Thread: File offset

Hi!

This is .pif file format:

PIF Format
Intel byte order

OFFSET Count TYPE Description
0000h 1 byte reserved
0001h 1 byte Checksum
0002h 30 char Title for the window
0020h 1 word Maximum memory reserved for program
0022h 1 word Minimum memory reserved for program
0024h 63 char Path and filename of the program
0063h 1 byte 0 - Do not close window on exit
other - Close window on exit
0064h 1 byte Default drive (0=A: ??)
0065h 64 char Default startup directory
00A5h 64 char Parameters for program
00E5h 1 byte Initial screen mode, 0 equals mode 3 ?
00E6h 1 byte Text pages to reserve for program
00E7h 1 byte First interrupt used by program
00E8h 1 byte Last interrupt used by program
00E9h 1 byte Rows on screen
00EAh 1 byte Columns on screen
00EBh 1 byte X position of window
00ECh 1 byte Y position of window
00EDh 1 word System memory ?? whatever
00EFh 64 char ?? Shared program path
012Fh 64 char ?? Shared program data file
016Fh 1 word Program flags

Now I want to know how to write a code. For example I want that my program will display text for the title.

Please, help.

My code:

int main()
{
FILE *fin;
char file1[100], Title[30], *TitlePtr;

clrscr();
TitlePtr = Title;
printf("Enter file name (*.pif): ");
gets(file1);
fin = fopen(file1, "rb");
fseek(fin, 0x0002, SEEK_SET);
fread(TitlePtr, sizeof(Title), 1, fin);
printf("Title is \"%s\"", Title);
return 0;
}

Ok, this is working. Well I get the title but I also get the file name.

It looks like that:

Title is "program filename.pif".

How do I place the 0 at the end of that string?

I'm not quite sure what you mean. You mean you want to split the string "program filename.pif" into "program" and "filename.pif"?

In that case you could search in your string for the space and place the '\0' in that place.

i = 0;
while (Title [i++] != ' ');
Title [i-1] = '\0';

Why are you using TitlePtr and Title[30]? I think it's not necessary to use TitlePtr. In your call to fread you are using TitlePtr as a pointer to the array, but since Title is also a pointer, you could use Title instead of TitlePtr.

No no, when the program prints out on the screen it looks something like that "title פ÷". This extra characters ( פ÷) are bugging me. How to get rid of them?

Hmm.. is this what you want?

Code:

int main() 
{ 
 FILE *fin; 
 char file1[100], Title[30]; 
 int i;

 clrscr(); 
 TitlePtr = Title; 
 printf("Enter file name (*.pif): "); 
 gets(file1); 
 fin = fopen(file1, "rb"); 
 fseek(fin, 0x0002, SEEK_SET); 
 fread(Title, sizeof(Title), 1, fin); 
 for (i = 0; i < 30; i++)
 {
  putchar (Title[i]);
 }
 return 0; 
}

Thanks! It's working now.