Creating text-based interactive scripts

The one thing that we haven't done so far is put any interaction in our scripts. The reason for this is simple – at this point, we've only discussed how to output information and not how to get it from the user or any other source. In the real world, interaction is something that we need to deal with because it is at the core of creating any script. We could say that there are two kinds of interaction. First, our script can interact with the system itself. This means using different variables and other information that we can get from the system – for example, free space in memory or on mounted disks. You could say that this is not real interaction but instead just reading real-time data from the system. But, still, it's a very useful way of making sure that a script does what it needs to do.

Another thing that we can do is interact with the user starting it. If the script is run by the system, it isn't something...