Try this :
1) do #defint to MYINT If no error comes means MYINT is #define.
NO error
#include<stdio.h>
#define MYINT int
#define MYINT int
main() { }
===============================================
ERROR :=
2) do typedef to MYINT If error comes means MYINT is typedef.
#include<stdio.h>
typedef int MYINT;
typedef int MYINT;
main() { }
define_typedef.c:3: error: redefinition of typedef âMYINTâ
define_typedef.c:2: error: previous declaration of âMYINTâ was here
Same #define is allowed but typedef is not allowed.