'endptr' is appropriate internally in strtol(3) because it's a pointer
to 'end', and 'end' itself is a pointer to one-after-the-last character
of the numeric string. In other words,
endptr == &end
However, naming the pointer whose address we pass to strtol(3)'s
'endptr' feels wrong, and causes me trouble while parsing the code; I
need to double check the number of dereferences, because something feels
wrong in my head.
Signed-off-by: Alejandro Colomar <alx@kernel.org>
strtou[l]l(3) silently converts negative numbers into positive. This
behavior is wrong: a negative value should be parsed as a negative
value, which would underflow unsigned (long) long, and so would return
the smallest possible value, 0, and set errno to ERANGE to report an
error.
Reviewed-by: Iker Pedrosa <ipedrosa@redhat.com>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
- 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>
