Hi Kayathri,
you have a few problems (or bugs, actually) in your code:
- you are using three large arrays (3x256 bytes) local to your function. If you have not allocated enough stack, this will be a problem.
- you are defining f_check[] twice.
- but the real problem is: strcmp() compares the strings up to a zero terminating byte. You don't have that as you initialize the buffers with a pattern, but you don't set the terminating character. I suggest you either fix that, or you are using strncmp() instead.
I hope this makes the problem clear and helps,
Erich