C / C++ / MFC

#include <windows.h>
#include <winsock.h>
#include <wsnetbs.h>
#include <wsipx.h>
#include <stdio.h>

#pragma comment(lib, "ws2_32.lib")

main()
{
    struct hostent FAR *pHostAddr;
    struct in_addr in;
    char   pszHostName [ 255 ];

    int      err;
    WORD     wVersionRequired;
    WSADATA  wsaData;
    wVersionRequired = MAKEWORD(1,1);
    err = WSAStartup(wVersionRequired, &wsaData);
    if (err != 0)
        exit(1);

    if (gethostname (pszHostName, sizeof(pszHostName)) != SOCKET_ERROR)
    {
        printf("Local Host Name: %s\n", pszHostName);
    }
    else
    {
        printf("gethostname error: %ld\n", WSAGetLastError());
        exit(-1);
    }

    // get local host address

    pHostAddr = gethostbyname ( pszHostName );
    if (pHostAddr == NULL)
    {
        printf("gethostbyname error: for %s\n",pszHostName);
        exit(-1);
    }
    else // print out details
    {
        printf("Host Name: %s\n",       pHostAddr->h_name);
        printf("Address Type: %x\n",    pHostAddr->h_addrtype);
        printf("Address Length: %d\n",  pHostAddr->h_length);
        printf("Host Address: %lx \n",  pHostAddr->h_addr);
        in.s_addr = *((u_long *)pHostAddr->h_addr);
        printf("Dotted Address: %s\n", inet_ntoa(in));
    }
}