Terminal-to-Terminal Chat Program using the UNIX User Datagram Protocol (UDP)

About the program

• The program allows users on different computers (or 2 terminals on the same computer) to communicate through the console.
• The program uses network sockets and IPC to allow different processes to communicate over the internet
• communication is done via UDP datagrams, which is an internet data transfer protocol

What is User Datagram Protocol (UDP)?

• UDP is a connectionless, loss-tolerating data transfer protocol, meaning no handshake is required before data can be sent, and no error-checking/resending of packets is done by the receiver upon receiving a message.
• UDP differs from TCP, which is another data transfer protocol that is connection-based and loss-intolerant.

What is Inter-Process Communication (IPC)?

• IPC is the mechanisms that allows processes to communicate with each other and synchronize their actions
• Typically, IPC is used to talk about communication between different processes, running within the same system

Starting the program

Compile the program and initiate a chat with a client at a remote terminal using

./s-talk [my port #] [remote machine IP] [remote port #]

During the chat

• type a single '!' to terminate s-talk session

• Program uses pthreads to manage 4 concurrent functions:

1. keyboard input for writing messages
2. sending these written messages to remote UNIX process using UDP
3. receiving messages from remote client
4. printing these received messages to console