When file.i extension required ?

Question

I read some where that .i extension "C source code should not be pre processed". When it is required and what is the advantage of it.

Answer 1

Here macro(VIKAS) is expanded

$ cat abc.c
    #define VIKAS printf("\n VIKAS \n");
    int main()
    {
            VIKAS
            return 0;
    }

$ gcc -E abc.c

# 1 "abc.c"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "abc.c"

int main()
{
 printf("\n VIKAS \n");
        return 0;
}

If you want to see the expanded macro and content included using #include.
Then you can generate abc.i.
using this command
gcc -E abc.c

Note : I did not include any header file in abc.i

Comments

Actually my query why programmer uses .i files ? what is the benefit to have these ?