| 1 | /* error-checking interface to strtod-like functions
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| 2 |
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| 3 | Copyright (C) 1996, 1999, 2000, 2003, 2004, 2005, 2006 Free
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| 4 | Software Foundation, Inc.
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| 5 |
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| 6 | This program is free software; you can redistribute it and/or modify
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| 7 | it under the terms of the GNU General Public License as published by
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| 8 | the Free Software Foundation; either version 2, or (at your option)
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| 9 | any later version.
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| 10 |
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| 11 | This program is distributed in the hope that it will be useful,
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| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 14 | GNU General Public License for more details.
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| 15 |
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| 16 | You should have received a copy of the GNU General Public License
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| 17 | along with this program; if not, write to the Free Software Foundation,
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| 18 | Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
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| 19 |
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| 20 | /* Written by Jim Meyering. */
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| 21 |
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| 22 | #include <config.h>
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| 23 |
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| 24 | #include "xstrtod.h"
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| 25 |
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| 26 | #include <errno.h>
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| 27 | #include <limits.h>
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| 28 | #include <stdio.h>
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| 29 |
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| 30 | #if LONG
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| 31 | # define XSTRTOD xstrtold
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| 32 | # define DOUBLE long double
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| 33 | #else
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| 34 | # define XSTRTOD xstrtod
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| 35 | # define DOUBLE double
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| 36 | #endif
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| 37 |
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| 38 | /* An interface to a string-to-floating-point conversion function that
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| 39 | encapsulates all the error checking one should usually perform.
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| 40 | Like strtod/strtold, but upon successful
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| 41 | conversion put the result in *RESULT and return true. Return
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| 42 | false and don't modify *RESULT upon any failure. CONVERT
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| 43 | specifies the conversion function, e.g., strtod itself. */
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| 44 |
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| 45 | bool
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| 46 | XSTRTOD (char const *str, char const **ptr, DOUBLE *result,
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| 47 | DOUBLE (*convert) (char const *, char **))
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| 48 | {
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| 49 | DOUBLE val;
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| 50 | char *terminator;
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| 51 | bool ok = true;
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| 52 |
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| 53 | errno = 0;
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| 54 | val = convert (str, &terminator);
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| 55 |
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| 56 | /* Having a non-zero terminator is an error only when PTR is NULL. */
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| 57 | if (terminator == str || (ptr == NULL && *terminator != '\0'))
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| 58 | ok = false;
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| 59 | else
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| 60 | {
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| 61 | /* Allow underflow (in which case CONVERT returns zero),
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| 62 | but flag overflow as an error. */
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| 63 | if (val != 0 && errno == ERANGE)
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| 64 | ok = false;
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| 65 | }
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| 66 |
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| 67 | if (ptr != NULL)
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| 68 | *ptr = terminator;
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| 69 |
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| 70 | *result = val;
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| 71 | return ok;
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| 72 | }
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