Re: Style Question

From: Bernd Petrovitsch
Date: Sun Mar 11 2007 - 10:23:01 EST


On Sun, 2007-03-11 at 22:15 +0800, Cong WANG wrote:
[...]
> Another question is about NULL. AFAIK, in user space, using NULL is
> better than directly using 0 in C. In kernel, I know it used its own
> NULL, which may be defined as ((void*)0),

Userspace has the usually same definition.

> but it's _still_ different
> from raw zero.

It is different that "0" as such has the type "int". But this int is
automatically promoted to a "0 pointer".

> So can I say using NULL is better than 0 in kernel?

Yes, because it is immediately clear that a pointer is (or should be)
there (and not an int).
And the same holds for userspace since this is a pure C question.

Bernd
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