1 /* $NetBSD: iftoa.c,v 1.1.1.1 2016/01/13 18:41:48 christos Exp $ */
2
3 /* Copyright (C) 1989, 1990, 1991, 1992, 2000, 2004
4 Free Software Foundation, Inc.
5 Written by James Clark (jjc@jclark.com)
6
7 This file is part of groff.
8
9 groff is free software; you can redistribute it and/or modify it under
10 the terms of the GNU General Public License as published by the Free
11 Software Foundation; either version 2, or (at your option) any later
12 version.
13
14 groff is distributed in the hope that it will be useful, but WITHOUT ANY
15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 for more details.
18
19 You should have received a copy of the GNU General Public License along
20 with groff; see the file COPYING. If not, write to the Free Software
21 Foundation, 51 Franklin St - Fifth Floor, Boston, MA 02110-1301, USA. */
22
23 #define INT_DIGITS 19 /* enough for 64-bit integer */
24
25 #ifdef __cplusplus
26 extern "C" {
27 #endif
28
if_to_a(int i,int decimal_point)29 char *if_to_a(int i, int decimal_point)
30 {
31 /* room for a -, INT_DIGITS digits, a decimal point, and a terminating '\0' */
32 static char buf[INT_DIGITS + 3];
33 char *p = buf + INT_DIGITS + 2;
34 int point = 0;
35 buf[INT_DIGITS + 2] = '\0';
36 /* assert(decimal_point <= INT_DIGITS); */
37 if (i >= 0) {
38 do {
39 *--p = '0' + (i % 10);
40 i /= 10;
41 if (++point == decimal_point)
42 *--p = '.';
43 } while (i != 0 || point < decimal_point);
44 }
45 else { /* i < 0 */
46 do {
47 *--p = '0' - (i % 10);
48 i /= 10;
49 if (++point == decimal_point)
50 *--p = '.';
51 } while (i != 0 || point < decimal_point);
52 *--p = '-';
53 }
54 if (decimal_point > 0) {
55 char *q;
56 /* there must be a dot, so this will terminate */
57 for (q = buf + INT_DIGITS + 2; q[-1] == '0'; --q)
58 ;
59 if (q[-1] == '.') {
60 if (q - 1 == p) {
61 q[-1] = '0';
62 q[0] = '\0';
63 }
64 else
65 q[-1] = '\0';
66 }
67 else
68 *q = '\0';
69 }
70 return p;
71 }
72
73 #ifdef __cplusplus
74 }
75 #endif
76