If fclose(0) is called, does this close stdin?

Question

If fclose(0) is called, does this close stdin?

The reason why I\'m asking this is that for some reason, stdin is being closed in my application and I cannot figure out

Answer 1

fclose(0) invokes undefined behavior, so yes, it could do anything, including closing stdin. But you have much bigger problems if fclose(0) appears in your code.