Extract the Nibble from an 8-bit Register

#include <stdio.h>
#include <stdint.h>
uint8_t extract_nibble(uint8_t reg, int pos){
    if(pos==0){
        return reg & 0x0F;
    } else {
        return(reg >> 4)& 0x0F;
    }
}
int main(){
    uint8_t reg;
    int pos;
    scanf("%hhu %d", &reg, &pos);
    printf("%u\n", extract_nibble(reg, pos));
    return 0;
}