Updated: 2014-10-02 02:46 EDT
PS1
Shell Promptfind
to list all the pathnamesDo 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.
12h00 (noon) Monday September 29, 2014 (start of Week 5)
copycommand.txt
)WARNING: Some inattentive students upload Assignment #2 into the Assignment #1 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.
less
pagination program.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.
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 these files and directories in place on the CLS as part of your deliverables. Do not delete any assignment work from the CLS 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.
All references to the “Source Directory” below are to the CLS directory ~idallen/cst8207/14f/assignment02/
and that name starts with a tilde character ~
followed by a userid 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.
PS1
Shell PromptThese worksheets prepare you to do the numbered tasks listed below by executing commands via Remote Login to the Course Linux Server.
You can download Libre Office (or Open Office) for Windows to edit the Worksheet *.odt
files and save your answers. (Or you can print the PDF and write your answers on paper.) Do not use MSWord; it will mangle the format of the worksheet.
Record and save all your worksheet answers for study and quizzes!
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.
PS1
variable syntax shown in Worksheet #02 HTML, set your prompt to include your user name, your computer name, and the basename of your current working directory. (See the definition of basename in the Pathnames class notes.)
[abcd0001@idallen-ubuntu ~]$
Set your
PS1
prompt every time you log in to the CLS, so that the prompt changes to tell you you the basename of your current working directory. This is faster than typingpwd
all the time! You will learn later how to create a.bashrc
file to make this happen automatically every time you log in to the CLS.
Bonus Feature: If you use
\w
instead of\W
in thePS1
prompt string, the shell will display the full absolute path of your current working directory instead of just the basename. You may or may not like this feature; it doesn’t leave much room on the command line to type commands without having the command line wrap around to the next line. You choose.
The CLS is on the public Internet; security is important. Choose your password carefully, or else Internet attackers will break into the CLS through your account.
Read on Wikipedia: Guidelines for strong passwords
Read this XKCD comic on good passwords
Now RTFM for the Unix command named passwd
(note the odd spelling). No arguments or options are needed to this command to change your own password. The passwd
command is also described in Worksheet #02 HTML.
Change your CLS password to one that is more secure than the one you were given. Find a way to remember your new password. If you forget your password, contact your Linux instructor to have it reset.
Accounts that do not have their passwords changed before the due date of this assignment will be disabled.
CST8207-14F
directory in your CLS HOME directory.Assignments
directory in the CST8207-14F
directory.assignment02
directory in the Assignments
directory.Hint: You can create the entire directory tree above using one single command with one option and one pathname argument, as you did at the end of Section 4 in Worksheet #02 HTML. System administrators like to work efficiently – they learn how to do things quickly.
Check the structure of this directory tree by making your HOME directory your current directory and using one of these tree
commands below. Try both command lines below and use the command that gives the best-looking output in your terminal.
$ tree CST8207-14F
$ tree -A CST8207-14F
The correct output will look similar to the ASCII tree diagram below. The spelling and capitalization must be exactly as shown.
CST8207-14F
`-- Assignments
`-- assignment02
This
assignment02
directory is the Base Directory for most pathnames in this assignment. Store your files and answers in this Base Directory.
Run the Checking Program to verify your work so far.
find
to list all the pathnamesMake the CST8207-14F
directory your current directory.
Use the find
command to print all the pathnames under the current directory on your screen.
Hint: You used this exact command to print all the pathnames under the current directory in Section 8 of Worksheet #02 HTML.
Recall that you can redirect any output that appears on your screen into a file by adding to the end of the command line a “greater than” angle bracket (
>
) followed by a file name or pathname. (We did this using thecal
command to create thecal.txt
file in Assignment #01.)
Repeat the same find
command and redirect the output into file found.txt
in your Base Directory.
Hint: For the redirection output file pathname, use a relative path from your current directory down into the Base Directory. The relative pathname will contain two embedded slashes separating three name components. The basename of the relative pathname is the destination file name.
Run the Checking Program to verify your work so far.
You may find it easier to type if you make the Base Directory you created above (
assignment02
) your current directory for this section. The file names in this section have been deliberately chosen to contain characters that look similar but are not the same. Pay strict attention to the names used.
Copy the cal.txt
file you created in Assignment #01 HTML into the Base Directory using the new name calnew,txt
for the file. (Note carefully the punctuation character used in this name.) The Base Directory now has two files in it (and nothing else).
l1dir
directory in the Base Directory. Pay careful attention to the name; the first two characters of the name are not the same.l1dir
create two new directories named one
and two
(three letters each).one
create new directory One0ne
(six characters, including one digit zero).two
create new directory twotwO
(six letters, including one that is upper-case).Hint: You can create the entire directory tree above using one single command with one option and two pathname arguments, as you did at the end of Section 4 in Worksheet #02 HTML. System administrators like to work efficiently – they learn how to do things quickly.
Check the structure of this directory tree using the same command as you used in the previous section. The correct directory tree under the Base Directory must look similar to the ASCII tree diagram below. The spelling and capitalization must be exactly as shown.
l1dir
|-- one
| `-- One0ne
`-- two
`-- twotwO
Copy the directory l1dir
to new directory Ildir
using the correct directory copy option, as you did in Section 3 of Worksheet #03 HTML. Pay careful attention to the new directory name; the first two characters of the name are not the same.
Hint: Ildir
should not exist before you do this! If it already exists, recursively remove it before you do the copy, or else you will get a spurious extra level of directory.
Check that the tree structure of Ildir
is exactly the same as the tree structure of the l1dir
directory from which you copied it.
Run the Checking Program to verify your work so far.
Make the Base Directory your current directory and then use a command to recursively generate a list of all pathnames using your l1dir
directory as the starting directory. (You used this recursive command above, and many times in the last section at the end of Worksheet #02 HTML. Do not use the tree
or ls
commands. Use the l1dir
directory as your starting directory.)
The recursive output of all pathnames under your l1dir
directory will be exactly five lines long and will contain this exact line in the output somewhere (along with another four lines):
l1dir/one/One0ne
Make sure the exact line above appears as one of the five lines!
When the five lines of recursive output above on your screen looks correct, redirect the output of the command into the file named paths.txt
in the One0ne
directory that you created earlier under the Ildir
directory.
Hint: For the output redirection file, use a relative path from your current directory down into the One0ne
directory under Ildir
. The relative pathname will contain three embedded slashes separating four name components. The basename of the relative pathname is the destination file name.
Make the One0ne
directory under Ildir
your current directory. (Make sure you get the right one under Ildir
and not l1dir
! Display your current working directory and make sure.)
Use a command to list the files in the current directory to confirm that the paths.txt
file is here. Use another command to display the contents of the paths.txt
file, and make sure it contains exactly five lines of pathnames from under the l1dir
directory.
From the One0ne
directory, copy the paths.txt
file (from the current directory) into the twotwO
directory that is also under the Ildir
directory, giving it the new name paths.txt.copy
as the destination file name for the copy.
Hint: Again, use relative paths to do the copy. Draw a file system hierarchy picture to help you derive the correct relative pathname. For the destination file, use a relative path from your current directory that goes up the tree and then down into the two
directory. The relative pathname will contain four embedded slashes separating five name components. The basename of the relative pathname is the destination file name.
echo
command to echo the whole command line onto the screen. The copy command name and its two relative pathname arguments that you used to make the above copy should echo onto the screen.copycommand.txt
in the Base Directory. No output should appear on screen.copycommand.txt
file should contain on one line the copy command name followed by two relative pathname arguments, exactly as you typed it in the preceding question.Hints: Because the copycommand.txt
output file must be located in the Base Directory, not in the current One0ne
directory, you need to specify a relative redirection output pathname that goes up several levels to the base directory. The relative pathname will contain three embedded slashes. The basename of the relative pathname is the destination file name.
Run the Checking Program to verify your work so far.
Execute this exact command line in your account on the CLS:
~idallen/cst8207/14f/assignment02/create_topdir
There is a leading tilde character ~
directly in front of the account name idallen
, indicating to the shell that the pathname starts with the HOME directory of idallen
(seven letters).
The command will create a directory named topdir
in your Base Directory. It will contain some sub-directories and files. Verify that topdir
has been created.
You can re-execute the above line to start over from scratch, if you make errors in this part of the assignment.
To know what files and directories have been created by the above command line, use a command that will recursively show all the files and directories under a starting directory. (You already used this command, above.)
All the following commands in this section apply to files and directories under the new
topdir
directory. You will have to use commands to find some of the file names mentioned here; they may be located under sub-directories. (See Searching and Finding Files.) Some of these tasks may require more than one command to complete.
Find and read the file named README.txt
(located somewhere under some directory under topdir
). You have to find this file.
Read and then delete the file foo.txt
that is in the same directory as the README.txt
file. (Do not delete any other decoy files named foo.txt
that may be in other directories.)
Move (rename) the file bar
to be bar.bak
(This is a move, not a copy. It renames the file.)
Directly under the topdir
directory, create a new empty directory named bar
(three letters). (Make sure you create bar
under topdir
, not in your HOME or any other directory.)
Find the file named stuff
(not the directory with the same name) and move (rename) that stuff
file to be named services
under the new directory bar
that you just created. (This is a move/rename, not a copy.) Make sure you move the file, not the directory with the same name.
Run the Checking Program to verify your work so far.
You may find it easier to type if you make the Base Directory your current directory for this section.
When the word count is given for a command, the numbers are the values you should get if you pipe the command output into the word count command, e.g.
date | wc
base1
in your base directory.base1
create two new directories named bdir1
and bdir2
(four letters and one digit each).bdir1
create new directory bdir1-1
(four letters, two digits, and one dash).bdir2
create new directory bdir2-1
(four letters, two digits, and one dash).Hint: You can create the entire directory tree above using one single command with one option and two pathname arguments, as you did at the end of Section 4 in Worksheet #02 HTML. System administrators like to work efficiently – they learn how to do things quickly.
Verify that the directory tree under base1
looks similar to the ASCII tree diagram below. The spelling and capitalization must be exactly as shown:
base1
|-- bdir1
| `-- bdir1-1
`-- bdir2
`-- bdir2-1
Make the Base Directory your current directory and then use a command to recursively generate a list of all pathnames using base1
as the starting directory.
Hints: You used this recursive command many times in Section 8 of Worksheet #02 HTML. Do not use the tree
or ls
commands. The recursive output of all pathnames will be exactly five lines long and will contain this exact line in the output somewhere (along with another four lines):
base1/bdir2/bdir2-1
Make sure the exact line above appears as one of the five lines! The word count of this command output must be: 5 5 70
and if the count is wrong, re-read all the words in ths step.
When the recursive output above on your screen looks correct, redirect the five lines of output of the command into the file named base1find.txt
in the Base Directory. (That file name has one digit in it.) The word count of this file must also be: 5 5 70
.
RTFM and find the single-letter option to the copy program that preserves mode, ownership, and timestamps when you copy. Make a note of this option in your own course notes; you will use it often as a system administrator.
Under your Base Directory create another directory base2
that contains a copy of everything you created under base1
, with the timestamps preserved.
Hint: The fastest way to do this is with a single recursive copy command, as you did in Section 3 of Worksheet #03 HTML, but add the option to preserve timestamps. Hint: Do not create the base2
directory before you copy, or else you will get a spurious extra level of directory.
Use a command to create an empty file named mt
in each of the five directories from base2
down. You will create five empty files, one in each of five directories. Hint: You can do this with one single command name and five relative pathnames.
Make the base2
directory your current directory and then use a command to recursively generate a list of all pathnames under your current directory. The recursive output of all pathnames under your current directory will be exactly ten lines long and will contain this exact line in the output somewhere (along with another nine lines):
./bdir2/bdir2-1/mt
Make sure the exact line above appears as one of the ten lines! The word count of this command output must be: 10 10 115
and if the count is wrong, re-read all the words in this step.
When the recursive output above on your screen looks correct, redirect the ten lines of output of the command into the file named base2find.txt
in your base directory (not in the current directory). The word count of this file must also be: 10 10 115
.
Under your Base Directory create another directory base3
that contains a copy of everything that you created under base2
, with timestamps preserved. Hint: See the previous Hint!
Under base3
rename each of the mt
files to have the number of the immediate parent directory that contains it, e.g. rename base3/mt
to be base3/mt3
and bdir2-1/mt
to be bdir2-1/mt2-1
, etc. You don’t know enough scripting yet to do this with a script; do each file manually.
Hint: The -type f
option to find
may be useful here to generate a list of only file names and not show directory names.
Make the base3
directory your current directory and then use a command to recursively generate a list of all pathnames under your current directory. The recursive output of all pathnames under your current directory will be exactly ten lines long and will contain this exact line in the output somewhere (along with another nine lines):
./bdir2/bdir2-1/mt2-1
Make sure the exact line above appears as one of the ten lines! The word count of this command output must be: 10 10 124
and if the count is wrong, re-read all the words in this step.
When the recursive output above on your screen looks correct, redirect the ten lines of output of the command into the file named base3find.txt
in your base directory (not in the current directory). The word count of this file must also be: 10 10 124
Run the Checking Program to verify your work so far.
Under the Source Directory there is a directory named maze
(four letters) with many, many sub-directories and sub-sub-directories, etc. (The maze contains over 18,000 pathnames.) In this large maze, find the one file with a 12-character basename that looks similar to abcd0001-txt
but where the eight-character abcd0001
part of the name is replaced by your own account userid.
maze
directory there because you know its name.maze
directory contains many hidden sub-directories; you need a special option to see hidden files and directories.cd
or ls
to find the file in the maze; the maze is very big. Use the correct command.b.
of Section 8 of Worksheet #02 HTML.When you have found your personal abcd0001-txt
file in the maze, create a new directory maze
in your Base Directory and copy your personal file from the maze into that new directory using the new file name treasure.txt
. Read the file to make sure it’s the right one before and after you copy it into your own maze
directory; the file content will tell you clearly that you have found the right file.
Run the Checking Program to verify your work so far.
That is all the tasks you need to do.
Check your work a final time using the Checking Program and save the output as described below. Submit your mark following the directions below.
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 marks file 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.
There is a Checking Program named assignment02check
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/cst8207/14f/assignment02/assignment02check
You will learn of ways to make this shorter in future assignments.
Execute the above check
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 want to paginate the long output so you can read all of it.)
You may run the check
program as many times as you wish, 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.
assignment02.txt
under your Base Directory on the CLS. Use that exact name. Case (upper/lower case letters) matters. Be absolutely accurate, as if your marks depended on it.
YOUR MARK for
assignment02.txt
file from the CLS to your local computer and 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. You may want to refer to your File Transfer notes.
YOUR MARK for
assignment02.txt
file from your local computer to the correct Assignment area on Blackboard (with the exact name) before the due date:
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 assignment02 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!