denyhosts/clamav/libclamav/tomsfastmath/bin/fp_toradix_n.c

72 lines
1.5 KiB
C

/* TomsFastMath, a fast ISO C bignum library.
*
* This project is meant to fill in where LibTomMath
* falls short. That is speed ;-)
*
* This project is public domain and free for all purposes.
*
* Tom St Denis, tomstdenis@gmail.com
*/
#include <tfm_private.h>
int fp_toradix_n(fp_int *a, char *str, int radix, int maxlen)
{
int digs;
fp_int t;
fp_digit d;
char *_s = str;
/* check range of the radix */
if (maxlen < 2 || radix < 2 || radix > 64)
return FP_VAL;
/* quick check for zero */
if (fp_iszero(a) == FP_YES) {
*str++ = '0';
*str = '\0';
return FP_OKAY;
}
fp_init_copy(&t, a);
/* if it is negative output a - */
if (t.sign == FP_NEG) {
/* we have to reverse our digits later... but not the - sign!! */
++_s;
/* store the flag and mark the number as positive */
*str++ = '-';
t.sign = FP_ZPOS;
/* subtract a char */
--maxlen;
}
digs = 0;
while (fp_iszero (&t) == FP_NO) {
if (--maxlen < 1) {
/* no more room */
break;
}
fp_div_d(&t, (fp_digit) radix, &t, &d);
*str++ = fp_s_rmap[d];
++digs;
}
/* reverse the digits of the string. In this case _s points
* to the first digit [exluding the sign] of the number]
*/
fp_reverse((unsigned char *) _s, digs);
/* append a NULL so the string is properly terminated */
*str = '\0';
if (maxlen < 1)
return FP_VAL;
return FP_OKAY;
}
/* $Source$ */
/* $Revision$ */
/* $Date$ */