klient UDP

#include <winsock.h>

#include <iostream>

#include <string>

#include <cstdlib>

using namespace std;

void UDPClient(char * hostaddress, short nPort);

int main()
{
    WORD wVersionRequested = MAKEWORD(2,2);

    WSADATA wsadata;

    int nRet;

    short nPort;

    char host_address[256];

    cout << "Klient UDP" << endl;

    cout << "Podaj adres hosta: ";

    cin.getline(host_address, 256, '\n');

    cout << "Podaj nr portu: ";

    cin >> nPort;

    nRet = WSAStartup(wVersionRequested, &wsadata);

    if(wsadata.wVersion != wVersionRequested)
    {
        cout << "WSADATA error: " << WSAGetLastError() << endl;

        return -1;
    }

    UDPClient(host_address, nPort);

    WSACleanup();

    cin.get();

    return 0;
}

void UDPClient(char * hostaddress, short nPort)
{
    cout << "Klient UDP" << endl;

    LPHOSTENT lpHostEntry;

    lpHostEntry = gethostbyname(hostaddress);

    if(lpHostEntry == NULL)
    {
        cout << "gethostbyname() error: " << WSAGetLastError() << endl;

        return;
    }

    cout << "Nawiazywanie polaczenia z serwerem: " << hostaddress << " na porcie: " << nPort << endl;

    SOCKET clientsocket;

    clientsocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);

    if(clientsocket == INVALID_SOCKET)
    {
        cout << "SOCKET error: " << WSAGetLastError() << endl;

        return;
    }

    SOCKADDR_IN serveraddr;

    serveraddr.sin_family = AF_INET;

    serveraddr.sin_addr = *((LPIN_ADDR)*(lpHostEntry->h_addr_list));

    serveraddr.sin_port = htons(nPort);

    char Buffer[256];

    cout << "Wpisz komunikat: ";

    cin >> Buffer;

    int nRet;

    int nLength = sizeof(serveraddr);

    nRet = sendto(clientsocket, Buffer, strlen(Buffer), 0, (LPSOCKADDR)&serveraddr, nLength);

    if(nRet == SOCKET_ERROR)
    {
        cout << "sendto() error: " << WSAGetLastError() << endl;

        closesocket(clientsocket);

        return;
    }

    memset(Buffer, 0, sizeof(Buffer));

    nRet = recvfrom(clientsocket, Buffer, sizeof(Buffer), 0, (LPSOCKADDR)&serveraddr, &nLength);

    if(nRet == SOCKET_ERROR)
    {
        cout << "recvfrom() error: " << WSAGetLastError << endl;

        closesocket(clientsocket);

        return;
    }

    cout << "Komunikat zwrotny: " << Buffer << endl;

    closesocket(clientsocket);

    cin.get();
}