dir.c~

模拟linux的ext3文件系统。采用位图法。用一个文件模拟硬盘。实现创建、删除目录、文件。读、写文件

#define MAIN
#include "structure.h"
// function mkdir()
u16 mkdir(u8 *path,u8 *name)
{
 u16 newi,block,parent_inode_num,offset;
 struct ext2_inode parent_inode,inode;
 tag='2';
 if((strlen(path))){
      if(!(parent_inode_num=get_dir(path))) {
             printf("Invalid pathname!\n");
             return 0;
      }
 }
 else parent_inode_num=current_dir;
 if(!(strlen(name))){
        printf("miss parameter!\n");
        return 0;
 }
 load_inode_entry(&parent_inode,parent_inode_num);
 if((block=search_name(&parent_inode,name,&offset)))    {
          printf("dir already exist\n");
          return 0;
 }
  if(!(newi=create_dir_entry(&parent_inode,name)))  {
	 printf("cannot make a dir!\n");
	 return 0;
 }
 update_inode_entry(&parent_inode,parent_inode_num);
 load_inode_entry(&inode,newi);
 init_dir(&inode,newi,parent_inode_num);
 update_inode_entry(&inode,newi);
 return 1;
}

//function rmdir()

u16 rmdir(u8 *path,u8 *name)
{
 u16 oldi,block,parent_inode_num,offset;
 struct ext2_inode parent_inode,inode;
 u8 buffer[512];
 if((strlen(path))){
      if(!(parent_inode_num=get_dir(path))) {
             printf("Invalid pathname!\n");
             return 0;
      }
 }
 else parent_inode_num=current_dir;
 if(!(strlen(name))){
        printf("miss parameter\n");
        return 0;
 }
 load_inode_entry(&parent_inode,parent_inode_num);
 if(!(block=search_name(&parent_inode,name,&offset))){
	 printf("name not exist\n"); 
	 return 0;
 }
 load_block_entry(buffer,block);
 oldi=buffer[offset]+buffer[offset+1]*0x100;
 load_inode_entry(&inode,oldi);
 if(!(empty_dir(&inode)))  { 
	 printf("you can not delete a directory when it is not empty !\n");
	 return 0;
 }
 free_blocks(&inode);
 free_inode(oldi);
 buffer[offset]=buffer[offset+1]=0;
 update_block_entry(buffer,block);
 return 1;
}
// function dir()

void dir_block(u16 block)
{
 u8 buffer[512];
 struct ext2_dir_entry *de;
 u16 i;
 if(!block)  return;
 load_block_entry(buffer,block);
 for(i=0,de=(struct ext2_dir_entry *)buffer;i<DIR_ENTRIES_PER_BLOCK;i++,de++){
         if(de->d_inode)
         {
               if(de->d_file_type=='1')
		{
                         printf("f------rwx ");
		}
		else
		{
			 printf("d------rwx ");
		}
	printf("%s\n",de->name);
	}
			
 }
}
void dir_ind(u16 block)
{
 u8 buffer[512];
 u16 i;
 if(!block)  return;
 load_block_entry(buffer,block);
 for(i=0;i<256;i++)
	 dir_block(buffer[2*i]+buffer[2*i+1]*0x100);
}
void dir_dind(u16 block)
{
 u8 buffer[512];
 u16 i;
 if(!block)  return;
 load_block_entry(buffer,block);
 for(i=0;i<256;i++)
	 dir_ind(buffer[2*i]+buffer[2*i+1]*0x100);
}

void dir( )
{
 struct ext2_inode inode;
 load_inode_entry(&inode,current_dir);
 if(!(test_inode(current_dir)))  {
                   printf("the dir not exist!!\n");
                   return;
 }
 u16 i;
 for(i=0;i<6;i++)
       dir_block(inode.i_block[i]);
 dir_ind(inode.i_block[6]);
 dir_dind(inode.i_block[7]);
}

//function cd()

u16 cd(u8 *path)
{
 u16 inode_num;
 u8 ch;
 if((!strlen(path))){
	 printf("miss parameter\n");
	 return 0;
 }
 if(!(inode_num=get_dir(path))){
         printf("wrong dir\n");        
	 return 0;
 }
 current_dir=inode_num;
 if((ch=*path)=='/'){
        strcpy(current_path,path);
 }
 else if(ch) strcat(current_path,path);
 return 1;
}