gnu/usr.bin/sort/xstrtod.c

   1 #ifdef HAVE_CONFIG_H
   2 #include <config.h>
   3 #endif
   4
   5 #ifdef STDC_HEADERS
   6 #include <stdlib.h>
   7 #else
   8 double strtod ();
   9 #endif
  10
  11 #include <errno.h>
  12 #include <stdio.h>
  13 #include <limits.h>
  14 #include <ctype.h>
  15 #include "xstrtod.h"
  16
  17 int
  18 xstrtod (str, ptr, result)
  19      const char *str;
  20      const char **ptr;
  21      double *result;
  22 {
  23   double val;
  24   char *terminator;
  25   int fail;
  26
  27   fail = 0;
  28   errno = 0;
  29   val = strtod (str, &terminator);
  30
  31   /* Having a non-zero terminator is an error only when PTR is NULL. */
  32   if (terminator == str || (ptr == NULL && *terminator != '\0'))
  33     fail = 1;
  34   else
  35     {
  36       /* Allow underflow (in which case strtod returns zero),
  37          but flag overflow as an error. */
  38       if (val != 0.0 && errno == ERANGE)
  39         fail = 1;
  40     }
  41
  42   if (ptr != NULL)
  43     *ptr = terminator;
  44
  45   *result = val;
  46   return fail;
  47 }
  48