Pointers inside Struct

Question

I have this code:

typedef struct s1{ void *x; } s1; typedef struct s2{ unsigned char y[5]; } s2; s1 *s1_g; s2 *s2_g;

What I wanted to do is to point pointer x to variable y.

I tried doing this:

s1_g->x = s2_g->y

but receives a segmentation error

Anyone can please enlighten me?

Jim Buck · Accepted Answer · 2013-12-08 04:29:49Z

If that's all of the code, then you haven't even initialized s1_g and s2_g. So dereferencing them will no doubt cause a segmentation error.

doptimusprime · Accepted Answer · 2013-12-08 04:30:45Z

There should be a valid object at the pointer location. Since, there is no valid object at s1_g, behaviour is undefined on dereferencing them.

2 Answers 2