[GRASS-dev] Re: r.mapcal rand() strangeness

[Ivan Shmakov]

>>>>> Maciej Sieczka <tutey at o2.pl> writes:

[...]

 >> I could change it to use strtol(), which sets errno to ERANGE on
 >> overflow.

	It may be better to check `*tailptr', like:

int
p_arg_long (const char *s, long *vp)
{
  char *t;
  long v;

  if ((v = strtol (s, &t, 0)),
      t == s || *t != '\0') {
    /* . */
    return -1;
  }
  if (vp != 0) *vp = v;

  /* . */
  return 0;
}

...

   if (p_arg_long (str, &val) != 0) {
     /* not a long integer */
   }

	Though `errno' may be used for finer diagnostics.

 > Would that make r.mapcalc accept integers bigger than int32?

	The sizes of the C types generally depend on the platform, but
	for x86-based platforms I'm familiar with, sizeof (long) is 32.

	It may make sense to use `long long' and strtoll () where
	available.

[...]