CS W1001-01 Introduction to Computer Science

Homework 0 (4 points)

Getting started with your computer account

For Homework 0, we would like you to:

• Get an AcIS extended account.
• Try out a variety of UNIX commands.
• Start using Pico
• Start using the web
• Send email using Pine (or your email program of choice).

Due Date:

Reading:

Things to try on your AcIS account:

• Go on the web to the course home page to see the office hours of the TAs: http://www.cs.columbia.edu/~evs/1001/ -- It is recommended to work on this and all assignments in the lab when a TA is there so you can get help if and when you get stuck.
• Go to http://www.columbia.edu/acis/publications/handouts.html to see what helpful handouts AcIS has available; get the ones you might need.
• Explore the topics in the online UNIX tutorial, by typing "tutor". (This and the commands below are at the (Unix) dollar sign prompt.)
• "mkdir W1001" will create a space (directory) for your work in this course
• "cd W1001" will go to that directory
• "pwd" will show you what directory you are in ("print working directory")
• "cp ~es66/W1001/dontreadthis ." will copy a file from my directory to yours (don't forget that "extra" period at the end, and the space right before it!)
• "ls" will show you there is a new file in your W1001 directory
• "cat dontreadthis" will show you the contents of the file. If it goes by too fast, try "more dontreadthis".
• Don't read it!
• Just kidding.
• Get the AcIS handout about Pico and use Pico to edit a file in your W1001 directory. Name this file hw0, or something that makes sense. You will type all your answers to this homework in that file, and then send it to a TA.
• Optional: EMACS is a more sophisticated editor than Pico. Most students of 1001 will use Pico to edit their assignments (e.g., html documents or computer programs). However, if you are interested, or if you may continue programming html or Java after this semester, EMACS makes a lot of things faster and more convenient. The big minus is that EMACS takes a lot longer to learn -- everything you want to do is some kind of control-character code. To find out, start up EMACS (type "emacs") and run the EMACS tutorial (control-h t) to learn EMACS. Also, AcIS has a handout overviewing the main commands.
• Type answers to the following questions in your file:
  1. Provide the answers to at least two of the puzzles from the "dontreadthis" file. Feel free to get as much help from anyone you want on this particular exercise. If your friend reads one out loud, sometimes you can tell what they are saying before they do! Also, it helps to repeat it out loud, faster and faster. The ones further down the list are more difficult.
  2. If your home page on the web linked to home pages of 5 friends, and each of them linked to 5 friends that you don't know, and so on and so on, how many different people could I get to from your web page with four clicks of my mouse? What about with 10 clicks? Hint: with one click, I could get to one of a possible five. With a second click, I could get to one of a possible 25. Show your work.
  3. Compute who your TA is. Do this by multiplying together the day of the month you were born, the month you were born (e.g., March is 3) and the last 3 digits of your student ID. Then divide that number by 5. What is the remainder? The remainder is called the modulus, and it is useful in many computer science problems. In this case it should be between 0 and 4. This number determines who your TA is. 0: Boyle, 1: Shen, 2: Clem, 3: Solomon, 4: Simin. Please show your work. By the way, you may be switched to a different TA soon, due to administrative shuffling (in which case you will be notified), and in any case you can always visit the office hours of any TA. If you want to switch to a TA with more compatible hours, wait a couple weeks before requesting this, since the office hours of TAs are only tentative at this time.
  4. Write a couple sentences for your TA describing what you personally hope to learn from this course, what you find most intriguing about computer science, and what you find most intimidating. This will be a nice thing for your TA to hear about.
  5. Try "man man" at the Unix prompt. Now, use the "man" command to figure out what a UNIX guru means when she says that "less" is "more". Hint: "less" and "more" are Unix commands.
• "Hand in" your answers by emailing them to your TA. The course web page has each TA's email address. Use Pine (or your favorite mailer) to send it -- you can use the control-r command (hold down the control key and press the r key at the same time) in Pine to read in a file.