#define _WINSOCK_DEPRECATED_NO_WARNINGS

#include <iostream>

#include <string>

#include <winsock2.h>

using namespace std;

void ShowErrorMessage(string message) {

cout << "[오류 발생]: " << message << '\n';

system("pause");

exit(1);

}

int main(void) {

WSADATA wsaData;

SOCKET clientSocket;

SOCKADDR_IN serverAddress;

int serverPort = 9876;

char received[256];

string sent;

if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0) ShowErrorMessage("WSAStartup()");

clientSocket = socket(PF_INET, SOCK_STREAM, 0); // TCP 소켓을 생성

if (clientSocket == INVALID_SOCKET) ShowErrorMessage("socket()");

memset(&serverAddress, 0, sizeof(serverAddress));

serverAddress.sin_family = AF_INET;

serverAddress.sin_addr.s_addr = inet_addr("127.0.0.1"); // 문자열 IP를 네트워크 바이트 형식으로

serverAddress.sin_port = htons(serverPort); // 2바이트 정수 네트워크 바이트 형식으로

if (connect(clientSocket, (SOCKADDR*)&serverAddress, sizeof(serverAddress)) == SOCKET_ERROR)ShowErrorMessage("connect()");

cout << "[현재 상태] connect()\n";

while (1) {

cout << "[메세지 전송]: ";

getline(cin, sent);

if (sent == "")continue;

send(clientSocket, sent.c_str(), sent.length(), 0);

int length = recv(clientSocket, received, sizeof(received), 0);

received[length] = '\0';

if (strcmp(received, "[exit]") == 0) {

cout << "[서버 종료]\n";

break;

}

cout << "[서버 메시지]: " << received << '\n';

}

closesocket(clientSocket);

WSACleanup();

system("pause");

return 0;

}

#define _WINSOCK_DEPRECATED_NO_WARNINGS

는 inet_addr(“127.0.0.1”); 을 이용하기 위해서 필요함

c_str : C++의 string을 C의 버퍼형태로 변환

TCP Echo Client