gethostbyname IPアドレス取得

#include <afxsock.h>
int GetIPAddr(LPCSTR hostname)
{
  int nAdapter = 0;
  if(AfxSocketInit())
  { 
    HOSTENT *pHostEnt = gethostbyname(hostname);
    
    if(pHostEnt)
    {
      if(pHostEnt->h_addrtype == AF_INET)
      {
        TRACE("[%s] Official name= [%s]
", hostname, pHostEnt->h_name);
        
        while ( pHostEnt->h_addr_list[nAdapter] )
        {
          in_addr *pAddr = (in_addr*)pHostEnt->h_addr_list[nAdapter];
          // pHostEnt->h_addr_list[nAdapter] -the current address in host order
          TRACE("IP(%d):%s
",  nAdapter+1, inet_ntoa(*pAddr));
          nAdapter++;
        }
      }
    }
    else
    {
      int iErr = WSAGetLastError();
      ASSERT(FALSE);
    }    
  }
  return nAdapter;
}

 

BOOL GetHostByAddr(LPCSTR lpszIP)
{
  if(AfxSocketInit())
  {
    unsigned long cPeer = inet_addr(lpszIP);
    HOSTENT *pHostEnt = gethostbyaddr((char*)&cPeer, 4, AF_INET);
    if(pHostEnt)
    {
      TRACE("IP [%s] host name = [%s]
", lpszIP, pHostEnt->h_name);

      return TRUE;
    }
    else
    {
      int iErr = WSAGetLastError();
      ASSERT(FALSE);
    } 
  }
  return FALSE;
}

 
 

// 
GetIPAddr( "www.sina.com.cn" );
GetHostByAddr( "192.168.0.91" );

 

// 
[www.sina.com.cn] Official name= [auriga.sina.com.cn]
IP(1):61.172.201.194
IP(2):61.172.201.195