From: Claudio Jeker <cjeker@...>
Date: 2006-02-09T09:41:55+09:00
Subject: Re: boolean annoyance

On Thu, Feb 09, 2006 at 09:15:54AM +0900, Austin Ziegler wrote:
> On 08/02/06, Claudio Jeker <cjeker@diehard.n-r-g.com> wrote:
> >> It's actually the most illogic part of languages like C that treat 0
> >> as false.  Believe me, having spent most of my programming life using
> >> C/C++ and being used to that, I make mistakes regularly whilst writing
> >> Ruby code.
> >>
> >> 0 is an integer and quite often a valid value. C's treatment of 0 as
> >> false is convenient in some situations but horribly inconvenient in
> >> others.  Because if I'm expecting an integer and zero is a legal
> >> value, then you have to start playing around in your conditionals...
> >> "Okay, today any -1 is false"...  or even at different levels than
> >> that.  Part of the problem is that C doesn't have an actual NULL...
> >> NULL is just defined as zero.  Overlap, explosions, crash and burn...
> > If you are inspecting a integer against nothing end everything is just
> > legal, why are you inspecting it?
> 
> Sorry, but that doesn't work. If you have something that returns an
> integer value -- consider strtol(3). This can return *any* valid integer
> value, but if you get a 0, LONG_MAX, or LONG_MIN, you have to *then*
> check errno to see if the conversion was, in fact, successful. (And the
> conversion could be unsuccessful for any number of reasons.)

This is not correct. strtol(3) does not return 0 in case of an error. It
sets errno to ERANGE and returns LONG_MAX or LONG_MIN.

-- 
:wq Claudio