Updated: 2015-03-23 17:08 EDT

1 Due Date and Deliverables

Do not print this assignment on paper!

WARNING: Some inattentive students upload Assignment #10 into the Assignment #09 upload area. Don’t make that mistake! Be exact.

2 Purpose of this Assignment

Do not print this assignment on paper! On paper, you cannot follow any of the hyperlink URLs that lead you to hints and course notes relevant to answering a question.

This assignment is based on your weekly Class Notes.

  1. Practice with Permissions in Lab Worksheet #08 HTML
  2. Practice setting Umask.

Remember to READ ALL THE WORDS to work effectively and not waste time.

3 Introduction and Overview

This is an overview of how you are expected to complete this assignment. Read all the words before you start working.

For full marks, follow these directions exactly.

  1. Complete the Tasks listed below.
  2. Verify your own work before running the Checking Program.
  3. Run the Checking Program to help you find errors.
  4. Submit the output of the Checking Program to Blackboard before the due date.
  5. READ ALL THE WORDS to work effectively and not waste time.

You will create file system structure in your CLS home directory containing various directories and files. You can use the Checking Program to check your work as you do the tasks. You can check your work with the Checking Program as often as you like before you submit your final mark. Some task sections below require you to finish the whole section before running the Checking Program; you may not always be able to run the Checking Program successfully after every single task step.

When you are finished the tasks, leave the files and directories in place on the CLS as part of your deliverables. Do not delete any assignment work until after the term is over!

Assignments may be re-marked at any time on the CLS; you must have your term work available on the CLS right until term end.

Since I also do manual marking of student assignments, your final mark may not be the same as the mark submitted using the current version of the Checking Program. I do not guarantee that any version of the Checking Program will find all the errors in your work. Complete your assignments according to the specifications, not according to the incomplete set of the mistakes detected by the Checking Program.

3.1 The Source Directory

All references to the Source Directory below are to the CLS directory ~idallen/cst8207/15w/assignment10/ and that name starts with a tilde character ~ followed by a user name with no intervening slash. The leading tilde indicates to the shell that the pathname starts with the HOME directory of the account idallen (seven letters).

You do not have permission to list the names of all the files in the Source Directory, but you can access any files whose names you already know.

3.2 Searching the course notes on the CLS

All course notes are available on the Internet and also on the CLS. You can learn about how to read and search these CLS files using the command line on the CLS under the heading Copies of the CST8207 course notes near the bottom of the page Course Linux Server.

4 Tasks

4.1 Set Up – The Base Directory on the CLS

You must keep a list of command names used each week and write down what each command does, as described in the List of Commands You Should Know. Without that list to remind you what command names to use, you will find assignments very difficult.

  1. Do a Remote Login to the Course Linux Server (CLS) from any existing computer, using the host name appropriate for whether you are on-campus or off-campus.

  2. Make the CLS directory ~/CST8207-15W/Assignments/assignment10 in which you will create the files and scripts resulting from the following tasks.

  3. Create the check symbolic link needed to run the Checking Program, as described in the section Checking Program below.

This assignment10 directory is called the Base Directory for most pathnames in this assignment. Store your files and answers in this Base Directory, not in your HOME directory or anywhere else.

Use the symbolic link to run the Checking Program to verify your work so far.

4.2 Part A – A file to record your permissions

You need to understand Permissions for this task.

You will need to record the permissions you set on each of the directories and files you create in the next Part, below. You will record these permissions by copying and editing a file that you get from your instructor. You can record each of the permissions as you create things step-by-step below, or you can record all of the permissions after you have finished, before you run the checking program.

  1. Copy the file record.txt from the Source Directory into your own file abcd0001.txt (no spaces) where the text abcd0001 is replaced by your own eight-character userid in the file name. This file copy should be located directly under your Base Directory.

  2. Fix the permissions on the file so that you can edit it and nobody else (group or other) has any permissions at all.

  3. As you work on the next Part below, edit your copy of the file with a text editor. (The vim editor is recommended, since that is the universal text editor for system administrators.) Replace each string of three underscores in the file with the correct three-digit numeric (octal) permission value that you record in the next Part below. Do not change anything else in the file. Note the word count at the bottom of the file. Your count must match exactly, at all times. If not, re-copy the file and start over.

4.3 Part B – Creating structure with permissions

You need to understand Permissions for this task. Do the permissions section of Lab Worksheet #08 ODT before continuing. Record all your answers for later quizzes.

Now you will create some directories and files, then set the correct permissions on them. The permissions to set are described below.

Because you are applying permissions to directories as a non-root user, be careful not to lock yourself out of directories by restricting permissions on them too soon. First, create all the file and directory structure from the top of the directory tree down, and then apply restrictive permissions afterward from the bottom of the tree upward, after you have created all the structure.

If you don’t apply permissions last, from the bottom up, you will deny yourself permissions that will prevent you from entering some directories lower down. Assign permissions from the bottom toward the top.

Make sure you create directories where directories are required and files where files are required.

  1. Create a directory named head under your Base Directory:
    1. Directory head has no permissions for others. The group can use ls to see the content, but cannot create files or cd into the directory. The user has full permissions. Record the permissions for head in the Record file.
  2. Underneath directory head create three three-letter directories named: usr grp oth
    1. Directory usr has no permissions for group or other. The user can cd into it, but cannot create any new content nor use ls to see any files in it. Record the permissions.
    2. Directory grp has no permissions for user or other. The group can cd into it and use ls in it, but cannot create any new content. Record the permissions.
    3. Directory oth has no permissions for user or group. Others have full permissions. Record the permissions.
  3. Underneath directory usr create three two-letter files named: rd wr xc
    1. None of the files have any permissions for group or other.
    2. File rd has read permission (only) for the user. Record the permissions.
    3. File wr has write permission (only) for the user. Record the permissions.
    4. File xc has execute permission (only) for the user. Record the permissions.
  4. Underneath directory grp create three two-letter files named: rw wx rx
    1. None of the files have any permissions for user or other.
    2. File rw has read and write permission (only) for the group. Record the permissions.
    3. File wx has write and execute permission (only) for the group. Record the permissions.
    4. File rx has read and execute permission (only) for the group. Record the permissions.
  5. Underneath directory oth create three three-character files named: rwx ??? *** (Some characters are meta-characters that are special to the shell and will need careful handling. See the Class Notes about Quoting.)
    1. None of the files have any permissions for user or group.
    2. File rwx has full permissions for other. Record the permissions.
    3. File ??? has no permissions for other. Record the permissions.
    4. File *** has only read permission for other. Record the permissions.

Remember to read all the words above about working from top to bottom and then from bottom to top in this Part.

Run the Checking Program to verify your work so far.

4.4 Part C – Minimal Permissions

You need to understand Permissions for this task. Do the permissions section of Lab Worksheet #08 ODT before continuing. Record all your answers for later quizzes.

Put the text below into file minimal.txt and replace all the sets of three underscore characters using your answers from Worksheet #08. Missing permissions should be given as dashes so that each set of three underscores is replaced with exactly three other characters:

*** Table of MINIMUM rwx symbolic permissions ***
1. copy a file:     srcdir=___  srcfile=___  targetdir=___
2. move a file:     srcdir=___  srcfile=___  targetdir=___
3. link to a file:  srcdir=___  srcfile=___  targetdir=___
4. delete a file:   srcdir=___  srcfile=___
5. read a file:     srcdir=___  srcfile=___
6. modify an existing file:  dir=___  oldfile=___
7. create a new file:        dir=___

Run the Checking Program to verify your work so far.

4.5 Part D – Using umask to mask default permissions

You need to understand Umask for this task. Do the umask section of Lab Worksheet #08 ODT before continuing. Record all your answers for later quizzes.

  1. Use a text editor to create and edit the file umask.txt in your Base Directory. The file should contain this content:

    1. drwxrwxrwx is created with a umask 0___
    2. drwxrwxr-x is created with a umask 0___
    3. drwxr-xr-x is created with a umask 0___
    4. drwxr-xr-- is created with a umask 0___
    5. drwxr-x--- is created with a umask 0___
    6. drwxr----- is created with a umask 0___
    7. drwx------ is created with a umask 0___
    8. d--x------ is created with a umask 0___
    9. d--------- is created with a umask 0___

    The file must have a word count of: 9 72 387 umask.txt You can get a copy of the file from the Source Directory.

  2. Edit the file and replace the three underscores ___ with the correct three-digit umask value that would result in each set of symbolic permissions for a new directory. (Check your work by setting your umask to the above value and then creating and examining the permissions of a new directory.)

The finished file must have the exact above word count. All correct answers will give a file checksum of 61603.

Do not leave your umask set incorrectly after this exercise.

Run the Checking Program to verify your work so far.

4.6 When you are done

That is all the tasks you need to do.

Check your work a final time using the Checking Program below and save the standard output of that program into a file as described below. Submit that file (and only that one file) to Blackboard following the directions below.

When you are done, log out of the CLS before you close your laptop or close the PuTTY window, by using the shell exit command:

$ exit

5 Checking, Marking, and Submitting your Work

Summary: Do some tasks, then run the Checking Program to verify your work as you go. You can run the Checking Program as often as you want. When you have the best mark, upload the single file that is the output of the Checking Program to Blackboard.

Since I also do manual marking of student assignments, your final mark may not be the same as the mark submitted using the current version of the Checking Program. I do not guarantee that any version of the Checking Program will find all the errors in your work. Complete your assignments according to the specifications, not according to the incomplete set of the mistakes detected by the Checking Program.

  1. There is a Checking Program named assignment10check in the Source Directory on the CLS. You can execute this program by typing its (long) pathname into the shell as a command name:

    $ ~idallen/cst8207/15w/assignment10/assignment10check

    You learn one way to make this shorter in the current assignment.

  2. Execute the above Checking Program as a command line on the CLS. This program will check your work, assign you a mark, and display the output on your screen.

    You may run the Checking Program as many times as you wish, allowing you to correct mistakes and get the best mark. Some task sections require you to finish the whole section before running the Checking Program at the end; you may not always be able to run the Checking Program successfully after every single task step.

  3. When you are done with this assignment, and you like the mark displayed on your screen by the Checking Program, you must redirect only the standard output of the Checking Program into the text file assignment10.txt in your Base Directory on the CLS, like this:

    $ ~idallen/cst8207/15w/assignment10/assignment10check >assignment10.txt
    $ cat assignment10.txt
    • Use output redirection with that exact assignment10.txt file name.
    • Use that exact name. Case (upper/lower case letters) matters.
    • Be absolutely accurate, as if your marks depended on it.
    • Do not edit the output file.
    • Make sure the file actually contains the output of the Checking Program!
    • The file should contain, near the bottom, a line starting with: YOUR MARK for
    • Really! MAKE SURE THE FILE HAS YOUR MARKS IN IT!
  4. Transfer the above single file assignment10.txt (containing the output from the Checking Program) from the CLS to your local computer.
    • You may want to refer to the File Transfer page for how to transfer the file.
    • Verify that the file still contains all the output from the Checking Program.
    • Do not edit this file! No empty files, please! Edited or damaged files will not be marked. Submit the file exactly as given.
    • The file should contain, near the bottom, a line starting with: YOUR MARK for
    • Really! MAKE SURE THE FILE YOU UPLOAD HAS YOUR MARKS IN IT!
  5. Upload the assignment10.txt file from your local computer to the correct Assignment area on Blackboard (with the exact name) before the due date:
    1. On your local computer use a web browser to log in to Blackboard and go to the Blackboard page for this course.
    2. Go to the Blackboard Assignments area for the course, in the left side-bar menu, and find the current assignment.
    3. Under Assignments, click on the underlined assignment10 link for this assignment.
      1. If this is your first upload, the Upload Assignment page will open directly; skip the next sentence.
      2. If you have already uploaded previously, the Review Submission History page will be open and you must use the Start New button at the bottom of the page to get to the Upload Assignment page.
    4. On the Upload Assignment page, scroll down and beside Attach File use Browse My Computer to find and attach your assignment file from your local computer. Make sure the assignment file has the correct name on your local computer before you attach it.
    5. After you have attached the file on the Upload Assignment page, scroll down to the bottom of the page and use the Submit button to actually upload your attached assignment file to Blackboard.

    Use only Attach File on the Upload Assignment page. Do not enter any text into the Text Submission or Comments boxes on Blackboard; I do not read them. Use only the Attach File section followed by the Submit button. If you need to comment on any assignment submission, send me EMail.

    You can revise and upload the file more than once using the Start New button on the Review Submission History page to open a new Upload Assignment page. I only look at the most recent submission.

    You must upload the file with the correct name from your local computer; you cannot correct the name as you upload it to Blackboard.

  6. Verify that Blackboard has received your submission: After using the Submit button, you will see a page titled Review Submission History that will show all your uploaded submissions for this assignment. Each of your submissions is called an Attempt on this page. A drop-down list of all your attempts is available.
    1. Verify that your latest Attempt has the correct 16-character, lower-case file name under the SUBMISSION heading.
    2. The one file name must be the only thing under the SUBMISSION heading. Only the one file name is allowed.
    3. No COMMENTS heading should be visible on the page. Do not enter any comments when you upload an assignment.
    4. Save a screen capture of the Review Submission History page on your local computer, showing the single uploaded file name listed under SUBMISSION. If you want to claim that you uploaded the file and Blackboard lost it, you will need this screen capture to prove that you actually uploaded the file. (To date, Blackboard has never lost an uploaded file.)

    You will also see the Review Submission History page any time you already have an assignment attempt uploaded and you click on the underlined assignment10 link. You can use the Start New button on this page to re-upload your assignment as many times as you like.

    You cannot delete an assignment attempt, but you can always upload a new version. I only mark the latest version.

  7. Your instructor may also mark files in your directory in your CLS account after the due date. Leave everything there on the CLS. Do not delete any assignment work from the CLS until after the term is over!

READ ALL THE WORDS. OH PLEASE, PLEASE, PLEASE READ ALL THE WORDS!

Author: 
| Ian! D. Allen  -  idallen@idallen.ca  -  Ottawa, Ontario, Canada
| Home Page: http://idallen.com/   Contact Improv: http://contactimprov.ca/
| College professor (Free/Libre GNU+Linux) at: http://teaching.idallen.com/
| Defend digital freedom:  http://eff.org/  and have fun:  http://fools.ca/

Plain Text - plain text version of this page in Pandoc Markdown format

Campaign for non-browser-specific HTML   Valid XHTML 1.0 Transitional   Valid CSS!   Creative Commons by nc sa 3.0   Hacker Ideals Emblem   Author Ian! D. Allen