1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
|
/* error-checking interface to strtod-like functions
Copyright (C) 1996, 1999-2000, 2003-2006, 2009-2025 Free Software
Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>. */
/* Written by Jim Meyering. */
#include <config.h>
#include "xstrtod.h"
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#if LONG
# define XSTRTOD xstrtold
# define DOUBLE long double
#else
# define XSTRTOD xstrtod
# define DOUBLE double
#endif
/* An interface to a string-to-floating-point conversion function that
encapsulates all the error checking one should usually perform.
Like strtod/strtold, but stores the conversion in *RESULT,
and returns true upon successful conversion.
CONVERT specifies the conversion function, e.g., strtod itself. */
bool
XSTRTOD (char const *str, char const **ptr, DOUBLE *result,
DOUBLE (*convert) (char const *, char **))
{
DOUBLE val;
char *terminator;
bool ok = true;
errno = 0;
val = convert (str, &terminator);
/* Having a non-zero terminator is an error only when PTR is NULL. */
if (terminator == str || (ptr == NULL && *terminator != '\0'))
ok = false;
else
{
/* Flag overflow as an error.
Flag gradual underflow as no error.
Flag flush-to-zero underflow as no error.
In either case, the caller can inspect *RESULT to get more details. */
if (val != 0 && errno == ERANGE)
{
if (val >= 1 || val <= -1)
/* Overflow. */
ok = false;
else
/* Gradual underflow. */
errno = 0;
}
}
if (ptr != NULL)
*ptr = terminator;
/* Callers rely on *RESULT even when !ok. */
*result = val;
return ok;
}
|
