From http://stackoverflow.com/questions/2249731/how-to-get-bit-by-bit-data-from-a-integer-value-in-c

bit-by-bit-reading.c

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char** argv)
{
    unsigned
        input = 0b0111u,
        n_bits = 4u,
        *bits = (unsigned*)malloc(sizeof(unsigned) * n_bits),
        bit = 0;

    for(bit = 0; bit < n_bits; ++bit)
        bits[bit] = (input >> bit) & 1;
        
    // Assuming that you want to calculate all bits as in this case, and
    // not a specific one, the loop can be further changed to
    for(bit = 0; bit < n_bits; ++bit, input >>= 1)
        bits[bit] = input & 1;
    // This modifies input in place and thereby allows the use of a
    // constant width, single-bit shift, which may be more efficient on
    // some architectures.

    for(bit = n_bits; bit--;)
        printf("%u", bits[bit]);
    printf("\n");

    free(bits);
}