Re: Nulls get converted to 0 problem

Поиск
Список
Период
Сортировка
От kdebisschop@alert.infoplease.com
Тема Re: Nulls get converted to 0 problem
Дата
Msg-id 1054918235.31564.1.camel@miles.debisschop.net
обсуждение исходный текст
Ответ на Re: Nulls get converted to 0 problem  (Samuel Tardieu <sam@rfc1149.net>)
Список pgsql-general
On Fri, 2003-06-06 at 11:31, Samuel Tardieu wrote:
> >>>>> "kdebisschop" == kdebisschop  <kdebisschop@alert.infoplease.com> writes:
>
> kdebisschop>   if (str == "")
> kdebisschop>     printf ("This comparison above can segfault on some
> kdebisschop>     systems\n");
>
> No, it can't. You are comparing pointers (str and a pointer to a NULL
> string). This is exactly the same as comparing integers. If any
> compiler generates code which does a segmentation fault, it is far
> from being (even remotely) a C compiler (and I'm not being pedantic
> here).
>
> If you meant strcmp(str, "") that's a completely different story.

I think you're right -- I was merely trying to illustrate that NULL and
"" are not the same in C. My example should probably have been labelled
as being more akin to psuedocode

Thanks for the clarification.


--
Karl DeBisschop <kdebisschop@alert.infoplease.com>


В списке pgsql-general по дате отправления:

Предыдущее
От: Bruno Wolff III
Дата:
Сообщение: Re: Select from multiple tables
Следующее
От: Jamie Lawrence
Дата:
Сообщение: Re: Postmaster only takes 4-5% CPU