use.cpp

在Linux Red Hat下用C++设计并实现一个多用户多级目录结构的文件系统。

#include"use.h"
#include<string.h>
#include<iostream.h>
#include<iomanip.h>

use::use()
{
   //初始化用户系统，当前用户指针，用户数目，根目录
   for(int yy=0;yy<userno;yy++)
   {
      iuser[yy]=NULL;
   }
   cuser=-1;
   usernum=0;

   rdir=iopenfile.openf(NULL,"#rdir",IFDIR);
  

}
use::~use()
{
   //关闭根目录
   iopenfile.closef(rdir);

}

int use::login(char*u_name,char*u_password)
{

   //在用户系统中寻找
   for(int xx=0;xx<userno;xx++)
   {
      if(iuser[xx]!=NULL)
      {
         if(strcmp(iuser[xx]->u_name,u_name)==0)
         {
            if(strcmp(iuser[xx]->u_password,u_password)==0)
            {
               cuser=xx;
               return OK;
            }else
            {
               cout<<"PASSWORD INCORRECT\n";
               return ERROR;
            }
         }
      }
   }
   //在uwords中寻找
   ofile *curfile;
   curfile=iopenfile.openf(rdir->o_fcb,"uwords",IFREG|IREAD|GREAD|OREAD);
   
   if(curfile->o_fcb->f_add[0]==0)
   {
      char name[]="root\0       1\0          A0"; 
      curfile->o_fcb->f_uid='a';
      curfile->o_fcb->f_gid='0';

      iopenfile.writef(curfile->o_fcb,0,26,name);
   }
   char*base=new char[curfile->o_fcb->f_fsize+1];
   iopenfile.readf(curfile->o_fcb,0,curfile->o_fcb->f_fsize,base);

   char name[12];
   char pw[12];
   char uid;
   char gid;
   for(int c=0;c<=(curfile->o_fcb->f_fsize-1)/26;c++)
   {
      
      for(int i=0;i<12;i++)
      {
         name[i]=base[26*c+i];
         pw[i]=base[26*c+i+12];
      }
 
      uid=base[26*c+24];
      gid=base[26*c+25];
     
      if(strcmp(name,u_name)==0)
      {
         
         if(strcmp(pw,u_password)==0)
         {
            
            for(int u=0;u<userno;u++)
            {
               if(iuser[u]==NULL)
               {
                  
                  iuser[u]=new struct user;
                  strcpy(iuser[u]->u_name,name);
                  strcpy(iuser[u]->u_password,pw);
                  iuser[u]->u_flag=UINC;
                  iuser[u]->u_number=c;
                  iuser[u]->u_uid=uid;
                  iuser[u]->u_gid=gid;
                  iuser[u]->u_cdir=0;
                  for(int kk=0;kk<16;kk++)
                  {
                     iuser[u]->u_ofile[kk]=NULL;
                  }
                  
                  iuser[u]->u_ofile[0]=iopenfile.openf(NULL,"#rdir",IFDIR);
                   
                  
                  cuser=u;
                  usernum++;
               
                  iopenfile.closef(curfile);
                  delete[]base;
            
                  return OK;
               }
            }
            iopenfile.closef(curfile);
            cout<<"USER FULL\n";
            delete[]base;
            return ERROR;
        }else
        {
            iopenfile.closef(curfile);
            cout<<"password incorrect\n";
            delete[]base;
            return ERROR;
        }
                  
      }
   }
   iopenfile.closef(curfile);
   cout<<"usename incorrect\n";
   delete[]base;
   return ERROR;
    
}

int use::logout()
{
   //关闭用户工作文件目录数组
   for(int l=iuser[cuser]->u_cdir;l>=0;l--)
   {
      iopenfile.closef(iuser[cuser]->u_ofile[l]);
   }
   if(iuser[cuser]->u_flag==UCHG)
   {
	  //存储用户信息
      ofile *curfile;
      curfile=iopenfile.openf(rdir->o_fcb,"uwords",MODE);
      char*base=new char[curfile->o_fcb->f_fsize-iuser[cuser]->u_number*26+1];
      iopenfile.readf(curfile->o_fcb,iuser[cuser]->u_number*26,curfile->o_fcb->f_fsize-iuser[cuser]->u_number*26,base);
      
      char name[12];
      char pw[12];
      for(int i=0;i<12;i++)
      {
         name[i]=base[i];
         pw[i]=base[i+12];
      }
      if(strcmp(name,iuser[cuser]->u_name)==0)
      {
         for(int dd=0;dd<12;dd++)
         {
             base[dd+12]=iuser[cuser]->u_password[dd];
         }
         iopenfile.writef(curfile->o_fcb,iuser[cuser]->u_number*26,curfile->o_fcb->f_fsize-iuser[cuser]->u_number*26,base);

         iopenfile.closef(curfile);
      }else
      {
        delete[]base;
        return ERROR;
      }
      delete[]base;
   }
   //删除用户在用户系统中的用户结构
   delete iuser[cuser];
   iuser[cuser]=NULL;
   usernum--;
   for(int ll=0;ll<userno;ll++)
   {
      if(iuser[ll]!=NULL)
      {
         cuser=ll;
         return OK;
      }
   }
   cuser=-1;
   return OK;
}
 

int use::createuser(char*u_name,char*password)
{
   //创建用户，并将新用户信息存储在文件uwords中
   if(strlen(u_name)>=12||strlen(password)>=12)
   {
     cout<<"the length of the username and password must be less than 12bytes\n";
     return OK;
   }
    
   if(strcmp(iuser[cuser]->u_name,"root")!=0)
   {
     cout<<"ONLY THE ROOT CAN CREAT USER\n";
     return OK;
   }else
   {
      ofile *curfile;
      curfile=iopenfile.openf(rdir->o_fcb,"uwords",MODE);
      char*base=new char[curfile->o_fcb->f_fsize+1];
   
      iopenfile.readf(curfile->o_fcb,0,curfile->o_fcb->f_fsize,base);
   
      char name[12];
      for(int c=0;c<=(curfile->o_fcb->f_fsize-1)/26;c++)
      {
         for(int i=0;i<12;i++)
         {
            name[i]=base[26*c+i];
         }
         if(strcmp(name,u_name)==0)
         {
           cout<<"THERE HAS BEEN A USER "<<u_name<<endl;
           delete[]base;
           iopenfile.closef(curfile);
           return OK;
         }
      }
      delete[]base;
      char buf[26+1];
      char uid=(curfile->o_fcb->f_fsize-1)/26+1+'A';
      for(int rr=0;rr<12;rr++)
      {
         buf[rr]=u_name[rr];
         buf[rr+12]=password[rr];
      }
      buf[24]=uid;
      buf[25]='0';
      buf[26]='\0';
      iopenfile.writef(curfile->o_fcb,curfile->o_fcb->f_fsize,26,buf);
      iopenfile.closef(curfile);
      return OK;
  }
}

int use::deleteuser(char*u_name)
{
   if(strcmp(iuser[cuser]->u_name,"root")!=0)
   {
     cout<<"ONLY THE ROOT CAN DELETE USER\n";
     return OK;
   }else
   {
	 //在用户系统中删除
     for(int xx=0;xx<userno;xx++)
     {
      if(iuser[xx]!=NULL)
      {
         if(strcmp(iuser[xx]->u_name,u_name)==0)
         {
           int temp=cuser;
           cuser=xx;
           logout();
           cuser=temp;
           break;
         }
      }
     }

   //在uwords中删除
   ofile *curfile;
   curfile=iopenfile.openf(rdir->o_fcb,"uwords",IFREG|IREAD|GREAD|OREAD);
   char*base=new char[curfile->o_fcb->f_fsize+1];
   iopenfile.readf(curfile->o_fcb,0,curfile->o_fcb->f_fsize,base);
   char name[12];
   for(int c=0;c<=(curfile->o_fcb->f_fsize-1)/26;c++)
   {
      for(int i=0;i<12;i++)
      {
         name[i]=base[26*c+i];
      }
      
      if(strcmp(name,u_name)==0)
      { 
         for(int jj=(c+1)*26;jj<=curfile->o_fcb->f_fsize-1;jj++)
         {
            base[jj-26]=base[jj];
         }
         iopenfile.writef(curfile->o_fcb,0,curfile->o_fcb->f_fsize-26,base);
         iopenfile.closef(curfile);

         delete[]base;
         iopenfile.closef(curfile);
         return OK;
      }
   }
     
   iopenfile.closef(curfile);
 
   delete[]base;
   return OK;
 }
}

//更改当前用户密码
int use::changepw(char*password)
{
   strcpy(iuser[cuser]->u_password,password);
   iuser[cuser]->u_flag=UCHG;
   return OK;
}




int use::create(char*name)
{
  if(iuser[cuser]->u_ofile[iuser[cuser]->u_cdir]->o_fcb->f_mode>=IFREG)
  {
    cout<<"Please close the file first\n";
     return OK;
  }
  ofile *curfile;
  curfile=iopenfile.openf(iuser[cuser]->u_ofile[iuser[cuser]->u_cdir]->o_fcb,name,IFREG,1);
  if(curfile!=NULL)
  {  
	 //文件存在，则返回
     iopenfile.closef(curfile);
     cout<<"THERE HAS BEEN THE FILE "<<name<<endl;
     return OK;
  }else
  {  
	 //不存在则创建
     curfile=iopenfile.openf(iuser[cuser]->u_ofile[iuser[cuser]->u_cdir]->o_fcb,name,MODE);
     curfile->o_fcb->f_uid=iuser[cuser]->u_uid;
     curfile->o_fcb->f_gid=iuser[cuser]->u_gid;
     iopenfile.closef(curfile);
     return OK;
  }
}

     
int use::del(char*name)
{

   
  ofile *curfile;
  curfile=iopenfile.openf(iuser[cuser]->u_ofile[iuser[cuser]->u_cdir]->o_fcb,name,IFREG,1);
  if(curfile==NULL)
  {
	//文件不存在则，返回
    cout<<"CANNOT FIND THE FILE "<<name<<endl;
    return OK;
  }else
  {
	//存在，则调用openfile的deletef删除文件
    if(curfile->o_fcb->f_uid=='a')
    {
      cout<<"this file is system file!you cannot delete!\n";
      iopenfile.closef(curfile);
      return OK;
    }
    if(curfile->o_fcb->f_uid!=iuser[cuser]->u_uid&&iuser[cuser]->u_uid!='A')
    {
      iopenfile.closef(curfile);
      cout<<"YOU CANNOT DELETE THIS FILE\n";
       return OK;
    }
    if(iopenfile.deletef(iuser[cuser]->u_ofile[iuser[cuser]->u_cdir],curfile)==-1)
    {
      iopenfile.closef(curfile);
    }
    return OK;
  }
}

      
int use::open(char*name)
{
 
  ofile *curfile;
  curfile=iopenfile.openf(iuser[cuser]->u_ofile[iuser[cuser]->u_cdir]->o_fcb,name,IFREG,1);
  if(curfile==NULL)
  {
	//不存在，则返回
    cout<<"CANNOT FIND THE FILE "<<name<<endl;
    return OK;
  }
  //存在打开
  return OK;
}
//关闭当前工作文件
int use::close(char*name)
{
   ofile *curfile;
   curfile=iopenfile.openf(iuser[cuser]->u_ofile[iuser[cuser]->u_cdir]->o_fcb,name,IFREG,0,1);
   if(curfile==NULL)
   {
     cout<<"maybe this file has not been opened or there is not the file"<<endl;
     return OK;
   }
   iopenfile.closef(curfile); 
   iopenfile.closef(curfile);
  
   return OK;
}
//读文件信息
int use::read(char*name)
{
   ofile *curfile;
   curfile=iopenfile.openf(iuser[cuser]->u_ofile[iuser[cuser]->u_cdir]->o_fcb,name,IFREG,0,1);
   if(curfile==NULL)
   {