/* xstrtod.c - error-checking interface to strtod
Copyright (C) 1996 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 2, 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, write to the Free Software Foundation,
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
/* Written by Jim Meyering. */
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#ifdef STDC_HEADERS
# include <stdlib.h>
#else
double strtod ();
#endif
#include <errno.h>
#include <stdio.h>
#include <limits.h>
#include "xstrtod.h"
/* An interface to strtod that encapsulates all the error checking
one should usually perform. Like strtod, but upon successful
conversion put the result in *RESULT and return zero. Return
non-zero and don't modify *RESULT upon any failure. */
int
xstrtod (str, ptr, result)
const char *str;
const char **ptr;
double *result;
{
double val;
char *terminator;
int fail;
fail = 0;
errno = 0;
val = strtod (str, &terminator);
/* Having a non-zero terminator is an error only when PTR is NULL. */
if (terminator == str || (ptr == NULL && *terminator != '\0'))
fail = 1;
else
{
/* Allow underflow (in which case strtod returns zero),
but flag overflow as an error. */
if (val != 0.0 && errno == ERANGE)
fail = 1;
}
if (ptr != NULL)
*ptr = terminator;
*result = val;
return fail;
}
