agree . However in repeated runs, the program variables are allocated the same memory location.
Even on reading in a very large string (20 chars) and sending it to sprintf, it is surprising how there is no segmentation fault.

At some point, unless 'k' is pointing to stdout, the length of the memory should cause violation, and program should get SEGV right?

Also, if at all 'k' points to stdout, on doing a flush immediately, i should see the contents of 'k' right? coz it sould overwrite previous contents of stdout.