Extract the Nibble from an 8-bit Register

Code

#include <stdio.h>
unsigned char extractNibble(unsigned char reg, int pos) {
    unsigned char s=0;
    if(pos == 0){
        s= (reg ) & 0x0F;
        return s;
    }
    else{
        s= (reg >> 4) & 0x0F;
        return s;
    }
}
int main() {
    unsigned char reg;
    int pos;
    scanf("%hhu %d", &reg, &pos);
    printf("%d", extractNibble(reg, pos));
    return 0;
}

Solving Approach