代码如下：

#include <winsock.h>
#include <iostream>
#pragma comment(lib, "ws2_32.lib")
using namespace std;

int main(void)
{
    int iflag;
    WSADATA wsadata;
    SOCKET m_socket;
    
    iflag = WSAStartup(MAKEWORD(2, 2), &wsadata);
    
    if (iflag != 0)
    {
        cout<<"Sock opens failed!!"<<endl;
        return 0;
    }
    else
    {
        cout<<"Sock opens successfully!!"<<endl;
        return 0;
    }
    
    m_socket = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
    
    if (m_socket == INVALID_SOCKET)
    {
        cout<<"Error at socket() "<<GetLastError()<<endl;
        WSACleanup();
        return 0;
    }
    
    return 0;
}

错误信息如下:
c:\........(省略的路径): undefined reference to "WSAStartup@8"
collect 2: ld returned 1 exit status

你没有加入“ws2_32.lib”

要include吗？？