Mega Code Archive
Calculate the checksum of a file
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Title: calculate the checksum of a file?
function GetCheckSum(FileName: string): DWORD;
var
F: file of DWORD;
P: Pointer;
Fsize: DWORD;
Buffer: array [0..500] of DWORD;
begin
FileMode := 0;
AssignFile(F, FileName);
Reset(F);
Seek(F, FileSize(F) div 2);
Fsize := FileSize(F) - 1 - FilePos(F);
if Fsize 500 then Fsize := 500;
BlockRead(F, Buffer, Fsize);
Close(F);
P := @Buffer;
asm
xor eax, eax
xor ecx, ecx
mov edi , p
@again:
add eax, [edi + 4*ecx]
inc ecx
cmp ecx, fsize
jl @again
mov @result, eax
end;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
ShowMessage(IntToStr(GetCheckSum('c:\Autoexec.bat')));
end;
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