Question

I need to define a struct, let’s say

//globalstruct.h
typedef struct _GlobalStruct {
    int a, b;
} GlobalStruct

and then use GlobalStruct wherever I want just by including globalstruct.h

For example:

//test.c
#include globalstruct.h
void test(GlobalStruct *gs){...}

How can I do this?

Regards

—-EDIT—-

I think I need to clarify a little bit more my question as I’m completely stuck.

//main.c
#include "gstruct.h"
#include "a.h"
#include "b.h"

...
void something(GlobalStruct *gs){...}

.

//gstruct.h
#ifdef gstruct_h
#define gstruct_h
typedef struct _GlobalStruct{
    int a, b;
} GlobalStruct;
#endif

.

//a.h
#ifdef a_h
#define a_h
#include "gstruct.h"
GlobalStruct a_something(...);
#endif

.

//a.c
#include "gstruct.h"
#include "a.h"
GlobalStruct a_something(...){...}

.

//b.h
#ifdef b_h
#define b_h
#include "gstruct.h"
GlobalStruct b_something(...);
#endif

.

//b.c
#include "gstruct.h"
#include "b.h"
GlobalStruct b_something(...){...}

.

Is this ok? Because if it is I’m missing something really silly/small/stupid.

BTW, I’m compiling with gcc main.c a.c b.c -o the_thing

—SECOND EDIT—-

I just created an online example so you can see it, download it and try it.
It’s ready-to-compile but it will fail at compilation time.

https://compilr.com/alexandernst/c-headers

Answer 1

In the header files, #ifdef should be #ifndef