[C] 소켓 공부

//실습 2번

#include 
#include 
#include 

#define BUFSIZE 512

//실습4번
int main(int argc, char* argv[])
{
	WSADATA wsa;
	if(WSAStartup(MAKEWORD(2,2),&wsa) != 0)
		return -1;

	char *ipaddr ="147.46.114.70";
		printf("IP주소 = %s \n",ipaddr);

	printf("변환후 = 0x%x\n",inet_addr(ipaddr));

	IN_ADDR temp;
	temp.s_addr = inet_addr(ipaddr);
	printf("변환 = %s\n", inet_ntoa(temp));

	WSACleanup();
	return 0;

}

/*
void err_quit(char *msg) ; void err_display(char *msg);

int main(int argc, char* argv[])
{
	int retval;

	
	WSADATA wsa;
	if(WSAStartup(MAKEWORD(2,2), &wsa) != 0) return -1;

	
	SOCKET listen_sock = socket(AF_INET, SOCK_STREAM, 0);
	if(listen_sock == INVALID_SOCKET) err_quit("socket()");


	SOCKADDR_IN serveraddr;
	ZeroMemory(&serveraddr, sizeof(serveraddr));
	serveraddr.sin_family = AF_INET;
	serveraddr.sin_port = htons(9000);
	serveraddr.sin_addr.s_addr = htonl(INADDR_ANY);
	retval = bind(listen_sock, (SOCKADDR *)&serveraddr, sizeof(serveraddr));
	if(retval == SOCKET_ERROR) err_quit("bind()");


	retval = listen(listen_sock, SOMAXCONN);
	if(retval == SOCKET_ERROR) err_quit("listen()");


	SOCKET client_sock;
	SOCKADDR_IN clientaddr;
	int addrlen;
	char buf[BUFSIZE+1];

	while(1) {

		addrlen = sizeof(clientaddr);
		client_sock = accept(listen_sock, (SOCKADDR *)&clientaddr, &addrlen);
		if(client_sock == INVALID_SOCKET) {
			err_display("accept()");
			continue;
		}
		printf("\n[TCP 서버] 클라이언트접속: IP 주소=%s, 포트、번호=%d\n",
			inet_ntoa(clientaddr.sin_addr), ntohs(clientaddr.sin_port));


		while(1) {
			retval = recv(client_sock, buf, BUFSIZE, 0);
			if(retval == SOCKET_ERROR) {
				err_display("recv()");
				break;
			}
			else if(retval == 0) {
				break;
			}
			else {
				buf[retval] = '\0';
				printf("%s", buf);
			}
					//보내기
		retval = send(client_sock, strupr(buf), BUFSIZE, 0);
		if( retval== SOCKET_ERROR){
			err_display("send()");
			break;
		}
		printf("[TCP 클라이언트] %d 바이트를 보냈습니다.\n",retval);
		}
		closesocket(client_sock);
		printf("\n[TCP 서버클라이언트 종료: IP 주소=%s, 포트번호=%d\n",
		      inet_ntoa(clientaddr.sin_addr), ntohs(clientaddr.sin_port));
	}

	closesocket(listen_sock);
	WSACleanup();
	return 0;
}

void err_quit(char *msg)
{
	LPVOID ipMsgBuf;
	FormatMessage(
		FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM, NULL,
		WSAGetLastError(),MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
		(LPTSTR)&ipMsgBuf,0,NULL);
	MessageBox(NULL, (LPCTSTR)ipMsgBuf, msg, MB_ICONERROR);
	LocalFree(ipMsgBuf);
	exit(-1);
}

void err_display(char *msg)
{
	LPVOID ipMsgBuf;
	FormatMessage(
		FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM, NULL,
		WSAGetLastError(),MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
		(LPTSTR)&ipMsgBuf,0,NULL);
	printf("[%s] %s", msg, (LPCTSTR)ipMsgBuf);
	LocalFree(ipMsgBuf);
}*/
//////////////////////////
/*

#include 
#include 
#include 

#define BUFSIZE 512

int recvn(SOCKET s, char *buf, int len, int flags);
void err_quit(char *msg);
void err_display(char *msg);

int main(int argc, char* argv[])
{
	int retval;

	WSADATA wsa;
	if(WSAStartup(MAKEWORD(2,2),& wsa) !=0)
		return -1;

	SOCKET sock = socket(AF_INET, SOCK_STREAM, 0);
	if(sock == INVALID_SOCKET) err_quit("socket()");

	SOCKADDR_IN serveraddr;
	ZeroMemory(&serveraddr, sizeof(serveraddr));
	serveraddr.sin_family = AF_INET;r
	serveraddr.sin_port = htons(9000);
	serveraddr.sin_addr.s_addr = inet_addr("127.0.0.1");
	retval - connect(sock, (SOCKADDR *)&serveraddr, sizeof(serveraddr));
	if(retval == SOCKET_ERROR) err_quit("connect()");

	char buf[BUFSIZE+1];
	int len;

	while(1)
	{
		ZeroMemory(buf, sizeof(buf));
		printf("\n[보낼 테이터]");
		if(fgets(buf, BUFSIZE+1, stdin) == NULL)
			break;

		// \n 문자제거
		len =strlen(buf);
		if(buf[len-1] == '\n')
			buf[len-1] = '\0';
		if(strlen(buf) == 0)
			break;

		retval = send(sock, buf, strlen(buf), 0);
		if( retval== SOCKET_ERROR){
			err_display("send()");
			break;
		}
		printf("[TCP 클라이언트] %d 바이트를 보냈습니다.",retval);

		retval = recvn(sock, buf, retval, 0);
		if(retval == SOCKET_ERROR)
		{
			err_display("recv()");
			break;
		}
		else if(retval == 0)
			break;
		buf[retval] = '\0';
		printf("[TCP 클라이언트] %d바이트를 받았습니다", retval);
		printf("[받은 데이터]%s\n", buf);

	}
	closesocket(sock);
	WSACleanup();
	return 0;

}
//리시브
int recvn(SOCKET s, char *buf, int len, int flags)
{
	int received;
	char *ptr = buf;
	int left = len;

	while(left >0){
		received =recv(s,ptr,left,flags);
		if(received == SOCKET_ERROR)
			return SOCKET_ERROR;
		else if(received == 0)
			break;
		left -= received;
		ptr += received;
	}
	return (len - left);
}


void err_quit(char *msg)
{
	LPVOID ipMsgBuf;
	FormatMessage(
		FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM, NULL,
		WSAGetLastError(),MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
		(LPTSTR)&ipMsgBuf,0,NULL);
	MessageBox(NULL, (LPCTSTR)ipMsgBuf, msg, MB_ICONERROR);
	LocalFree(ipMsgBuf);
	exit(-1);
}

void err_display(char *msg)
{
	LPVOID ipMsgBuf;
	FormatMessage(
		FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM, NULL,
		WSAGetLastError(),MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
		(LPTSTR)&ipMsgBuf,0,NULL);
	printf("[%s] %s", msg, (LPCTSTR)ipMsgBuf);
	LocalFree(ipMsgBuf);
}*/