17. Extract the Nibble from an 8-bit Register

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
    if(pos){
        // upper nibble
        return (reg & 0xf0) >> 4;
    }else{
        // lower
        return reg & 0xf;
    }
}

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