Extract the Nibble from an 8-bit Register

Code

#include <stdio.h>

unsigned char extractNibble(unsigned char reg, int pos) {
    unsigned char l_ret_u8 = 0u;
    unsigned char l_mask_u8 = 0u;
    if(pos == 0)
    {
        /* do nothing */
    }
    else
    {
        reg = reg>>4u;
    }
    l_ret_u8 = reg & 0x0F;
    return l_ret_u8;
}

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

Solving Approach