Line data    Source code

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