17. Extract the Nibble from an 8-bit Register

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
 if (pos==0) {
    return reg & 0x0F; // extract lower nibble
 }
 else {
    return (reg>>4)&0x0F; // extract upper nibble
 }
}

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