How can I find source code of printf in macOS?

Question

Sorry for my bad english.

I'm using macOS 12.3 in M1 Pro MacBook Pro

I want to know about source code of printf in C standard library.

I can find stdio.h file in usr/include directory.

But I can't find printf.c or stdio.c file in same directory.

And I think Apple Open Source's printf.c is too complicate, dosen't looks like a real code in macOS and dosen't helpful for me. Is that Apple Open Source printf.c code is really used in macOS?

https://opensource.apple.com/source/xnu/xnu-201/osfmk/kern/printf.c.auto.html

Answer 1

The newest Apple Open Source libc implementation of vfprintf (which is the generic underlying function that plain printf calls) can be found here on opensource.apple.com.

It's about 1400 lines, and yes, it is complex.

Some other alternate implementations (which are complex too) are:

• musl libc: 696 lines
• GNU glibc: 2289 lines
• uClibc: 1928 lines