You can use [IDA Pro][1] by [Hex-Rays][2]. You will usually not get good C++ out of a binary unless you compiled in debugging information. Prepare to spend a **lot** of manual labor reversing the code.

If you didn&#39;t strip the binaries there is some hope as IDA Pro can produce C-alike code for you to work with. Usually it is very rough though, at least when I used it a couple of years ago.


  [1]: http://www.hex-rays.com/idapro/
  [2]: http://www.hex-rays.com/

information is discarded in the compiling process.  Even if a decompiler could produce the logical equivalent code with classes and everything (it probably can&#39;t), the self-documenting part is gone in optimized release code.  No variable names, no routine names, no class names - just addresses.

Yes, but none of them will manage to produce readable enough code to worth the effort. You will spend more time trying to read the decompiled source with assembler blocks inside, than rewriting your old app from scratch.

I haven&#39;t seen any decompilers that generate C++ code. I&#39;ve seen a few experimental ones that make a reasonable attempt at generating C code, but they tended to be dependent on matching the code-generation patterns of a particular compiler (that may have changed, it&#39;s been awhile since I last looked into this). Of course any symbolic information will be gone. Google for &quot;decompiler&quot;. 

Depending on how large and how well-written the original code was, it might be worth starting again in your favourite language (which might still be C++) and learning from any mistakes made in the last version. Didn&#39;t someone once say about writing one to throw away?

n.b. Clearly if this is a huge product, then it may not be worth the time.

I&#39;ve been looking for a simple regex for URLs, does anybody have one handy that works well?  I didn&#39;t find one with the zend framework validation classes and have seen several implementations.



PHP validation/regex for URL

Just wondering what little scripts/programs people here have written that helps one with his or her everyday life (aka not work related).

Anything goes, groundbreaking or not. For me right now, it&#39;s a small python script to calculate running pace given distance and time elapsed.

What is the most useful script you&#39;ve written for everyday life?

I have a program in which I&#39;ve lost the C++ source code.  Are there any good C++ decompilers out there?

I&#39;ve already ran across [Boomerang][1].


  [1]: http://boomerang.sourceforge.net/

Is there a C++ decompiler?

<p>I have a program in which I've lost the C++ source code.  Are there any good C++ decompilers out there?</p>
<p>I've already ran across <a href="http://boomerang.sourceforge.net/" target="_blank" rel="noopener noreferrer">Boomerang</a>.</p>


Why does the C++ STL not provide any &quot;tree&quot; containers, and what&#39;s the best thing to use instead?

I want to store a hierarchy of objects as a tree, rather than use a tree as a performance enhancement...






Why does the C++ STL not provide any &quot;tree&quot; containers?

*[This question is related to but not the same as [this one][1].]*

If I try to use values of certain types as boolean expressions, I get a warning.  Rather than suppress the warning, I sometimes use the ternary operator (`?:`) to convert to a bool.  Using two not operators (`!!`) seems to do the same thing.

Here&#39;s what I mean:

    typedef long T;       // similar warning with void * or double
    T t = 0;
    bool b = t;           // performance warning: forcing &#39;long&#39; value to &#39;bool&#39;
    b = t ? true : false; // ok
    b = !!t;              // any different?

So, does the double-not technique really do the same thing?  Is it any more or less safe than the ternary technique?  Is this technique equally safe with non-integral types (e.g., with `void *` or `double` for `T`)?

I&#39;m not asking if `!!t` is good style.  I am asking if it is semantically different than `t ? true : false`.

  [1]: https://stackoverflow.com/questions/206564/what-is-the-performance-implication-of-converting-to-bool-in-c

Is !! a safe way to convert to bool in C++?

I have a shared library that I wish to link an executable against using GCC. The shared library has a nonstandard name not of the form libNAME.so, so I can not use the usual -l option. (It happens to also be a Python extension, and so has no &#39;lib&#39; prefix.)

I am able to pass the path to the library file directly to the link command line, but this causes the library path to be hardcoded into the executable.

For example:

    g++ -o build/bin/myapp build/bin/_mylib.so

Is there a way to link to this library without causing the path to be hardcoded into the executable?


How to link using GCC without -l nor hardcoding path for a library that does not follow the libNAME.so naming convention?

I have a bunch of enum types in some library header files that I&#39;m using, and I want to have a way of converting enum values to user strings - and vice-versa. 

RTTI won&#39;t do it for me, because the &#39;user strings&#39; need to be a bit more readable than the enumerations.

A brute force solution would be a bunch of functions like this, but I feel that&#39;s a bit too C-like.

    enum MyEnum {VAL1, VAL2,VAL3};
    
    String getStringFromEnum(MyEnum e)
    {
      switch e
      {
      case VAL1: return &quot;Value 1&quot;;
      case VAL2: return &quot;Value 2&quot;;
      case VAL1: return &quot;Value 3&quot;;
      default: throw Exception(&quot;Bad MyEnum&quot;);
      }
    }


I have a gut feeling that there&#39;s an elegant solution using templates, but I can&#39;t quite get my head round it yet.


**UPDATE:** Thanks for suggestions - I should have made clear that the enums are defined in a third-party library header, so I don&#39;t want to have to change the definition of them.

My gut feeling now is to avoid templates and do something like this:


    char * MyGetValue(int v, char *tmp); // implementation is trivial
    
    #define ENUM_MAP(type, strings) char * getStringValue(const type &amp;T) \
     { \
     return MyGetValue((int)T, strings); \
     }
    
    ; enum eee {AA,BB,CC}; - exists in library header file 
    ; enum fff {DD,GG,HH}; 
    
    ENUM_MAP(eee,&quot;AA|BB|CC&quot;)
    ENUM_MAP(fff,&quot;DD|GG|HH&quot;)

    // To use...

		eee e;
		fff f;
		std::cout&lt;&lt; getStringValue(e);
		std::cout&lt;&lt; getStringValue(f);


How to easily map c++ enums to strings

Very basic question: how do I write a `short` literal in C++?

I know the following:

* `2` is an `int`
* `2U` is an `unsigned int`
* `2L` is a `long`
* `2LL` is a `long long`
* `2.0f` is a `float`
* `2.0` is a `double`
* `&#39;\2&#39;` is a `char`.

But how would I write a `short` literal?  I tried `2S` but that gives a compiler warning.

How do I write a short literal in C++?

Quite often I come across a nice looking or functional website, and wonder what technology was used to create it. What techniques are available to figure out what a
particular website was built with?

Few frameworks seem to include any kind of generator meta tag like web editors do. Are there any tell-tale signs of particular languages and/or frameworks?

----------

***Summary of answers***

Site URLs may betray the framework and/or programming language but cannot be relied upon (e.g. file extensions such as .asp). HTTP response headers, cookies, stylesheets and source comments may also give clues.

Some nice tools for querying site details (no doubt there are many more):

  - [BuiltWith][1]
  - [DomainTools][2]
  - [NetCraft][3]
  - [W3Techs][4]
  - [SimilarTech][9]

Firefox addons:

  - [Wappalyzer][8] - CMS, frameworks/libraries, e-commerce, message boards etc.
  - [Domain Details][5] - IP, country and webserver details
  - [Library Detector][6] - Javascript libraries in use

Chrome Extensions:

  - [Wappalyzer][8]
  - [SimilarTech][10]
  - [PageXray][11]

Bookmarklets:

  - [WTFramework][7] - shows Javascript framework in use


  [1]: http://builtwith.com/
  [2]: http://www.domaintools.com/
  [3]: http://news.netcraft.com/
  [4]: http://w3techs.com/sites
  [5]: https://addons.mozilla.org/en-US/firefox/addon/2166
  [6]: https://addons.mozilla.org/en-US/firefox/addon/10083
  [7]: http://blog.olicio.us/2008/11/08/wtframework-bookmarklet/
  [8]: http://wappalyzer.com/
  [9]: http://www.similartech.com
  [10]: https://chrome.google.com/webstore/detail/similartech-site-technolo/jiabgmelnfhgjkfdaoiccfcbaedjfcnm
  [11]: https://chrome.google.com/webstore/detail/pagexray/aedmpdookgbneegaeajpoldpnpfbpmlb

How do you determine what technology a website is built on?

Java `.class` files can be decompiled fairly easily. How can I protect my database if I have to use the login data in the code?

How can I protect MySQL username and password from decompiling?

**What tools are available to aid in decoding unknown binary data formats?**

I know Hex Workshop and 010 Editor both support structures. These are okay to a limited extent for a known fixed format but get difficult to use with anything more complicated, especially for unknown formats. I guess I&#39;m looking at a module for a scripting language or a scriptable GUI tool.

For example, I&#39;d like to be able to find a structure within a block of data from limited known information, perhaps a magic number. Once I&#39;ve found a structure, then follow known length and offset words to find other structures. Then repeat this recursively and iteratively where it makes sense.

In my dreams, perhaps even automatically identify possible offsets and lengths based on what I&#39;ve already told the system!

Tools to help reverse engineer binary file formats

Obfuscation is one way, but it can&#39;t protect from breaking the piracy protection security of the application. How do I make sure that the application is not tampered with, and how do I make sure that the registration mechanism can&#39;t be reverse engineered?

Also it is possible to convert a C# application to native code, and [Xenocode][1] is too costly.

C# provides lot of features, and is the ideal language for my code, so writing the whole codebase again in C++ is out of the question.

Secure certificates can be easily removed from the signed assemblies in .NET.

  [1]: http://en.wikipedia.org/wiki/Spoon_%28software%29


Protect .NET code from reverse engineering?

There have been a few articles recently about Google&#39;s new imageless buttons:

- http://stopdesign.com/archive/2009/02/04/recreating-the-button.html
- http://stopdesign.com/eg/buttons/3.0/code.html
- http://stopdesign.com/eg/buttons/3.1/code.html
- http://gmailblog.blogspot.com/2009/02/new-ways-to-label-with-move-to-and-auto.html

I really like how these new buttons work in Gmail.  How can I use these or similar buttons on my site?  Are there any open source projects with a similar look &amp; feel?

If I wanted to roll my own button package like this using JQuery/XHTML/CSS, what elements could I use?  My initial thoughts are:

1. Standard `&lt;input type=&quot;button&quot;&gt;` with css to improve the look (the design article talked mostly about the css/imges involves.)

2. Jquery javascript to bring up a custom dialog rooted to the button on the &quot;onclick&quot; event which would have `&lt;a&gt;` tags in them and a search bar for filtering?  Would a table layout for that popup be sane?


I&#39;m terrible at reverse engineering things on the web, what are some of the tools that I could use to help reverse engineer these buttons?  Using Firefox&#39;s web developer toolbar I can&#39;t really see the css or javascript (even if it is minified) that is used on the buttons popup dialogs.  What browser tool or other method could I use to peek at them and get some ideas?

I&#39;m not looking to steal any of Google&#39;s IP, just get an idea of how I could create similar button functionality.

Google&#39;s Imageless Buttons

A friend of mine downloaded some malware from Facebook, and I&#39;m curious to see what it does without infecting myself. I know that you can&#39;t really decompile an .exe, but can I at least view it in Assembly or attach a debugger? 

Edit to say it is not a .NET executable, no CLI header.

Is it possible to &quot;decompile&quot; a Windows .exe? Or at least view the Assembly?

I lost the source code from one project I did on the company I&#39;m working for and haven&#39;t been able to find a Visual Basic 6 decompiler; does that even exists?

I only have the EXE that I&#39;ve rescued from a user&#39;s machine.

Is there a Visual Basic 6 decompiler?

One if the first things I learned when I started with C# was the most important one. You can decompile any .NET assembly with Reflector or other tools. Many developers are not aware of this fact and most of them are shocked when I show them their source code.

Protection against decompilation is still a difficult task. I am still looking for a fast, easy and secure way to do it. I don&#39;t want to obfuscate my code so my method names will be a,b,c or so. Reflector or other tools should be unable to recognize my application as .NET assembly at all. I know about some tools already but they are very expensive. Is there any other way to protect my applications?

EDIT:

The reason for my question is not to prevent piracy. I only want to stop competitors from reading my code. I know they will and they already did. They even told me so.
Maybe I am a bit paranoid but business rivals reading my code doesn&#39;t make me feel good. 




How can I protect my .NET assemblies from decompilation?

Are the users able to convert the apk file of my application back to the actual code?
If they do - is there any way to prevent this?

Content Type	Original Author	Original Content on Stackoverflow
Question	Bryan Denny	View Question on Stackoverflow
Solution 1 - C++	David Holm	View Answer on Stackoverflow
Solution 2 - C++	Dustin Getz	View Answer on Stackoverflow
Solution 3 - C++	m_pGladiator	View Answer on Stackoverflow
Solution 4 - C++	Ferruccio	View Answer on Stackoverflow
Solution 5 - C++	harriyott	View Answer on Stackoverflow

Is there a C++ decompiler?

C++ Problem Overview

C++ Solutions

Solution 1 - C++

Solution 2 - C++

Solution 3 - C++

Solution 4 - C++

Solution 5 - C++

What is the most useful script you've written for everyday life?

PHP validation/regex for URL

Attributions