Abstract:

This paper describes the author's experience with laboratory activities based on Unix terminals and command-line programs. This experience may seem as a back step to the past with respect to modern GUI-based operating systems. However, as the carried-out laboratory activities show, working with distraction-free terminals can be a quite challenging learning experience for the students.

In [1], the author has described advantages and disadvantages of the usage of a particular software package, called Dome, for the laboratory activities of modules on power system analysis, control and stability. The software package itself is outlined in [2]. Howeer, an important aspect that has not been discussed in previous publications is the impact of the “command line” approach that is required when using Dome on the overall realisation of the laboratory activities.

The author had the chance to observe the reactions of students of two different countries, namely Spain, at University of Castilla-La Mancha (UCLM), and, more recently, Ireland, at University College Dublin (UCD), to the same laboratory activities designed to explore the effect of basic controllers such as primary voltage and frequency controllers and ULTC voltage regulators on power system transient behavior.

In both cases, i.e., at UCLM and UCD, the labs were attended by students at the fourth stage of their undergraduate course of Electrical Engineering. Moreover, in both universities, laboratory facilities are standard 3- to 4-year old personal computers mounting a Windows operating system. So, the design and the sequence of the laboratory activities has been carried out taking into account that the students have no previous knowledge on how to remotely connect to a Unix server and subsequently on how to use the basic commands of a Unix shell. It has to be noted that the current generation of students is not used to terminals and shell commands. The closest application to a terminal that most students have used is generally just the Matlab IDE. However, Matlab differs from a Unix terminal in several relevant aspects. To cite a couple, Matlab help is available as a GUI and the Matlab main windows provides several short-cuts that can be accessed through the mouse.

In summary, the main contributions of this paper are the following:
1. A description on how a generation of engineering students not used to Unix terminals and command-line-based applications approaches this apparently “vintage” tool.
2. A discussion on the very short learning curve of students and their ability to quickly adapt to a different way to interact with computers. The laboratory activities discussed in the paper clearly shows that students become quite efficient in few hours.
3. A discussion on the didactic benefits of using “old-style” Unix shells in a time dominated by touch-screen tablets and graphical user interfaces that prevent the user to understand how the underlying computing machine is working.
4. A demonstration based on students' feedback on how the Unix philosophy based on “simple programs that do well just one thing” is quickly accepted as a “right” approach by the students. Although statistics cannot be based on large numbers, the good acceptance of the students of the “Unix way” is a clear sign that the current trend to increase the hiatus between users and software developers is not necessarily a good trend, at least for students of engineering matters.

Keywords:

Unix shell, command line, electrical engineering, power systems control.