Program that can write its own code in C++?

[Vacrin]

Hello everyone, im looking for code that i can make write its own kind of code if i tell it to. I know that it can be done, but i have yet to see the code for such a program.


Thank you

[ca0s]

You mean a quine?

http://en.wikipedia.org/wiki/Quine_(computing)

[Polyphony]

I know there are ways to do this with zip files too.

Code: [Select]

http://www.steike.com/code/useless/zip-file-quine/droste.zip for example

[pllaybuoy]

Ugh ugh , provide more details please

[Vacrin]

a quine just displays its own source code, im looking for a program or the code of a program that can write more code into itself while it is compiled or in runtime.

so basically if i have a program that does nothing but accept code, then i can give it the location of a piece of code i want to insert lets say it was cout << "hello"; well then now the code can say hello when it is activated, but i dont want to go into the source code to edit it, i would like to edit it while it is in runtime or something.

this is much different from a quine because a quine only displays its own code which can be done with cout << easily

[flowjob]

AFAIK, you won't be able to do this with a AOT (ahead of time) compiled program (e.g. most C compilers), but it can be possible by using a JIT (just in time) compiler (like py2exe)

[ca0s]

You can make a process execute dynamic code that it reads / receives from somewhere.
If you are using a compiled language you will have to send it pre-compiled (or include a compiler in your executable, which is not very efficient).
With scripting languages you can use eval().

[flowjob]

If you are using a compiled language you will have to send it pre-compiled (or include a compiler in your executable, which is not very efficient).

JIT compiler have a compiler included wich compiles bytecode to machine code.That makes loading the application much more efficient than with AOT compiler, and as it compiles the code segment just before executing,executing it is faster than with a interpreter...

So a JIT compiler combine the advantages of a AOT compiler and a Interpreter

[Vacrin]

So using one of these compilers code i write a program that can then access its own code through the compiler and then write and recompile itself all while it is still running or would it have to restart itself?

[Live Wire]

I'm 90 percent sure that it would have to restart itself. Whenever I've tried something like this, I always end up writing a program to execute, and a program to modify. I'm actually interested in the answer now.

[Vacrin]

i had that idea or a back and forth kinda idea, meaning i would make 2 programs, but they can edit each other so when one has to write a new code it adds it to the other and runs it and closes itself and then when the other one has to add a line it adds what was added to it and the line it has to add and then runs the other one and closes itself... dont know how productive it would be however

[Satan911]

What can be done is have a compiled exe (since we are in the C/C++ section) that does nothing until you append data (or information) to the existing binary file. See http://stackoverflow.com/questions/2266735/make-an-executable-at-runtime

You could also right code that invoke a compiler (GCC).

But having code compiled at runtime by a compiled executable is far from simple. It is way easier to do with scripting languages.

[techb]

Yes, just use a scripting language. You can modify the source at runtime, the have itself restart or like mentioned something like eval() (not recommended though). Using eval() or similar method to execute code from an outside source is a big security hole.

[Daemon]

isn't that just self-modifying code?

 http://en.m.wikipedia.org/wiki/Self-modifying_code

[Vacrin]

Yes, that is what it is, i just said it differently xD