memcpy, memmove with NULL pointers?

[Jef Driesen]

Hi,

Is it safe to pass a NULL pointer to the memcpy, memmove functions (and
other similar ones) if the size parameter is zero?

memcpy (dest, NULL, 0);

Or is that implementation defined and do I explicitly have to check for
this condition?

Thanks,

Jef

 

[Erik Trulsson]

Hi,

Is it safe to pass a NULL pointer to the memcpy, memmove functions (and
other similar ones) if the size parameter is zero?

memcpy (dest, NULL, 0);

No, it is not safe. You need to pass valid pointers even if the size is zero.

Or is that implementation defined and do I explicitly have to check for
this condition?

It is not even implementation defined - it is undefined behaviour.