Le jeudi 25 mars 2010 à 14:35 +0800, Liu Aleaxander a écrit :
> On Thu, Mar 25, 2010 at 2:19 PM, Américo Wang <xiyou.wangcong@xxxxxxxxx> wrote:
> > On Thu, Mar 25, 2010 at 2:16 PM, Liu Aleaxander <aleaxander@xxxxxxxxx> wrote:
> >> On Thu, Mar 25, 2010 at 1:50 PM, Américo Wang <xiyou.wangcong@xxxxxxxxx> wrote:
> [ snip ]
> >>
> >> If so, I don't think so this can handle the case like the following one:
> >> /sbin/losetup -o 0x7e00fdjfkk /dev/loop0 disk.img
> >
> > Why not refer man pages? Everything is clear:
> >
> > If endptr is not NULL, strtoul() stores the address of the first
> > invalid character in *endptr. If there were no digits at all, str-
> > toul() stores the original value of nptr in *endptr (and returns 0).
> > In particular, if *nptr is not '\0' but **endptr is '\0' on return, the
> > entire string is valid.
>
> Hi,
> Am I miss something, or misunderstood something?
>
> In fact, I did just by what the man page said:
> In particular, if *nptr is not '\0' but **endptr is '\0' on return, the
> entire string is valid.
>
Here is an example of code which handle invalid data and overflow:
static int
convert_ullong(const char *s, unsigned long long *value)
{
unsigned long long result;
char *endptr = NULL;
if (s == NULL || *s == '\0') {
return -1;
}
errno = 0;
result = strtoull(s, &endptr, 0);
if (s == endptr ||
(endptr != NULL && *endptr != '\0') ||
((result == 0 || result == ULLONG_MAX) && errno != 0)) {
return -1;
}
if (value != NULL) {
*value = result;
}
return 0;
}
Regards
--
Yann Droneaud
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