記得要 link Ws2_32.lib, 如果用的是 Visual C++, 選 Project, Settings...

  選 Link, 在 Object/library modules: 加進 Ws2_32.lib, 選 OK 即可~

--


#include<stdio.h>
#include<string.h>
#include<Winsock2.h>


int main()
{
        SOCKET sockfd;
        int result,len;
        char host[20] = "140.112.30.49";
        struct sockaddr_in address;
        char ch[10];


        {
WORD wVersionRequested;
WSADATA wsaData;
int err;

wVersionRequested = MAKEWORD( 2, 2 );

err = WSAStartup( wVersionRequested, &wsaData );
if ( err != 0 ) {
    return 0;
}


if ( LOBYTE( wsaData.wVersion ) != 2 ||
        HIBYTE( wsaData.wVersion ) != 2 ) {
    WSACleanup( );
    return 0;
}

        }

        sockfd = socket(AF_INET, SOCK_STREAM, 0);
        if(sockfd<0) {
                perror("Open socket Error!\n");
                exit(-1);
        }
        address.sin_family=AF_INET;

        if((address.sin_addr.s_addr=inet_addr("140.112.30.125"))==INADDR_NONE) {
                exit(-1);
        }

        address.sin_port=1234;//ntohs(1234);
        for(int i=0;i<8;i++)
                address.sin_zero[i] = 0;

        len=sizeof(address);
        result = connect(sockfd,(struct sockaddr *)&address,len);

        if(result == SOCKET_ERROR){

        //if(result==-1){
                printf("%d\n",WSAGetLastError());
                perror("connect socket Error!\n");
                exit(-1);
        }
        strcpy(ch,"a");
        send(sockfd,ch,1,1);
    strcpy(ch,"Q");
        send(sockfd,ch,1,1);
        closesocket(sockfd);
        //shutdown(sockfd,0);
        return 0;
}