do not BSD in some test apps I have. it did not check if input buffer for the convert...
[reactos.git] / reactos / lib / crt / stdlib / strtod.c
1 /* Copyright (C) 1996 DJ Delorie, see COPYING.DJ for details */
2 /* Copyright (C) 1994 DJ Delorie, see COPYING.DJ for details */
3
4 #include <precomp.h>
5
6 /*
7 * @implemented
8 */
9 double
10 strtod(const char *s, char **sret)
11 {
12 long double r; /* result */
13 int e; /* exponent */
14 long double d; /* scale */
15 int sign; /* +- 1.0 */
16 int esign;
17 int i;
18 int flags=0;
19
20 r = 0.0;
21 sign = 1;
22 e = 0;
23 esign = 1;
24
25 if (s == NULL)
26 return r;
27
28
29 while ((*s == ' ') || (*s == '\t'))
30 s++;
31
32 if (*s == '+')
33 s++;
34 else if (*s == '-')
35 {
36 sign = -1;
37 s++;
38 }
39
40 while ((*s >= '0') && (*s <= '9'))
41 {
42 flags |= 1;
43 r *= 10.0;
44 r += *s - '0';
45 s++;
46 }
47
48 if (*s == '.')
49 {
50 d = 0.1L;
51 s++;
52 while ((*s >= '0') && (*s <= '9'))
53 {
54 flags |= 2;
55 r += d * (*s - '0');
56 s++;
57 d *= 0.1L;
58 }
59 }
60
61 if (flags == 0)
62 {
63 if (sret)
64 *sret = (char *)s;
65 return 0;
66 }
67
68 if ((*s == 'e') || (*s == 'E'))
69 {
70 s++;
71 if (*s == '+')
72 s++;
73 else if (*s == '-')
74 {
75 s++;
76 esign = -1;
77 }
78 if ((*s < '0') || (*s > '9'))
79 {
80 if (sret)
81 *sret = (char *)s;
82 return r;
83 }
84
85 while ((*s >= '0') && (*s <= '9'))
86 {
87 e *= 10;
88 e += *s - '0';
89 s++;
90 }
91 }
92
93 if (esign < 0)
94 for (i = 1; i <= e; i++)
95 r *= 0.1L;
96 else
97 for (i = 1; i <= e; i++)
98 r *= 10.0;
99
100 if (sret)
101 *sret = (char *)s;
102 return r * sign;
103 }