I am trying to implement a code using 'extern' keyword, IDE: VS Code (using code runner...)

Question

extrn.c

#include <stdio.h>

extern int var;

int main()
{
    printf("%d", var);
    return 0;
}

var.c

int var = 5;

I go to file extrn.c and I run the code and I get this:

undefined reference to `var'

and this is what my output is looking like:

How exactly are you trying to build those two files into an executable? Which commandline do you try? Makefile? Ide config? — Yunnosch, May 21 '22 at 09:09
@Yunnosch Its a bit clear ```I go to 1st file and I run the code and I get this:``` — Darth-CodeX, May 21 '22 at 09:10
@Yunnosch According to me OP is new, he was using VSCODE with code runner extension, which only compiled the `extrn.c` file. — Darth-CodeX, May 21 '22 at 09:13
@Darth-CodeX According to me your guesses are 1/3 probable 2/3 daring. I prefer to not assume for an answer. — Yunnosch, May 21 '22 at 09:15
ok, so I AM using vs code and code runner... rest I've pasted the whole output window there... — Shrayansh, May 23 '22 at 19:44

score 1 · Accepted Answer · answered May 21 '22 at 09:04

1

Compile your both C files together to fix this undefined reference error.

gcc extrn.c var.c -o main

clang extrn.c var.c -o main

answered May 21 '22 at 09:04

Darth-CodeX

not working... ... – Shrayansh May 23 '22 at 19:53
@Shrayansh You are just running `gcc extrn.c -o extrn` run instead `gcc extrn.c var.c -o main`. ***Accept my answer if it worked*** – Darth-CodeX May 24 '22 at 05:27
buff@d605:/media/buff/92AA5210AA51F0E9/Documents/Coding/C/C_programming_NESO$ gcc extern.c var.c -o main gcc: error: extern.c: No such file or directory – Shrayansh May 25 '22 at 04:36
@Shrayansh Use `cd` command and go into that directory in which both files are stored. – Darth-CodeX May 25 '22 at 04:54
buff@d605:~/Documents/Coding/C/C_programming_NESO$ pwd /home/buff/Documents/Coding/C/C_programming_NESO buff@d605:~/Documents/Coding/C/C_programming_NESO$ gcc extern.c var.c -o main gcc: error: extern.c: No such file or directory Brother, thank you for your effort, it is not much of an issue, leave it, and thanks again. – Shrayansh May 26 '22 at 09:20

1 Answers1