I was trying to understand the source code of aircrack-ng which is written in C today.
Suddenly I saw sth strange !
WTF !! what is #ifdef ??? I've never seen that before !
So I told myself : hey ! You have to download a complete C programming course!
so I did , but when I skimmed through the titles , again:
WTF ! I know all of them! So why the fuck I could not fully understand the code ? Where can I find anything I missed ?

So... I'm asking U :)

@theNSA is this your work? to get all the WiFi passwords?

@heyheni well I'm a pentester :)
Wireless pentest is also my duty

The actual WTF is that there are C courses out there that don't even mention #ifdef. And probably not #error either.

Maybe the classic book by Kernighan & Ritchie? Though of course this is missing some newer stuff like C99 and C11.

@R1100 Well I'm a graphic designer who can't code. I downloaded Kali Linux. So I'm a pentester myself now, right? 😆

@heyheni That's for noobs. I got a Kali wallpaper on my Windows machine. h4xx0r 1337 alert!

@Fast-Nop 😲

@heyheni cool ! CSS stuff ?

@R1100 css with kali? No that would be wastetd 13373$. ARP poisening and creating pdfs that execute remote code. Teaching Blue Team what fear means. 😆

@heyheni cool 👊
Keep going but also try to read the codes (otherwise you'll be just a skiddie and you won't penetrate cool servers)

Most courses are basics only, what you should have learned is to fucking look for shit in the documentation.

Here, let me give you the most important skill there is:
http://bfy.tw/O8Jj

@mundo03 never knew this site existed. This will help me deal with a lot of people, thank you!

@nofckingcluedev it is an internet oldie :p you are welcome

#ifdef is a compiler preprocessor, it needs to allways be followed by some symbol. (e. g.
#ifdef MY_SYM) A ifdef block is ended with a #endif .

It does the following. Let's say we have this code:

#ifdef WIN64
... my c code...
#endif

Then `... my c code...` only gets _compiled_ if the symbol `WIN64` is defined. The symbol `WIN64` is defined when using some windows compiler on a 64bit system. The purpose of this is to allow one codebase to contain the code for many systems.

There also are the directives:
#elifdef
#else

These work as you would expect.
Here one longer example to show how these work. (NOTE: I am making up the symbol names as this is dependent on the compiler you use)

#ifdef WIN64
... c code for 64bit windows...
#elifdef WIN32
... c code for 32bit windows...
#elifdef LINUX64
... c code for 64bit linux...
#else
... c code for 32bit linux...

#endif

just blunder your way through with badly-written language docs.