操作系统文件管理系统模拟实验文件管理系统模拟1.实验目的通过一个简单多用户文件系统的设计，加深理解文件系统的内部功能及内部实现 2.实验内容为Linux系统设计一个简单的二级文件系统。

要求做到以下几点:(1)可以实现下列几条命令(至少4条)login 用户登录dir 列文件目录create 创建文件delete 删除文件open 打开文件close 关闭文件read 读文件write 写文件(2)列目录时要列出文件名、物理地址、保护码和文件长度;(3)源文件可以进行读写保护。

3.实验提示(1)首先应确定文件系统的数据结构:主目录、子目录及活动文件等。

主目录和子目录都以文件的形式存放于磁盘，这样便于查找和修改。

(2)用户创建的文件，可以编号存储于磁盘上。

入file0,file1,file2…并以编号作为物理地址，在目录中进行登记。

4.源代码#include<stdio.h> DISK_NUM*sizeof(struct fatitem)#include<string.h> //FAT表大小#include<stdlib.h> #define ROOT_DISK_NOFATSIZE/DISKSIZE+1 #define MEM_D_SIZE 1024*1024 //根目录起始盘块号//总磁盘空间为1M #define ROOT_DISK_SIZE #define DISKSIZE 1024sizeof(struct direct) //根//磁盘块的大小1K 目录大小#define DISK_NUM 1024 #define DIR_MAXSIZE 1024//磁盘块数目1K //路径最大长度为1KB #define FATSIZE #define MSD 5 //最大子目录数5 }openitem[MOFN]; #define MOFN 5 int cur_size; /*当前打文件的//最大文件深度为5 数目*/#define MAX_WRITE 1024*128 };//最大写入文字长度128KBstruct fatitem *fat; /*FAT表*/ struct fatitem /* size 8*/ struct direct *root; /*根目录*/ { struct direct *cur_dir; /*当前int item; /*存放文件下一个磁目录*/盘的指针*/ struct opentable u_opentable; /*char em_disk; /*磁盘块是否空闲文件打开表*/标志位 0 空闲*/ int fd=-1; /*文件打开表的序}; 号*/char *bufferdir; /*记录当前路struct direct 径的名称*/{ char *fdisk; /*虚拟磁盘起始地/*-----文件控制快信息-----*/ 址*/struct FCB{ void initfile();char name[9]; /*文件/目录void format();8位*/ void enter(); 名char property; /*属性 1位void halt(); 目录 0位普通文件*/ int create(char *name);int size; /*文件/目录字int open(char *name); 节数、盘块数)*/ int close(char *name);int firstdisk; /*文件/目int write(int fd,char *buf,int 录起始盘块号*/ len);int next; /*子目录起始盘int read(int fd,char *buf); 块号*/ intdel(char *name);int sign; /*1是根目录 0int mkdir(char *name); 不是根目录*/ int rmdir(char *name);void dir();}directitem[MSD+2]; int cd(char *name);void print();}; void show();struct opentable void initfile() { {struct openttableitem fdisk = (char{ *)malloc(MEM_D_SIZE*sizeof(char)char name[9]; /*文件名*/ ); /*申请 1M空间*/int firstdisk; /*起始盘块 format();号*/int size; /*文件的大小*/ }me,".");void format() root->directitem[0].next = { root->directitem[0].firstdisk;int i; root->directitem[0].propertyFILE *fp; = '1';root->directitem[0].size =fat = (struct fatitem ROOT_DISK_SIZE;*)(fdisk+DISKSIZE); /*计算FAT表-------指向上一级目录的目录 /*地址，引导区向后偏移 1k)*/ 项---------*//*-----初始化FAT表 root->directitem[1].sign = 1; ------------*/ root->directitem[1].firstdiskfat[0].item=-1; /*引导块*/ = ROOT_DISK_NO;fat[0].em_disk='1'; strcpy(root->directitem[1].name,"..");for(i=1;i<ROOT_DISK_NO-1;i++) root->directitem[1].next = /*存放 FAT 表的磁盘块号*/ root->directitem[0].firstdisk;{ root->directitem[1].propertyfat[i].item=i+1; = '1';fat[i].em_disk='1'; root->directitem[1].size =} ROOT_DISK_SIZE;if((fp =fat[ROOT_DISK_NO].item=-1; fopen("disk.dat","wb"))==NULL) /*存放根目录的磁盘块号*/ {fat[ROOT_DISK_NO].em_disk='1' printf("Error:\n Cannot ; open file \n");return;for(i=ROOT_DISK_NO+1;i<DISK_N }UM;i++) for(i=2;i<MSD+2;i++) /*-子目{ 录初始化为空-*/fat[i].item = -1; {fat[i].em_disk = '0'; root->directitem[i].sign =} 0;/*-----------------------------------------------*/ root->directitem[i].firstdiskroot = (struct direct = -1;*)(fdisk+DISKSIZE+FATSIZE); /*根目录的地址*/ strcpy(root->directitem[i].na/*初始化目录*/ me,"");/*---------指向当前目录的目录 root->directitem[i].next = 项---------*/ -1;root->directitem[0].sign = 1;root->directitem[0].firstdisk root->directitem[i].property =ROOT_DISK_NO; = '0';strcpy(root->directitem[0].na root->directitem[i].size =0; }} fat = (struct fatitem*)(fdisk+DISKSIZE); /*找到FAT表地址*/root = (struct direct if((fp =fopen("disk.dat","wb"))==NULL) *)(fdisk+DISKSIZE+FATSIZE);/*找{ 到根目录地址*/printf("Error:\n Cannot fclose(fp);open file \n"); /*--------------初始化用户打return; 开表------------------*/} for(i=0;i<MOFN;i++)if(fwrite(fdisk,MEM_D_SIZE,1, {fp)!=1) /*把虚拟磁盘空间保存到磁盘文件中*/ strcpy(u_opentable.openitem[i{ ].name,"");printf("Error:\n Fileu_opentable.openitem[i].firstwrite error! \n");disk = -1; }fclose(fp); u_opentable.openitem[i].size= 0; } }void enter() u_opentable.cur_size = 0; {FILE *fp; cur_dir = root; /*当前目录为根int i; 目录*/bufferdir = (charfdisk = (char*)malloc(DIR_MAXSIZE*sizeof(char*)malloc(MEM_D_SIZE*sizeof(char)));); /*申请 1M空间*/ strcpy(bufferdir,"Root:");if((fp=fopen("disk.dat","rb")})==NULL){ void halt()printf("Error:\nCannot {open file\n"); FILE *fp;return; int i;}if(!fread(fdisk,MEM_D_SIZE,1, if((fp=fopen("disk.dat","wb")fp)) /*把磁盘文件disk.dat 读入)==NULL)虚拟磁盘空间(内存)*/ {{ printf("Error:\nCannotprintf("Error:\nCannot open file\n");read file\n"); return;exit(0); }if(!fwrite(fdisk,MEM_D_SIZE,1 return(-2);,fp)) /*把虚拟磁盘空间(内存)内容读入磁盘文件disk.dat */ if(u_opentable.cur_size>=MOFN) /*{ 打开文件太多*/printf("Error:\nFile write return(-3);error!\n");}fclose(fp);for(j=ROOT_DISK_NO+1;j<DISK_NUM;free(fdisk); j++) /*找到空闲盘块 j 后退出*/free(bufferdir); {return; if(fat[j].em_disk=='0') } break;}int create(char *name) if(j>=DISK_NUM){ return(-5);fat[j].em_disk = '1'; /*将空int i,j; 闲块置为已经分配*//*-----------填写目录项if(strlen(name)>8) /*文件名大-----------------*/于 8位*/return(-1); strcpy(cur_dir->directitem[i].name,name);for(j=2;j<MSD+2;j++) /*检查创建文件是否与已存在的文件重名*/ cur_dir->directitem[i].firstdisk{ = j;cur_dir->directitem[i].size =if(!strcmp(cur_dir->directite0;m[j].name,name)) cur_dir->directitem[i].next =break; j;}if(j<MSD+2) /*文件已经存cur_dir->directitem[i].property = 在*/ '0'; return(-4);/*------------------------------for(i=2;i<MSD+2;i++) /*找到第---*/一个空闲子目录*/ fd = open(name);{ return 0;if(cur_dir->directitem[i].fir}stdisk==-1)break; int open(char *name)} {if(i>=MSD+2) /*无空目录项*/ int i, j;/*--------------填写表项的相for(i=2;i<MSD+2;i++) /*文件是关信息------------------------*/ 否存在*/{ u_opentable.openitem[j].firstdisk =if(!strcmp(cur_dir->directitecur_dir->directitem[i].firstdiskm[i].name,name)) ;break;} strcpy(u_opentable.openitem[j].nif(i>=MSD+2) ame,name);return(-1); u_opentable.openitem[j].size/*--------是文件还是目录= cur_dir->directitem[i].size; -----------------------*/ u_opentable.cur_size++;if(cur_dir->directitem[i].pro /*----------返回用户打开表表perty=='1') 项的序号return(-4); --------------------------*/return(j);件是否打开 /*--------文}-----------------------*/for(j=0;j<MOFN;j++) int close(char *name){ {int i;if(!strcmp(u_opentable.openitem[j].name,name)) for(i=0;i<MOFN;i++)break; {}if(j<MOFN) /*文件已经打开*/ if(!strcmp(u_opentable.openitreturn(-2); em[i].name,name))break;}if(i>=MOFN)if(u_opentable.cur_size>=MOFN) /* return(-1);文件打开太多*/ /*-----------清空该文件的用return(-3); 户打开表项的内容---------------------*//*--------查找一个空闲用户打开表项-----------------------*/ strcpy(u_opentable.openitem[i].n for(j=0;j<MOFN;j++) ame,"");{u_opentable.openitem[i].firstdisif(u_opentable.openitem[j].fik = -1;rstdisk==-1) u_opentable.openitem[i].sizebreak; = 0;} u_opentable.cur_size--;下标-*//*------找到的item 是该文件的return 0; 最后一块磁盘块} -------------------*/while(fat[item].item!=-1) int write(int fd, char *buf, int { len) item =fat[item].item; /*-*/ { 查找该文件的下一盘块--} char *first;int item, i, j, k;int ilen1, ilen2, modlen, temp; /*-----计算出该文件的最末地址/*----------用 $ 字符作为空格 -------*/# 字符作为换行符 first =-----------------------*/ fdisk+item*DISKSIZE+u_opentable. char Space = 32; openitem[fd].size%DISKSIZE;char Endter= '\n';/* -----如果最后磁盘块剩余的大for(i=0;i<len;i++) 小大于要写入的文件的大小{ -------*/if(buf[i] == '$') if(DISKSIZE-u_opentable.openibuf[i] = Space; tem[fd].size%DISKSIZE>len)else if(buf[i] == '#') {buf[i] = Endter; strcpy(first,buf);}u_opentable.openitem[fd].size/*----------读取用户打开表对=应表项第一个盘块号u_opentable.openitem[fd].size+le-----------------------*/ n;item = cur_dir->directitem[temp].sizu_opentable.openitem[fd].firstdie = sk; cur_dir->directitem[temp].size+len;/*-------------找到当前目录所 }对应表项的序号 else-------------------------*/ {for(i=2;i<MSD+2;i++){ for(i=0;i<(DISKSIZE-u_opentable.openitem[fd].size%DISKSIZE);iif(cur_dir->directitem[i].fir++)stdisk==item) {/*写一部分内容到最后一块break; 磁盘块的剩余空间(字节)*/} first[i] = buf [i];temp = i; /*-存放当前目录项的 }/*-----计算分配完最后一块=buf[k];磁盘的剩余空间(字节) 还剩下多少 }字节未存储-------*/ilen1 = fat[item].item = i; len-(DISKSIZE-u_opentable.openit--找到一块后将它的序号存放在上/*em[fd].size%DISKSIZE); 一块的指针中-*/ilen2 = ilen1/DISKSIZE; fat[i].em_disk = '1';modlen = ilen1%DISKSIZE; --置找到的磁盘快的空闲标志位为/*if(modlen>0) 已分配-*/ilen2 = ilen2+1; /*-- fat[i].item = -1; /*--还需要多少块磁盘块-*/ 它的指针为 -1 (即没有下一块)-*/}for(j=0;j<ilen2;j++) /*--修改长度-*/{u_opentable.openitem[fd].sizefor(i=ROOT_DISK_NO+1;i<DISK_N=UM;i++)/*寻找空闲磁盘块*/ u_opentable.openitem[fd].size+len; {cur_dir->directitem[temp].siz if(fat[i].em_disk=='0')break; e =} cur_dir->directitem[temp].size+lif(i>=DISK_NUM) /*--如en;果磁盘块已经分配完了-*/ }return(-1); return 0;first = }fdisk+i*DISKSIZE; /*--找到的那块空闲磁盘块的起始地址-*/ int read(int fd, char *buf)if(j==ilen2-1) /*--如{果是最后要分配的一块-*/ int len ={ u_opentable.openitem[fd].size;char *first;for(k=0;k<len-(DISKSIZE-u_ope int i, j, item;ntable.openitem[fd].size%DISKSIZ int ilen1, modlen; E)-j*DISKSIZE;k++) first[k] = item =buf[k]; u_opentable.openitem[fd].firstdi} sk;else/*-如果不是要最后分配的一块--*/{ ilen1 = len/DISKSIZE;modlen = len%DISKSIZE;for(k=0;k<DISKSIZE;k++) if(modlen!=0)first[k] ilen1 = ilen1+1; /*--计算文件所占磁盘的块数-*/ 项的序号,供释放目录中-*/first = fdisk+item*DISKSIZE; if(i>=MSD+2) /*--如果不在当前/*--计算文件的起始位置-*/ 目录中-*/return(-1);for(i=0;i<ilen1;i++){ if(cur_dir->directitem[cur_itif(i==ilen1-1) /*--如果在em].property!='0') /*--如果删除的最后一个磁盘块-*/ (不)是目录-*/{ return(-3);for(j=0;j<len-i*DISKSIZE;j++) for(i=0;i<MOFN;i++) /*--如果buf[i*DISKSIZE+j] = 文件打开,则不能删除,退出-*/first[j]; {}else /*--不在最后一块磁盘 if(!strcmp(u_opentable.openit块-*/ em[i].name,name)){ return(-2);}for(j=0;j<len-i*DISKSIZE;j++) item =cur_dir->directitem[cur_item].fi buf[i*DISKSIZE+j] =first[j]; rstdisk;/*--该文件的起始盘块号item = fat[item].item; -*//*-查找下一盘块-*/ while(item!=-1) /*--释放空间,first = 将FAT表对应项进行修改-*/fdisk+item*DISKSIZE; {} temp = fat[item].item;} fat[item].item = -1;return 0; fat[item].em_disk = '0'; } item = temp;}int del(char *name) /*-----------------释放目录项{ -----------------------*/int i,cur_item,item,temp; cur_dir->directitem[cur_item].sign = 0;for(i=2;i<MSD+2;i++) /*--查找 cur_dir->directitem[cur_item]要删除文件是否在当前目录中-*/ .firstdisk = -1;{ strcpy(u_opentable.openitem[cur_item].name,"");if(!strcmp(cur_dir->directitem[i].name,name)) cur_dir->directitem[cur_item].nebreak; xt = -1;}cur_item = i; /*--用来保存目录cur_dir->directitem[cur_item].pr operty = '0'; {cur_dir->directitem[cur_item] if(fat[j].em_disk=='0') .size = 0; break;}if(j>=DISK_NUM) return 0;} return(-5);fat[j].em_disk='1'; /*-将该空int mkdir(char *name) 闲块设置为已分配-*/{int i,j; /*-------------填写目录项struct direct *cur_mkdir; ----------*/strcpy(cur_dir->directitem[i]if(!strcmp(name,".")) .name,name);return(-4); cur_dir->directitem[i].firstdif(!strcmp(name,"..")) isk=j;return(-4); cur_dir->directitem[i].size=Rif(strlen(name)>8) /*-如果目OOT_DISK_SIZE;8位-*/ 录名长度大于 cur_dir->directitem[i].next=jreturn(-1); ;cur_dir->directitem[i].properfor(i=2;i<MSD+2;i++) /*-如果ty='1';有空闲目录项退出-*/{/*-所创目录在虚拟磁盘上的地址if(cur_dir->directitem[i].fir(内存物理地址)-*/stdisk==-1) cur_mkdir=(struct directbreak; *)(fdisk+cur_dir->directitem[i].} firstdisk*DISKSIZE);if(i>=MSD+2) /*-目录/文件已满-*/ /*-初始化目录-*/return(-2); /*-指向当前目录的目录项-*/for(j=2;j<MSD+2;j++) /*-判断 cur_mkdir->directitem[0].sign是否有重名-*/ =0;{ cur_mkdir->directitem[0].firstdisk=cur_dir->directitem[i].firif(!strcmp(cur_dir->directitestdisk;m[j].name,name)) strcpy(cur_mkdir->directitem[break; 0].name,".");} cur_mkdir->directitem[0].nextif(j<MSD+2) /*-如果有重名-*/ =cur_mkdir->directitem[0].firstdreturn(-3); isk;for(j=ROOT_DISK_NO+1;j<DISK_N cur_mkdir->directitem[0].propUM;j++) /*-找到空闲磁盘块 j 后退erty='1';出-*/ cur_mkdir->directitem[0].size=ROOT_DISK_SIZE; int i,j,item;struct direct *temp_dir;/*-指向上一级目录的目录项-*/ /*-检查当前目录项中有无该目录cur_mkdir->directitem[1].sign-*/=cur_dir->directitem[0].sign; for(i=2;i<MSD+2;i++)cur_mkdir->directitem[1].firs {tdisk=cur_dir->directitem[0].firstdisk; if(!strcmp(cur_dir->directitestrcpy(cur_mkdir->directitem[m[i].name,name))1].name,".."); break;cur_mkdir->directitem[1].next }=cur_mkdir->directitem[1].firstd if(i>=MSD+2) /*-没有这个文件isk; 或目录-*/cur_mkdir->directitem[1].prop return(-1);erty='1'; if(cur_dir->directitem[i].procur_mkdir->directitem[1].sizeperty!='1')/*-删除的不是目录-*/=ROOT_DISK_SIZE; return(-3);for(i=2;i<MSD+2;i++) /*-子目录都初始化为空-*/ /*-判断要删除的目录有无子目录{ -*/cur_mkdir->directitem[i].sign temp_dir=(struct direct =0;*)(fdisk+cur_dir->directitem[i].next*DISKSIZE);cur_mkdir->directitem[i].firs for(j=2;j<MSD+2;j++) tdisk=-1; { strcpy(cur_mkdir->directitem[ if(temp_dir->directitem[j].nei].name,""); xt!=-1)break;cur_mkdir->directitem[i].next }=-1; if(j<MSD+2) /*-有子目录或文件-*/cur_mkdir->directitem[i].prop return(-2);erty='0'; /*------------找到起始盘块号,并将其释放----------------*/cur_mkdir->directitem[i].size item=cur_dir->directitem[i].f=0; irstdisk;} fat[item].em_disk='0';return 0; /*-修改目录项-*/} cur_dir->directitem[i].sign=0;int rmdir(char *name) cur_dir->directitem[i].firstd{ isk=-1;strcpy(cur_dir->directitem[i] str=name;.name,"");cur_dir->directitem[i].next=- if(!strcmp("\\",name)) 1; {cur_dir->directitem[i].proper cur_dir = root; ty='0';cur_dir->directitem[i].size=0 strcpy(bufferdir,"Root:"); ; return 0;}return 0;} temp = (char*)malloc(DIR_MAXSIZE*sizeof(charvoid dir() ));/*-最长路径名字分配空间-*/ {int i; for(i=0;i<(int)strlen(str);i+for(i=2;i<MSD+2;i++) +){ temp[i]=str[i];temp[i]='\0';if(cur_dir->directitem[i].firfor(j=0;j<MSD+2;j++) /*-查找stdisk!=-1) /*-如果存在子目录-*/该子目录是否在当前目录中-*/ {{printf("%s\t",cur_dir->directitem[i].name); if(!strcmp(temp_dir->directitem[j].name,temp))if(cur_dir->directitem[i].pro break;perty=='0') /*-文件-*/ }printf("%d\t\t\n",cur_dir->di free(temp);/*释放申请的临时空rectitem[i].size); 间*/else //if(temp_dir->directitem[j].printf("\t<目property!='1') /*-打开的不是目录录>\t\n"); -*/} //return(-2);} if(j>=MSD+2) /*-不在当前目录} -*/return(-1);int cd(char *name){ item=temp_dir->directitem[j].int i,j,item; firstdisk;char *str; /*-当前目录在磁盘中位置-*/char *temp,*point,*point1; temp_dir=(struct directstruct direct *temp_dir; *)(fdisk+item*DISKSIZE);temp_dir=cur_dir;}if(!strcmp("..",name)){ void print(){if(cur_dir->directitem[j-1].s printf("*********************ign!=1) /*-如果上级目录不是根目录******************************** -*/ ****\n");printf("********************* {*文件系统设计point=strchr(bufferdir,'\\'); ***********************\n");//查找字符串bufferdir中首次出现 printf("*\t命令格式说明字符\ 的位置 *\n");printf("*\tcd 目录名更改while(point!=NULL) 当前目录 *\n");{ printf("*\tmkdir 目录名point1=point+1; /*- 创建子目录 *\n"); 减去'\'所占的空间,记录下次查找的 printf("*\trmdir 目录名*/ \n"); 起始地址- 删除子目录 *printf("*\tdir 显示point=strchr(point1,'\\当前目录的子目录 *'); \n");文件名 } printf("*\tcreate*(point1-1)='\0'; /*- 创建文件 *\n"); 将上一级目录删除-*/printf("*\tdel 文件名} 删除文件 *\n");printf("*\topen 文件名} 打开文件 *\n");printf("*\tclose 文件名else 关闭文件 *\n");{ printf("*\tread 读文//if(name[0] !='\\') 件 *\n");bufferdir = printf("*\twrite 写文strcat(bufferdir,"\\"); /*-修改当件*\n"); 前目录-*/ printf("*\texit 退出bufferdir = 系统 *\n"); strcat(bufferdir,name);printf("*********************} ********************************cur_dir=temp_dir; /*-将当前****\n"); 目录确定下来-*/return 0; }}void main() void show() {{ FILE *fp;printf("%s>",bufferdir); char ch;char a[100];char code[11][10]; while(1)char name[10]; {int i,flag,r_size; scanf("%s",a);char *contect; for(i=0;i<11;i++){contect = (char if(!strcmp(code[i],a))*)malloc(MAX_WRITE*sizeof(char)) break;} ;if((fp=fopen("disk.dat","rb") switch(i))==NULL) {{ case 0: //退出文件系统printf("You have not free(contect); format,Do you want format?(y/n)"); halt();return; scanf("%c",&ch);case 1: //创建文件if(ch=='y') scanf("%s",name);{ flag = create(name);initfile(); if(flag==-1)printf("Successfully {format! \n"); printf("Error: \n} The length is too long !\n");else }{ else if(flag==-2)return; {} printf("Error: \n} The direct item is alreadyfull !\n");enter(); }print(); else if(flag==-3)show(); {printf("Error: \nstrcpy(code[0],"exit"); The number of openfile is too strcpy(code[1],"create"); much !\n");strcpy(code[2],"open"); }strcpy(code[3],"close"); else if(flag==-4)strcpy(code[4],"write"); {strcpy(code[5],"read"); printf("Error: \nstrcpy(code[6],"del"); The name is already in the strcpy(code[7],"mkdir"); direct !\n");strcpy(code[8],"rmdir"); }strcpy(code[9],"dir"); else if(flag==-5)strcpy(code[10],"cd"); {printf("Error: \n show();The disk space is full!\n"); break;}else case 3://关闭文件scanf("%s",name); {flag = close(name);printf("Successfully create a if(flag == -1) { file! \n");} printf("Error:\nThe file is not opened ! \n");show(); }break; else{case 2://打开文件scanf("%s",name); printf("Successfully closed! fd = open(name); \n");if(fd == -1) }{ show();printf("Error: \n break;The open file not exit! \n");case 4://写文件 }else if(fd == -2) if(fd ==-1){ {printf("Error: \n printf("Error:\n The file have already opened!\n"); The file is not opened ! \n");} }else if(fd == -3) else{ {printf("Error: \n printf("Please The number of open file is too much! input the file contect:"); \n");} scanf("%s",contect);else if(fd == -4){ flag=write(fd,contect,strlen(printf("Error: \n contect));It is a direct,can not open for read if(flag == 0) or write! \n"); { }else printf("Successfully write!{ \n");}printf("Successfully opened! else\n"); {}printf("Error:\n The disk size close it ! \n"); is not enough!\n"); }} else if(flag == -3)} {show(); printf("Error:\nbreak; The delete is not file ! \n");}case 5://读文件 elseif(fd ==-1) {{printf("Error:\n printf("Successfully delete! The file is not opened ! \n"); \n");} }else show();{ break;flag =read(fd,contect); case 7://创建子目录if(flag == 0) scanf("%s",name);{ flag = mkdir(name);if(flag == -1)for(i=0;i<u_opentable.openite {m[fd].size;i++) printf("Error:\n{ The length of name is to long! \n");}printf("%c",contect[i]); else if(flag == -2)} {printf("\t\n"); printf("Error:\n} The direct item is already full !} \n");show(); }break; else if(flag == -3){case 6://删除文件 printf("Error:\nscanf("%s",name); The name is already in the direct !flag = del(name); \n");if(flag == -1) }{ else if(flag == -4)printf("Error:\n {The file not exit! \n"); printf("Error: \n} '..' or '.' can not as the name ofelse if(flag == -2) the direct!\n");{ }printf("Error:\n else if(flag == -5) The file is opened,please first {printf("Error: \n }The disk space is full!\n"); show();} break;else if(flag == 0)case 9://显示当前子目录 {dir();printf("Successfully make show();break; dircet! \n");}show(); case 10://更改当前目录break; scanf("%s",name);flag = cd(name);case 8://删除子目录 if(flag == -1)scanf("%s",name); {flag = rmdir(name); printf("Error:\nif(flag == -1) The path no correct!\n");{ }printf("Error:\n else if(flag == -2) The direct is not exist! \n"); {}else if(flag == -2) printf("Error:\nThe opened is{ not direct!\n");}printf("Error:\nThe direct hasson direct ,please first remove the show();son dircct!\n"); break;}else if(flag == -3) default:{ printf("\n Error!\n Theprintf("Error:\n command is wrong! \n"); The remove is not direct ! \n"); show();}else if(flag == 0) }{ }}printf("Successfully removedircet! \n");5.程序运行截图6.实验总结通过这一次计算机操作系统的上机实验，使我对不同环境下的操作系统有了进一步的了解，使我学到了很多关于Linux的操作和相关知识。