fatfs.h

一个小型的操作系统,采用gcc进行开发,几千行的代码,方便初学者学习

/*
*  Snixos Project version 1.0, 2003.6
*  (C) Copyright 2003,2004,2005 Jockeyson,KeqiangGao <[e-mail]>
*  All Rights Reserved.
*  Distributed under the terms of the GNU General Public License.
*
*  This program is a free and open source software and you can redistribute 
*  it and/or modify it under the terms of the GNU General Public License as
*  published by the Free Software Foundation. As no any liablity is assumed 
*  for any incidental or consequential damages in connection with the 
*  information or program fragments contained herein,so any exception arised
*  is at your own risk. It is ABSOLUTELY WITHOUT ANY WARRANTY.
*  Bug report please send to [e-mail] .
*/
/*
  fatfs.h: header file for FAT file system implemented in fatfs.c for Snixos Project
  Author : [e-mail]
  Time   : 2003.6

*/
#ifndef _FATFS_H
#define _FATFS_H

#define BLKSIZE 512
#define BLKCOUNT 1024*2
#define VACANT_FAT_ITEM 0X00
#define EOF_FAT_ITEM -1
#define ERASED 0XE5
#define ROOTSIZE 20
#define FILE_NAME_LENGTH 32

typedef struct {
    char filename[FILE_NAME_LENGTH];
    int filesize;
    int firstfat;
    int datetime;
} direntry;

char *diskspace;
int *fat_tab;
direntry *dir_tab;

void initfat_tab(int *fat);
void initdir_tab(direntry * dir);
void listdir(direntry * dir);
int seekfat(int *fat);
int seekdir_tab(direntry * dir);
int wrdir_tab(direntry * dirs, char *fnames, int fsizes, int firstfat);
int getfilefromos(char *fname, char *buf);
int wrfile(char *fnames, char *bufs, int flen);
int readdir(char *fnames, direntry * dirs);
void wrsect(char *data, int sectno, int bytes);
void fillfat_tab(int *fat_tab, int fatno, int fatdata);
int rdfile(char *fnames, char *outputbuf);
int rdsect(int sectno, int cnt, char *outputbuf);
char *strlwr(char *str);
char *strupr(char *str);
void freefat(int firstfat);
int freedir(char *fname);
int nextfat(int prevfat);
void initFileSystem();
void listFat();
int copyFile(char *srcFileName, char *dstFileName);
void fsver();

/*open read write close */
// unbuffered file io
int errno;                      // global variable to save errno number while any error occured in operation
typedef enum errNums {
    ENAMETOOLONG,
    ENAMEVACANT,
    ENOSUCHFILE,
    EMALLOC,
    ENOFILEDESC
} errNum;


typedef enum openModes {
    READONLY, WRITEONLY, READWRITE, CREATEWRITE
} openMode;

typedef enum seekFrom {
    SEEK_SET1, SEEK_CUR1, SEEK_END1
} seekWhence;

#define OPEN_MAX 20
#define FREED 0
#define OCCUPIED 1

typedef struct fileDesc {
    int fileHdl;                // file handler ,a mutual exclusive positive integer
    char fileName[FILE_NAME_LENGTH];
    int curPosition;            // r/w pointer
    char *IObuffer;             // buffer for file
    int fileLen;                // file size
    int eof;                    // flag of EOF, 1,reach EOF
    int IOMode;                 //readonly, writeonly, read/write
    int status;                 // 0 freed, 1 occupied
} fileDescriptor;
// end of unbuffered file io

/////////////////////////////////////////////
// standard file IO function based above ones
// fopen fclose getc putc
////////////////////////////////////////////

typedef struct files {
    fileDescriptor *fd;
} MFILE;

int Mopen(char *pathname, openMode oflags);
int Mclose(int fds);
int Mread(int fds, char *buff, int nbytes);
int Mseek(int fds, int offset, int whence);
int Mwrite(int fds, char *buff, int nbytes);
void perrstr();

MFILE *Mfopen(char *fileName, char *mode);
int Mfclose(MFILE * fstream);
char Mfgetc(MFILE * fstream);
int Mfeof(MFILE * fstream);
int Mfputc(char c, MFILE * fstream);
int Mfseek(MFILE * fstream, int offset, int whence);
void testread(char *fname);
void testas(char *fileName);

#define fopen Mfopen
#define fclose Mfclose
#define fgetc Mfgetc
#define feof Mfeof
#define fputc Mfputc
#define fseek Mfseek
#define FILE MFILE

#define getc fgetc
#define putc fputc
/* end of open read write close */

#endif