chip@ateng.ateng.com (Chip Salzenberg) (11/13/88)
WARNING -- NULL ALERT.
If you understand NULL pointers, skip this article.
According to crossgl@ingr.UUCP (Gordon Cross):
> Wouldn't it be much nicer to be able to call the
> function with the single line
>
> yourfunction ("arg1", "arg2", ... , 0);
Correct ways to code this function call would be:
yourfunction ("arg1", "arg2", ... , (char *) 0);
or
yourfunction ("arg1", "arg2", ... , (char *) NULL);
The reason? Neither uncasted 0 nor uncasted NULL [1] is acceptable as an
actual function parameter of any pointer type. (Except in the presence
of a function prototype, of course; but this is a variadic function
we're discussing, so prototypes are almost irrelevant.)
[1] According to K&R and the dpANS, "#define NULL 0" is permitted.
--
Chip Salzenberg <chip@ateng.com> or <uunet!ateng!chip>
A T Engineering Me? Speak for my company? Surely you jest!
Beware of programmers carrying screwdrivers.