17. Extract the Nibble from an 8-bit Register

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
    unsigned char nibble = 0;
    if( pos == 0)
    {
        for(int i =0 ; i< 4; i ++)
        {
            unsigned char bit = (reg >> i) & 1 ;
            nibble |= bit << i;
        }
    }
    else
    {
        for(int i =4 ; i< 8; i ++)
        {
            unsigned char bit = (reg >> i) & 1 ;
            nibble |= bit << (i % 4);
        }
    }
    return nibble;
}

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