Well your code is pretty messy, Id sugest you start from 0 with a better design.
There are plenty of uncontrolled stuff happening specially with string buffer handling like so:
After the recv() call there is no way to make sure that 'message' is a proper 0 terminated string, so strlen() can go outside the buffer size and cause some weird stuff to happen after memset() runs. But this is probably not the major cause of problem for you.
Your client probably is not working because the parent process (childpid != 0) calls exit() before waiting for the child to clean up. If parent exits while child is still running kernel will send SIGINT to your child that will cause premature termination of it. You either need to call wait() function on the child or implement a better design.
Last edited by expl; 10-19-2012 at 03:24 PM..
Reason: typo
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)
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)
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)
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)
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)
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)
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)
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)
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)
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
LEARN ABOUT ULTRIX
vfork
vfork(2) System Calls Manual vfork(2)Name
vfork - spawn new process in a virtual memory-efficient way
Syntax
pid = vfork()
int pid;
Description
The can be used to create new processes without fully copying the address space of the old process, which is inefficient in a paged envi-
ronment. It is useful when the purpose of would have been to create a new system context for an The system call differs from in that the
child borrows the parent's memory and thread of control until a call to or an exit (either by a call to or abnormally.) The parent process
is suspended while the child is using its resources.
The system call returns a value of zero (0) in the child's context and, later, the pid of the child in the parent's context.
The system call can normally be used just like It does not work, however, to return while running in the childs context from the procedure
which called because the eventual return from would then return to a nonexistent stack frame. Be careful, also, to call _exit rather than
exit if you cannot call because exit will flush and close standard I/O channels and thereby cause problems in the parent process's standard
I/O data structures. Even with it is wrong to call exit, because buffered data would then be flushed twice.
Restrictions
To avoid a possible deadlock situation, processes which are children in the middle of a are never sent SIGTTOU or SIGTTIN signals. Rather,
output or ioctls are allowed, and input attempts result in an end-of-file indication.
Diagnostics
Same as for
See Alsoexecve(2), fork(2), sigvec(2), wait(2)vfork(2)