 [det]tcp_close_socket(+SocketId)Closes the indicated socket, making SocketId invalid. 
Normally, sockets are closed by closing both stream handles returned by
open_socket/3. There are two cases where tcp_close_socket/1 
is used because there are no stream-handles:
[det]tcp_close_socket(+SocketId)Closes the indicated socket, making SocketId invalid. 
Normally, sockets are closed by closing both stream handles returned by
open_socket/3. There are two cases where tcp_close_socket/1 
is used because there are no stream-handles:
- If, after tcp_accept/3, the 
server uses fork/1 to handle the 
client in a sub-process. In this case the accepted socket is not longer 
needed from the main server and must be discarded using tcp_close_socket/1.
- If, after discovering the connecting client with
tcp_accept/3, the server does 
not want to accept the connection, it should discard the accepted socket 
immediately using tcp_close_socket/1.