CSci 553
Spring 2006
LAB #1
Due Wed, Feb 1, 2006


(1) If you have not already, review all of the commands and concepts
    presented in chapters 2-4 making sure you can understand and run
    the commands by following allong at a Linux command line while
    doing the reading.

(2) Do projects #1 and #2 from [UPU] on page 144.  Show an entire
    command pipeline for each project.  Use the script function to
    trace the result of the execution and save an example run to a
    file.  Please create a directory under your home directory called
    lab1 and place your script output and the shell scripts you create
    in this directory.

Project #1

    Write a command pipeline that compresses the contents of a file
    and then encrypts it, using a known key, and writes the result to
    a new file.  What is the corresponding command pipeline to take
    this encrypted file and decrypt and uncompress it to produce the
    original file?

Project #2

    Write a command pipeline to find files in a directory hierarchy
    (e.g. your home directory) that have not been accessed for 30 days
    and compress them.  

(3) Write a small essay (at least 1000 words) on some topic (maybe
    about your future career plans, for example).  Use the vi or emacs
    editor.  Then write an awk program to count the number of
    occurrences of the following words: "I", "the", "was", "when",
    "on", "this", "it", "in", "time", "and", "have".  Experiment with
    different words.  As in (2), save an example output of your
    session using the script command and put this output in a file in
    your lab1 directory.


(4) Do exercise 4.2 from [UPU] on page 180.  Again save your work in
    your lab1 directory.

Exercise 4.2

    Experiment with the exec command by writing a series of three
    shell scripts called "a.sh" "b.sh" and "c.sh", each of which
    displays its name, executes ps, and then exec's the next script in
    the sequence.  Observe what happens when you start the first
    script by executing: $ exec a.sh