/* Function to Hide (and show) Cursor on the screen */
show_hide_cursor ( 32, 0 );
gotoxy(15,18);cprintf("[ %d ] Files Recovered...",
num);
/* search for the data until the ending sector of the
disk */
while(loop<Sectors_in_HDD2)
{
/* Read one Sector (Sector No. = loop) */
readabsolutesectors ( 0x81, loop, 1, buffer );
gotoxy(19,16);cprintf("Scanning Sector Number = % ld",
loop);
if(kbhit())
{
show_hide_cursor ( 6, 7 ); /* Retrieve the
cursor before
Exit the program
*/
exit(0);
}
/* if specified header is found */
if((memcmp ( buffer, header,7))==0)
{
/* logic to provide the file name to automatically
create the files to save the recovered data */
strcpy(filename, path);
itoa(num,temp,10);
strcat(filename, temp);
strcat(filename,".DOC");
start_file=loop; /* starting sector of file */
gotoxy(5,19);cprintf("File Found..., Saving As %s",
filename);
num++;
////////////// File Close Conditions \\\\\\\\\\\\\\\\
file_size=0;
while( file_size<5000000)
{
loop++;
file_size+=512;
readabsolutesectors ( 0x81, loop, 1, buffer );
gotoxy(19,16);cprintf("Scanning Sector Number = % ld" ,
loop);
/* if file size reaches up to maximum size of 5MB */
if(file_size>=5000000)
{
end_file=loop; /* Ending Sector of File */
Recover_the_file();/* write the data to file */
break;
}
/* if footer of DOC file is found */
for(i=0;i<512;i++)
{
if( memcmp(buffer+i,DOC_footer,12)==0 )
{
end_file=loop; /* Ending Sector of File */
Recover_the_file();/* write the data to file */
break;
}
}
/* if another header is found */
if( memcmp(buffer,header,7)==0 )
{
loop=loop-1;
end_file=loop; /* Ending Sector of File */
Recover_the_file();/* write the data to file */
break;
}
if(kbhit())
{
show_hide_cursor ( 6, 7 );
exit(0);
}
}
}
loop++;
} ////////While Loop Ends Here
/* display message for completion of search and recovery */ if(loop>=Sectors_in_HDD2 )
{
gotoxy(17,23);cprintf("The Saving of files in the Disk is
Completed !!");
gotoxy(17,24);cprintf("Press Any Key to Exit...");
show_hide_cursor ( 6, 7 );
getch();
}
}
Comments on coding:
The structure geometry is used by getdrivegeometry function using INT 13H Extension, Function Number 0x48 to get the various parameters of the disk.
The structure diskaddrpacket is for Disk Address packet format, to be used by the readabsolutesectors Function.
The Function getdrivegeometry (int drive) is to get Drive Parameters of the disk specified physical drive number drive.
(char) peekb(0x0040, 0x0075) is used to find the number of hard disks connected to the computer, stored at memory location represented by segment 0040H:offset 0075H. If total number of hard disks attached is less then two Display Error Message and Exit.
Sectors_in_HDD2=getdrivegeometry (0x81); finds the various parameters of the second physical hard disk (0x81) and returns the total number of sectors of the disk.
The statement if(access(path, 0) != 0) checks the accessibility of the path given by the user. If destination directory does not exist, the destination is created up to one level and if the given path checked by condition if(mkdir(path)!=0) is illegal, error message is displayed.
The file names of automatically created files to save the recovered data are created such that the first three characters of the files are given PTT by strcat(path,"\\Ptt"); function. It is done so to avoid the duplicate file names in the destination directory. Therefore the file names of recovered files are given in format of “PTTxxxxx.DOC”
The Function show_hide_cursor ( 32, 0 ); is used to Hide the Cursor from the screen where show_hide_cursor ( 6, 7 ); retrieves the cursor back to screen.
The function readabsolutesectors (0x81, loop, 1, buffer); Reads one Sector of the second physical hard disk specified by sector number loop.
If the header of the file is found, start_file = loop; sets the start_file to starting sector number of the file to be recovered. The program follows the three conditions given next, to find the ending sector of the file:
- If file size reaches up to maximum size of 5MB
- If footer of DOC file is found
- If another header is found
The long integer end_file is set to the ending sector number of the file by end_file=loop; if any one condition out of three is satisfied. Now the data of the sectors, starting from sector number start_file to sector number end_file is saved to the file with the function Recover_the_file( ).
| Sample Chapters from book DATA RECOVERY WITH AND WITHOUT PROGRAMMING by Author Tarun Tyagi |
|
Publishers of the Book
Number of Pages
ISBN
Price of the Book
|
BPB Publications, New Delhi, India
540
81-7656-922-4
$69.00 (Including Shipping Charges, Cost of Book and Other expenses, Free Source Code CD included with the Book)
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