Sponsored Content
Top Forums Programming Trouble with pipes in chat client on linux Post 302718281 by vindy on Friday 19th of October 2012 11:34:33 AM
Old 10-19-2012
Trouble with pipes in chat client on linux

I'm writing a simple chat client in C++ on linux to connect to a win32 chat server on my computer also written in C++. I'm confident that the server works but the chat client is giving me some trouble. I'm forking the chat client and have one process dealing with incoming messages and another dealing with sending messages. I'm using two pipes in the chat client so each process can tell the other when it has terminated so the other process can go ahead and terminate. The pipes don't seem to be working though and I'm not sure where I'm going wrong. If you guys could take a look at my code I'd appreciate it. Maybe one of you will notice something I'm not doing right. Here's my code:

Code:
#define ChildRead pipefd1[0]
#define ChildWrite pipefd2[1]
#define ParentRead pipefd2[0]
#define ParentWrite pipefd1[1]

int main()
{
  int nret, theSocket, theMode = 1, pipefd1[2], pipefd2[2];
  struct sockaddr_in server;
  char buf[2] = {0}, message[999] = {0}, ipAddy[20]= {0}, scrName[20] = {0};
  pid_t childpid;

  printf("Enter the IP address to connect to.\n\n");
  scanf("%s", ipAddy);

  printf("\nEnter your screen name.\n\n");
  scanf("%s", scrName);

  theSocket = socket(AF_INET, SOCK_STREAM, 0);

  if(theSocket < 0)
   printf("\nCouldn't create socket\n");

  memset(&server, 0, sizeof(server));
  server.sin_family = AF_INET;
  server.sin_addr.s_addr = inet_addr(ipAddy);
  server.sin_port = htons(8888);

  printf("\nAttempting to connect to %s\n", ipAddy);

  nret = connect(theSocket, (struct sockaddr *)&server, sizeof(server));

  if(nret < 0)
   printf("\nCouldn't connect\n");

  ioctl(theSocket, FIONBIO, &theMode);

  printf("\nConnected to server!\n\n");

  memset(message, 0, strlen(message));

  pipe(pipefd1);
  pipe(pipefd2);

  fcntl(ParentRead, F_SETFL, O_NONBLOCK);
  fcntl(ParentWrite, F_SETFL, O_NONBLOCK);
  fcntl(ChildRead, F_SETFL, O_NONBLOCK);
  fcntl(ChildWrite, F_SETFL, O_NONBLOCK);

  childpid = fork();

  if(childpid == 0)
  {
    close(ParentRead);
    close(ParentWrite);

    while(1)
    {
      read(ChildRead, &buf, 1);

      if(buf[0] == 'q')
      {
       close(ChildRead);
       close(ChildWrite);
       close(theSocket);
       exit(0);
      }

      if((nret = recv(theSocket, message, 999, 0)) < 1)
       continue; 

      if(message[7] == '~' && message[8] == 'q')
      {
        printf("\nChat server disconnected..\n");  
        write(ChildWrite, "q\0", 1);
        close(ChildRead);
        close(ChildWrite); 
        close(theSocket); 
        exit(0);
      }

      printf("%s\n", message);

      memset(message, 0, strlen(message));
    }
  }
  else
  {  
     strcpy(message, scrName);
     strcpy(&message[strlen(message)], ": ");

     close(ChildWrite);
     close(ChildRead);

     while(1)
     {
       read(ParentRead, &buf, 1);

       if(buf[0] == 'q')
       {
         close(ParentRead);
         close(ParentWrite);   
         close(theSocket);
         exit(0); 
       }

       scanf("%s", &message[strlen(message)]);

       if(strcmp(&message[strlen(scrName) + 2], "~q\0") == 0)
       {
         write(ParentWrite, "q\0", 1);
         close(ParentRead);
         close(ParentWrite);
         close(theSocket);
         exit(0);          
       }

       send(theSocket, message, strlen(message), 0);

       memset(&message[strlen(scrName) + 2], 0, strlen(&message[strlen(scrName) + 2]));     
     }  
  } 

  return 0;
}

 

10 More Discussions You Might Find Interesting

1. Programming

multiuser chat server closes when one client closes. code included

I have been trying to write a very basic chat program but at the moment I am having problems getting it to be multiuser as it closes all connections when one client shutsdown. I have also been having problems trying to get the program to display a list of usernames to the clients. I have tried... (0 Replies)
Discussion started by: dooker
0 Replies

2. Programming

Chat client-server program

Good day everyone, I'm doing a chat client-server program:server is to receive messages from clients through a TCP port and multicast them back to all clients through a UDP port. This is my client program. I'd not know why it just sends and receives msg from server once, then it stops. Is... (1 Reply)
Discussion started by: powermind
1 Replies

3. Programming

client /server pipes

here is the concept: the client reads a pathname from the standard input and writes it to pipe1.The server reads this pathname from the pipe1 and tries to open the file for reading.If the server can open the file ,the server responds by reading the file and writting it to pipe2;otherwise the... (2 Replies)
Discussion started by: tolkki
2 Replies

4. UNIX for Dummies Questions & Answers

Server/client chat

I want to make the following programm. Using the server/client model I want 2 client to connect to the server then the server sends back to the clients the ip address and a number of a poort in order to open a udp connection between clients without using the server? What I have done since now is... (2 Replies)
Discussion started by: kasma
2 Replies

5. Programming

How can i make two client to chat with each other?

How can i make two client to chat with each other.. without any work of server, i mean peer to peer i am making chat messenger on which all host will connect to/via server and if any host want private chat then thay work independently... this is code(attached) which i have made for server... (1 Reply)
Discussion started by: bt87
1 Replies

6. UNIX for Dummies Questions & Answers

Server-client chat with a bit more

The task is to create a server client chat that contains a few basic safeguards against floods etc and which is capable of issuing at least one or two commands on the client computer. Working samples of such arrangements abound but freeware/shareware samples are not readily available. A catch in... (3 Replies)
Discussion started by: Bobby
3 Replies

7. Homework & Coursework Questions

Help with server client chat system

request create a chat system in linux where a user type smth and all the other users connected to server get the message.then a user have to create join leave or delete a channel of chat if he created it.i did the server and the client but i dont know how to implemt the chat rooms.i was ... (1 Reply)
Discussion started by: demonmind
1 Replies

8. Programming

please help a problem in client-server ipc message 2 pipes communication simple example

I want to have a message send & receive through 2 half-duplex pipes Flow of data top half pipe stdin--->parent(client) fd1--->pipe1-->child(server) fd1 bottom half pipe child(server) fd2---->pipe2--->parent(client) fd2--->stdout I need to have boundary structed message... (1 Reply)
Discussion started by: ouou
1 Replies

9. Programming

logic understanding for inter client chat server

hello everyone, i am making chat server in linux using c. i have made programs in which group chat can take place between multiple clients but i am not able to understand how to make 2 particular clients chat with each other. please help!!! (1 Reply)
Discussion started by: sweetbella
1 Replies

10. UNIX for Advanced & Expert Users

Linux chat with other users

Besides talk and write are there any other good programs for talking to a particular user on the same Linux system. (1 Reply)
Discussion started by: cokedude
1 Replies
bntext(5)							File Formats Manual							 bntext(5)

NAME
bnmotd.txt, bnnews.txt bnissue.txt - messages for the Unix Battle.net daemon DESCRIPTION
The file bnmotd.txt contains text displayed by bnetd(1), when users first log into the server. The file bnnews.txt contains text displayed when the user uses the /news chat command. The files consist of raw text with printf-style formatting escapes. Each line of a file can contain a type formatter from the following list: %B Use the broadcast attribute (???). %C Execute the line as if the user entered it as a command. %E Use the error attribute (red). %I Use the info attribute (yellow). This is the same was %W. %M Normal chat message (white). This will appear as if the user said it. %T Emote chat message (???). This will appear as if the user said it. %W Use the warning attribute (yellow). This is the same was %I. Within a line, any of the following format formatters may be used: %% Expand to a literal percent sign (%). %a Expand to the number of accounts on the server. %c Expand to the number of channels on the server. This includes all permanent and current temporary channels. %g Expand to the number of games on the server. This includes both public and private (passworded) games. %h Expand to the hostname of the server (as returned by gethostname(2)). %i Expand to this user's account ID number, formatted with a leading pound (#) sign and leading zeros. %l Expand to this user's current chat name which is usually the same %r Expand to the IP of the remote machine (the client). %t Expand to four character client tag. %u Expand to the number of users logged into the server. %v Expand to the version number of the server. SEE ALSO
bnetd(1) AUTHOR
Ross Combs (ross@bnetd.org) 2 August, 2001 bntext(5)
All times are GMT -4. The time now is 10:57 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy