it is known that dennis rithie made c with only 32 keywords and writing functions is the responsibility of the programmer. who wrote the functions printf, scanf . what is it's sourcr code?

it is known that dennis rithie made c with only 32 keywords and writing functions is the responsibility of the programmer. who wrote the functions printf, scanf?

Usually the author of the compiler that has the functions defined.

>who wrote the functions printf, scanf .
You mean who "writes" the functions. Generally every new compiler re-implements printf and most or all of the standard library and the author of the compiler does it (or someone on the team if there's more than one programmer).

>what is it's sourcr code?
I'll attach an example implementation of C89's stdio library.