how to understand this program

[winecoding]

There is a code snippet:

#include <stdio.h>

char* fun()
{
  return "awake";
}
int main()
{
  printf("%s",fun()+ printf("I see you"));
  getchar();
  return 0;
}

I do not understand why the program print out unpredictable stuff. In specific, this code segment really confuses me:

printf("%s",fun()+ printf("I see you"));

[Bazzy]

printf("I see you") returns 9, the number of the printed characters
adding that to fun(), will move the returned pointer passed the length of the char sequence it's pointing to

[winecoding]

Hi, Bazzy:

Thanks for the reply.

Here, fun() returns pointer to char array, i.e., awake. As an example, just assume the pointer is 10, so what you suggested is that "fun() + 9" will points to 19? And printf ("%s",...) will print the stuff pointed by 19? Is my understanding correct?

[Bazzy]

Let's assume this is a fragment of your program memory:

some random stuff awake\0 some other random stuff \0

where \0 is a single byte with value 0
Assume that the first 's' of 'some' has an address value of 0

fun() returns a pointer to the first 'a' of 'awake' so 18 in this case
- notice: the pointer points to that 'a' and the value of the pointer is 18

fun()+ printf("I see you") returns 27, a pointer to the 'm' in the second 'some'

printf("%s",fun()+ printf("I see you")); will print from 27 up to the following \0, so the output would be

me other random stuff