bitc.c

 #include <stdio.h>

void PrintBit(int integer)
{
    (integer & 128)?putchar('1'):putchar('0');
    (integer & 64)?putchar('1'):putchar('0');
    (integer & 32)?putchar('1'):putchar('0');
    (integer & 16)?putchar('1'):putchar('0');
    (integer & 8)?putchar('1'):putchar('0');
    (integer & 4)?putchar('1'):putchar('0');
    (integer & 2)?putchar('1'):putchar('0');
    (integer & 1)?putchar('1'):putchar('0');
}

int main(int argc, char **argv)
{
    unsigned uns;
    argv++;
    for(; argc > 1; argc--, argv++)
    {
        uns = atoi(*argv);
        printf("%3d: ", uns);
        PrintBit(uns);
        putchar('\n');
    }
    return(0);

}

This program take numbers as parameters.. convert from char to unsinedsthen print in binary form.. I make this to smooth the study of bitwises operators
it's useful in this form:
./bitc.o 21 11 $((21&11))
OUTPUT:
21: 00010101
11: 00001011
   1: 00000001