Include variables in seperate file in C? - c

Question

I created a structure item:
typedef struct item
{
char name[20];
char desc[100];
int lp;
int shield;
int weapon;
} item;
I need 36 of them so I create an array item treasure[6][6];
For each item I insert the data as so:
strcpy(treasure[0][0].name, "name");
strcpy(treasure[0][0].desc, "none");
treasure[0][0].lp = 0;
treasure[0][0].shield = 0;
treasure[0][0].weapon = 200;
I do this 36 times and takes a lot of space in editor, my question: Can I put this in a separate .c/.h file maybe? I've been trying to but can't make it work.
Thanks for any help!

Answer 1

I suggest that use a file, like init.h with the following content
#include <string.h>
typedef struct item {
char name[20];
char desc[100];
int lp;
int shield;
int weapon;
} item;
item treasure[1][1] = {
{{.name = "name", .desc = "none", .lp = 0, .shield = 0, .weapon = 200}}};
In that way you must be able to initialize the struct of you matrix 6, 6 in another file, then you must be able to access it from the main program calling it like this:
#include "init.h"
#include <stdio.h>
int main() {
printf("%s\n", treasure[0][0].name);
return 0;
}
I hope this work for you, there a another ways to initialize structs, but this one is what I use more often. You can find more information here
https://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html

Answer 2

If you want to learn how to do proper C program design from the start, then this is how.
The correct way to do this is to create an item.h and a item.c file. Together they form a "code module" (or class, if you will).
Your header file item.h should contain the typedef and header guards. You should write an initialization function too.
// item.h
#ifndef ITEM_H
#define ITEM_H
#include <string.h>
typedef struct {
char name[20];
char desc[100];
int lp;
int shield;
int weapon;
} item_t;
void item_init (item_t* item,
const char name[20],
const char desc[100],
int lp,
int shield,
int weapon);
#endif
You can then implement the init function in init.c:
// item.c
#include "item.h"
void item_init (item_t* item,
const char name[20],
const char desc[100],
int lp,
int shield,
int weapon)
{
strcpy(item->name, name);
strcpy(item->desc, desc);
item->lp = lp;
item->shield = shield;
item->weapon = weapon;
}
These two files, init.h and init.c are only concerned about the behavior of all item_t variables. You can expand them with more functions as you go. They do not and should not contain any actual data.
Now if you want to keep the data separate, you could create a separate pair of files for it like this:
// item_data.h
#include "item.h"
#define ITEMS_N 36
item_t* item_data_get (int item_n);
This is just a "getter" function that lets you access the data. The actual data is encapsulated in the .c file:
// item_data.c
#include "item_data.h"
static item_t items [ITEM_N] =
{
[0] = {.name="name", .desc="none", .lp=0, .shield=0, .weapon=200},
[1] = ... // fill up data here
};
item_t* item_data_get (int item_n)
{
return items[n];
}
If you later on want to change the data of a given item, you can do so by calling item_init(item_data_get(n), ...);