C / C++ / MFC

if(lpHostEnt == NULL)
{
 CString sOutput;
 sOutput.Format("Non existing hostname, error %d", ::WSAGetLastError());
 AfxMessageBox(sOutput);
}

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modified on Thursday, May 6, 2010 3:47 AM

Non existing hostname, error 10093

SOCKET CSmtp::ConnectRemoteServer(CString sServer, UINT nPort)
{
	short nProtocolPort;
	LPHOSTENT lpHostEnt;
	LPSERVENT lpServEnt;
	SOCKADDR_IN sockAddr;
	SOCKET hServerSocket = INVALID_SOCKET;
	struct in_addr addr;

	// If the user input is an alpha name for the host, use gethostbyname()
	// If not, get host by addr (assume IPv4)

	if(atoi(sServer.Left(1)) == 0)lpHostEnt = gethostbyname(sServer);
	else
	{
		addr.s_addr = inet_addr(sServer);
		if(addr.s_addr == INADDR_NONE)
		{
			m_nError = CSMTP_BAD_IPV4_ADDR;
			return INVALID_SOCKET;
		}
		else lpHostEnt = gethostbyaddr((char *)&addr,4,AF_INET);
	}

	if(lpHostEnt != NULL)
	{
		if((hServerSocket = socket(PF_INET,SOCK_STREAM,0)) != INVALID_SOCKET)
		{
			if(nPort)nProtocolPort = htons(nPort);
			else
			{
				lpServEnt = getservbyname("mail",0);
				if(lpServEnt == NULL)nProtocolPort = htons(25);
				else nProtocolPort = lpServEnt->s_port;
			}

			sockAddr.sin_family = AF_INET;
			sockAddr.sin_port = nProtocolPort;
			sockAddr.sin_addr = *((LPIN_ADDR)*lpHostEnt->h_addr_list);
			if(connect(hServerSocket,(PSOCKADDR)&sockAddr,sizeof(sockAddr)) == SOCKET_ERROR)
			{
				m_nError = CSMTP_WSA_CONNECT;
				hServerSocket = INVALID_SOCKET;
			}
		}
		else
		{
			m_nError = CSMTP_WSA_INVALID_SOCKET;
			return INVALID_SOCKET;
		}
	}
	else
	{
		m_nError = CSMTP_WSA_GETHOSTBY_NAME_ADDR;
		return INVALID_SOCKET;
	}

	return hServerSocket;
}

// connecting to remote host
CString sServer = "smtp.gmail.com";
if((m_hSocket = ConnectRemoteServer(sServer,25)) == INVALID_SOCKET)
{
    m_nError = CSMTP_WSA_INVALID_SOCKET;
    return FALSE;
}

#include <stdlib.h>
#include <stdio.h>
#include <time.h>

int main( void )
{
   int i;
   
   // Seed the random-number generator with current time so that
   // the numbers will be different every time we run.
   //
   srand( (unsigned)time( NULL ) );

   // Display 10 numbers.
   for( i = 0;   i < 10;i++ )
      printf( "  %6d\n", rand() );

  printf("\n");

  // Usually, you will want to generate a number in a specific range,
  // such as 0 to 100, like this:
  {
     int RANGE_MIN = 0;
     int RANGE_MAX = 100;
     for (i = 0;    i < 10; i++ )
      {
         int rand100 = (((double) rand() / 
                         (double) RAND_MAX) * RANGE_MAX + RANGE_MIN);
         printf( "  %6d\n", rand100);
      }
  }
}

Xing Chen wrote:

int rand100 = (((double) rand() /
(double) RAND_MAX) * RANGE_MAX + RANGE_MIN);

int rand100 = (((double) rand() /
(double) RAND_MAX) * (RANGE_MAX - RANGE_MIN) + RANGE_MIN);

COLORREF getPixelFromRawData(int x, int y)
{
    char *data, r, g, b;
    long index;

    data = rawData;
    
    index = (y*widthPixels*3) + (x*3)
    
    r = data[index+0];
    g = data[index+1];
    b = data[index+2];
    return RGB(r,g,b)
}