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241d0215 RN |
1 | // |
2 | // strtod.c | |
3 | // | |
4 | // Convert string to double | |
5 | // | |
6 | // Copyright (C) 2002 Michael Ringgaard. All rights reserved. | |
7 | // | |
8 | // Redistribution and use in source and binary forms, with or without | |
9 | // modification, are permitted provided that the following conditions | |
10 | // are met: | |
11 | // | |
12 | // 1. Redistributions of source code must retain the above copyright | |
13 | // notice, this list of conditions and the following disclaimer. | |
14 | // 2. Redistributions in binary form must reproduce the above copyright | |
15 | // notice, this list of conditions and the following disclaimer in the | |
16 | // documentation and/or other materials provided with the distribution. | |
17 | // 3. Neither the name of the project nor the names of its contributors | |
18 | // may be used to endorse or promote products derived from this software | |
19 | // without specific prior written permission. | |
20 | // | |
21 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND | |
22 | // ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
23 | // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
24 | // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE | |
25 | // FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
26 | // DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
27 | // OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
28 | // HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
29 | // LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
30 | // OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
31 | // SUCH DAMAGE. | |
32 | // | |
33 | ||
81687a73 RN |
34 | // Tweaked version for Viking project to read in values containing ',' or '.' as the decimal separator |
35 | // Modified functions to prevent clashing with the system ones | |
36 | ||
241d0215 RN |
37 | #include <errno.h> |
38 | #include <ctype.h> | |
39 | #include <math.h> | |
40 | #include <float.h> | |
41 | #include <stdlib.h> | |
42 | ||
81687a73 | 43 | double strtod_i8n(const char *str, char **endptr) { |
241d0215 RN |
44 | double number; |
45 | int exponent; | |
46 | int negative; | |
47 | char *p = (char *) str; | |
48 | double p10; | |
49 | int n; | |
50 | int num_digits; | |
51 | int num_decimals; | |
52 | ||
53 | // Skip leading whitespace | |
54 | while (isspace(*p)) p++; | |
55 | ||
56 | // Handle optional sign | |
57 | negative = 0; | |
58 | switch (*p) { | |
59 | case '-': negative = 1; // Fall through to increment position | |
60 | case '+': p++; | |
61 | } | |
62 | ||
63 | number = 0.; | |
64 | exponent = 0; | |
65 | num_digits = 0; | |
66 | num_decimals = 0; | |
67 | ||
68 | // Process string of digits | |
69 | while (isdigit(*p)) { | |
70 | number = number * 10. + (*p - '0'); | |
71 | p++; | |
72 | num_digits++; | |
73 | } | |
74 | ||
75 | // Process decimal part | |
81687a73 | 76 | if (*p == '.' || *p == ',') { |
241d0215 RN |
77 | p++; |
78 | ||
79 | while (isdigit(*p)) { | |
80 | number = number * 10. + (*p - '0'); | |
81 | p++; | |
82 | num_digits++; | |
83 | num_decimals++; | |
84 | } | |
85 | ||
86 | exponent -= num_decimals; | |
87 | } | |
88 | ||
89 | if (num_digits == 0) { | |
90 | errno = ERANGE; | |
91 | return 0.0; | |
92 | } | |
93 | ||
94 | // Correct for sign | |
95 | if (negative) number = -number; | |
96 | ||
97 | // Process an exponent string | |
98 | if (*p == 'e' || *p == 'E') { | |
99 | // Handle optional sign | |
100 | negative = 0; | |
101 | switch (*++p) { | |
102 | case '-': negative = 1; // Fall through to increment pos | |
103 | case '+': p++; | |
104 | } | |
105 | ||
106 | // Process string of digits | |
107 | n = 0; | |
108 | while (isdigit(*p)) { | |
109 | n = n * 10 + (*p - '0'); | |
110 | p++; | |
111 | } | |
112 | ||
113 | if (negative) { | |
114 | exponent -= n; | |
115 | } else { | |
116 | exponent += n; | |
117 | } | |
118 | } | |
119 | ||
120 | if (exponent < DBL_MIN_EXP || exponent > DBL_MAX_EXP) { | |
121 | errno = ERANGE; | |
122 | return HUGE_VAL; | |
123 | } | |
124 | ||
125 | // Scale the result | |
126 | p10 = 10.; | |
127 | n = exponent; | |
128 | if (n < 0) n = -n; | |
129 | while (n) { | |
130 | if (n & 1) { | |
131 | if (exponent < 0) { | |
132 | number /= p10; | |
133 | } else { | |
134 | number *= p10; | |
135 | } | |
136 | } | |
137 | n >>= 1; | |
138 | p10 *= p10; | |
139 | } | |
140 | ||
141 | if (number == HUGE_VAL) errno = ERANGE; | |
142 | if (endptr) *endptr = p; | |
143 | ||
144 | return number; | |
145 | } | |
146 | ||
81687a73 RN |
147 | float strtof_i8n(const char *str, char **endptr) { |
148 | return (float) strtod_i8n(str, endptr); | |
241d0215 RN |
149 | } |
150 | ||
151 | ||
81687a73 RN |
152 | long double strtold_i8n(const char *str, char **endptr) { |
153 | return strtod_i8n(str, endptr); | |
241d0215 RN |
154 | } |
155 | ||
81687a73 RN |
156 | double atof_i8n(const char *str) { |
157 | return strtod_i8n(str, NULL); | |
241d0215 | 158 | } |