Decompilers...?

[Hackmaster]

Hi everyone.

I just have a question about Decompliers. I have looked at lots of programs over the years and thought..."Gee, I wonder how they coded that...", and usually, I would find out later in a class, or online. However, I've always wanted to see the full code for a program like 'paint' or 'calculator'. Sure, People make very effective emulators, but It would be interesting to see the code that started it, you know?

Then I heard about decompilers. I kind of want to know what exactly they do, although in my looking around, I've also heard that they are mostly used for criminal purposes, and thus aren't commonly found anywhere. I would like to know more about them, and if possible (and not illegal) where I could find one. thanks!

[Mazer]

I'm afraid I haven't any time to answer your question in detail, but when I'm curious about something I have this trick where I go to google and do a search for "wiki" + [thing-I'm-interested-in]. And I'm not trying to sound like a "just fucking google it!" jerk, I realy do this all the time. Just look!
http://en.wikipedia.org/wiki/Decompiler

[[Gandalf]]

By far the most common 'decompiler' you will find is a disassembler, which will give you the assembly equivalent of your program. The thing is, the output will most definately be extremely long, and require a decent knowledge of assembly to begin to understand.

Sure, there exists programs to give you the equivalent in, say, C, but the fact is that this will have little resemblance to the original code and will look more like assembly than C. That's why we have open source projects.

[wtd]

Indeed. Save yourself the trouble and just study open source projects.

[Dan]

You are going to have a very hard time decompling any langue that complies to an noraml excuatable. As stated above the best you can do is to translate it in to aseembly. However the time it whould take to understand the assembly comands whould be much greater then trying to learn the conspect you are decomplining noramly. So far i have only seen one person who can read in the hex comands for an exe and tell you what it is doing, but they had a phd in computer sci and have been teaching aseembely for years. Even then it was only for basic code and i terms of puting what value in what regiester and only for one kind of assembly.

There are some langues like java that can be decomplied back in to somthing close to there sorce but even then you lose all the varibale names, coments and foramting of the code.

Decomining code is not illgeal in Canada to my knowalge but it can be in the USA in terms of reverses engering.