Often when programming simple TCP/IP server (for monitoring of services and other non-GUI-based applications, etc.) we need to know IP of the host computer so that clients can connect to it; to retrieve this IP from within the server-side program, use the following snippet:

WORD wVersionRequested;
WSADATA wsaData;
wVersionRequested = MAKEWORD(2, 0);

if (WSAStartup(wVersionRequested, &wsaData ) != 0)
{
    printf("WSAStartup() failed!n");
    return 0;
}

// Get the local host information
hostent* localHost = gethostbyname("");
char* localIP = inet_ntoa(*(struct in_addr *)*localHost->h_addr_list);

printf("Local host IP is: %sn", localIP);

WSACleanup();

Includes
WinSock2.h, Ws2tcpip.h

Link libraries
ws2_32.lib

Once I get some time on my hands, I’ll clean up and post the code of my WinSock-based TCP/IP library for simple development of both server and client side.