Assignment 5-A
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Updated: 2000-11-18 16:25

Assignment 5-A - UNIX

This assignment is for sections taught by Ian Allen.  It is the first half of Assignment 5.

Hand in:
One printed and hand-annotated telnet session log file in hard copy form.  For full marks, follow the Assignment Submission Standards.  In particular, make sure you use Courier font and annotate your output (see below) before you hand it in.
Preparations:
You must complete the work in the previous Chapters (1, 2, 13, 7, and 3) as well as Chapters 4 and 5 in your Unix text before doing this assignment.
 

Step 1.  (Readings in Chapter 4 and Chapter 5)

Use the vi text editor to type the answers to the following Chapter Reading/Study Exercises into the file named my5answers in your home directory.  Number each answer clearly.  You will find the Chapter Exercises under the Unix button on the course page.
    Put your name and your Algonquin e-mail address at the top of the file.
    Answer the Chapter 4 Exercises 4-1, 4-2, 4-3, 4-5, 4-6, and 4-14 through 4-19.
    Answer the Chapter 5 Exercises 5-3 through 5-8, and 5-12 through 5-18.

Put your name and your Algonquin e-mail address at the top of this file.  Number each answer clearly.

Step 2.  (Shell Script my5tree)

First: Before you begin this step, in your HOME directory, follow the text and Figure 4-6 (p.266) to create the directory tree named Projects.  Make sure that this Projects tree has two sub-directories and six files in it, exactly as it appears in the Figure.  Delete any files and directories under Projects that do not appear in Figure 4-6 on page 266.

Practice online to develop Unix command lines and/or pipelines that perform the following actions, one-by-one. As you figure out each correct command line, add the command line to a new executable Unix script file named my5tree in your home directory.  Test the script after each added line.  Add lines to the script file one at a time; do not put all the actions in the script and then try to debug it!

Notes on this script:

  1. Some actions may be done by a single Unix command; some actions may need a pipeline of one or more Unix commands.  Do not add extra commands to this script.  Do exactly what is requested and no more.  (For example, do not change working directories unless the action requires it.)
  2. The actions below must not depend on the script running in any particular working directory.  The script should work no matter what your current working directory is.
  3. Your actual account or userid and home directory name must not appear in any pathnames used in the script.  Use the appropriate environment variables any time you need these values.  (For example, use $HOME not /shome/abcd0001.)

 Here are the actions your script must execute:

  1. The very first line of the script must indicate what program is to run the script:
    #!/bin/sh -u
  2. Next, include one or more comment lines with your name, your Algonquin email address, and the date you began creating the script.
  3. Use an echo command to display the following text on the screen:
       echo "$0 Start of script for $USER in $PWD on `date`"
    Pay attention to the kind of quotes used in this line!  Make sure the three shell variables expand correctly and that the date command executes.  (Note the use of back-quotes around `date`.)
  4. Create a directory under the /var/tmp directory and name it with your userid using the contents of the USER environment variable: /var/tmp/$USER
  5. Use ls to list the above directory to make sure that it exists and is empty.  (Do not change your current working directory!)
  6. Using the Projects directory tree you created in your home directory at the beginning of this step, use a single Unix command to recursively copy your entire Projects directory tree to the directory you just created: /var/tmp/$USER You may need to look up online (in the Unix manual) the option that makes the Unix copy command copy one entire directory recursively to another directory.  (Look for the word recursive.)
  7. Using one single Unix command, list the entire /var/tmp/$USER directory tree, including all the subdirectories and files.  You should see two sub-directories and a total of six file names in the output, exactly like Figure 4-6.  You may need to look up online (in the Unix manual) the option to turn on a recursive listing of a directory and all its subdirectories.
  8. For this next action, use a Unix command that locates files by name.  The directory in which to look is the new /var/tmp/$USER directory you just created.  The name to look for is report3 - find this file by name and display its pathname.
  9. Create name /var/tmp/$USER/rep3 as a second name for the report3 file you found in the previous action.  The new name must be a link to the same file; it must not be a copy of the file.
  10. Use the -i and -l options of the ls command to show a long listing including the inode numbers of the two file names in the previous action.  (The inode numbers and all file details should be the same, since they are the same file!)
  11. Remove the entire /var/tmp/$USER directory tree using a single Unix command.  (The entire directory must be removed.)
  12. Use the ls command to verify that the directory in the previous action no longer exists.  (You should get an error message about the nonexistent directory.)

Put the command lines that perform the above actions into the Unix script file named my5tree in your home directory, make it executable, and verify that the script file works exactly the same as if you had typed in the commands yourself.  The only error message you should see is the one from the final ls command in the script.

Does the script follow the Notes given at the start of this step?

Step 3.  (Shell Script scriptA)

Write and test the following script file.  Save this script - you will use it again in the next assignment.

Copy the six-line programA script file from Step 2 on page 355 of the text to a new file named scriptA.  Make the following changes to the new file:
  1. Replace the first line of the script (echo hello) with:
        echo "$0 --- scriptA PID $$ in $PWD starts here ---"
  2. Replace the ps command line with:   ps -f
  3. Replace the fourth line of the script (another echo) with:
        echo "$0 scriptA's PID is $$"
  4. Replace the name Gene Calhoun with your own name
  5. Add this line to the bottom of the script:
    echo "$0 scriptA PID $$ is done on `date`!"
  6. Insert a correct #!/bin/sh -u line at the start of the script.

Save the modified script as scriptA and make sure it is executable by you.  Your new script must have only seven executable lines plus the #!/bin/sh -u line at the top.  Pay attention to the quoting!  Test it.  Ensure that the modified script runs error-free.  Do not add the commands given in Step 4 on page 356.  Pay attention to the different types of quotes being used (some quotes may be difficult to read in this web page, depending on your browser and font):  DoubleQuote ",   SingleQuote ',   and BackQuote `

Step 4. (Shell Script scriptB)

Write and test the following script file.  Save this script - you will use it again in the next assignment.  This script requires scriptA  to work.

Make a copy of the eight-line script scriptA from Step 3 and name the new copy scriptB. Modify the new copy by making the following changes to the new scriptB file:

  1. Inside scriptB, change the every word scriptA to scriptB.  (Keen students will find a quick way to do this using one line in vi on page 776.)
  2. Delete the line that echoes the contents of the HOME environment variable.
  3. Replace the b= line containing your name and the echo command line that follows it with these three new command lines (delete those two lines; add the following three new ones in their place):
       echo "$0 scriptB PID $$ I'm calling scriptA now"
       ./scriptA
       echo "$0 scriptB PID $$ after call to scriptA"

Save the modified script as scriptB and make sure it is executable by you.  Your new script will have exactly eight lines.  Test it in the same directory that contains scriptA.  (This script calls scriptA.)  Ensure that the modified script runs error-free.  Pay attention to the different types of quotes being used.

Step 5. (Shell Script scriptC)

Write and test the following script file.  Save this script - you will use it again in the next assignment.  This script requires scriptB  to work.

Make a copy of the eight-line script scriptB from Step 4 and name the new copy scriptC. Modify the new copy by making the following changes to the new scriptC file (and do these changes in this order):

  1. Inside scriptC, change every occurrence of word scriptB to scriptC.
  2. Inside scriptC, change every occurrence of word scriptA to scriptB.  

Test  scriptC in the same directory that contains scriptB.  (This script calls scriptB.)  Ensure that the output of all the scripts used in this step is error-free.   (To debug the script output you may need to pipe the output into a command that pages the output for you; or, you can redirect the output to a file and look at it there.)

Save these three scripts for use in the next assignment.

Step 6. (Creating the Telnet Log File)

You need to have done all the readings, completed all the prerequisite Chapters, and completed all previous steps of this Assignment to do this logging Step.

Login to Unix and then turn on telnet logging to record the following Unix session on your A: diskette or on your N: drive.  When asked to display the contents a file or script, use the  cat command.  (For full marks, do not use an editor or any commands that paginate the file, since the pagination mis-formats the display of the file in the log.)  Perform the following actions for the log file:

  1. Set your shell prompt to be your Algonquin userid.  (You learned this in Chapter 1.)
  2. Display the contents of your USER environment variable.
  3. Display the current date.
  4. Display the contents of the my5answers file created in Step 1.
  5. Display the contents of the completed my5tree script of Step 2.
  6. Execute the  my5tree script to show that it works correctly and that it generates the correct output, without unexpected errors.
  7. Display the contents of the scriptA file of Step 3.
  8. Display the contents of the scriptB file of Step 4.
  9. Display the contents of the scriptC file of Step 5.
  10. Execute the scriptC file to show that it (and the scripts it calls) works correctly.

Turn off telnet logging.  Print the Telnet log file using a monospace (Courier) font.

Step 7. (Annotating the Telnet Log File)

 Annotate your printed Telnet log file output by hand as follows:

  1. Take a pen or marker and draw long, page-width lines between each of the numbered actions you performed in the previous step.
  2. Write in (using pen or marker) the number of the action beside each of the actions.  Use the action numbers given in the previous step.
  3. Highlight or underline each of the Unix command lines you typed to the shell to do the actions in the previous step.  Do not highlight the output of the command lines.  Highlight only the Unix command lines that you typed in.

There is only one telnet session log file to hand in.  It comes from Step 6.  Do not log or hand in anything else other than the one log file from Step 6.  Make sure you annotate the log file by hand as required in Step 7.  

Web Author: Ian! D. Allen idallen@ncf.ca
Updated: 2000-11-18 16:25