1 /* nearzero.c: bcmath library file. */
2 /*
3 Copyright (C) 1991, 1992, 1993, 1994, 1997 Free Software Foundation, Inc.
4 Copyright (C) 2000 Philip A. Nelson
5
6 This library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2 of the License, or (at your option) any later version.
10
11 This library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details. (LICENSE)
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with this library; if not, write to:
18
19 The Free Software Foundation, Inc.
20 59 Temple Place, Suite 330
21 Boston, MA 02111-1307 USA.
22
23 You may contact the author by:
24 e-mail: philnelson@acm.org
25 us-mail: Philip A. Nelson
26 Computer Science Department, 9062
27 Western Washington University
28 Bellingham, WA 98226-9062
29
30 *************************************************************************/
31
32 #include <config.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <ctype.h>
36 #include <stdarg.h>
37 #include "bcmath.h"
38 #include "private.h"
39
40 /* In some places we need to check if the number NUM is almost zero.
41 Specifically, all but the last digit is 0 and the last digit is 1.
42 Last digit is defined by scale. */
43
44 char
bc_is_near_zero(num,scale)45 bc_is_near_zero (num, scale)
46 bc_num num;
47 int scale;
48 {
49 int count;
50 char *nptr;
51
52 /* Error checking */
53 if (scale > num->n_scale)
54 scale = num->n_scale;
55
56 /* Initialize */
57 count = num->n_len + scale;
58 nptr = num->n_value;
59
60 /* The check */
61 while ((count > 0) && (*nptr++ == 0)) count--;
62
63 if (count != 0 && (count != 1 || *--nptr != 1))
64 return FALSE;
65 else
66 return TRUE;
67 }
68
