Last revisedSeptember 02, 2016, 02:08:16 PM PDT
This work is licensed under a Creative
Commons Attribution-Noncommercial-Share Alike 3.0 United States License.
We will be using a particular
tool on these computers that you may not be familiar with, known as the
command line.
In the 1960s and 1970s, there weren’t fancy displays. Most computer monitors were only capable of extremely simple graphics, and generally they were restricted to displaying only alphanumeric characters, 80 columns by 25 lines.
Therefore, the entire interaction was by typing the names of commands into this window, then pressing return to begin the command. Imagine that every time you wanted to run Firefox, you had to type “Firefox” and press return. That’s how it all worked. (Of course, there wouldn’t have been any program with graphics as fancy as Firefox, but that’s beside the point.)
It may sound terrible, but the command line was (and still is) an essential tool for a programmer. Although it may be hard to believe, there are certain interactions that are much easier with a command line interface than with the WIMP (Windows, Icons, Menus, Pointer) interface you are used to.
In fact, if you’re interested about the history of the early days of computer interaction, and the first 30 years of operating system evolution, you can download and read Neal Stephenson's essay, In the Beginning was the Command Line. (This is in no way required for this assignment or the course, but it’s interesting and funny.)
To learn the command line, log in to one of the lab machines in Olin 124.
Once you have logged in, run the Application Terminal. (It should have a shortcut in the dock.) This will open up small window that displays text characters (specifically, it is 80 columns by 25 lines). In the window you’ll see something like this:
davisj@hopper:~$Voila! This is your command line. The line of text there is known as
the
prompt. There is actually a lot of information in that
cryptic line: It is telling you your username (in my case, davisj),
your computer name
(hopper), and your current directory (~,
which is a special name for the current
user’s home directory.)
Now, go through Typograhical Conventions, Introduction to the UNIX Operating System, and Tutorials 1-4 of this tutorial. The tutorial was originally written for the Unix operating system and for students at the University of Surrey (note British spellings), but it is still accurate enough for us.
One difference is that on their system, the final character of the
prompt is a %,
but on our systems it is a $. So all their examples of
what to type begin with a %
character. Don’t type this in to the command line. It is simply an
indicator of
what the prompt looks like.
Upload the file named slist, which you created in Tutorial 3.3, using the online turnin form. If you haven't created
a file named slist, then turn in the file biglist
instead.
Created August 31, 2016
Last revisedSeptember 02, 2016, 02:08:16 PM PDT
This work is licensed under a Creative
Commons Attribution-Noncommercial-Share Alike 3.0 United States License.