Creating arbitrary sockets

For defined operations such as file transfer, remote shells, and so on, we have prebuilt tools such as ftp and ssh respectively. However, in some cases you will find the need to do a customized network operation. An example for this might be writing a script which will do something when a remote client connects to your machine. In this recipe, we will create simple network sockets and use them for communication.

Getting ready

To perform these things, we will need to create network sockets which enable us to do data transfer over a TCP/IP network. The easiest way to do this is by using the command netcat (or nc). We need two sockets: one listens for connections and the other connects to this one.

How to do it...

1. Set up the listening socket using the following:

   nc -l 1234
   

   This will create a listening socket on port 1234 on the local machine.

2. Connect to the socket using the following:

   nc HOST 1234
   

   If you are running this on the same machine that the listening socket is...