Enumeration of Computer Names and their IP address

Introduction

This code snippet allows you to retrieve the names of the computers in the network and their associated IP addresses. You can use this code to retrieve the host information in a network and also get the IP address of each pc. Its something similar to what you see in the Network Neighborhood list. All luck.

Things to do

1. #include winsock2.h
2. In the Menu, go to Project--Settings and in the Link tab, you can see a text box named Object/Library Modules. In that, add ws2_32.lib mpr.lib to the existing entries there. Those 2 libraries have to be added for this code snippet to compile without any linker errors.

Program listing

CString strTemp;
struct hostent *host;

struct in_addr *ptr; // To retrieve the IP Address 

DWORD dwScope = RESOURCE_CONTEXT;
NETRESOURCE *NetResource = NULL;
HANDLE hEnum;
WNetOpenEnum( dwScope, NULL, NULL, 
             NULL, &hEnum );

WSADATA wsaData;
WSAStartup(MAKEWORD(1,1),&wsaData);

if ( hEnum )
{
    DWORD Count = 0xFFFFFFFF;
    DWORD BufferSize = 2048;
    LPVOID Buffer = new char[2048];
    WNetEnumResource( hEnum, &Count, 
        Buffer, &BufferSize );
    NetResource = (NETRESOURCE*)Buffer;

    char szHostName[200];
    unsigned int i;

    for ( i = 0; 
        i < BufferSize/sizeof(NETRESOURCE); 
        i++, NetResource++ )
    {
        if ( NetResource->dwUsage == 
            RESOURCEUSAGE_CONTAINER && 
            NetResource->dwType == 
            RESOURCETYPE_ANY )
        {
            if ( NetResource->lpRemoteName )
            {
                CString strFullName = 
                    NetResource->lpRemoteName;
                if ( 0 == 
                    strFullName.Left(2).Compare("\\\\") )   
                    strFullName = 
                        strFullName.Right(
                            strFullName.GetLength()-2);

                gethostname( szHostName, 
                    strlen( szHostName ) );
                host = gethostbyname(strFullName);

                if(host == NULL) continue; 
                ptr = (struct in_addr *) 
                    host->h_addr_list[0];                    

                // Eg. 211.40.35.76 split up like this.             
                int a = ptr->S_un.S_un_b.s_b1;  // 211           
                int b = ptr->S_un.S_un_b.s_b2;  // 40
                int c = ptr->S_un.S_un_b.s_b3;  // 35
                int d = ptr->S_un.S_un_b.s_b4;  // 76

                strTemp.Format("%s -->  %d.%d.%d.%d",
                    strFullName,a,b,c,d);
                AfxMessageBox(strTemp);
            }
        }
    }

    delete Buffer;
    WNetCloseEnum( hEnum ); 
}

WSACleanup();