Making a deep copy of a struct…making a shallow copy of a struct

Question

There are questions LIKE this one, but they are not similar enough to my specific question FOR ME to pick up on.

My question is about how to make a deep copy of a struct

Answer 1

Instead of this:

newStudentp -> last_name = (malloc((strlen(last_name) + 1)  * sizeof(char)));

do:

newStudentp -> last_name = strdup (last_name);

Your deep copy wants to do something similar (not exactly what cnicutar suggested):

s2->first_name = strdup (s1->first_name);

The problem with cnicutar's suggestion is that it needs to manually allocate the buffer before the strcpy.

And if I remember correctly:

*s2 = *s1;

will do a shallow copy.

Of course, in both the deep and shallow copies you must make sure that you free the destination pointers, otherwise you'll get a memory leak. But even freeing the pointers can lead to problems if you deep copy to a structure that was previously shallow copied to.