Extract the Nibble from an 8-bit Register

Code

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
    // Use a nibble mask 4 lower bits and shift it if required by using the pos argument (it can be used as a flag).
    reg &= (0x0F << (4*pos));
    // After the value is masked shift it to the lowest significant position using again the pos argument as a flag.
    return (reg >> (4*pos));
}

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

Solving Approach