systable.c

最新推荐文章于 2022-11-26 16:39:25 发布

CCodes

最新推荐文章于 2022-11-26 16:39:25 发布

阅读量493

点赞数

CC 4.0 BY-SA版权

分类专栏： S 文章标签： table structure struct file system fp

本文链接：https://blog.youkuaiyun.com/CCodes/article/details/1875083

S 专栏收录该内容

172 篇文章

订阅专栏

name="google_ads_frame" marginwidth="0" marginheight="0" src="http://pagead2.googlesyndication.com/pagead/ads?client=ca-pub-5572165936844014&dt=1194442938015&lmt=1194190197&format=336x280_as&output=html&correlator=1194442937843&url=file%3A%2F%2F%2FC%3A%2FDocuments%2520and%2520Settings%2Flhh1%2F%E6%A1%8C%E9%9D%A2%2FCLanguage.htm&color_bg=FFFFFF&color_text=000000&color_link=000000&color_url=FFFFFF&color_border=FFFFFF&ad_type=text&ga_vid=583001034.1194442938&ga_sid=1194442938&ga_hid=1942779085&flash=9&u_h=768&u_w=1024&u_ah=740&u_aw=1024&u_cd=32&u_tz=480&u_java=true" frameborder="0" width="336" scrolling="no" height="280" allowtransparency="allowtransparency"> #include <stdio.h>
#include <dos.h>
#include <stdlib.h>

void main(void)
{
union REGS inregs, outregs;
struct SREGS segs;
int i, j;
int structure_size;
struct SystemTableEntry
{
  struct SystemTableEntry far *next; //Next SFT entry
  unsigned file_count;    //Files in table
  unsigned handle_count;    //Handles to this file
  unsigned open_mode;     //File open mode
  char file_attribute;    //Attribute byte
  unsigned local_remote;    //Bit 15 set means remote
  unsigned far *DPD;     //Drive parameter block
  unsigned starting_cluster;
  unsigned time_stamp;
  unsigned date_stamp;
  long file_size;
  long current_offset;
  unsigned relative_cluster;
  long directory_sector_number;
  char directory_entry_offset;
  char filename_ext[11];    //No period, space padded
           //Ignore SHARE fields for example
} far *table_ptr, far *file;
long far *system_table;

//Get DOS version
inregs.x.ax = 0x3001;
intdos (&inregs, &outregs);
if (outregs.h.al < 3)
{
  printf("This program requires DOS version 3 or later/n");
  exit (1);
}
else if (outregs.h.al == 3)
  structure_size = 0x35;
else if (outregs.h.al >= 4)
  structure_size = 0x3B;
//Get the list of losts pointer
inregs.h.ah = 0x52;
intdosx (&inregs, &outregs, &segs);
//The pointer to the system file table is at offset 4
system_table = MK_FP(segs.es, outregs.x.bx + 4);
table_ptr = (struct SystemTableEntry far *) *system_table;
do
{
  printf("%d entries in table/n", table_ptr->file_count);
  for (i = 0; i < table_ptr->file_count; i++)
  {
   file = MK_FP(FP_SEG(table_ptr), FP_OFF(table_ptr) +
    (i * structure_size));
   if (file->handle_count)
   {
    for (j = 0; j < 8; j++)
     if (file->filename_ext[j] != ' ')
      putchar(file->filename_ext[j]);
     else
      break;
     if (file->filename_ext[8] != ' ')
      putchar('.');
     for (j = 8; j < 11; j++)
      if (file->filename_ext[j] != ' ')
       putchar(file->filename_ext[j]);
      printf (" %ld bytes %x attribute %d references/n",
       file->file_size, file->file_attribute,
       file->handle_count);
   }
  }
  table_ptr = table_ptr->next;
} while (FP_OFF(table_ptr) != 0xFFFF);
}