ソケットプログラミングでは、他端(クライアント)に接続されたipアドレスを取得する方法、acceptまたはgetpeernameを使用する方法

#include <iostream>
#include <winsock.h>
#include <stdio.h>

#pragma comment(lib, "wsock32")
using namespace std;

void main() 
{
	int ret = 0;
	WSADATA wsadata;
	WORD version = MAKEWORD(2,0);
	ret = WSAStartup(version,&wsadata);

	//       
	SOCKET m_hServerSocket;
	m_hServerSocket = socket(AF_INET,SOCK_STREAM,0);

	//       
	SOCKADDR_IN m_addr;
	m_addr.sin_family = AF_INET;
	m_addr.sin_addr.S_un.S_addr = INADDR_ANY;//          ，        ip  ；      ，          ip  
	m_addr.sin_port = htons(10000);
	ret = bind(m_hServerSocket,(LPSOCKADDR)&m_addr,sizeof(m_addr));
	
	//         
	ret = listen(m_hServerSocket,10);//               

	WSADATA cli_wsadata;
	ret = WSAStartup(version,&cli_wsadata);

	//       
	SOCKET m_hClientSocket;
	m_hClientSocket = socket(AF_INET,SOCK_STREAM,0);


	//             
	SOCKADDR_IN m_addr1;
	m_addr1.sin_family = AF_INET;
	m_addr1.sin_addr.S_un.S_addr = inet_addr("192.168.100.57");//    ip  
	m_addr1.sin_port = htons(10000);//   socket    
	ret = connect(m_hClientSocket,(LPSOCKADDR)&m_addr1,sizeof(m_addr1));//      m_hClientSocket      m_addr1      
	
	//0xCD,0xCD,0xCD,0XCD.   DEBUG        0xcd(204),        IP，             。 
	//    accept getpeername    204.204.204.204   

	SOCKET com_Sock;
	SOCKADDR_IN addr_conn;
	int nSize = sizeof(addr_conn);
	//initialize the memory block via the memset function
	memset((void *)&addr_conn,0,sizeof(addr_conn));

	com_Sock = accept(m_hServerSocket,NULL,NULL);			//                
	//                  (int *)(sizeof(addr_conn))，               ！！！
	//com_Sock = accept(m_hServerSocket,(SOCKADDR *)&addr_conn,&nSize); //or
	getpeername(com_Sock,(SOCKADDR *)&addr_conn,&nSize);

	char szPeerAddress[16];
	//Sets buffers to a specified character.
	memset((void *)szPeerAddress,0,sizeof(szPeerAddress));
	cout << szPeerAddress << "**************" <<endl;
	//If no error occurs, inet_ntoa returns a character pointer to a static buffer 
	//containing the text address in standard ".'' notation
	strcpy(szPeerAddress,inet_ntoa(addr_conn.sin_addr));
	//Copy a string.the second parameter strSource Null-terminated source string
	cout << szPeerAddress << endl;
	//so remember that every time use the inet_ntoa, you must copy the result by yourself
	//or it will be covered by the other value
	addr_conn.sin_addr.S_un.S_addr = inet_addr("192.168.111.2");
	cout << inet_ntoa(addr_conn.sin_addr) << endl;

	cout << endl;

}