如果标题误导我很抱歉。我真的没有想到更好的选择。这是一些简单的套接字程序:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/poll.h>
#include <iostream>

#define BACKLOG 10

void error(const char *msg)
{
    perror(msg);
    exit(1);
}


int main(int argc, char *argv[])
{
     if (argc < 2) {
         fprintf(stderr,"ERROR, no port provided\n");
         exit(1);
     }


     int sockfd = socket(AF_INET, SOCK_STREAM, 0);
     if (sockfd < 0)
        error("ERROR opening socket");


     struct sockaddr_in serv_addr;
     bzero((char *) &serv_addr, sizeof(serv_addr));
     int portno = atoi(argv[1]);
     serv_addr.sin_family = AF_INET;
     serv_addr.sin_addr.s_addr = INADDR_ANY;
     serv_addr.sin_port = htons(portno);

     auto bindsuccess = bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));

     if (bindsuccess < 0)
        error("ERROR on binding");

     struct pollfd newPollFD[1];
     newPollFD[0].fd = sockfd;
     newPollFD[0].events = POLLIN;

     char buffer[256];
     bzero(buffer,256);

     listen(sockfd, BACKLOG);

     struct sockaddr_in cli_addr;
     socklen_t clilen = sizeof(cli_addr);

     int newsockfd;

     int rv = poll(newPollFD, 1, -1);

     if (rv == -1) {
        error("Error occured in Poll");
     }
     else {
        if (newPollFD[0].revents & POLLIN){

            newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen);
            if (newsockfd < 0)
                error("ERROR on accept");

            int rwsuccess;

            rwsuccess = read(newsockfd,buffer,255);
            if (rwsuccess < 0)
                error("ERROR reading from socket");

            printf("Here is the message: %s\n",buffer);

            rwsuccess = write(newsockfd,"I got your message \n",18);

            if (rwsuccess < 0)
                error("ERROR writing to socket");
        }
     }

     close(newsockfd);
     close(sockfd);
     return 0;
}

如果我使用端口号执行此代码,然后使用telnet到该端口号,则服务器会监听,但是一旦我发送第一条消息,连接就会终止。我希望服务器在从telnet发送消息时继续监听和发送回确认。我该怎么做?

提前致谢!

最佳答案

continue奇怪地无关紧要,并导致编译中断。 (现在已在您的编辑中更正。)但是,您缺少for循环。并且,您应该添加检查read是否返回0

        for (;;) {
          int rwsuccess;

          rwsuccess = read(newsockfd,buffer,255);
          if (rwsuccess < 0)
              error("ERROR reading from socket");
          if (rwsuccess == 0) break;

          printf("Here is the message: %s\n",buffer);

          rwsuccess = write(newsockfd,"I got your message \n",18);

          if (rwsuccess < 0)
              error("ERROR writing to socket");
        }

关于c++ - 轮询TCP套接字空闲监听,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/11461896/

10-11 22:34
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