handle

Hello, everyone!
Joan here. I am trying to modify "TTY"_a sample program provided by Visual C++.I want change
it to a program without any user interface. Now the problem that I face is the handle GETNPTTYINFO
is always NULL, so the program can not execute the rest after it. Can anybody tell me how can I solve
this problem? Thank you very much!

Check whether the object associated with the handle is there. If the Handle is NULL, then there is some problem with the object associated with the handle.