Keskustelu: Ohjelmointikysymykset: C++: Socket-ohjelma ei käänny

// Code Block 2.1 - Header Includes
// This code block includes all of the standard Sockets API/Winsock headers
#ifdef WIN32                // Windows 95 and above
    #include "winsock2.h"
    #include "Ws2tcpip.h"
#else                       // UNIX/Linux
    #include <sys/types.h>
    #include <sys/socket.h>
    #include <netinet/in.h>
    #include <unistd.h>
    #include <netdb.h>
    #include <arpa/inet.h>
#endif
// End Code Block 2.1 - Header Includes

#ifdef WIN32
    closesocket( sock );
#else
    close( sock );
#endif

// Code Block 2.2 - Redefinitions and globals for cross-compatibility
#ifdef WIN32                // Windows 95 and above
    WSADATA g_wsadata;      // Winsock data holder
    #define CloseSocket closesocket
    #define GetSocketError WSAGetLastError
    #define StartSocketLib WSAStartup( MAKEWORD( 2, 2 ), &g_wsadata );
    #define CloseSocketLib WSACleanup();
    #ifndef socklen_t
        typedef int socklen_t;
    #endif
#else                       // UNIX/Linux
    #define CloseSocket close
    #define GetSocketError errno
    #define StartSocketLib {}
    #define CloseSocketLib {}
#endif
// End Code Block 2.2 - Redefinitions and globals for cross-compatibility

#include <iostream>
using namespace std;
int main() {
    int err;
    StartSocketLib;

// BEGIN CODE BLOCK 2.3 - Create a Listening Socket on port 4000
    int sock = socket( AF_INET, SOCK_STREAM, IPPROTO_TCP );
    if( sock == -1 ) {
        cout << "Socket creation error!" << endl;
        return 0;
    }
    cout << "Socket created!" << endl;
// create a sockaddr_in for binding, listening on port 4000
    struct sockaddr_in socketaddress;
    socklen_t sa_size = sizeof( struct sockaddr_in );
    socketaddress.sin_family = AF_INET;
    socketaddress.sin_port = htons( 4000 );
    socketaddress.sin_addr.s_addr = htonl( INADDR_ANY );
    memset( &(socketaddress.sin_zero), 0, 8 );

    // bind the socket
    err = bind( sock, (struct sockaddr*)&socketaddress, sa_size );

    // listen on the socket
    err = listen( sock, 16 );
    // END CODE BLOCK 2.3 - Create a Listening Socket on port 4000

    // wait for an incomming connection now
    int datasock;
    datasock = accept( sock, (struct sockaddr*)&socketaddress, &sa_size );

    // receive data
    char buffer[128];
    err = recv( datasock, buffer, 128, 0 );

    cout << "Data received:" << endl;
    cout << buffer << endl;

    shutdown( datasock, 2 );
    CloseSocket( datasock );

    shutdown( sock, 2 );
    CloseSocket( sock );

    CloseSocketLib;
}