printf int in binary format

http://mathforum.org/library/drmath/view/54347.html
http://www.experts-exchange.com/Programming/Programming_Languages/C/Q_20287908.html
http://www.experts-exchange.com/Programming/Programming_Languages/C/Q_21912996.html

Cheers!
sunnycoder

This is a function I wrote sometime back, can be used to print in any base(between 2 and 36).
for base >36, we need more symbols than just numbers and alphabets.
maxwidth is the size of the dest buffer.

char * toString(int num, char * dest, unsigned radix, unsigned  maxwidth)
{
        if(!dest)
                return dest;
        if (radix < 2 || radix > 36)
        {
                dest[0] = 0;
                return dest;
        }

        int out = num;
        unsigned len = 0, i =0;
        int rem;

        while(out&& len<maxwidth)
        {
                rem = out % radix;
                out =  out/radix;
                if (rem > 9)
                        dest[len] = (char)(rem - 10) + 'a';
                else
                        dest[len] = (char)rem + '0';

                ++len;
        }

        if(!len)
                dest[len++]='0';//for number 0

        dest[len] = 0;

        // reverse digits
        for (i = 0; i < (len >> 1); ++i)
        {
                char c = dest[i];
                dest[i] = dest[len-1-i];
                dest[len-1-i] = c;
        }
}

>>How are you deciding how many leading 0s are in the binary form?
You did not mention the number of zeros you want. (there is no straight answer to this, it is best not to display any leading zeros or always display fixed width numbers; say 32 or 64 digits)

BTW, the function I posted works for unsigned numbers, negative numbers will get printed in 2's compliment format.

There is a miss-by-one error in the while loop condition,
it should be
while(out && len<maxwidth-1)

if memory is an issue, char should be used. if it is a big issue and a lot of bools are needed, use each bit of an int as a bitmap.
if there are only a few bool on modern systems with memory running into GBs, it will not even me measurable, so does not matter at all.

however, i think the idea of using int where bool could be because:
-IMHO int as greater readability than char when used as bool (char 0 is non printable, while int 0 is)
-int used to be the default(implicit) datatype for lot of cases in C(not sure about this though)

Typically chars indeed are used for bool. 1 (non zero or !0) being true and 0 being false. chars are internally stored as ints. To print 0 and 1, use %d flag instead of %c - this would print the ASCII value of the char.