17. Extract the Nibble from an 8-bit Register

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
    unsigned char nible_mask = 15;
    if(pos == 1){
        nible_mask = nible_mask << 4;
        reg = reg & nible_mask;
        reg = reg >> 4;
        return reg;
    }
    else{
        reg = reg & nible_mask;
        return reg;
    }
}

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