freebsd-nq/contrib/groff/libgroff/iftoa.c
1996-09-07 16:18:32 +00:00

66 lines
1.8 KiB
C

/* Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
Written by James Clark (jjc@jclark.com)
This file is part of groff.
groff is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.
groff is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License along
with groff; see the file COPYING. If not, write to the Free Software
Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
#define INT_DIGITS 19 /* enough for 64-bit integer */
char *iftoa(i, decimal_point)
int i, decimal_point;
{
/* room for a -, INT_DIGITS digits, a decimal point, and a terminating '\0' */
static char buf[INT_DIGITS + 3];
char *p = buf + INT_DIGITS + 2;
int point = 0;
buf[INT_DIGITS + 2] = '\0';
/* assert(decimal_point <= INT_DIGITS); */
if (i >= 0) {
do {
*--p = '0' + (i % 10);
i /= 10;
if (++point == decimal_point)
*--p = '.';
} while (i != 0 || point < decimal_point);
}
else { /* i < 0 */
do {
*--p = '0' - (i % 10);
i /= 10;
if (++point == decimal_point)
*--p = '.';
} while (i != 0 || point < decimal_point);
*--p = '-';
}
if (decimal_point > 0) {
char *q;
/* there must be a dot, so this will terminate */
for (q = buf + INT_DIGITS + 2; q[-1] == '0'; --q)
;
if (q[-1] == '.') {
if (q - 1 == p) {
q[-1] = '0';
q[0] = '\0';
}
else
q[-1] = '\0';
}
else
*q = '\0';
}
return p;
}