On Fri, 10 Mar 2017 16:24:32 +0000
"Legacy, Allain" <allain.leg...@windriver.com> wrote:
> The robustness of the strtoul() could be improved with something like the
> following to catch non-integer characters following the port number.
>
> char *end = NULL;
> tmp = strtoull(val, &end, 0);
> if ((val[0] == '\0') || (end == NULL) || (*end != '\0') || (errno != 0))
Extra () no necessary here.
Also errno is not set unless the return value is ULLONG_MAX. It will be last
value.
Something like:
tmp = strtoull(val, &end, 0);
if (!*val || !*end || (tmp == ULLONG_MAX && errno))
...
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.
...
RETURN VALUE
The strtoul() function returns either the result of the conversion or,
if there was a leading minus sign, the negation of the result of the
conversion represented as an unsigned value, unless the original (non‐
negated) value would overflow; in the latter case, strtoul() returns
ULONG_MAX and sets errno to ERANGE. Precisely the same holds for str‐
toull() (with ULLONG_MAX instead of ULONG_MAX).
