Updated: 2017-04-02 02:32 EDT
Do not print this assignment on paper!
- On paper, you will miss updates, corrections, and hints added to the online version.
- On paper, you cannot follow any of the hyperlink URLs that lead you to hints and course notes relevant to answering a question.
- On paper, scrolling text boxes will be cut off and not print properly.
23h59 (11:59pm) Monday April 3, 2017 (start of Week 12)
WARNING: Some inattentive students upload Assignment #10 into the Assignment #09 upload area. Don’t make that mistake! Be exact.
This assignment is based on your weekly Class Notes and covers these topics:
tar
archives from Tar and Gzipcron
and at
)For full marks, follow these directions exactly:
These tasks must be done in your account via Remote Login to the Course Linux Server.
Do the tasks in order, from top to bottom. Do not skip steps. Most tasks are independent, but some depend on successful completion of a previous task.
READ ALL THE WORDS in each task before you begin the task, especially all the Hints and links.
Verify your own work before running the Checking Program. You won’t have a checking program at your job interview and the Checking Program is not guaranteed to check everything.
Run the Checking Program at the end of the task to grade your work and help you find some of your errors. A perfect mark from the Checking Program does not mean your answers are correct.
When you are done with this Assignment, submit the output of the Checking Program to Blackboard before the due date, following the directions given at the end of this Assignment.
You can use the Checking Program to check your work after you have completed each task.
Most task sections below require you to finish the whole task section before running the Checking Program. You may not always be able to run the Checking Program successfully in the middle of a task or after every single task sub-step. The assignment tells you where you can safely check your work.
You will create file system structure in your CLS home directory containing various directories and files. When you are finished the tasks, leave the files and directories in place on the CLS as part of your deliverables for your instructor to verify.
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. Do not delete any assignment work until after the term is over!
You can modify your work and check it with the Checking Program as often as you like before you submit your final mark to Blackboard. You can upload your marks to Blackboard as many times as you like before the due date. Partial marks are accepted.
Your instructor will also mark on the due date the work you do in your account on the CLS. Leave all your work on the CLS and do not modify it after you have submitted your final mark to Blackboard.
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 future assignments very difficult.
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. You also learned how to search the notes in Assignment #05 HTML.
All references to the Source Directory below are to the CLS directory ~idallen/cst8207/17w/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.
Have you completed all the prerequisites, before attempting these tasks?
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. All work in this assignment must be done on the CLS.
Create the assignment10
directory in your usual Assignments
directory.
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.
check
check
symbolic link needed to run the Checking Program, as you did in a previous assignment and as described in the section Checking Program below.Hints: See your previous assignment for hints on doing the above.
Use the symbolic link to run the Checking Program to verify your work so far.
tar
Archive and ListingIndexYou need to know Disk Usage and Tar and Gzip to do this task.
Make your Base Directory your current directory and do not change directories for this entire task. All recorded pathnames must be relative to the Base Directory.
Later in this assignment you will need to copy all the command lines you use in this part into a script file. All command lines must create and use pathnames relative to the current (base) directory.
dumaze10
abcd0001
mzblocks.txt
In the current directory (the Base Directory), create a directory named dumaze10
. Without changing directories, create a symbolic link in that dumaze10
directory that is the name of your 8-character CLS userid. The symlink should point to the absolute path of the maze
directory that is in the Assignment #03 Source Directory. The symbolic link will have a size of exactly 43 characters (the absolute path of the maze
directory), e.g. for userid abcd0001
the left part of the symlink long listing would look similar to this:
lrwxrwxrwx 1 abcd0001 abcd0001 43 Nov 10 10:00 dumaze10/abcd0001 ->
The rest of the symlink (not shown) is the absolute path of the maze
directory.
You probably have it right if ls dumaze10/
abcd0001
(use your own accout name) shows over 1300 (non-hidden) pathnames from the maze.
Use redirection to save a long listing of the one symlink (only the one symlink, not the whole directory) into a new file mzblocks.txt
in the dumaze10
directory. The new file will contain one line, 11 words, 112 characters. Do not use any options other than the one that produces a long listing.
dumaze10/
abcd0001
/.0
sub-directory inside the maze. Do not change directories to do this!
abcd0001
mzblocks.txt
mzblocks.txt
file.
YYYYMMDD
.tar.gz
tar
archive in the dumaze10
directory containing the contents of the .0
directory from above. Use the relative pathname from above as the source of the files to archive. Name the new archive YYYYMMDD
.tar.gz
(no spaces) under dumaze10
, where YYYYMMDD
is the numeric year-month-day date of the final exam in this course.
tar
command display the file names as they are added to the archive; add the files silently, not verbosely.tar
archive file must be relative paths with dumaze10/abcd0001/.0/
at the beginning of every name.YYYYMMDD
.tar.bz2
tar
archive in the dumaze10
directory of the same .0
directory from above. Use the same name as for the gzip archive, but use the file extension .bz2
instead of the .gz
extension.
tar
archive file must be relative paths with dumaze10/abcd0001/.0/
at the beginning of every name.ls
that gives just “the allocated size of each file, in blocks” and use that option (and only that option) to display the size and name of the two tar
archives you just created in the dumaze10
directory.
dumaze10
directory as arguments to ls
.mzblocks.txt
ls
changes to separate lines when output is to a file instead of directly to your screen. This is one of the few commands that does this.tar
archives are much smaller (fewer disk blocks) than the original disk space used.tartable.txt
Generate a verbose listing of the table of contents of your gzip-style tar
archive file, showing the contents of the archive including all the owners and date/time stamps, but don’t display it directly on your screen since it’s over 1400 lines long. (Generate the verbose listing and verify that it outputs over 1400 lines by counting them with a pipe.)
Once you know you can generate the verbose listing, save just the first five and last five lines of the verbose listing into file tartable.txt
under your dumaze10
directory. The file word count will be 10 62 798
and the first line and last line should look similar to this (where abcd0001
is replaced by your userid):
drwxr-xr-x idallen/idallen 0 2014-10-25 03:16 dumaze10/abcd0001/.0/
drwxr-xr-x idallen/idallen 0 2014-10-25 03:16 dumaze10/abcd0001/.0/.1/.1/.1/
Hints: You will need to use one command pipeline to generate the first five lines into the output file, and then use a second command pipeline to generate the last five lines and append them to the output file to make a total of ten lines in the file. If the checking program says you have unprintable characters in your file, you have not used the right command to generate a verbose listing of a tar
file; re-read the notes on how to use tar
given at the top of this Part A section.
The bzip2 compression algorithm is better than the gzip compression algorithm; bzip2 produces smaller compressed files. Answer this question:
True or False: Because bzip2 is smaller than gzip, generating the verbose table of contents of the bzip2-style tar
archive file will produce fewer lines than the table of contents of the gzip-style archive.
Append your one-word answer true
or false
to the tartable.txt
file. (The file will now contain 11 lines.) (The checking program will not check this answer. Your instructor will check the answer and mark it after you hand in your assignment.)
Run the Checking Program on the CLS to verify your work so far.
If you have errors, go back and re-read the first step #1 in this task.
puzzle.txt
After you have run the Checking Program at least once, you will find created for you in the Source Directory a puzzle file named with your userid puzzle/
abcd0001
.mystery
(where abcd0001
is replaced by your own userid). This file contains many layers of compression and tar
archiving.
Extract the ASCII text file from deep inside this puzzle file and save the ASCII text as file puzzle.txt
in your Base Directory.
Hints: Repeatedly unpack the compression and tar
archiving until you find an ASCII text file. I demonstrated this example in class after the lecture showing you the tar
command – see your class notes. The file
command will be helpful to decode the nested layers of the puzzle.
Run the Checking Program on the CLS to verify your work so far.
You need to know Processes and Jobs to do this task.
psBSD.txt
Place a list of your own processes in BSD format, text user name (not numeric UID) into file psBSD.txt
in your Base Directory. Only a few lines will display and your userid will be at the start of every line. The top header line of the output must look like this (this is BSD format):
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
Append a full list of all processes for all users, BSD format, text user name (not numeric UID), full wide listing (not truncated at all) to the same file psBSD.txt
. The file should now be more than 105 lines and 9KB. One of the very long lines will be a dhclient
line similar to this (use a text-searching command to find it in the output):
root 3262 0.0 0.0 7268 512 ? Ss Mar22 0:00 dhclient3 -e IF_METRIC=9999 -pf /var/run/dhclient.eth0.pid -lf /var/lib/dhcp/dhclient.eth0.leases -1 eth0
psUNIX.txt
Place a list of your own processes in UNIX (System V) format, text user name (not numeric UID) into file psUNIX.txt
in your Base Directory. Only a few lines will display and your userid will be at the start of every line. The top header line of the output must look like this (this is UNIX format):
UID PID PPID C STIME TTY TIME CMD
Append a full list of all processes for all users, UNIX (System V) format, text user name (not numeric UID), long format, full wide listing (not truncated at all) to the same file psUNIX.txt
. The file should be more than 105 lines and 7KB. One of the very long lines will be a dhclient
line similar to this (use a text-searching command to find the it in the output):
root 3262 1 0 Mar22 ? 00:00:00 dhclient3 -e IF_METRIC=9999 -pf /var/run/dhclient.eth0.pid -lf /var/lib/dhcp/dhclient.eth0.leases -1 eth0
psmine.txt
psBSD.txt
file and put the one line into the file psmine.txt
(1 line, 11 words, 73 characters).
psBSD.txt
that contain your userid anywhere in the line and append those lines to the psmine.txt
file. (Some of the lines in this file may be very long.)Run the Checking Program on the CLS to verify your work so far.
You need to know System Log Files to do this task.
syslog2.txt
psBSD.txt
and psUNIX.txt
that contains this name and redirect the results (two lines, one from each file) into file syslog2.txt
. (The result will be 2 lines and 21 words.)authlogi.txt
The system authentication log file is named auth.log
in the system log directory. Generate an ls
long listing showing inode number of this file using the full absolute pathname, and put the results of the ls
(the output of ls
) into file authlogi.txt
. (The output of the ls
command should be one line, starting with a number, showing the permissions, owner, group, etc.)
Create an absolute symbolic link in your Base Directory to the above system log file. Name the symlink al
– a nice short name. You might find this symlink useful in subsequent items.
Append a long listing of the above symlink to the authlogi.txt
file. (The file will now contain two lines.)
meIDs.txt
meIDs.txt
. The result will be 1 (long) line, 3 words. See Permissions for the command to use to do this. Do not edit the output of the command.meperms.txt
Use a text editor (or other means) to enter just the numeric UID for your account into file meperms.txt
(one number). (The UID number was displayed by the command you used in the previous step.)
Look at the contents of the meIDs.txt
and authlogi.txt
files. Note that your account is in a group that matches the group of the system auth.log
file, giving you group permissions on this file. Using a text editor, append the matching group name (one word), the symbolic group permissions (three characters), and the octal group permissions (one digit), onto three more lines in file meperms.txt
. (The appended result will make the file 4 lines and 4 words.)
authhead.txt
The system auth.log
file contains (March 2017) over 980,670 lines. Use a command to extract just the first line (one line) from the head of this file and redirect that one line into new file authhead.txt
. (The result will be 1 line 13 words 111 chars.) The time and date at the start of this line is when this copy of the log file was started.
Append the same information that you put in the last line of the authlogi.txt
file above (about the al
symlink) to the authhead.txt
file, making the file two lines long.
failedpass.txt
If you count the number of lines in the system auth.log
containing the exact text string Failed password
, the count is more than 17,690 lines (March 2017). Of those lines (the lines containing that exact text string), use a command pipeline to extract just lines 111 through 120 (inclusive) and put only those lines into file failedpass.txt
. Every line should contain the above exact text string somewhere.
Hint: You solved a similar problem in Worksheet #05 PDF and on your midterm and practice tests. The correct output should contain 160 words and 1185 bytes. All the selected log lines have a date on January 2.
Run the Checking Program on the CLS to verify your work so far.
This section assumes that you have no personal crontab
created. If you have created one, remove it before you begin and work all the way to the end of this Part before you check your work.
You need to know Crontab and At Job Schedulers and Differences between text files to do this task.
Re-read the Notes on doing assignment work before you continue. You cannot check your work in the middle of this task part.
minutepid.txt
Create a personal crontab
entry, often called a cron job, that echoes the value of the shell process ID variable into file minutepid.txt
in your Base Directory every minute of every day. Redirect the command output into the shortest relative pathname to the minutepid.txt
file.
Verify that the pid number in the file changes every minute. (You may have to wait up to a minute before the cron runs your job for the first time.)
Hints: If it doesn’t work, read your Linux EMail for EMail messages from the Cron daemon suggesting possible errors. See Reading EMail for help. The single working crontab
line should have five fields for the date/time, an echo command with a single shell variable argument, and redirection into a relative pathname into your Base Directory, not into your HOME directory. Do not use an absolute pathname.
crontab_list1.txt
Use a command to list your personal crontab
that you just created (one entry, with perhaps some comment lines) and redirect the output into file crontab_list1.txt
in your Base Directory. This crontab
entry is the one that runs every minute.
Delete your personal crontab
(the one that runs every minute).
differ.txt
Use a command and two absolute pathnames that shows the Differences between text files between the Linux group file and its backup copy. (The backup copy has the same name with a dash “-
” appended.) A few lines should display, or perhaps none if the files are identical.
When you have the group file line difference command correct, create a personal crontab
entry that runs that same command and redirects the output into the file differ.txt
in your Base Directory at your Personal Crontab Time. Also use a relative pathname to the output file, not an absolute pathname.
crontab_list2.txt
crontab
(just one entry running at your Personal Crontab Time, with perhaps some comment lines) and redirect the output into file crontab_list2.txt
. Do not delete this personal crontab
entry; leave it for marking. Make sure your displayed cron
job is scheduled to run at your Personal Crontab Time.Run the Checking Program on the CLS to verify your work so far.
Re-read the Notes on doing assignment work if you are trying to check your work in the middle of a task instead of at the end of a task.
Re-read the Notes on doing assignment work if you are trying to check your work in the middle of a task instead of at the end of a task.
You need to know Crontab and At Job Schedulers to do this task.
Create an at
job that prints the list of logged-in users on the system, one per line, at your Personal Crontab Time in the year 2020. You can use any of several commands from this course to show the list of logged-in users one per line; see the List of Commands You Should Know.
Hints: You need to get the order of the date correct on the at
command line; see the Crontab and At Job Schedulers course notes or RTFM to find out how to specify both a time and a date for an at
job. No pipes or redirection or files are needed for this command in the at
job; it’s just running one single command name.
Display your list of at
jobs to confirm the correct scheduling date and time in 2020.
Create an at
job that runs the command that prints the log messages in the kernel ring buffer. Schedule the job at your Personal Crontab Time in the year 2020. (See the List of Commands You Should Know.)
Hints: No pipes are needed for this at
job; it’s just one command name that displays the in-memory kernel log buffer. Look in your weekly command list for the command name you need.
Create an at
job that echoes the five words of text CST8207 Final Exam 08:00am Friday
as a mail message to your Algonquin Live EMail account at 1 PM on the day before your final exam in this course. The EMail message sent at 1pm must have the exact message text above and the exact subject line (six different words): CST8207 Final Exam 08:00am Tomorrow (Friday)
Hints: A pipe will be needed to connect the one-line output of echo
with the standard input of the mail program. See Sending EMail for help in sending EMail with a subject line. Did you use the exact (different) words given to you for the message and Subject texts?
Did you test that your pipeline works (sends you email) before you copied the pipeline into the at
job for later execution? Make sure that you your pipeline actually works!
Check the queue of at
jobs and make sure the scheduled times are correct for all three jobs.
Delete just the (first) at
job that shows the list of users.
atjob.txt
Display both your queued at
jobs and redirect the output into file atjob.txt
. You will only have two jobs – two lines. If you have more than two lines, delete the other jobs.
Leave these two jobs queued on the CLS for marking.
Run the Checking Program on the CLS to verify your work so far.
Re-read the Notes on doing assignment work if you are trying to check your work in the middle of a task instead of at the end of a task.
You need to know basic Shell Scripts to do this task.
partA.sh
Write an executable Bourne shell script named partA.sh
that does automatically almost all the manual work you did creating files in Part A of this assignment. Do not put anything from the mystery puzzle file section into the script. The script must create and use the new output directory name dumaze99
(in the current directory) instead of the original directory name dumaze10
. The script should show no output on your screen; it should create all its files with no output on your screen.
Observe these points in the script:
#
comment lines after the first line, but not before it.KEY:
line for this script file. Use the partA.sh
name as the second (file) argument. Insert the whole one-line KEY:
into your script file as a #
comment line somewhere after the first line of the script file.dumaze99
from the current directory at the start of the script. (You used a command to do this silent recursive removal in almost every new Lab section of every Worksheet.)dumaze99
in the current directory.dumaze99
directory.dumaze99
directory for all output.Hints: Having already done Part A, your
bash
shell history already contains all the command lines you need for your script. All you need to do is adapt each command line to use thedumaze99
directory instead of the original directory. My solution script contained three lines of Standard Script Header followed by about ten command lines to create the directory, the symlink, and the four files from Part A. Make sure you test run your script before you run the Checking Program!
Run the Checking Program on the CLS to verify your work so far.
bin
directoryIndexYou need to know Shell Scripts, Search Path, Start-Up Files, and Symbolic Links to do this task.
bin
Create your own personal bin
directory in which to keep your own personal Linux commands. Use the exact name bin
and create it in your HOME directory.
Append your bin
directory path to the end (tail) of your search PATH. Do this at login time in your shell start-up file so that it applies to all shells.
Hints: Review Search Path, Start-Up Files, and Working with your search PATH in Assignment #07 HTML.
partA
Create a relative symlink named partA
in your bin
directory. The symlink should point to (have a target of) your partA.sh
script file that you just created.
Hints: Review Symbolic Links. The relative symlink target from the bin
directory to your script will contain four slashes.
Make sure that you can now type your new command name partA
at your shell to execute your partA.sh
shell script.
Run the Checking Program on the CLS to verify your work so far.
That is all the tasks you need to do.
Read your CLS Linux EMail and remove any messages that may be waiting. See Reading EMail for help.
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.
Your instructor will also mark the Base Directory in your account on the due date. Leave everything there on the CLS. Do not delete anything.
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
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.
check
There is a Checking Program named assignment10check
in the Source Directory on the CLS. Create a symbolic link named check
in your Base Directory that links to the above Checking Program in the Source Directory, as you did in a previous assignment.
Execute the above Checking Program as a command line on the CLS. The checking program will check your work, assign you a mark, and display the output on your screen:
$ ./check | less
If the Checking Program is not yet ready, it will say NOT FINISHED YET
and DO NOT SUBMIT THIS FILE
. No mark is shown; do not submit the file. Wait until the checking program is finished (it gives you a mark) before you save and submit your marks.
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.
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:
$ ./check >assignment10.txt
$ less assignment10.txt
assignment10.txt
file name.YOUR MARK for
assignment10.txt
(containing the output from the Checking Program) from the CLS to your local computer.
YOUR MARK for
assignment10.txt
file from your local computer to the correct Assignment area on Blackboard (with the exact name) before the due date:
assignment10.txt
file from your local computer. Make sure the assignment file has the correct name on your local computer before you attach it. Attach only your assignment10.txt
file for upload. Do not attach any other file names.assignment10.txt
file on the Upload Assignment page, scroll down to the bottom of the page and use the Submit button to actually upload your attached assignment10.txt
file to Blackboard.Use only Attach File, Browse My Computer on the Upload Assignment page. Do not enter any text into the Write Submission or Add Comments boxes on Blackboard; I do not read them. Use only the Attach File, Browse My Computer 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. Make sure the file name on Blackboard is correct!
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.
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!
I do not accept any assignment submissions by EMail. Use only the Blackboard Attach File, Browse My Computer. No word processor documents. Plain Text only.
Use the exact file name given above. Upload only one single file of Linux-format plain text, not HTML, not RTF, not MSWord. No fonts, no word-processing. Linux plain text only.
NO EMAIL, WORD PROCESSOR, PDF, RTF, or HTML DOCUMENTS ACCEPTED.
No marks are awarded for submitting under the wrong assignment number or for using the wrong file name. Use the exact 16-character, lower-case name given above.
WARNING: Some inattentive students don’t Read All The Words. Don’t make that mistake! Be exact.
READ ALL THE WORDS. OH PLEASE, PLEASE, PLEASE READ ALL THE WORDS!
This section shows you how to calculate your Personal Crontab Time for use in your cron and at jobs. You need to know your nine-digit student number and how to calculate the arithmetic modulus of a number.
- Take your 9-digit student number and remove the first three digits (probably
040
), leaving six digits. Use these last six digits as follows:- Take the first two of those six digits as a number, modulo 12, and then add 1, giving a number between 1 and 12. This is your month number.
- Take the next (middle) two of those six digits as a number, modulo 24, giving a number between 0 and 23. This is your hour number.
- Take the last two of those six digits as a number, modulo 60, giving a number between 0 and 59. This is your minute number.
- Take the same last two of those six digits as a number, modulo 28, and then add 1, giving a number between 1 and 28. This is your day-of-the-month number.
For example, if your nine-digit student number were 123456789
:
123
, leaving the last six digits 45 67 89
45
, the month would be (45 mod 12) + 1 = 10
(October)67
, the hour would be 67 mod 24 = 19
(7pm)89
, the minute would be 89 mod 60 = 29
89
, the day of the month would be (89 mod 28) + 1 = 6
The Personal Crontab Time for student number 123456789
is October 6 at 19h29 (7:29pm).
Exercise: Show that the Personal Crontab Time for student number 987654321
is
65 43 21
6
(June)19
(7pm)21
22
which is June 22 at 19h21 (7:21pm).