Develop Reference

RTMPS protocol c#/vb.net

does anyone has a clue how the RTMPS-Protocoll works? I haven't found any source code, documentation or libraries for vb.net/c# on the web!
I read somewhere that it's only a TCP connection, but is this right?
If yes, how can I use this?
Could you pleas provide me source code, a library or a documentation?
Thanks in advance!
--
coolerfarmer

Check out RTMPdump I used to work with it a while back so I don't know how well it has been maintained in the mean time. However be sure to have a look at the clean-room specification. I used that document as a starting point to implement my own RTMPS protocol, however I wasn't able to ever finish it.
On a personal note, I would recommend using C# or even C++ to implement a client, if you know those languages as well as vb.net

C# protecting application from code injection

I just found out that even though I obfuscate my application it can still be cracked using code injection. This pretty much makes C# completely useless for me. Is there really no way to protect or make the process very difficult to do? Do 'crackers' have to know any class names etc. to do this? Thanks!
UPDATE: I'm trying to protect a binary (exe) not code.

I've read somewhere on here from several users that whatever the code is written in, it can be decompiled. Think of it like this, how else would the system know how to run the code? It is the same concept.
Usually though, most developers(that I know of) don't worry so much about this. Of course, this is a good reason not to have any sensitive details within your code but rather somewhere else.

If you're worried about protected industry secrets, it's impossible to send a computer the right instructions, but expect those instructions cannot be read by a capable person. If your goal is to stop somebody from modifying your EXE, why not simply sign your executable?
http://blogs.msdn.com/b/shawnfa/archive/2007/01/10/combining-strong-names-with-authenticode.aspx

Any of the .NET languages, and Java can be de-compiled. This includes .Exe and .dll files. What you will need to do is get an tool that obfuscates the code.
I've listed one below for you so you can get an idea:
http://www.red-gate.com/products/dotnet-development/smartassembly/

Are you sure your code is worth the trouble for someone to do that? Very very few applications are.

Running CPython functions from C#

I'm working on a project where I need to be able to run a python function that depends on SciPy/NumPy. Due to this being an add-on to a project already in progress, using IronPython would not be an option.
Additional info:
Python.NET seemed to be a good fit, but I was unable to get the return value from RunString() (it would only return NULL).
Passing arguments and catching the return value (a tuple) is necessary.
The function is in a statistical package that was created by a support group for the team, so modification of that would also not be possible.
I'm at quite a loss for what to do. Any hints in the right direction are appreciated. Thanks for any help you can give!
I understand that this may be quite vague, but I cannot give explicit details to the project. If any clarification is needed please let me know and I'll do my best!

I guess you could write a DLL that uses the CPython API to expose the function, then call it in C#?
It's possible to embed the Python interpreter; although I've never done this personally, I guess it would be useful: http://docs.python.org/extending/embedding.html

Does it need to be portable beyond Windows? If not, perhaps you can embed the CPython interpreter with C++/CLI, wrap that in a nice .Net-ish interface and use the resulting code from C#. Never tried that, so I don't know if it's going to work.
Regardless if you go through this route or the 'write a native DLL' route, it will probably be easier to to embed python using Boost.Python, though I'm not sure if your wrapper code enough is going to be large enough to make all of this (compiling the Boost behemoth, learning Boost.Python, making sure it works with C++/CLR, increasing your target file size) worth it.

IronPython using DLR might be the way to go. Mind you it won't be the fastest way, but it seems like something worth pursuing if you're going to do this a lot. Another useful link

The ironclad project was started to allow using CPython extensions from IronPython, especially SciPy/NumPy it seems. I don't know how usable it is (and how actively it is still being developed)

c# compile source code from database

I would like to build an application framework that is mainly interpreted.
Say that the source code would be stored in the database that could be edited by the users and always the latest version would be executed.
Can anyone give me some ideas how does one implement sth like this !
cheers,
gabor

In .Net, you can use reflection and CodeDOM to compile code on the fly. But neither approach is really very simple or practical. Mono has some ability to interpret c# on the fly as well, but I haven't looked closely at it yet.
Another alternative is to go with an interpreted .Net language like Boo or IronPython as the language for your database code.
Either way, make sure you think long and hard about the security of your platform. Allowing users to execute arbitrary code is always an exercise fraught with peril. It's often too tempting to look for a simple eval() method, and even if one exists, that is not good enough for this kind of scenario.

Try Mono ( http://www.monoproject.org ). It supports many scripting languages including JavaScript.

If you don't want to use any scripting you can use CodeDOM or Reflection (see Reflection.Emit).
Here are really useful links on the topic :
Dynamically executing code in .Net (Here you can find a tool which can be very helpul)
Late Binding and On-the-Fly Code
Generation Using Reflection in C#
Dynamic Source Code Generation and
Compilation

Usually the Program uses a scripting language for the scriptable parts, i.e. Lua or Javascript.

To answer your technical question: You don't want to write your own language and interpreter. That's too much work for you to do. So pick some other language, say Python or Lua, and look for the documentation that lets your C program hand it blocks of code to execute. Of course, the script needs to be able to do something, so you'll need to find how to expose your program's objects to the script. Also, what will happen if a client is running the program when you update its source code in the database? Should the client restart? Are you going to store the entire program as a single row in this database, or did you want to store individual functions? That affects how you structure your updates.
To address other issues with your question: Why do you want to do this? Making "interpreted language" part of your design spec for a system is not often a good sign. Is the real requirement something like this: "I update the program often and I want users to always have the latest copy?" If so, there are other, better ways to go about this (just give us your actual scenario and requirements).

Lex/Yacc for C#?

Actually, maybe not full-blown Lex/Yacc. I'm implementing a command-interpreter front-end to administer a webapp. I'm looking for something that'll take a grammar definition and turn it into a parser that directly invokes methods on my object. Similar to how ASP.NET MVC can figure out which controller method to invoke, and how to pony up the arguments.
So, if the user types "create foo" at my command-prompt, it should transparently call a method:
private void Create(string id) { /* ... */ }
Oh, and if it could generate help text from (e.g.) attributes on those controller methods, that'd be awesome, too.

I've done a couple of small projects with GPLEX/GPPG, which are pretty straightforward reimplementations of LEX/YACC in C#. I've not used any of the other tools above, so I can't really compare them, but these worked fine.
GPPG can be found here and GPLEX here.
That being said, I agree, a full LEX/YACC solution probably is overkill for your problem. I would suggest generating a set of bindings using IronPython: it interfaces easily with .NET code, non-programmers seem to find the basic syntax fairly usable, and it gives you a lot of flexibility/power if you choose to use it.

I'm not sure Lex/Yacc will be of any help. You'll just need a basic tokenizer and an interpreter which are faster to write by hand. If you're still into parsing route see Irony.
As a sidenote: have you considered PowerShell and its commandlets?

Also look at Antlr, which has C# support.

Still early CTP so can't be used in production apps but you may be interested in Oslo/MGrammar:
http://msdn.microsoft.com/en-us/oslo/

Jison is getting a lot of traction recently. It is a Bison port to javascript. Because of it's extremely simple nature, I've ported the jison parsing/lexing template to php, and now to C#. It is still very new, but if you get a chance, take a look at it here: https://github.com/robertleeplummerjr/jison/tree/master/ports/csharp/Jison

If you don't fear alpha software and want an alternative to Lex / Yacc for creating your own languages, you might look into Oslo. I would recommend you to sit through session recordings of sessions TL27 and TL31 from last years PDC. TL31 directly addresses the creation of Domain Specific Languages using Oslo.

Coco/R is a compiler generator with a .NET implementation. You could try that out, but I'm not sure if getting such a library to work would be faster than writing your own tokenizer.
http://www.ssw.uni-linz.ac.at/Research/Projects/Coco/

I would suggest csflex - C# port of flex - most famous unix scanner generator.

I believe that lex/yacc are in one of the SDKs already (i.e. RTM). Either Windows or .NET Framework SDK.

Gardens Point Parser Generator here provides Yacc/Bison functionality for C#. It can be donwloaded here. A usefull example using GPPG is provided here

As Anton said, PowerShell is probably the way to go. If you do want a lex/ yacc implementation then Malcolm Crowe has a good set.
Edit: Direct Link to the Compiler Tools

Just for the record, implementation of lexer and LALR parser in C# for C#:
http://code.google.com/p/naive-language-tools/
It should be similar in use to Lex/Yacc, however those tools (NLT) are not generators! Thus, forget about speed.