c++ - 在winsocks中逐行将文本文件从服务器发送到客户端

Question

我有一个客户端和一个服务器，当客户端连接到服务器时，服务器会读取一个文本文件，将其转换为大写并逐行发送给客户端。文本文件名为 "text.txt"，如下所示:

服务器代码

 #include<io.h>
 #include<iostream>
 #include <string>
 #include<fstream>
 #include<winsock2.h>
 #include<winsock2.h>


 #pragma comment(lib,"ws2_32.lib") //Winsock Library

  using namespace std;

void stringToUpper(string &s)
  {
 for(unsigned int l = 0; l < s.length(); l++)
  {
   s[l] = toupper(s[l]);
  }
  }

   int main()
  {
    WSADATA wsa;
    SOCKET s , new_socket;
     struct sockaddr_in server , client;
     int c;
    char *message;

     cout<<"\nInitialising Winsock...";
    if (WSAStartup(MAKEWORD(2,2),&wsa) != 0)
    {
       cout<<"Failed. Error Code"<<WSAGetLastError();
        return 1;
     }

   cout<<"Initialised.\n";

     //Create a socket
     if((s = socket(AF_INET , SOCK_STREAM , 0 )) == INVALID_SOCKET)
    {
        cout<<"Could not create socket "<< WSAGetLastError();
     }

      cout<<"Socket created.\n";

    //Prepare the sockaddr_in structure
      server.sin_family = AF_INET;
    server.sin_addr.s_addr = INADDR_ANY;
     server.sin_port = htons( 8888 );

    //Bind
    if( bind(s ,(struct sockaddr *)&server , sizeof(server)) == SOCKET_ERROR)
    {
      cout<<"Bind failed with error code : "<< WSAGetLastError();
       exit(EXIT_FAILURE);
  }

   puts("Bind done");

    //Listen to incoming connections
     listen(s , 3);

    //Accept and incoming connection
    puts("Waiting for incoming connections...");

     c = sizeof(struct sockaddr_in);

 while( (new_socket = accept(s , (struct sockaddr *)&client, &c)) != INVALID_SOCKET )
    {
       puts("Connection accepted");

      //Reply to the client
    string STRING;
ifstream infile;
infile.open ("text.txt");
     while(!infile.eof()) 
         {
        getline(infile,STRING); 
    stringToUpper(STRING);
        const char *STRING_mod = STRING.c_str();
        send(new_socket , STRING_mod , strlen(STRING_mod) , 0);
        }
         char *end_msg="end";
    send(new_socket , end_msg , strlen(end_msg) , 0);

   infile.close();



       }

     if (new_socket == INVALID_SOCKET)
      {
        cout<<"accept failed with error code : " << WSAGetLastError();
         return 1;
      }

       closesocket(s);
       WSACleanup();



      return 0;
       }

客户端代码

  #include<iostream>
  #include<winsock2.h>

   #pragma comment(lib,"ws2_32.lib") //Winsock Library

   using namespace std;
 int main(int argc , char *argv[])
  {
   WSADATA wsa;
   SOCKET s;
   struct sockaddr_in server;
   char *message , server_reply[2000];
int recv_size;

   printf("\nInitialising Winsock...");
   if (WSAStartup(MAKEWORD(2,2),&wsa) != 0)
    {
    cout<<"Failed. Error Code : "<<WSAGetLastError();
    return 1;
    }

     cout<<"Initialised.\n";

    //Create a socket
      if((s = socket(AF_INET , SOCK_STREAM , 0 )) == INVALID_SOCKET)
   {
     cout<<"Could not create socket : " << WSAGetLastError();
   }

   cout<<"Socket created.\n";


   server.sin_addr.s_addr = inet_addr("127.0.0.1");
   server.sin_family = AF_INET;
   server.sin_port = htons( 8888 );

    //Connect to remote server
     if (connect(s , (struct sockaddr *)&server , sizeof(server)) < 0)
    {
       puts("connect error");
       return 1;
   }

   puts("Connected");






  recv_size = recv(s, server_reply, 2000, 0);
    server_reply[recv_size] = '\0';
    while ( server_reply != "end"){

        cout<<server_reply<<endl;
       recv_size = recv(s, server_reply, 2000, 0);
       server_reply[recv_size] = '\0';

    }






       closesocket(s);
      WSACleanup();


   return 0;
    }

当我运行服务器然后运行客户端时，我有以下响应:

但这不是必需的行为，我希望文本显示为它在文本文件中的样子，“逐行”.....那么我的代码中的问题在哪里以及我如何解决它？为什么客户端会卡在 while 循环中？

谢谢。

Answer 1

您还需要发送换行符。 getline 读取所有字符直到换行符，但不将换行符存储在字符串中。所以当你发送字符串时，它没有换行符。

您可以单独发送一个 "\n"，但最好在现有字符串中添加一个换行符。

例如:

  stringToUpper(STRING);
  STRING += "\n";
  ...