Updated: 2015-11-27 02:00 EST
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) Friday November 27, 2015 (end of Week 12)
WARNING: Some inattentive students upload Assignment #10 into the Assignment #09 upload area. Don’t make that mistake! Be exact.
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.
tar
archives from Package Managementcron
and at
)Remember to READ ALL THE WORDS to work effectively and not waste time.
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.
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.
You will create file system structure in your HOME directory on the CLS, with various directories, files, and links. When you are finished the tasks, leave these files, directories, and links in place as part of your deliverables on the CLS. Do not delete any assignment work until after the term is over! Assignments may be re-marked at any time; you must have your term work available right until term end.
All references to the Source Directory below are to the CLS directory ~idallen/cst8207/15f/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.
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 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.
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.
Base Directory: Make the CLS directory named ~/CST8207-15F/Assignments/assignment10
in which you will create the files and scripts resulting from the following tasks. (You do not have to create any directories that you have already created in a previous assignment.) Spelling and capitalization must be exactly as shown:
check
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.
tar
Archive and ListingIndexYou need to know Disk Usage and Package Management to do this task.
maze10
abcd0001
In the current directory (the Base Directory), create a directory named maze10
. Without changing directories, create a symbolic link in that maze10
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 symlink long listing would start like this:
lrwxrwxrwx 1 abcd0001 abcd0001 43 Mar 22 12:03 maze10/abcd0001 ->
The rest of the symlink is the absolute path of the maze
directory.
You probably have it right if ls maze10/abcd0001
shows about 2600 (non-hidden) pathnames from the maze.
maze10/abcd0001/.0
sub-directory inside the maze. Do not change directories to do this!
abcd0001
mazeblocks.txt
mazeblocks.txt
in the maze10
directory.
YYYYMMDD
.tar.gz
tar
archive in the maze10
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 maze10
, where YYYYMMDD
is the numeric year-month-day date of the final exam in this course.
tar
archive file must be relative paths with maze10/abcd0001/.0/
at the beginning of every name.YYYYMMDD
.tar.bz2
tar
archive in the maze10
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.
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 maze10
directory.
maze10
directory as arguments to ls
.mazeblocks.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.tar_table.txt
Generate a verbose listing 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 1,700 lines long. (Generate the verbose listing and verify that it outputs over 1,700 lines by counting them.)
Once you know you can generate the verbose listing, save just the first five and last five lines of the verbose listing into file tar_table.txt
under maze10
directory. The file word count will be 10 61 786
and the first line and last line should look like this (where abcd0001
is replaced by your userid):
drwxr-xr-x idallen/idallen 0 2014-10-25 03:16 maze10/abcd0001/.0/
-rw-r--r-- idallen/idallen 156 2014-10-25 03:16 maze10/abcd0001/.0/jawo0006*txt
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 tar_table.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 in this task.
You need to know Processes and Jobs to do this task.
psbsd.txt
Place a full list of all processes for all users, BSD format, all users, text user name (not numeric UID), full wide listing (not truncated at all), into file psbsd.txt
in your Base Directory. It should be at least 105 lines and 9KB. The top header line and 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):
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 4078 0.0 0.0 7264 388 ? Ss Nov11 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 full list of all processes for all users, UNIX (System V) format, text user name (not numeric UID), full wide listing (not truncated at all), into file psunix.txt
in your Base Directory. It should be at least 105 lines and 7KB. The top header line and 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):
UID PID PPID C STIME TTY TIME CMD
root 4078 1 0 Nov11 ? 00:00:00 dhclient3 -e IF_METRIC=9999 -pf /var/run/dhclient.eth0.pid -lf /var/lib/dhcp/dhclient.eth0.leases -1 eth0
mine.txt
psbsd.txt
file and put the one line into file mine.txt
. (1 11 73 mine.txt
)
psbsd.txt
that contain your userid anywhere in the line and append those lines to the mine.txt
file. (Some of the lines in this file may be very long.)You need to know System Log Files to do this task.
syslog.txt
psbsd.txt
and psunix.txt
that contains this name and redirect the results (two lines, one from each file) into file syslog.txt
. (The result will be 2 lines and 21 words.)authlog.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 authlog.txt
. (The output of the ls
command should be one line, starting with a number, showing the permissions, owner, group, etc.)
(Optional: You may find it convenient to set a shell variable to this absolute pathname, so that you can use the short variable name rather than the long absolute pathname in the rest of these exercises. Or, you could make a short symbolic link to this file.)
me.txt
me.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.myperms.txt
me.txt
and authlog.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, put the matching group name, the symbolic group permissions (three characters), and the octal group permissions (one digit), onto three lines in file myperms.txt
. (The result will be 3 lines, 3 words, 10 characters. Do you remember why a file containing seven alphanumeric characters on three lines is counted as a 10-character file on Linux? Review Line End Differences.)authhead.txt
auth.log
file contains (November 2015) over 1,119,704 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 14 words 110 chars.) The time and date at the start of this line is when this copy of the log file was started.failedpass.txt
auth.log
containing the exact text string Failed password
, the count is more than 6,959 lines (November 2015). Of those lines (the lines containing that exact text string), extract just lines 100 through 110 (inclusive) and put only those lines into file failedpass.txt
. The word count for the file will be 11 170 1291
. Every line should contain the exact text string somewhere.Run the Checking Program on the CLS to verify your work so far.
You need to know Crontab and At Job Schedulers to do this task. Re-read the Notes on checking your work before you continue.
crontab.txt
Create a personal crontab
entry that uses a command with one pathname argument to update the access and modify times on file crontab.txt
in your Base Directory (not in your HOME
directory) every minute of every day. Use the shortest relative pathname to your crontab.txt
file. Do not use an absolute pathname. Verify that the time of the file changes every minute.
Hints: If it doesn’t work, read your Linux EMail for EMail messages from the Cron daemon showing possible errors. See Reading EMail for help. The single working crontab
line should be seven words: five for the date/time, a command name, and a relative file name.
crontab1.txt
List your personal crontab
that you just created (one entry, with perhaps some comment lines) and redirect the output into file crontab1.txt
in your Base Directory. This crontab entry should run every minute.
Delete your personal crontab
(the one that runs every minute).
crontab.txt
crontab
entry that redirects the current date and time into the same file crontab.txt
at The Crontab Time. Also use a relative pathname, not an absolute pathname.crontab2.txt
crontab
(one entry, with perhaps some comment lines) and redirect the output into file crontab2.txt
. Do not delete this personal crontab
entry; leave it for marking. Make sure your displayed cron
job is scheduled at The Crontab Time.Run the Checking Program on the CLS to verify your work so far.
Re-read the Notes on checking your 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 users on the system, one per line, at The Crontab Time in the year 2016. You can use any of several commands to show the list of 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 are needed for this at
job; it’s just one command name.
Display your list of at
jobs to confirm the correct scheduling date and time in 2016.
Create an at
job that runs the command that prints the log messages in the kernel ring buffer. Schedule the job at The Crontab Time in the year 2016. (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 are needed for this at
job; it’s just one command name that displays the in-memory kernel log buffer.
Create an at
job that echoes the five words of text CST8207 Final Exam 8am Saturday
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 (also five words, but different): CST8207 Final Exam 8am Tomorrow
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 words given to you for the message and Subject texts?
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.
You need to know Shell Scripts to do this task.
partA.sh
Write an executable Bourne shell script that does all the work done in Part A of this assignment. Create and use the output directory maze99
(in the current directory) instead of the original directory maze10
. Do not change directories inside the script.
maze99
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.)maze99
in the current directory.maze99
directory.maze99
directory for all output.Hint: 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 themaze99
directory instead of the original directory. My solution script contained three lines of Standard Script Header followed by ten command lines to create the directory, the symlink, and the four files from Part A.
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.
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.
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. You can execute this program by typing its (long) pathname into the shell as a command name:
$ ~idallen/cst8207/15f/assignment10/assignment10check | less
Create a symbolic link named check
in your Base Directory that links to the Checking Program in the Source Directory, as you did in a previous assignment. Use the symlink to check your work:
$ ./check | less
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.
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 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.
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. 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 these 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 Crontab Time for student number 123456789
is October 6 at 19h29 (7:29pm).
Exercise: Show that The Crontab Time for student number 987654321
is
65 43 21
6
(June)19
(7pm)21
22
which is June 22 at 19h21 (7:21pm).