effect of free()

[Doug Gwyn]

In article <10828 at riks.csl.sony.co.jp> diamond at ws.sony.junet (Norman Diamond) writes:
>Scott-Engineering's posting implies these questions (among others):
>(1) if a pointer variable contains a NULL value, then may that pointer
>     be compared to a NULL constant?
>(2) if a pointer variable contains a NULL value, then may that pointer
>     be compared to a valid pointer value?

No, it doesn't.  If you were following this thread, it should have been
clear that we were discussing invalid pointers that were "poison" to
inspect.  Null pointers are something entirely different, and of course
the Standard allows you to do the obvious things with null pointers.