close socket

Hi,

I use closesocket to close a socket, it return 0, looks like success, but the socket number remains. When I try to open a new socket, it fails, return 0xfffffff.

I’m wondering is this because the old one close is not success or other reason?

Thanks

Jiaxin

Are you calling close() or closesocket()? In NET+OS the proper routine to call is closesocket().

“but the socket number remains”?

================================
SOCKET fds = socket();

closesocket(fds);

Naturally fds will still have a number in it. You need to set it to INVALID_SOCKET (-1) after you call closesocket().

================================
fds = -1;

Could you please post your code so we could take a look to see where opening the new socket fails?

-Erik

I use closesocket().

Another similar thing is serial port.
I use close() for it.

Do you have a socket connection with the device and you can control the GPIO?