Luigi, here's the xtoa function, maybe it will help you:

Code:

static void __cdecl xtoa (
unsigned long val,
char *buf,
unsigned radix,
int is_neg
)
{
char *p; /* pointer to traverse string */
char *firstdig; /* pointer to first digit */
char temp; /* temp char */
unsigned digval; /* value of digit */
p = buf;
if (is_neg) {
/* negative, so output '-' and negate */
*p++ = '-';
val = (unsigned long)(-(long)val);
}
firstdig = p; /* save pointer to first digit */
do {
digval = (unsigned) (val % radix);
val /= radix; /* get next digit */
/* convert to ascii and store */
if (digval > 9)
*p++ = (char) (digval - 10 + 'a'); /* a letter */
else
*p++ = (char) (digval + '0'); /* a digit */
} while (val > 0);
/* We now have the digit of the number in the buffer, but in reverse
order. Thus we reverse them now. */
*p-- = '\0'; /* terminate string; p points to last digit */
do {
temp = *p;
*p = *firstdig;
*firstdig = temp; /* swap *p and *firstdig */
--p;
++firstdig; /* advance to next two digits */
} while (firstdig < p); /* repeat until halfway */
}

and the itoa function that uses xtoa:

Code:

char * __cdecl _itoa (
int val,
char *buf,
int radix
)
{
if (radix == 10 && val < 0)
xtoa((unsigned long)val, buf, radix, 1);
else
xtoa((unsigned long)(unsigned int)val, buf, radix, 0);
return buf;
}