Binary to decimal in c

Question

I have a simple code to convert binary to decimal numbers. In my compiler, the decomposition works just fine for number less than 1000, beyond the output is always the same

Answer 1

Shift left is the same than multiply by 2 and is more efficient, so I think it is a more c-like answer:

#include 
#include 

int bin2int(const char *bin) 
{
    int i, j;
    j = sizeof(int)*8;
    while ( (j--) && ((*bin=='0') || (*bin=='1')) ) {
        i <<= 1;
        if ( *bin=='1' ) i++;
        bin++;
    }
    return i;
}

int main(void) 
{ 
    char* input = NULL;
    size_t size = 0;

    while ( getline(&input, &size, stdin) > 0 ) {
        printf("%i\n", bin2int(input)); 
    }
    free(input);
}