putchar() vs printf() - Is there a difference?

Question

I am currently in chapter 1.5.1 File copying and made a program like so:

#include 

/* copy input to output; 1st version */
main()
{
    int c         


        

Answer 1

I compiled an example using printf("a") with -S and got call putchar in the assembly code. Looks like when you have only one char in the printf the compiler turns it into a putchar(). I did another example using printf("ab") and got call printf, with the text section in the %edi register.