Help for Socket Programming C++

cplusplus.Jr · 04-02-2007, 01:41 AM

Im still new to socket programming in C++. Currently i am doing a client-server communication. Not very understand how the code meant. Can someone help me to teach line-by-line the codes meaning.

The code as follows:

Code:

void CSampleClientDlg::OnButtonSend() 
{
	SOCKET TempSoc;
	TempSoc = (SOCKET)m_hComm;
	TCHAR szBuf[255]={0};
	m_bDataToSend = TRUE;
	CString strText = "";
	m_Send.GetWindowText(strText);
	_tcscpy(szBuf,strText);
	int nRet = send(TempSoc,szBuf,strText.GetLength(),0);
	if(nRet == SOCKET_ERROR)
		AfxMessageBox("Error in Sending");

}

Niara · 04-02-2007, 04:43 AM

Using easy words, the winsock work on that piece of code can be understand as:

Code:

SOCKET TempSoc;
TempSoc = (SOCKET)m_hComm;

Here you assign a global variable 'm_hComm' to a local var (to simplify the work).

Code:

int nRet = send(TempSoc,szBuf,strText.GetLength(),0);

'send' is a winsock function that sends the text 'szBuf' (wich length is 'strText.GetLength()') to the socket 'TempSock'; that function returns the length of the text that have been received by the other side or an error code like 'SOCKET_ERROR'. In that case, if 'nRet==strText.GetLength()' (after the send) means that you have send all the data, else means that the other side only have received the first 'nRet' characters of 'strText'.

Hope that will help; also you can take a look to the 'Useful links and books' thread on that networking board.

Niara

04-02-2007, 01:41 AM	#1
cplusplus.Jr Registered User Join Date: Apr 2007 Posts: 4	Help for Socket Programming C++ Im still new to socket programming in C++. Currently i am doing a client-server communication. Not very understand how the code meant. Can someone help me to teach line-by-line the codes meaning. The code as follows: Code: void CSampleClientDlg::OnButtonSend() { SOCKET TempSoc; TempSoc = (SOCKET)m_hComm; TCHAR szBuf[255]={0}; m_bDataToSend = TRUE; CString strText = ""; m_Send.GetWindowText(strText); _tcscpy(szBuf,strText); int nRet = send(TempSoc,szBuf,strText.GetLength(),0); if(nRet == SOCKET_ERROR) AfxMessageBox("Error in Sending"); }
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04-02-2007, 04:43 AM	#2
Niara Registered User Join Date: Mar 2005 Location: Juneda Posts: 229	Using easy words, the winsock work on that piece of code can be understand as: Code: SOCKET TempSoc; TempSoc = (SOCKET)m_hComm; Here you assign a global variable 'm_hComm' to a local var (to simplify the work). Code: int nRet = send(TempSoc,szBuf,strText.GetLength(),0); 'send' is a winsock function that sends the text 'szBuf' (wich length is 'strText.GetLength()') to the socket 'TempSock'; that function returns the length of the text that have been received by the other side or an error code like 'SOCKET_ERROR'. In that case, if 'nRet==strText.GetLength()' (after the send) means that you have send all the data, else means that the other side only have received the first 'nRet' characters of 'strText'. Hope that will help; also you can take a look to the 'Useful links and books' thread on that networking board. Niara Last edited by Niara; 04-02-2007 at 04:48 AM.
Niara is offline

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