para.h

linux文件系统试验 一、实验目的 学习有关linux文件管理程序如何组织的知识

/***************************************************************************
                          para.h  -  description
                             -------------------
    begin                : Wed Jul 23 2003
    copyright            : (C) 2003 by Jeremy
    email                : [e-mail]
 ***************************************************************************/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <iostream.h>
#include <iomanip.h>
#include <stdlib.h>
#include <math.h>
#include <sys/types.h>
#include <stdio.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>

#define NULL 0
#define FLEN sizeof (file_node)
#define NAME_LENGTH 8
#define SEEK_SET 0
#define OFF_SET 9728
#define BPS 512
#define FILE_EMPTY 0
#define FILE_DEL 229
#define INP_LEN  12 //the length of command or filename that you inpur in your commands

/* start of struct and class*/

struct file_node{
	char file_name[8], ext_name[3];
	int readonly,hidden,system,isdir,isfile;/* and ithers*/
	int hour,minute,second;
	int year,month,day;
	int start_cluster;
	int file_length;
	struct file_node *prev, *next,*down;
	int num_cluster;	//there is no such ones in linux ,use this to record the cluster where the direntry is
	int num_index;		//and this to record the index of the file at one cluster(from 0 to 15)
};


struct super_block{
	int sector_p_cluster;  		 //1 in fat12
	int num_fat;							 //2 in fat12
	int num_root_dir_entry;		//14 in fat12
	int num_log_sector;			//logic numbers 2880 in fat12 11*256+64
	int sector_p_fat;					//09 in fat12
	int num_hid_sector;			//
	int other_use_sector;			//1 in fat12
};


class perbyte		/*use this class to change one unsigned char to 10 and ASCII*/
{
	public:
		unsigned char b_input,b_output;unsigned char buf[BPS];
		unsigned binary[8];
		int l_10,h_10;
		perbyte(unsigned char temp);
		~perbyte();
};

perbyte::perbyte(unsigned char temp)
{
	unsigned a,b,c,d=15;	// d/15 is 0000,1111 in binary
	unsigned w0=128,w1=64,w2=32,w3=16,w4=8,w5=4,w6=2,w7=1;
	b_input=(unsigned char)'\0';b_output=(unsigned char)'\0';
	b_input=temp;
	
	if (((b_input>64)&&(b_input<91))||((b_input>96)&&(b_input<128)))
		b_output=b_input;
	else
	b_output='.';	//the word can't be shown will putout . instead
	c=b_input;
	a=c>>4;			//move four bits to the right then a is the four bits of the higher one
	b=c&d;			//b is the four bits of the lower one
	h_10=(int)a;
	l_10=(int)b;
	//binary[i] is designed for the attrib byte
	binary[0]=w0&temp;binary[0]=binary[0]>>7;
	binary[1]=w1&temp;binary[1]=binary[1]>>6;
	binary[2]=w2&temp;binary[2]=binary[2]>>5;
	binary[3]=w3&temp;binary[3]=binary[3]>>4;
	binary[4]=w4&temp;binary[4]=binary[4]>>3;
	binary[5]=w5&temp;binary[5]=binary[5]>>2;
	binary[6]=w6&temp;binary[6]=binary[6]>>1;
	binary[7]=w7&temp;	
}

perbyte::~perbyte()
{//cout<<"you"<<endl;
}

/* end of struct and class*/

struct file_node *head,*cur_head,*head_per_cluster,*p_end;
struct super_block sb_fat12;


unsigned char buffer[BPS];

off_t offset=9728;  ///????????
int fid;
int clu_num,form_clu_num;
int log_num,form_log_num;