How to print binary number via printf

Question

Possible Duplicate:
Is there a printf converter to print in binary format?

Here is my program

#include<stdio.h>
int main ()
{
    int i,a=2;
    i=~a;
    printf("a=%d\ni=%d\n",a,i);

    return 0;
}

The output is

a=2
i=-3

I want this to print in binary. There are...

• %x (hexadecimal)
• %o (octal)
• %d (decimal)

...but what is for printing binary in printf?

Answer 1

printf() doesn't directly support that. Instead you have to make your own function.

Something like:

while (n) {
    if (n & 1)
        printf("1");
    else
        printf("0");

    n >>= 1;
}
printf("\n");