1 /* str2num.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 /* Convert strings to bc numbers. Base 10 only.*/
41
42 int
bc_str2num(bc_num * num,char * str,int scale)43 bc_str2num (bc_num *num, char *str, int scale)
44 {
45 int digits, strscale;
46 char *ptr, *nptr;
47 char zero_int;
48
49 /* Prepare num. */
50 bc_free_num (num);
51
52 /* Check for valid number and count digits. */
53 ptr = str;
54 digits = 0;
55 strscale = 0;
56 zero_int = FALSE;
57 if ( (*ptr == '+') || (*ptr == '-')) ptr++; /* Sign */
58 while (*ptr == '0') ptr++; /* Skip leading zeros. */
59 while (*ptr >= '0' && *ptr <= '9') ptr++, digits++; /* digits */
60 if (*ptr == '.') ptr++; /* decimal point */
61 while (*ptr >= '0' && *ptr <= '9') ptr++, strscale++; /* digits */
62 if ((*ptr != '\0') || (digits+strscale == 0))
63 {
64 *num = bc_copy_num (BCG(_zero_));
65 return *ptr == '\0';
66 }
67
68 /* Adjust numbers and allocate storage and initialize fields. */
69 strscale = MIN(strscale, scale);
70 if (digits == 0)
71 {
72 zero_int = TRUE;
73 digits = 1;
74 }
75 *num = bc_new_num (digits, strscale);
76
77 /* Build the whole number. */
78 ptr = str;
79 if (*ptr == '-')
80 {
81 (*num)->n_sign = MINUS;
82 ptr++;
83 }
84 else
85 {
86 (*num)->n_sign = PLUS;
87 if (*ptr == '+') ptr++;
88 }
89 while (*ptr == '0') ptr++; /* Skip leading zeros. */
90 nptr = (*num)->n_value;
91 if (zero_int)
92 {
93 *nptr++ = 0;
94 digits = 0;
95 }
96 for (;digits > 0; digits--)
97 *nptr++ = CH_VAL(*ptr++);
98
99
100 /* Build the fractional part. */
101 if (strscale > 0)
102 {
103 ptr++; /* skip the decimal point! */
104 for (;strscale > 0; strscale--)
105 *nptr++ = CH_VAL(*ptr++);
106 }
107
108 if (bc_is_zero (*num))
109 (*num)->n_sign = PLUS;
110
111 return 1;
112 }
113
