Tell me more ×
Game Development Stack Exchange is a question and answer site for professional and independent game developers. It's 100% free, no registration required.
up vote 3 down vote favorite

I downloaded a game called Brain Exercise with Dr.Kawashima. This game contains only one exe and no data files. However, the game can create saves. I wanted to ask how does it do that since it doesn't have any data files, just only the exe file?

share|improve this question
Is it even possible to modify you own exe for game saves? I'm primarily a Linux/Mac guy so I don't know what Windows allows in this area. – deft_code Sep 2 '10 at 16:21
caspin, yes it is possible! Check out LockNote (steganos.com/us/products/for-free/locknote/overview) for an incredibly useful example of saving data into an executable. – Ricket♦ Sep 2 '10 at 16:47
@Ricket - that's bolting an executable onto existing data, sort of like self extracting archives. I suspect that they're not actually modifying the file itself, rather recreating it on "save". – dash-tom-bang Sep 2 '10 at 17:10
You may want to be careful it's not picked up as a virus. – The Communist Duck Sep 2 '10 at 19:56
4  
I would suggest downloading Process Monitor to verify that the program in question is in fact writing to it's own executable. I think you will find that it is writing to other files or the registry. – Benjamin Manns Sep 3 '10 at 0:01
show 2 more comments

2 Answers

up vote 17 down vote

It may be making saves in the Registry or somewhere under your %APPDATA% folder, or in your homedir's "My Documents" or "My Games" subfolders. Or anywhere else on your hard drive, for that matter. It is unlikely to be modifying its own exe to save, although I suppose that is possible (if a very bad idea: see AttackingHobo's comment below for a sample of the reasons why).

share|improve this answer
7  
It is really really bad practice to even attempt to change the exe. First off you run into the problem of not being able to modify files that are open. Secondly after you have worked around that problem, if you are saving to exe and there is an error, or something crashes, you are going to have a corrupt game exe and users will be comfused. – AttackingHobo Sep 2 '10 at 16:20
2  
And if it wants to communicates with the internet, some desktop firewalls will constantly ask again for permission because the checksum does not match. – Hendrik Brummermann Sep 2 '10 at 17:52
I don't have data to back this up, but a self-editing .exe might even be interfered with by antivirus software. That said, Window's shadow copy service allows you to do some cool, somewhat non-intuitive things with locked files. en.wikipedia.org/wiki/Shadow_Copy – ojrac Sep 2 '10 at 22:10
1  
On Windows Vista or 7, elevated privileges are needed in order to modify files in the Program Files directory. It is reasonable to run an installer as admin, but running the executable as a normal user will not allow this type of modification. (Just strengthening AttackingHobo's comment.) – eli Sep 3 '10 at 21:25
up vote 0 down vote

While it's perfectly possible to modify the executable (it's what viruses do all the time, and you can append whatever you want to an exe and read from the end of the file - not sure how windows user levels interfere with it, haven't done it since the golden days of MS-DOS) I'd indeed suspect the registry is used.
Copy the executable over an install on another system and see if it has your savegame, if it does you know it's the exe being modified.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.