- Set errno = 0 before the call. Otherwise, it may contain anything.
- ERANGE is not the only possible errno value of these functions. They
can also set it to EINVAL.
- Any errno value after these calls is bad; just compare against 0.
- Don't check for the return value; just errno. This function is
guaranteed to not modify errno on success (POSIX).
- Check endptr == str, which may or may not set EINVAL.
Suggested-by: Iker Pedrosa <ipedrosa@redhat.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
asprintf(3) is non-standard, but is provided by GNU, the BSDs, and musl.
That makes it portable enough for us to use.
This function is much simpler than the burdensome code for allocating
the right size. Being simpler, it's thus safer.
I took the opportunity to fix the style to my preferred one in the
definitions of variables used in these calls, and also in the calls to
free(3) with these pointers. That isn't gratuituous, but has a reason:
it makes those appear in the diff for this patch, which helps review it.
Oh, well, I had an excuse :)
Reviewed-by: Iker Pedrosa <ipedrosa@redhat.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
