How to use a static C variable across multiple files?

Question

I have two C files 1.c and 2.c

2.c

#include<stdio.h>

static int i;

int func1(){
   i = 5;
   printf("\nfile2 : %d\n",i);
   return 0;
}

1.c

#include<stdio.h>

int i;

int main()
{
   func1();
   printf("\nFile1: %d\n",i);
   return 0;
}

I compiled both the files with "gcc 1.c 2.c -o st" The output is as follows

file2 : 5

File2: 0

I was expecting output as follows

file2 : 5

File2: 5

I want to access the same variable "i" in both the files. How can I do it?

Answer 1

Choose one file which will store the variable. Do not use static. The whole point of static is to keep the variable private and untouchable by other modules.

In all other files, use the extern keyword to reference the variable:

extern int i;