(*
 * PEFileSize function, inspired by The Swash
 * by Khronos
*)
 
function PEFileSize(FileName: string): Cardinal;
var
i: integer;
FileStream: TFileStream;
IDH: IMAGE_DOS_HEADER;
INH: IMAGE_NT_HEADERS;
ISH: IMAGE_SECTION_HEADER;
begin
result:= 0;
  try
    FileStream:= TFileStream.Create(FileName, fmOpenRead or fmShareDenyWrite);
    FileStream.Read(IDH, SizeOf(IDH));
    if IDH.e_magic = IMAGE_DOS_SIGNATURE then
      begin
        FileStream.Seek(IDH._lfanew, 0);
        FileStream.Read(INH, SizeOf(INH));
        if INH.Signature = IMAGE_NT_SIGNATURE then
          begin
            for I := 0 to INH.FileHeader.NumberOfSections - 1 do
              begin
                FileStream.Seek(IDH._lfanew + SizeOf(INH) + SizeOf(ISH) * i, 0);
                FileStream.Read(ISH, SizeOf(ISH));
                result:= result + ISH.SizeOfRawData;
              end;
            result:= result + INH.OptionalHeader.SizeOfHeaders;
          end;
      end;
  finally
    FileStream.Free;
  end;
end;