【文件系统学习】+yufanyufan77+第二周 tar解析

发布于 2018-07-28 23:06:44 浏览：2093 订阅该版

* 本帖最后由 yufanyufan77 于 2018-7-28 23:27 编辑 *

[align=center]** **```这个位置添加错了，怎么才能删掉```**1****、开发环境：**原子stm32f4探索者、ENV、rt_thread **2****、参考文档**[http://www.moon-soft.com/program/FORMAT/comm/tar.htm](http://www.moon-soft.com/program/FORMAT/comm/tar.htm)[https://www.rt-thread.org/document/site/rtthread-development-guide/rtthread-manual-doc/zh/1chapters/12-chapter_filesystem/](https://www.rt-thread.org/document/site/rtthread-development-guide/rtthread-manual-doc/zh/1chapters/12-chapter_filesystem/) **3****、这次的任务主要有以下几个要点：**熟读tar格式Tar格式解析在SD卡建文件夹在文件夹中写入解析的数据
**tar.h文件**```#ifndef __UNRAR_H__
#define __UNRAR_H__

/*
 * standard archive format - standard tar - ustar
 */
#define  recordsize  512
#define  namsiz      100
#define  tunmlen      32
#define  tgnmlen      32

#define  lf_oldnormal '\0'       /* normal disk file, unix compatible */
#define  lf_normal    '0'        /* normal disk file */
#define  lf_link      '1'        /* link to previously dumped file */
#define  lf_symlink   '2'        /* symbolic link */
#define  lf_chr       '3'        /* character special file */
#define  lf_blk       '4'        /* block special file */
#define  lf_dir       '5'        /* directory */
#define  lf_fifo      '6'        /* fifo special file */
#define  lf_contig    '7'        /* contiguous file */

/* further link types may be defined later. */
/* bits used in the mode field - values in octal */
#define  tsuid    04000        /* set uid on execution */
#define  tsgid    02000        /* set gid on execution */
#define  tsvtx    01000        /* save text (sticky bit) */
/* file permissions */
#define  turead   00400        /* read by owner */
#define  tuwrite  00200        /* write by owner */
#define  tuexec   00100        /* execute/search by owner */
#define  tgread   00040        /* read by group */
#define  tgwrite  00020        /* write by group */
#define  tgexec   00010        /* execute/search by group */
#define  toread   00004        /* read by other */
#define  towrite  00002        /* write by other */
#define  toexec   00001        /* execute/search by other */

typedef struct tar_header
{
        char name[100];
        char mode[8];
        char uid[8];
        char gid[8];
        char size[12];
        char mtime[12];
        char chksum[8];
        char typeflag;
        char linkname[100];
        char magic[6];
        char version[2];
        char uname[32];
        char gname[32];
        char devmajor[8];
        char devminor[8];
        char prefix[155];
        char padding[12];
}tar_header_Type;

typedef struct untarCon
{
        unsigned char startFlag;
        char filename[100];
        char* filedata ;
        unsigned int fileSizes;
        unsigned int writeDataLen;
        unsigned int readFinshDataLen;
        
}untarCon_Type;

#endif

```

**untar.c文件**```/*
 * File : led.h
 * This file is part of SS_FYF
 * COPYRIGHT (C) 2009, yufanyufan77
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * QQ：765637468
 *
 * Change Logs:
 * Date Author Notes
 * 2018-07-28 yufanyufan77 first implementation
 */
#include "unrar.h"
#include <rtthread.h>
#include <rtdevice.h>
#include <dfs_posix.h> /* 当需要使用文件操作时，需要包含这个头文件 */
//切换到上一层目录
#define changeLastDir() chdir("/..")
tar_header_Type tarHead;

static untarCon_Type untarCons;
//检测到目录，创建目录
rt_err_t untar_makdir(tar_header_Type tarHead);
//tar格式解析
rt_err_t untar_file(tar_header_Type tarHead);
//检测到文件，创建创建文件到相应目录下
rt_err_t untar_writefiles(untarCon_Type* untarCons);
void read_tarFile(const char* fpaths,int x)
{
 char buf[512];
 int i = 0;
 int fd = 0;
 int len = 0;
 
 rt_memset((char*)&untarCons,0,sizeof(untarCons));
 untarCons.filedata = buf;
 fd = open(fpaths,O_RDONLY);
 if(fd == RT_NULL)
 rt_kprintf("%d open file fail!");
 
 
 for(i=0;;i++)
 {
 
 seekfile(fd , sizeof(tarHead)*i);
 if(!untarCons.startFlag)
 {
 len = read(fd,(char*)&tarHead,sizeof(tarHead));
 
 }
 else
 {
 len = read(fd,buf,512);
 }
 
 if(len <= 0)
 {
 rt_kprintf(" read file finsh! ");
 break;
 }
 
 
 if(!untarCons.startFlag)
 {
 untar_file(tarHead);
 }
 else//向指定目录写文件
 {
 untar_writefiles(&untarCons);
 }
 
 }
 
 
 close(fd);
}

unsigned int cal(unsigned int data,unsigned char n)
{
        unsigned int datatemp=1;
        if(!n)
                return 1;
        while(n--)
        {
                datatemp*=data;
        }
        return datatemp;
}

//8进制转换
unsigned int eightToten(unsigned int data)
{
 unsigned int tempeight = 0;
 unsigned int temp = data;
 unsigned int tempy = 0;
 unsigned char i = 0;
 for(i=0; ;i++)
 {
 tempy = temp%10;
 tempeight = tempeight+(tempy<<3*i);
 temp = data/cal(10,i+1);
 if(!temp)
 break;
 }
 return tempeight;
}
//tar格式解析
rt_err_t untar_file(tar_header_Type tarHead)
{
 unsigned int temp;
 if(tarHead.name[0]==RT_NULL)
 return RT_EOK;
 //根据文件类型判断进行相应的处理
 switch(tarHead.typeflag)
 {
 case lf_oldnormal:
 break;
 case lf_normal://普通磁盘文件
 rt_memcpy(untarCons.filename,tarHead.name,sizeof(tarHead.name));
 untarCons.startFlag = 1;
 temp=atoi(tarHead.size);
 untarCons.fileSizes = eightToten(temp);
 rt_kprintf("untarCons.fileSizes = %d ",untarCons.fileSizes);
 break;
 case lf_link:
 break;
 case lf_symlink:
 break;
 case lf_chr:
 break;
 case lf_blk:
 break;
 case lf_dir://目录
 //创建目录
 untar_makdir(tarHead);
 break;
 case lf_fifo:
 break;
 case lf_contig:
 break;
 }
}

//检测到目录，创建目录
rt_err_t untar_makdir(tar_header_Type tarHead)
{
 char nameStr[100];
 int dirid = 0;
 DIR* dirtemp ;
 dirtemp = opendir("/sd");
 if(dirtemp == RT_NULL)
 {
 rt_kprintf("open %s dir faill! ",nameStr);
 return RT_ERROR;
 }
 sprintf(nameStr,"/sd/%s",tarHead.name);
 dirid = mkdir(nameStr,0x777);
 if(dirid == RT_EOK)
 {
 rt_kprintf("creat %s dir ok! ",nameStr);
 return RT_EOK;
 }
 else
 rt_kprintf("creat %s dir faill! ",nameStr);
 closedir(dirtemp);
 return RT_ERROR;
}

//检测到文件，创建创建文件到相应目录下
rt_err_t untar_writefiles(untarCon_Type* untarCons)
{
 char nameStr[100];
 int dirid = 0;
 DIR* dirtemp ;
 int fd;
 int size;
 int len = 0;
 
 sprintf(nameStr,"/sd/%s",untarCons->filename);
 
 
 fd = open(nameStr, O_WRONLY | O_CREAT);//向SD写入数据
 if (fd >= 0)
 {
 struct stat buf; 
 char* str;
 stat(nameStr, &buf); 
 seekfile(fd , buf.st_size);
 if(untarCons->fileSizes > 512)
 {
 untarCons->fileSizes -= 512;
 len = write(fd,untarCons->filedata,512);
 }
 else
 {
 len = write(fd,untarCons->filedata,untarCons->fileSizes);
 untarCons->fileSizes = 0;
 untarCons->startFlag = 0;
 }
 
 if(!len)
 rt_kprintf("write %s file faill ",untarCons->filename);
 
 close(fd);
 
 return RT_EOK;
 }
 
 untarCons->startFlag = 0;
 return RT_ERROR;
 
}

#ifdef RT_USING_FINSH
#include <finsh.h>
FINSH_FUNCTION_EXPORT(read_tarFile, startup read_tarFile);
#endif /* RT_USING_FINSH */
```

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