This. In the case of AIX, IBM designed every component of the platform: the CPU, the operating system and the compiler. When they tell you that it’s safe to rea

This. In the case of AIX, IBM designed every component of the platform: the CPU, the operating system and the compiler. When they tell you that it’s safe to read up to 4K (or whatever) of zero bytes from NULL, they can make that promise. But obviously such code is not portable.