------------------------*/
- root = (struct direct *)(fdisk+DISKSIZE+FATSIZE); /*根目录的地址*/
- /*初始化目录*/
- /*---------指向当前目录的目录项---------*/
- root->directitem[0].sign = 1;
- root->directitem[0].firstdisk = ROOT_DISK_NO;
- strcpy(root->directitem[0].name,".");
- root->directitem[0].next = root->directitem[0].firstdisk;
- root->directitem[0].property = '1';
- root->directitem[0].size = ROOT_DISK_SIZE;
- /*-------指向上一级目录的目录项---------*/
- root->directitem[1].sign = 1;
- root->directitem[1].firstdisk = ROOT_DISK_NO;
- strcpy(root->directitem[1].name,"..");
- root->directitem[1].next = root->directitem[0].firstdisk;
- root->directitem[1].property = '1';
- root->directitem[1].size = ROOT_DISK_SIZE;
- for(i=2;i<MSD+2;i++) /*-子目录初始化为空-*/
- {
- root->directitem[i].sign = 0;
- root->directitem[i].firstdisk = -1;
- strcpy(root->directitem[i].name,"");
- root->directitem[i].next = -1;
- root->directitem[i].property = '0';
- root->directitem[i].size = 0;
- }
- if((fp = fopen("disk.dat","wb"))==NULL)
- {
- printf("Error:/n Cannot open file /n");
- return;
- }
- if(fwrite(fdisk,MEM_D_SIZE,1,fp)!=1) /*把虚拟磁盘空间保存到磁盘文件中*/
- {
- printf("Error:/n File write error! /n");
- }
- fclose(fp);
- }
- /*----------------------------------------------------------------------------------------------*/
- /*--------------------------------进入文件系统--------------------------------------------------*/
- void enter()
- {
- FILE *fp;
- int i;
- fdisk = (char *)malloc(MEM_D_SIZE*sizeof(char)); /*申请 1M空间*/
- if((fp=fopen("disk.dat","rb"))==NULL)
- {
- printf("Error:/nCannot open file/n");
- return;
- }
- if(!fread(fdisk,MEM_D_SIZE,1,fp)) /*把磁盘文件disk.dat 读入虚拟磁盘空间(内存)*/
- {
- printf("Error:/nCannot read file/n");
- exit(0);
- }
- fat = (struct fatitem *)(fdisk+DISKSIZE); /*找到FAT表地址*/
- root = (struct direct *)(fdisk+DISKSIZE+FATSIZE);/*找到根目录地址*/
- fclose(fp);
- /*--------------初始化用户打开表------------------*/
- for(i=0;i<MOFN;i++)
- {
- strcpy(u_opentable.openitem[i].name,"");
- u_opentable.openitem[i].firstdisk = -1;
- u_opentable.openitem[i].size = 0;
- }
- u_opentable.cur_size = 0;
- cur_dir = root; /*当前目录为根目录*/
- bufferdir = (char *)malloc(DIR_LENGTH*sizeof(char));
- strcpy(bufferdir,"Root:"); /*显示根目录为E:*/
- }
- /*----------------------------------------------------------------------------------------------*/
- /*------------------------------------退出文件系统----------------------------------------------*/
- void halt()
- {
- FILE *fp;
- int i;
- if((fp=fopen("disk.dat","wb"))==NULL)
- {
- printf("Error:/nCannot open file/n");
- return;
- }
- if(!fwrite(fdisk,MEM_D_SIZE,1,fp)) /*把虚拟磁盘空间(内存)内容读入磁盘文件disk.dat */
- {
- printf("Error:/nFile write error!/n");
- }
- fclose(fp);
- free(fdisk);
- free(bufferdir);
- for(i=0;i<MOFN;i++) /*撤销用户打开表 (好像没有必要,系统自动会回收)*/
- {
- strcpy(u_opentable.openitem[i].name,"");
- u_opentable.openitem[i].firstdisk = 0;
- u_opentable.openitem[i].size = 0;
- }
- u_opentable.cur_size = 0; /*用户打开文件数清零*/
- return;
- }
- /*----------------------------------------------------------------------------------------------*/
- /*----------------------------------------创建文件----------------------------------------------*/
- int create(char *name)
- {
- int i,j;
- if(strlen(name)>8) /*文件名大于 8位*/
- return(-1);
- for(i=2;i<MSD+2;i++) /*找到第一个空闲子目录*/
- {
- if(cur_dir->directitem[i].firstdisk==-1)
- break;
- }
- for(j=2;j<MSD+2;j++) /*检查创建文件是否与已存在的文件重名*/
- {
- if(!strcmp(cur_dir->directitem[j].name,name))
- break;
- }
- if(i>=MSD+2) /*无空目录项*/
- return(-2);
- if(u_opentable.cur_size>=MOFN) /*打开文件太多(第五层)*/
- return(-3);
- if(j<MSD+2) /*文件已经存在*/
- return(-4);
- for(j=ROOT_DISK_NO+1;j<DISK_NUM;j++) /*找到空闲盘块 j 后退出*/
- {
- if(fat[j].em_disk=='0')
- break;
- }
- if(j>=DISK_NUM)
- return(-5);
- fat[j].em_disk = '1'; /*将空闲块置为已经分配*/
- /*-----------填写目录项-----------------*/
- strcpy(cur_dir->directitem[i].name,name);
- cur_dir->directitem[i].firstdisk = j;
- cur_dir->directitem[i].size = 0;
- cur_dir->directitem[i].next = j;
- cur_dir->directitem[i].property = '0';
- /*cur_dir->directitem[i].sign 丢失*/
- /*---------------------------------*/
- fd = open(name); /*打开所创建的文件*/
- return 0;
- }
- /*----------------------------------------------------------------------------------------------*/
- /*----------------------------------------打开文件----------------------------------------------*/
- int open(char *name)
- {
- int i, j;
- for(i=2;i<MSD+2;i++) /*文件是否存在*/
- {
- if(!strcmp(cur_dir->directitem[i].name,name))
- break;
- }
- if(i>=MSD+2) /*文件不存在*/
- return(-1);
- /*--------是文件还是目录-----------------------*/
- if(cur_dir->directitem[i].property=='1')/*是目录，不可打开读写*/
- return(-4);
- /*--------文件是否打开-----------------------*/
- for(j=0;j<MOFN;j++)
- {
- if(!strcmp(u_opentable.openitem[j].name,name))
- break;
- }
- if(j<MOFN) /*文件已经打开*/
- return(-2);
- if(u_opentable.cur_size>=MOFN) /*文件打开太多*/
- return(-3);
- /*--------查找一个空闲用户打开表项-----------------------*/
- for(j=0;j<MOFN;j++)
- {
- if(u_opentable.openitem[j].firstdisk==-1)
- break;
- }
- /*--------------填写表项的相关信息------------------------*/
- u_opentable.openitem[j].firstdisk = cur_dir->directitem[i].firstdisk;
- strcpy(u_opentable.openitem[j].name,name);
- u_opentable.openitem[j].size = cur_dir->directitem[i].size;
- u_opentable.cur_size++;
- /*----------返回用户打开表表项的序号--------------------------*/
- return(j);
- }
- /*----------------------------------------------------------------------------------------------*/
- /*----------------------------------------关闭文件----------------------------------------------*/
- int close(char *name)
- {
- int i;
- for(i=0;i<MOFN;i++)
- {
- if(!strcmp(u_opentable.openitem[i].name,name))
- break;
- }
- if(i>=MOFN) /*--文件没有打开-*/
- return(-1);
- /*-----------清空该文件的用户打开表项的内容---------------------*/
- strcpy(u_opentable.openitem[i].name,"");
- u_opentable.openitem[i].firstdisk = -1;
- u_opentable.openitem[i].size = 0;
- u_opentable.cur_size--;
- fd = -1; /*文件打开表的序号为 -1 */
- return 0;
- }
- /*----------------------------------------------------------------------------------------------*/
- /*----------------------------------------写文件------------------------------------------------*/
- int write(int fd, char *buf, int len)
- {
- char *first;
- int item, i, j, k;
- int ilen1, ilen2, modlen, temp;
- /*----------用 $ 字符作为空格 # 字符作为换行符-----------------------*/
- char Space = 32; /*SPACE的ASCII码值*/
- char Endter= '/n';
- for(i=0;i<len;i++)
- {
- if(buf[i] == '$') /*用 $ 字符作为空格*/
- buf[i] = Space;
- else if(buf[i] == '#')
- buf[i] = Endter;
- }
- /*----------读取用户打开表对应表项第一个盘块号-----------------------*/
- item = u_opentable.openitem[fd].firstdisk;
- /*-------------找到当前目录所对应表项的序号-------------------------*/
- for(i=2;i<MSD+2;i++)
- {
- if(cur_dir->directitem[i].firstdisk==item)
- break;
- }
- temp = i; /*-存放当前目录项的下标-*/
- /*------找到的item 是该文件的最后一块磁盘块-------------------*/
- while(fat[item].item!=-1)
- {
- item =fat[item].item; /*-查找该文件的下一盘块--*/
- }
- /*-----计算除该文件的最末地址-------*/
- first = fdisk+item*DISKSIZE+u_opentable.openitem[fd].size%DISKSIZE;
- /*-----如果最后磁盘块剩余的大小大于要写入的文件的大小-------*/
- if(DISKSIZE-u_opentable.openitem[fd].size%DISKSIZE>len)
- {
- strcpy(first,buf);
- u_opentable.openitem[fd].size = u_opentable.openitem[fd].size+len;
- cur_dir->directitem[temp].size = cur_dir->directitem[temp].size+len;
- }
- else
- {
- for(i=0;i<(DISKSIZE-u_opentable.openitem[fd].size%DISKSIZE);i++)
- {/*写一部分内容到最后一块磁盘块的剩余空间(字节)*/
- first[i] = buf [i];
- }
- /*-----计算分配完最后一块磁盘的剩余空间(字节) 还剩下多少字节未存储-------*/
- ilen1 = len-(DISKSIZE-u_opentable.openitem[fd].size%DISKSIZE);
- ilen2 = ilen1/DISKSIZE;
- modlen = ilen1%DISKSIZE;
- if(modlen>0)
- ilen2 = ilen2+1; /*--还需要多少块磁盘块-*/
- /*调试时特别注意*/
- for(j=0;j<ilen2;j++)
- {
- for(i=ROOT_DISK_NO+1;i<DISK_NUM;i++)/*寻找空闲磁盘块*/
- {
- if(fat[i].em_disk=='0')
- break;
- }
- if(i>=DISK_NUM) /*--如果磁盘块已经分配完了-*/
- return(-1);
- first = fdisk+i*DISKSIZE; /*--找到的那块空闲磁盘块的起始地址-*/
- if(j==ilen2-1) /*--如果是最后要分配的一块-*/
- {
- for(k=0;k<len-(DISKSIZE-u_opentable.openitem[fd].size%DISKSIZE)-j*DISKSIZE;k++)
- first[k] = buf[k];
- }
- else/*-如果不是要最后分配的一块--*/
- {
- for(k=0;k<DISKSIZE;k++)
- first[k] =buf[k];
- }
- fat[item].item = i; /*--找到一块后将它的序号存放在上一块的指针中-*/
- fat[i].em_disk = '1'; /*--置找到的磁盘快的空闲标志位为已分配-*/
- fat[i].item = -1; /*--它的指针为 -1 (即没有下一块)-*/
- }
- /*--修改文件打开表用户的长度-*/
- u_opentable.openitem[fd].size = u_opentable.openitem[fd].size+len;
- /*--修改目录项的文件长度-*/
- cur_dir->directitem[temp].size = cur_dir->directitem[temp].size+len;
- }
- return 0;
- }
- /*----------------------------------------------------------------------------------------------*/
- /*----------------------------------------读文件------------------------------------------------*/
- int read(int fd, char *buf)
- {
- int len = u_opentable.openitem[fd].size;
- char *first;
- int i, j, item;
- int ilen1, modlen;
- item = u_opentable.openitem[fd].firstdisk;
- if(len>u_opentable.openitem[fd].size) /*--欲读出的文件长度比实际文件长度长-*/
- return(-1);
- ilen1 = len/DISKSIZE;
- modlen = len%DISKSIZE;
- if(modlen!=0)
- ilen1 = ilen1+1; /*--计算文件所占磁盘的块数-*/
- first = fdisk+item*DISKSIZE; /*--计算文件的起始位置-*/
- for(i=0;i<ilen1;i++)
- {
- if(i==ilen1-1) /*--如果在最后一个磁盘块-*/
- {
- for(j=0;j<len-i*DISKSIZE;j++)
- buf[i*DISKSIZE+j] = first[j];
- }
- else /*--不在最后一块磁盘块-*/
- {
- for(j=0;j<len-i*DISKSIZE;j++)
- buf[i*DISKSIZE+j] = first[j];
- item = fat[item].item; /*-查找下一盘块-*/
- first = fdisk+item*DISKSIZE;
- }
- }
- return 0;
- }
- /*----------------------------------------------------------------------------------------------*/
- /*----------------------------------------删除文件----------------------------------------------*/
- int del(char *name)
- {
- int i,cur_item,item,temp;
- for(i=2;i<MSD+2;i++) /*--查找要删除文件是否在当前目录中-*/
- {
- if(!strcmp(cur_dir->directitem[i].name,name))
- break;
- }
- cur_item = i; /*--用来保存目录项的序号,供释放目录中-*/
- if(i>=MSD+2) /*--如果不在当前目录中-*/
- return(-1);
- if(cur_dir->directitem[cur_item].property!='0') /*--如果删除的(不)是目录-*/
- return(-3);
- for(i=0;i<MOFN;i++) /*--如果文件打开,则不能删除,退出-*/
- {
- if(!strcmp(u_opentable.openitem[i].name,name))
- return(-2);
- }
- item = cur_dir->directitem[cur_item].firstdisk;/*--该文件的起始盘块号-*/
- while(item!=-1) /*--释放空间,将FAT表对应项进行修改-*/
- {
- temp = fat[item].item;
- fat[item].item = -1;
- fat[item].em_disk = '0';
- item = temp;
- }
- /*-----------------释放目录项-----------------------*/
- cur_dir->directitem[cur_item].sign = 0;
- cur_dir->directitem[cur_item].firstdisk = -1;
- strcpy(u_opentable.openitem[cur_item].name,"");
- cur_dir->directitem[cur_item].next = -1;
- cur_dir->directitem[cur_item].property = '0';
- cur_dir->directitem[cur_item].size = 0;
- return 0;
- }
- /*----------------------------------------------------------------------------------------------*/
- /*---------------------------------------创建子目录---------------------------------------------*/
- int mkdir(char *name)
- {
- int i,j;
- struct direct *cur_mkdir;
- if(strchr(name,'//'))/*如果目录名中有 '/'字符*/
- return(-4);
- if(!strcmp(name,"."))
- return(-6);
- if(!strcmp(name,".."))
- return(-6);
- if(strlen(name)>8) /*-如果目录名长度大于 8位-*/
- return(-1);
- for(i=2;i<MSD+2;i++) /*-如果有空闲目录项退出-*/
- {
- if(cur_dir->directitem[i].firstdisk==-1)
- break;
- }
- if(i>=MSD+2) /*-目录/文件 已满-*/
- return(-2);
- for(j=2;j<MSD+2;j++) /*-判断是否有重名-*/
- {
- if(!strcmp(cur_dir->directitem[j].name,name))
- break;
- }
- if(j<MSD+2) /*-如果有重名-*/
- return(-3);
- for(j=ROOT_DISK_NO+1;j<DISK_NUM;j++) /*-找到空闲磁盘块 j 后退出-*/
- {
- if(fat[j].em_disk=='0')
- break;
- }
- if(j>=DISK_NUM)
- return(-5);
- fat[j].em_disk='1'; /*-将该空闲块设置为已分配-*/
- /*-------------填写目录项----------*/
- strcpy(cur_dir->directitem[i].name,name);
- cur_dir->directitem[i].firstdisk=j;
- cur_dir->directitem[i].size=ROOT_DISK_SIZE;
- cur_dir->directitem[i].next=j; /*-指向子目录(其实就是其本身)的起始盘块号-*/
- cur_dir->directitem[i].property='1';
- /*-sign=1为根标志,这里可以省略-*/
- /*-所创目录在虚拟磁盘上的地址(内存物理地址)-*/
- cur_mkdir=(struct direct *)(fdisk+cur_dir->directitem[i].firstdisk*DISKSIZE);
- /*-初始化目录-*/
- /*-指向当前目录的目录项-*/
- cur_mkdir->directitem[0].sign=0;
- cur_mkdir->directitem[0].firstdisk=cur_dir->directitem[i].firstdisk;
- strcpy(cur_mkdir->directitem[0].name,".");
- cur_mkdir->directitem[0].next=cur_mkdir->directitem[0].firstdisk;
- cur_mkdir->directitem[0].property='1';
- cur_mkdir->directitem[0].size=ROOT_DISK_SIZE;
- /*-指向上一级目录的目录项-*/
- cur_mkdir->directitem[1].sign=cur_dir->directitem[0].sign;/*-指向上一级目录的目录项-*/
- cur_mkdir->directitem[1].firstdisk=cur_dir->directitem[0].firstdisk;
- strcpy(cur_mkdir->directitem[1].name,"..");
- cur_mkdir->directitem[1].next=cur_mkdir->directitem[1].firstdisk;
- cur_mkdir->directitem[1].property='1';
- cur_mkdir->directitem[1].size=ROOT_DISK_SIZE;
- for(i=2;i<MSD+2;i++) /*-子目录都初始化为空-*/
- {
- cur_mkdir->directitem[i].sign=0;
- cur_mkdir->directitem[i].firstdisk=-1;
- strcpy(cur_mkdir->directitem[i].name,"");
- cur_mkdir->directitem[i].next=-1;
- cur_mkdir->directitem[i].property='0';
- cur_mkdir->directitem[i].size=0;
- }
- return 0;
- }
- /*----------------------------------------------------------------------------------------------*/
- /*---------------------------------------删除子目录---------------------------------------------*/
- int rmdir(char *name)
- {
- int i,j,item;
- struct direct *temp_dir;
- /*-检查当前目录项中有无该目录-*/
- for(i=2;i<MSD+2;i++)
- {
- if(!strcmp(cur_dir->directitem[i].name,name))
- break;
- }
- if(cur_dir->directitem[i].property!='1')/*-删除的不是目录-*/
- return(-3);
- if(i>=MSD+2) /*-没有这个文件或目录-*/
- return(-1);
- /*-判断要删除的目录有无子目录-*/
- /*-要删除的目录起始地址-*/
- temp_dir=(struct direct *)(fdisk+cur_dir->directitem[i].next*DISKSIZE);
- for(j=2;j<MSD+2;j++)
- {
- if(temp_dir->directitem[j].next!=-1)
- break;
- }
- if(j<MSD+2) /*-有子目录或文件-*/
- return(-2); /*-有关联则报错,也可以采取级联删除,像Windows-*/
- /*------------找到起始盘块号,并将其释放----------------*/
- item=cur_dir->directitem[i].firstdisk;
- fat[item].em_disk='0';
- /*-修改目录项-*/
- cur_dir->directitem[i].sign=0;
- cur_dir->directitem[i].firstdisk=-1;
- strcpy(cur_dir->directitem[i].name,"");
- cur_dir->directitem[i].next=-1;
- cur_dir->directitem[i].property='0';
- cur_dir->directitem[i].size=0;
- return 0;
- }
- /*----------------------------------------------------------------------------------------------*/
- /*-------------------------------显示当前目录的子目录-------------------------------------------*/
- void dir()
- {
- int i;
- for(i=0;i<MSD+2;i++)
- {
- if(cur_dir->directitem[i].firstdisk!=-1) /*-如果存在子目录-*/
- { /*-其本身和父目录也算?-*/
- printf("%s/t",cur_dir->directitem[i].name);
- if(cur_dir->directitem[i].property=='0') /*-文件-*/
- printf("%d/t/t/n",cur_dir->directitem[i].size);
- else /*-目录-*/
- printf("/t<DIR>/t/n");
- }
- }
- }
- /*----------------------------------------------------------------------------------------------*/
- /*---------------------------------------更改当前目录-------------------------------------------*/
- int cd(char *name)
- {
- int i,j,item;
- char *str,*str1;
- char *temp,*point,*point1;
- struct direct *temp_dir;
- temp_dir=cur_dir; /*-先用临时目录代替当前目录-*/
- str=name; /*-str用来记录下次查找的起始地址-*/
- if(!strcmp("//",name)) /*如果输入"/" ,回根目录*/
- {
- cur_dir = root;
- strcpy(bufferdir,"Root:");
- return 0;
- }
- j=0;
- for(i=0;i<(int)strlen(str);i++)/*查找有两个连续是"/",即"//",退出 */
- {
- if(name[i]=='//')
- {
- j++;
- if(j>=2)
- {
- return -3;
- }
- }
- else
- j=0;
- }
- if(name[0]=='//') /*如果最后一个是"/" ,去掉这个"/"*/
- {
- temp_dir = root;
- strcpy(bufferdir,"Root:");
- str++;
- }
- if(str[strlen(str)-1] == '//')
- {
- str[strlen(str)-1] = '/0';
- }
- str1=strchr(str,'//'); /*-找到'/'字符的位置-*/
- temp = (char *)malloc(DIR_LENGTH*sizeof(char));/*-为子目录的名字分配空间-*/
- while(str1!=NULL) /*-找到-*/
- {
- for(i=0;i<str1-str;i++)
- {
- temp[i]=str[i];
- }
- temp[i]='/0';
- for(j=2;j<MSD+2;j++) /*-查找该子目录是否在当前目录中-*/
- {
- if(!strcmp(temp_dir->directitem[j].name,temp))
- break;
- }
- if(j>=MSD+2) /*-不在当前目录-*/
- return(-1);
- item=temp_dir->directitem[j].firstdisk;
- temp_dir=(struct direct *)(fdisk+item*DISKSIZE); /*-计算当前目录物理位置-*/
- str=str1+1;
- str1=strchr(str,'//');
- //free(temp);
- }
- str1=str1+strlen(str);
- for(i=0;i<(int)strlen(str);i++)
- temp[i]=str[i];
- temp[i]='/0';
- for(j=0;j<MSD+2;j++) /*-查找该子目录是否在当前目录中-*/
- {
- if(!strcmp(temp_dir->directitem[j].name,temp))
- break;
- }
- free(temp);/*释放申请的临时空间*/
- if(temp_dir->directitem[j].property!='1') /*-打开的不是目录-*/
- return(-2);
- if(j>=MSD+2) /*-不在当前目录-*/
- return(-1);
- item=temp_dir->directitem[j].firstdisk;
- /*-当前目录在磁盘中位置-*/
- temp_dir=(struct direct *)(fdisk+item*DISKSIZE);
- if(!strcmp("..",name))
- {
- if(cur_dir->directitem[j-1].sign!=1) /*-如果子目录不是根目录-*/
- {
- point=strchr(bufferdir,'//');
- while(point!=NULL)
- {
- point1=point+1; /*-减去'/'所占的空间,记录下次查找的起始地址-*/
- point=strchr(point1,'//');
- }
- *(point1-1)='/0'; /*-将上一级目录删除-*/
- }
- else
- {
- }
- }
- else if(!strcmp(".",name))
- {
- bufferdir=bufferdir; /*-如果是当前目录则不变-*/
- }
- else
- {
- if(name[0] !='//')
- bufferdir = strcat(bufferdir,"//"); /*-修改当前目录-*/
- bufferdir = strcat(bufferdir,name);
- }
- cur_dir=temp_dir; /*-将当前目录确定下来-*/
- return 0;
- }
- /*----------------------------------------------------------------------------------------------*/
- /*---------------------------------------显示当前路径-------------------------------------------*/
- void show()
- {
- printf("%s>",bufferdir);
- }
- /*----------------------------------------------------------------------------------------------*/
- /*--------------------------------------输出提示信息--------------------------------------------*/
- void print()
- {
- printf("********************************************************************************/n");
- printf("/t/t/tWelcome to DOS File system!/n");
- printf("--------------------------------------------------------------------------------/n");
- printf("/t/t 退出文件系统 halt/n");
- printf("/t/t 创建文件 create 文件名/n");
- printf("/t/t 删除文件 del 文件名/n");
- printf("/t/t 打开文件 open 文件名/n");
- printf("/t/t 关闭文件 close 文件名/n");
- printf("/t/t 写文件 write/n");
- printf("/t/t 读文件 read/n/n");
- printf("/t/t 创建子目录 mkdir 目录名/n");
- printf("/t/t 删除子目录 rmdir 目录名/n");
- printf("/t/t 显示当前目录的子目录 dir/n");
- printf("/t/t 更改当前目录 cd 目录名/n");
- printf("--------------------------------------------------------------------------------/n");
- }
- /*----------------------------------------------------------------------------------------------*/
- /*------------------------------------------主函数----------------------------------------------*/
- void main()
- {
- FILE *fp;
- char ch;
- char a[100];
- char code[11][10];
- char name[10];
- int i,flag,r_size;
- char *contect;
- contect = (char *)malloc(MAX_WRITE*sizeof(char));
- if((fp=fopen("disk.dat","rb"))==NULL)/*如果还没有进行格式化，则要格式化*/
- {
- printf("You have not format,Do you want format?(y/n)");
- scanf("%c",&ch);
- if(ch=='y')
- {
- initfile();
- printf("Successfully format! /n");
- }
- else
- {
- return;
- }
- }
- enter();
- print();
- show();
- /*将命令全部保存在CODE数组中*/
- strcpy(code[0],"halt");
- strcpy(code[1],"create");
- strcpy(code[2],"open");
- strcpy(code[3],"close");
- strcpy(code[4],"write");
- strcpy(code[5],"read");
- strcpy(code[6],"del");
- strcpy(code[7],"mkdir");
- strcpy(code[8],"rmdir");
- strcpy(code[9],"dir");
- strcpy(code[10],"cd");
- while(1)
- {
- scanf("%s",a);
- for(i=0;i<11;i++)
- {
- if(!strcmp(code[i],a))
- break;
- }
- switch(i)
- {
- case 0: //*--退出文件系统--//
- free(contect);
- halt();
- return;
- case 1: //*--创建文件--//
- scanf("%s",name);
- flag = create(name);
- if(flag==-1)
- {
- printf("Error: /n The length is too long !/n");
- }
- else if(flag==-2)
- {
- printf("Error: /n The direct item is already full !/n");
- }
- else if(flag==-3)
- {
- printf("Error: /n The number of openfile is too much !/n");
- }
- else if(flag==-4)
- {
- printf("Error: /n The name is already in the direct !/n");
- }
- else if(flag==-5)
- {
- printf("Error: /n The disk space is full!/n");
- }
- else
- {
- printf("Successfully create a file! /n");
- }
- show();
- break;
- case 2://--打开文件--//
- scanf("%s",name);
- fd = open(name);
- if(fd == -1)
- {
- printf("Error: /n The open file not exit! /n");
- }
- else if(fd == -2)
- {
- printf("Error: /n The file have already opened! /n");
- }
- else if(fd == -3)
- {
- printf("Error: /n The number of open file is too much! /n");
- }
- else if(fd == -4)
- {
- printf("Error: /n It is a direct,can not open for read or write! /n");
- }
- else
- {
- printf("Successfully opened! /n");
- }
- show();
- break;
- case 3://--关闭文件--//
- scanf("%s",name);
- flag = close(name);
- if(flag == -1)
- {
- printf("Error:/n The file is not opened ! /n");
- }
- else
- {
- printf("Successfully closed! /n");
- }
- show();
- break;
- case 4:/*--写文件--*/
- if(fd ==-1)
- {
- printf("Error:/n The file is not opened ! /n");
- }
- else
- {
- printf("Please input the file contect:");
- scanf("%s",contect);
- flag=write(fd,contect,strlen(contect));
- if(flag == 0)
- {
- printf("Successfully write! /n");
- }
- else
- {
- printf("Error:/n The disk size is not enough! /n");
- }
- }
- show();
- break;
- case 5:/*--读文件--*/
- if(fd ==-1)
- {
- printf("Error:/n The file is not opened ! /n");
- }
- else
- {
- flag = read(fd,contect);
- if(flag == -1)
- {
- printf("Error: /n The size is over the length of the file! /n");
- }
- else
- {
- //printf("Successfully read! /n The contect is :");
- for(i=0;i<u_opentable.openitem[fd].size;i++)
- {
- printf("%c",contect[i]);
- }
- printf("/t/n");
- }
- }
- show();
- break;
- case 6://*--删除文件--
- scanf("%s",name);
- flag = del(name);
- if(flag == -1)
- {
- printf("Error:/n The file not exit! /n");
- }
- else if(flag == -2)
- {
- printf("Error:/n The file is opened,please first close it ! /n");
- }
- else if(flag == -3)
- {
- printf("Error:/n The delete is not file ! /n");
- }
- else
- {
- printf("Successfully delete! /n");
- }
- show();
- break;
- case 7://*--创建子目录--/
- scanf("%s",name);
- flag = mkdir(name);
- if(flag == -1)
- {
- printf("Error:/n The length of name is to long! /n");
- }
- else if(flag == -2)
- {
- printf("Error:/n The direct item is already full ! /n");
- }
- else if(flag == -3)
- {
- printf("Error:/n The name is already in the direct ! /n");
- }
- else if(flag == -4)
- {
- printf("Error:/n // can not in the name of a direct ! /n");
- }
- else if(flag == -5)
- {
- printf("Error: /n The disk space is full!/n");
- }
- else if(flag == -6)
- {
- printf("Error: /n '..' or '.' can not as the name of the direct!/n");
- }
- else if(flag == 0)
- {
- printf("Successfully make dircet! /n");
- }
- show();
- break;
- case 8://*--删除子目录--/
- scanf("%s",name);
- flag = rmdir(name);
- if(flag == -1)
- {
- printf("Error:/n The direct is not exist! /n");
- }
- else if(flag == -2)
- {
- printf("Error:/nThe direct has son direct ,please first remove the son dircct!/n");
- }
- else if(flag == -3)
- {
- printf("Error:/n The remove is not direct ! /n");
- }
- else if(flag == 0)
- {
- printf("Successfully remove dircet! /n");
- }
- show();
- break;
- case 9://*--显示当前子目录--/
- dir();
- show();
- break;
- case 10:/*--更改当前目录--*/
- scanf("%s",name);
- flag = cd(name);
- if(flag == -1)
- {
- printf("Error:/n The path no correct!/n");
- }
- else if(flag == -2)
- {
- printf("Error:/nThe opened is not direct!/n");
- }
- else if(flag == -3)
- {
- printf("Error:/nThe '//' is too much !/n");
- }
- show();
- break;
- default:
- printf("/n Error!/n The command is wrong! /n");
- show();
- }
- }
- }