Extract the Nibble from an 8-bit Register

Code

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
   unsigned char val_nib;
   if(pos == 0){
    val_nib = reg & 0x0F; 
   }else{
    val_nib = (reg >> 4) & 0x0F;
   }
   return val_nib;
}

int main() {
    unsigned char reg;
    int pos;
    scanf("%hhu %d", &reg, &pos);
    printf("%d", extractNibble(reg, pos));
    return 0;
}

Solving Approach