Is it possible to compile Ruby to byte code as with Python?

Question

In Python, if I want to give out an application without sources I can compile it into bytecode .pyc, is there a way to do something like it in Ruby?

Answer 1

I wrote a much more detailed answer to this question in the question "Can Ruby, PHP, or Perl create a pre-compiled file for the code like Python?"

The answer is: it depends. The Ruby Language has no provisions for compiling to bytecode and/or running bytecode. It also has no specfication of a bytecode format. The reason for this is simple: it would be much too restricting for language implementors if they were forced to use a specific bytecode format, or even bytecodes at all. For example, XRuby and JRuby compile to JVM bytecode, Ruby.NET and IronRuby compile to CIL bytecode, Cardinal compiles to PAST, SmallRuby compiles to Smalltalk/X bytecode, MagLev compiles to GemStone/S bytecode. For all of these implementations it would be plain stupid to use any other bytecode format than the one they currently use, since their whole point is interoperating with other language implementations that use the same bytecode format.

Simlar for MacRuby: it compiles to native code, not bytecode. Again, using bytecode would be stupid, since one of the goals is to run Ruby on the iPhone, which pretty much requires native code.

And of course there is MRI, which is a pure AST-walking script interpreter and thus doesn't have a bytecode format.

That being said, there are some Ruby Implementations which allow compiling to and loading from bytecode. Rubinius allows that, for example. (Indeed, it has to have that functionality since its Ruby compiler is written in Ruby, and thus the compiler must be compiled to Rubinius bytecode first, in order to solve the Catch-22.)

YARV also can save and load bytecode, although the loading functionality is currently disabled until a bytecode verifier is implemented that prevents users from loading manipulated bytecode that could crash or otherwise subvert the interpreter.

But, of course, both of these have their own bytecode formats and don't understand each other's (nor tinyrb's or RubyGoLightly's or ...) Also, neither of those formats is understood by a JVM or a CLR and vice versa.

However, the whole point is irrelevant because, as Mark points out, you can always reverse engineer the byte code anyway, especially in cases like CPython, PyPy, Rubinius, YARV, tinyrb, RubyGoLightly, where the bytecode format was specifically designed to be very close to the source language.

In general it is simply impossible to protect code that way. The reason is simple: you want the machine to be able to execute the code. (Otherwise what's the point in writing it in the first place?) However, in order to execute the code, the machine must understand the code. Since machines are much dumber than humans, it follows that any code that can be understood by a machine can just as well be understood by a human, no matter whether that code happens to be in source form, bytecode, assembly, native code or a deck of punch cards.

There is only one workable technical solution: if you control the entire execution pipeline, i.e. build your own CPU, your own computer, your own operating system, your own compiler, your own interpreter, and so forth and use strong cryptography to protect all of those, then and only then might you be able to protect your code. However, as e.g. Microsoft found out the hard way with the XBox 360, even doing all of that and hiring some of the smartest cryptographers and mathematicians on the planet, doesn't guarantee success.

The only real solution is not a technical but a social one: as soon as you have written your code, it is automatically fully protected by copyright law, without you having to do one single thing. That's it. Your code is protected.

Answer 2

The short answer is "YES",

check rubini.us

It will solve your problem.

Here is how to compile ruby code:

http://rubini.us/2011/03/17/running-ruby-with-no-ruby/