client.cpp

网络实验网络实验网络实验网络实验网络实验

#include <winsock2.h>
#include <stdio.h>
#include <stdlib.h>

#define DEFAULT_COUNT       20
#define DEFAULT_PORT        4000
#define DEFAULT_BUFFER      2048
#define DEFAULT_MESSAGE     "This is a test of the emergency \
broadcasting system"


char  szServer[128],          // Server to connect to
      szMessage[1024];        // Message to send to sever
int   iPort     = DEFAULT_PORT;  // Port on server to connect to
int dwCount     = DEFAULT_COUNT; // Number of times to send message
BOOL  bSendOnly = false;         // Send data only; don't receive

// Function: main
//
// Description:
//    Main thread of execution. Initialize Winsock, parse the 
//    command line arguments, create a socket, connect to the 
//    server, and then send and receive data.
//
int main(int argc, char **argv)
{
    WSADATA       wsd;
    SOCKET        sClient;
    char          szBuffer[DEFAULT_BUFFER];
    int           ret,i;
                  
	char          inputip[40];
    struct        sockaddr_in server;
    struct        hostent  *host = NULL;
	char          * ip; //服务器ip地址
	unsigned short port;  //端口
	char           if_receive_echo;//是否接收应答信息

    if (WSAStartup(MAKEWORD(2,2), &wsd) != 0)
    {
        printf("Failed to load Winsock library!\n");
        return 1;
    }
    strcpy(szMessage, DEFAULT_MESSAGE);
    //
    // Create the socket, and attempt to connect to the server
    //
    sClient = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (sClient == INVALID_SOCKET)//如果有错误产生，返回INVALID_SOCKET错误，应用程序可通过调用WSAGetLastError()来获得特定的错误代码。
    {
        printf("socket() failed: %d\n", WSAGetLastError());
        return 1;
    }
    server.sin_family = AF_INET;
    server.sin_port = htons(iPort);// 把16位的数字从主机字节顺序转换到网络字节顺序
    server.sin_addr.s_addr = inet_addr(szServer);// 把一个Internet标准的"."记号地址转换成Internet地址数值。

     printf("Please input SERVER IP:");
	 scanf("%s",&inputip);

	 ip=inputip;

	 printf("Please input a PORT(1024--65536):");
	 scanf("%d",&port);

	 printf("only send?('y' or 'n')\n");
	 scanf("%s",&if_receive_echo);

	 if(if_receive_echo=='Y'||if_receive_echo=='y')
         bSendOnly=true;

	 printf("please input the number of send massages!\n");
	 scanf("%d",&dwCount);

	 sClient=socket(AF_INET,SOCK_STREAM,0);
	
	 server.sin_family=AF_INET;
	 server.sin_port=htons(port);
	 server.sin_addr.S_un.S_addr=inet_addr(ip);

    if (connect(sClient, (struct sockaddr *)&server, 
        sizeof(server)) == SOCKET_ERROR)
    {
        printf("connect() failed: %d\n", WSAGetLastError());
        return 1;
    }
    // Send and receive data 
    //
    for(i = 0; i < dwCount; i++)
    {
        ret = send(sClient, szMessage, strlen(szMessage), 0);
        if (ret == 0)
            break;
        else if (ret == SOCKET_ERROR)
        {
            printf("send() failed: %d\n", WSAGetLastError());
            break;
        }
        printf("Send %d bytes\n", ret);
        if (!bSendOnly)
        {
            ret = recv(sClient, szBuffer, DEFAULT_BUFFER, 0);
            if (ret == 0)        // Graceful close
                break;
            else if (ret == SOCKET_ERROR)
            {
                printf("recv() failed: %d\n", WSAGetLastError());
                break;
            }
            szBuffer[ret] = '\0';
            printf("RECV [%d bytes]: '%s'\n", ret, szBuffer);
           }
    }
    closesocket(sClient);


    WSACleanup();
    return 0;
}