error: conflicting types for 'f' and previous declaration of 'f' was here

Question

This code is just a situation that I found in my actual code which is very big so I\'m giving this.here in this code the structure \"struct node\" is not defined it

Answer 1

In your test2.h you have declared f as extern, that's why you are getting the error. In test.c there is no extern declaration in prototype.