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66 lines
1.9 KiB
C
66 lines
1.9 KiB
C
/* error-checking interface to strtod-like functions
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Copyright (C) 1996, 1999, 2000, 2003, 2004, 2005 Free Software
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Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software Foundation,
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Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
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/* Written by Jim Meyering. */
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include "xstrtod.h"
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#include <errno.h>
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#include <limits.h>
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#include <stdio.h>
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/* An interface to strtod that encapsulates all the error checking
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one should usually perform. Like strtod, but upon successful
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conversion put the result in *RESULT and return true. Return
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false and don't modify *RESULT upon any failure. CONVERT
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specifies the conversion function, e.g., strtod itself. */
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bool
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xstrtod (char const *str, char const **ptr, double *result,
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double (*convert) (char const *, char **))
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{
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double val;
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char *terminator;
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bool ok = true;
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errno = 0;
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val = convert (str, &terminator);
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/* Having a non-zero terminator is an error only when PTR is NULL. */
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if (terminator == str || (ptr == NULL && *terminator != '\0'))
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ok = false;
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else
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{
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/* Allow underflow (in which case strtod returns zero),
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but flag overflow as an error. */
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if (val != 0.0 && errno == ERANGE)
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ok = false;
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}
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if (ptr != NULL)
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*ptr = terminator;
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*result = val;
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return ok;
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}
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