* Jonny Grant <jg@xxxxxxxx>, 2018-11-11, 14:26:
BTW, C Spec says NULL is a pointer that doesn't have a type,
Not quite. NULL is a “null pointer constant”, which could be an integer, not necessarily a pointer.
That said, the POSIX.1-2008 standard guarantees it's a pointer. (AFAICT, the earlier standards did not guarantee this.)
On the other hand, NULL is not defined as a pointer in C++.
there is no need to cast it to (char *) -- should that be taken out?
The execl*() functions are variadic, which makes them picky about argument types. Theses casts are certainly needed when NULL is not defined as a pointer.
It's less clear to me if they are still necessary when NULL is defined as (void*)0.
Either way, I recommend keeping the cast for the sake of portability. -- Jakub Wilk
