Question

客户端 - 服务器连接使用使用TCP的传输套接字（传输控制协议

我首先在服务器之前运行两个程序，然后使用这些命令运行客户端

cyse510@cyse510-VirtualBox:~/Desktop$ ./server 51717
cyse510@cyse510-VirtualBox:~/Desktop$ ./client 172.0.0.1 51717

我在客户端出现了这个错误

ERROR连接：连接超时

在服务器端，屏幕上没有任何内容

     /* A simple server in the internet domain using TCP
      The port number is passed as an argument */
       #include <stdio.h>
       #include <stdlib.h>
       #include <string.h>
       #include <unistd.h>
       #include <sys/types.h> 
       #include <sys/socket.h>
       #include <netinet/in.h>

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

       int main(int argc, char *argv[])
       {
          int sockfd, newsockfd, portno;
          socklen_t clilen;
          char buffer[256];
          struct sockaddr_in serv_addr, cli_addr;
          int n;
          if (argc < 2) {
              fprintf(stderr,"ERROR, no port provided\n");
             exit(1);
        }
       sockfd = socket(AF_INET, SOCK_STREAM, 0);
       if (sockfd < 0) 
       error("ERROR opening socket");
     bzero((char *) &serv_addr, sizeof(serv_addr));
     portno = atoi(argv[1]);
     serv_addr.sin_family = AF_INET;
     serv_addr.sin_addr.s_addr = INADDR_ANY;
     serv_addr.sin_port = htons(portno);
     if (bind(sockfd, (struct sockaddr *) &serv_addr,
          sizeof(serv_addr)) < 0) 
          error("ERROR on binding");
     listen(sockfd,5);
     clilen = sizeof(cli_addr);
     newsockfd = accept(sockfd, 
             (struct sockaddr *) &cli_addr, 
             &clilen);
     if (newsockfd < 0) 
          error("ERROR on accept");
     bzero(buffer,256);
     n = read(newsockfd,buffer,255);
     if (n < 0) error("ERROR reading from socket");
     printf("Here is the message: %s\n",buffer);
     n = write(newsockfd,"I got your message",18);
     if (n < 0) error("ERROR writing to socket");
     close(newsockfd);
     close(sockfd);
     return 0; 
     }

客户代码 - ＆gt;

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

 void error(const char *msg)
  {
     perror(msg);
     exit(0);
   }

  int main(int argc, char *argv[])
  {
     int sockfd, portno, n;
     struct sockaddr_in serv_addr;
     struct hostent *server;

   char buffer[256];
    if (argc < 3) {
        fprintf(stderr,"usage %s hostname port\n", argv[0]);
        exit(0);
   }
    portno = atoi(argv[2]);
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) 
        error("ERROR opening socket");
    server = gethostbyname(argv[1]);
    if (server == NULL) {
        fprintf(stderr,"ERROR, no such host\n");
        exit(0);
    }
      bzero((char *) &serv_addr, sizeof(serv_addr));
      serv_addr.sin_family = AF_INET;
      bcopy((char *)server->h_addr, 
     (char *)&serv_addr.sin_addr.s_addr,
     server->h_length);
     serv_addr.sin_port = htons(portno);
     if (connect(sockfd,(struct sockaddr *) &serv_addr,sizeof(serv_addr)) < 0) 
    error("ERROR connecting");
     printf("Please enter the message: ");
     bzero(buffer,256);
     fgets(buffer,255,stdin);
      n = write(sockfd,buffer,strlen(buffer));
     if (n < 0) 
     error("ERROR writing to socket");
      bzero(buffer,256);
      n = read(sockfd,buffer,255);
      if (n < 0) 
     error("ERROR reading from socket");
     printf("%s\n",buffer);
     close(sockfd);
     return 0;
    }

Answer 1

cyse510 @ cyse510-VirtualBox：〜/ Desktop $。/client 172.0.0.1 51717

我怀疑你的意思是172.0.0.1。 Localhost是127.0.0.1。

c中使用TCP的服务器客户端

1 个答案: