Thread: macOS C Programming Help

I had to switch environments for work and I am feeling like a total fish out of water on macOS between the actual macOS API stuff ("Core Foundation" I believe it's called), and the Unix wrapper stuff, etc...

I need some help. The best way I can describe what I am trying to do is to give a Windows example. On Windows, I'm used to being able to do something like:

Code:

#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
int main(void)
{
    fH = CreateFile(....)

   HANDLE myMem = HeapAlloc(...)

   return EXIT_SUCCESS;
}

And so on...

However, I cannot find the <windows.h> equivalent for macOS. I checked their docs and it seems they only support either Swift or "Objective C" and I have no knowledge of those languages. However, I am having a hard time believing that I cannot access macOS API calls with just C itself... Is this the case? Is there a C API for these funcs?

Also note that even the Windows API claims it's "C++" but I can do everything from within C by using header files like <windows.h> for example. Can I also do something similar in Mac? If not, can I use an Objective-C Compiler and still build C with it like how I can use a C++ compiler to build C for the most part?

To make it even more confusing, macOS is based off of Unix and is POSIX and so that also means I can use Unix calls, but I'm finding strange inconsistencies from actual Linux and I imagine those calls are also just wrappers around some macOS API which I'd rather learn and use.


Any guidance in this area would be greatly appreciated because there seems to be a lot less info on it online when compared with Windows.

Thank you.

You are thinking of the "wrapper" in the wrong way.
The base operating system is BSD Unix.
The mac stuff is the "wrapper".

Originally Posted by john.c

You are thinking of the "wrapper" in the wrong way.
The base operating system is BSD Unix.
The mac stuff is the "wrapper".

So what you're saying John is that the core OS is mostly BSD and all of the NS and CF functions eventually make BSD calls at some level?I realize this is quite a bit of assumptions but is that the general idea?Kind of like how kernel32.dll -> ntdll.dll -> the Windows kernel interface?

I think it works something like that, but I don't use it so you should read up on it yourself. Read these and let me know the scoop:
Apple'&#39;'s Operating System Guru Goes Back to His Roots | WIRED
macOS - Wikipedia

From: Architecture of macOS - Wikipedia

john.c,

Thanks for the links and especially that diagram - it's a big help. So I did some homework and came up with this:

macOS has a lot of lingo… So based on my research on the topic, macOS is a platform which contains a GUI much like Gnome for Linux (called Aqua in the graphic)
but the actual OS is called Darwin, which is open source
and their entire kernel is called XNU which is also all open source
XNU is made up of 2 main components: BSD and Mach
Mach was a microkernel and BSD is BSD… They took parts of both and combined them into one
and that created their XNU kernel
Apparently you can call “Core OS” functions which are much like ntdll.dll on Windows or the native API
but people rarely do that anymore… Mostly its using managed Cocoa which uses Swift or Objective-C
much like C# on Windows
ALso I noted that processes on Mac are called Tasks instead
and what Windows called HANDLEs are called Ports on Mac
so a thread can have ports

After all of that, it's also POSIX compliant so I think the best solution here, to spare myself months of reading through managed-code funcs, is just to use the POSIX API. I was not that familiar with POSIX coming from Windows world but actually, it's pretty easy to use and I used it today to solve the problems I needed to like iterating through directories and running programs. To do this natively on Windows, I would typically use the Windows API which involved a lot more lines of code than using <dirent.h> in POSIX.