Using original pointer after realloc?

Question

I was reading Richard Reese\'s new (May 2013) O\'Reilly book \"Understanding and Using C Pointers\", and I have a question about some code therein, on page 87.

Answer 1

It is safe to use the dangling pointer (e.g. for "pointer arithmetic") as long as you don't try to dereference the pointer (i.e. apply the operator *).