Is there a printf converter to print in binary format?

Question

I can print with printf as a hex or octal number. Is there a format tag to print as binary, or arbitrary base?

I am running gcc.

printf(\"%d %x %o         


        

Answer 1

Here is a quick hack to demonstrate the techniques for what you want.

#include    /* printf */
#include   /* strcat */
#include   /* strtol */

const char *byte_to_binary(int x)
{
    static char b[9];
    b[0] = '\0';

    int z;
    for (z = 128; z > 0; z >>= 1) {
        strcat(b, ((x & z) == z) ? "1" : "0");
    }

    return b;
}

int main(void) {
    {
        /* binary string to int */
        char *tmp;
        char *b = "0101";
        printf("%d\n", strtol(b, &tmp, 2));
    }
    {
        /* byte to binary string */
        printf("%s\n", byte_to_binary(5));
    }
    return 0;
}