81 lines
2.3 KiB
C
81 lines
2.3 KiB
C
/* 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;
|
|
}
|