C header issue: #include and “undefined reference”

Question

Alright, I\'ve been trying to work with this for the longest time, and I simply can\'t seem to get it to work right. I have three files, main.c, hello_world.c

Answer 1

gcc main.c hello_world.c -o main

Also, always use header guards:

#ifndef HELLO_WORLD_H
#define HELLO_WORLD_H

/* header file contents go here */

#endif /* HELLO_WORLD_H */