Since the source code is not available for this game I definitely coudn't look there for answers. But you can basically open any program/game that doesn't have some special protection in any of those special programs called disassemblers/debuggers which show you the program code in assembly language, which is the lowest-level language you can still work with but it's very difficult to figure that kind of code out, what it does, how it does. Two well known programs of that kind are OllyDbg and IDA (Interactive Disassembler).
When you compile your program/game, your source code, written in some higher-level language like C++, is translated into computer architecture specific machine instructions, in this case into instructions specific to all x86 compatible processors. The final result of compilation process is the executable file. In the process, all details like variable names, function names, how complex data structures are formed and everything in the source code that makes it coder-friendly are lost. So unless the developer made the program/game open-sourced, disassemblers/debuggers are the only options you have left to figure out how certain parts of the code work and perhaps fix some less complex bugs. You can also insert your own code (in assembly ofcourse) at the end of the executable's file code section, but the space there is limited. The technique is called codecave and here are some details
for those who are interested.
One thing that's very helpful are human-readable words (coders call them strings) found in the executable file. It's how I managed to find the function that takes field of view for its parameter so easily which enabled me to implement widescreen code in AiO Patch. By searching for word "fov" I found a whole function in Dragon.rfl at address 0x10920 (plus base address) which compares what you type in-game at chat prompt with commands the game knows and if it finds a match, executes whatever cheat/command you wanted it to execute. And apparently this function isn't the only place that processess whatever you type in chat prompt. I actually haven't found out about "exit" command there, I just randomly typed in "exit", hoping it would work and it just worked.
And to answer your question, I don't think such command that would list every code exists. Or maybe it just hasn't been discovered yet.