Marc Quinton tells you about the CommonWidget. The CommandWidget is nearly like a terminal and allows the user to issue commands to a shell and view the result in a GtkTextView widget.

This widget can be used if you want to run some commands in the background and do not want to use any printf. Also, if you have some text output at console and would like to see it in a window, CommandWidget can perform this function for you.

CommandWidget is an external process or a shell connected to a GtkTextview to display results. This connection is made through a pipe. You can read and write to this external process. This can be a nearly full interactive process, just like terminals. There is a special class with output only and is easy to use. It could be used to provide feedback to some management tasks using external commands.

He provides an example code to explain the concept.