Convert Binary String to Integer Without strtol function or Libraries

#include <stdio.h>
#include <stdint.h>

uint16_t binary_to_uint(const char *str) {
    int result = 0;
    for(int i=0; str[i] != '\0'; i++ ){
        int bit = str[i] - '0';
        result = (result << 1) | bit; 
    }
    return result;
}

int main() {
    char bin[20];
    scanf("%s", bin);

    printf("%u", binary_to_uint(bin));
    return 0;
}