Assignment 1: Shell introduction

Due: 5:00pm, Friday, August 29. (Note, though: Any submissions by 5:00pm, Friday, September 5, will be accepted without penalty. This is because other students may enter CSCI 230 late.) Value: 25 pts.

In this assignment, we will be studying how to use the Linux command line. It is good to become proficient with the Linux command line anyway, but later in this course we will be studying how Linux interprets and executes commands, so it's important that you start now.

Getting started

I suggest reading the tutorial Introducing the Linux command line, which provides the information about using the Linux command line necessary to completing this assignment. We will use only Sections 2 through 9 of this document, but of course the remaining sections are also useful for you to read.

You will need an account on the computer science department's Linux computers, which can be found in MCRey 316 and 318. This network is managed independently of the college network, and your password that works for your e-mail, Campus Web, and the Windows and MacOS computers around campus will not work with the Linux computers.

If you don't already have a Linux account from a previous semester, please stop by Dr. Burch's office in MCRey 310. (If Dr. Burch is unavailable, you might ask Dr. Ferrer if he'd be willing to help.) If you do have an account but have forgotten your password — shame on you! But, again, you can stop by Dr. Burch's office for help with resetting your password.

After you have successfully logged into a Linux computer, you will want to start the Terminal program. Go to the Application's menu in the screen's upper left corner, then select the Accessories submenu, and then select the Terminal option.

What to submit

You should submit your solutions to the below problems as a text file via the Moodle course page. If you have completed this assignment with a partner, please indicate both partners' names at the top of the file; only one partner should submit a solution.

Please note: When I say a text file, I mean something created in a genuine text editor that saves simple ASCII (or UTF-8) files. Do NOT submit a document saved from Microsoft Word or LibreOffice, unless you have exported it into “Plain Text” format.

Your submitted file should start with your name (and your partner's) and after that simply have each problem's number followed by the single command that solves the problem. You do not need to try to explain why the command works.

Note: Your answers should rely only on the information provided in the document Introducing the Linux command line.

Setting up your file

After logging in, the first thing you will want to do is to fetch the file that you'll be working with throughout this assignment. To copy the file into your directory, issue the following command while at the command prompt: Enter the portion in green boldface and then press the Enter key.

me@computer:~$ cp /export/shared/courses ~

This copies the file named courses into your home directory. The courses file lists all CSCI and MATH courses taught at Hendrix from Fall 2004 to Spring 2011. Here is an example of the first three lines from the file:

2004 1S   CSCI150   01   8:10am    MTWF 15   MCRey315  D.Collins
2004 1S   CSCI151   01   11:10am   MTWF 5    MCRey317  C.Burch
2004 1S   CSCI250   01   10:10am   MWF  3    MCRey317  G.Ferrer

Each line of the file contains several pieces, separated by tab characters:

  1. Academic year the course was taught; for example, 2004 represents the 2004–05 school year.
  2. Semester it was taught (1S for fall, 2S for spring)
  3. Course number (e.g., CSCI150)
  4. Section number (e.g., 01)
  5. Time taught (e.g., 8:10am)
  6. Days taught (e.g., MTWF)
  7. Number of students who earned a grade in the course (e.g., 15)
  8. Building and room where taught (e.g., MCRey315)
  9. Instructor (e.g., D.Collins)

No space characters are included on any of the lines — the only whitespace in the file are the tab characters separating columns within each line and the newline character at the end of each line.


This assignment consists of a set of problems for which you are to write one-line commands that solve the problem concisely. For each problem, I have provided the output that would result from executing the correct command using the provided courses file. Of course, your solution should represent a command that actually computes the answer as specified in the problem.

  1. List all lines corresponding to sections taught in rooms that were not in the Morgan Center (that is, not in MCRey or MCAcx).

    2005 1S   MATH120   01   9:10am    MWF  21   MillsC    D.Collins
    2008 1S   MATH120   01   9:10am    MWF  12   Fause10   Z.Barel
    2008 2S   MATH120   02   11:10am   MWF  17   Mills304  J.Nail

    Note: Each question includes a sample output, which is actually the correct answer based on the distributed courses file. Your solution should include only the information in these lines, though sometimes the question (like this one) will allow the lines to be reordered. Don't worry about the number of spaces between columns.

    While the questions give the appropriate output for the distributed courses file, your solution should work as specified even if courses is changed to add additional courses. For example, I might get the above output by finding all MATH120 courses with an enrollment of 12, 17, or 21, but this answer would be wrong with some changes to the courses file.

  2. List all lines corresponding to sections taught in MCRey115 that were not sections of MATH 140.

    2006 2S   MATH130   02   12:10pm   MTWF 15   MCRey115  Z.Barel
    2007 2S   MATH130   02   12:10pm   MTWF 20   MCRey115  Z.Barel
    2008 1S   MATH120   02   12:10pm   MWF  40   MCRey115  J.Nail
    2012 1S   MATH270   01   1:10pm    MWF  27   MCRey115  C.Camfield
    2012 2S   MATH120   01   12:10pm   MWF  36   MCRey115  D.Collins
  3. For each time CSCI 420 has been taught over the years, list the year it was taught and the instructor who taught it.

    2005 D.Hoffman
    2007 D.Collins
    2009 D.Leonard
    2011 D.Hoffman
    2013 C.Burch
  4. List the year, semester, and instructor for the seven earliest sections of CSCI 135 (starting from 2004, the earliest year represented in the file).

    2004 2S   G.Ferrer
    2005 1S   G.Ferrer
    2006 2S   M.Clark
    2006 2S   G.Ferrer
    2007 1S   G.Ferrer
    2007 2S   A.Wright
    2007 2S   G.Ferrer
  5. Show the lines corresponding to the six sections with the highest enrollments, in descending order of enrollments. (Your output may differ from the example output due to breaking ties differently.)

    2006 2S   MATH120   01   12:10pm   MWF  46   MCAcx119  D.Collins
    2012 2S   MATH140   02   11:10am   MTWF 42   MCRey110  C.Camfield
    2009 2S   MATH130   02   12:10pm   MTWF 42   MCRey110  L.Seme
    2008 1S   MATH130   02   11:10am   MTWF 40   MCRey110  D.Sutherland
    2008 1S   MATH120   02   12:10pm   MWF  40   MCRey115  J.Nail
    2007 2S   MATH120   01   10:10am   MWF  40   MCRey110  J.Nail
  6. List the number of sections of MATH 130 taught in each year.

          4 2004
          4 2005
          5 2006
          5 2007
          5 2008
          5 2009
          6 2010
          6 2011
          5 2012
          7 2013
  7. List the total number of sections of CSCI 150 taught by each instructor over the years.

          8 C.Burch
          3 D.Collins
         12 G.Ferrer
  8. List the number of sections taught by each instructor in the 2009–10 academic year (that is, with 2009 in the line's first field).

          6 B.Wood
          5 C.Burch
          6 D.Campbell
          1 D.Collins
          3 D.Leonard
          2 D.Sutherland
          5 G.Ferrer
          6 L.Seme
          6 Z.Barel
  9. Extra credit: List the number of distinct courses taught by each instructor over the years listed. By distinct courses, I mean that somebody may have taught several sections of CSCI 150 (for example), but all these sections together count as just one distinct course. But if the person teaches CSCI 230 just once, that also counts as having taught a separate course.

          1 A.Wright
          1 A.Zimmerman
         10 B.Cha
         11 B.Wood
         12 C.Burch
         11 C.Camfield
         13 D.Campbell
         12 D.Collins
          4 D.Hoffman
          4 D.Leonard
          5 D.Sutherland
         10 G.Ferrer
          2 H.Liang
          1 J.Nail
          7 L.Seme
          1 M.Clark
          1 N.French
         15 Z.Barel