How can I implement two way communication between one server and several clients?
It is possible that more than one client is communicating with your server at once. As long as each command they send to the server is smaller than PIPE_BUF (see above), they can all use the same named pipe to send data to the server. All clients can easily know the name of the server’s incoming fifo. However, the server can not use a single pipe to communicate with the clients. If more than one client is reading the same pipe, there is no way to ensure that the appropriate client receives a given response. A solution is to have the client create its own incoming pipe before sending data to the server, or to have the server create its outgoing pipes after receiving data from the client. Using the client’s process ID in the pipe’s name is a common way to identify them. Using fifos named in this manner, each time the client sends a command to the server, it can include its PID as part of the command. Any returned data can be sent through the appropriately named pipe.
