Updated: 2017-10-01 23:57 EDT

1 Due Date and DeliverablesIndexup to index

Do not print this assignment on paper!

WARNING: Some inattentive students upload Assignment #03 into the Assignment #02 upload area. Don’t make that mistake! Be exact.

2 Purpose and BackgroundIndexup to index

This assignment is based on your weekly Class Notes and covers these topics:

2.1 Prerequisites: Do Worksheet 2 and Worksheet 3Indexup to index

You must complete the two Worksheets before attempting this assignment. The worksheets depend on the Readings in the weekly course notes, especially Command Arguments and Options and File System and Pathnames.

These worksheets prepare you to do the rest of the tasks listed below. Failure to complete the worksheets will make the rest of this assignment very difficult. Do the worksheets first! Record and save all your worksheet answers for study and quizzes!

You must 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 Microsoft Word; it will mangle the numbering and format of the worksheet.

  1. Do a Remote Login to the Course Linux Server (CLS). All work in this assignment must be done on the CLS.

  2. Use LibreOffice or OpenOffice to open, complete, and save Worksheet #02 ODT. (View online: Worksheet #02 HTML.)
    • Do not use Microsoft Word to open this file; it damages the file.
    • You must read the week’s Class Notes before you do the worksheet.
    • You will find it easier to write over the red underscores using “OVERWRITE” typing mode instead of the default “INSERT” mode.
    • Another way to fill in answers is to double-click to select the entire line of underscores and then simply type or paste to replace it.
    • Record and save all your worksheet answers for study and quizzes!
    • The worksheet will not be marked, but your professor may ask to see it.
  3. Use LibreOffice or OpenOffice to open, complete, and save Worksheet #03 ODT. (View online: Worksheet #03 HTML.)
    • See the notes above for the previous worksheet.
    • The worksheet will not be marked, but your professor may ask to see it.

3 How to complete this AssignmentIndexup to index

For full marks, follow these directions exactly:

  1. These tasks must be done in your account via Remote Login to the Course Linux Server.

  2. 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.

  3. READ ALL THE WORDS in each task before you begin the task, especially all the Hints and links.

  4. 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.

  5. 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.

  6. 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.

3.1 Notes on doing assignment workIndexup to index

  1. 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.

  2. 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!

  3. 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.

  4. 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.

  5. 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.

3.2 Searching the course notes on the CLSIndexup to index

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.

3.3 Draw File System DiagramsIndexup to index

Many students find it extremely helpful to draw a quick graph/picture of their file system directory structure on paper before attempting to answer questions about relative pathnames.

You need to be able to visualize the relative locations of names in the file system tree to answer these questions. Draw the trees on paper!

3.4 The Source DirectoryIndexup to index

All references to the Source Directory below are to the CLS directory ~idallen/cst8207/17f/assignment03/ 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.

4 TasksIndexup to index

Have you completed all the prerequisites, before attempting these tasks?

4.1 Log in to the Course Linux ServerIndexup to index

  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. All work in this assignment must be done on the CLS.

4.2 Set your PS1 Shell PromptIndexup to index

  1. Using the PS1 variable syntax shown in Section 2 of Worksheet #02 HTML, set your shell prompt to include your user name, your computer name, and the basename of your current working directory. (See the definition of basename in the File System and Pathnames class notes.)
    • Your shell prompt should look similar to this:   [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 typing pwd 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.

Tip Feature: If you use \w instead of \W in the PS1 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.

4.3 Set Up – The Base Directory on the CLSIndexup to index

  1. Create the following directory structure in your CLS personal HOME directory and record (for study purposes) the series of Unix commands you used to create it. (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:
    1. Create the CST8207-17F directory in your CLS HOME directory.
    2. Create the Assignments directory in the CST8207-17F directory.
    3. Create the assignment03 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.

  1. 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 CST8207-17F
    $ tree -A CST8207-17F

    The correct output will look similar to the ASCII tree diagram below. The spelling and capitalization must be exactly as shown.

    CST8207-17F
    `-- Assignments
        `-- assignment03

This assignment03 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.

Run the Checking Program to verify your work so far.

4.4 Using echo with Command Arguments and RedirectionIndexup to index

You need to understand The Unix/Linux Shell and Command Arguments and Options to do this task.

  1. Make Base Directory you created above (assignment03) your current directory for this task.

second_argument.txt

  1. The echo command displays its arguments on your screen, separated by spaces. It can also put the arguments into a file if you use output redirection, for example you can give it two arguments:

    $ echo hi there
    hi there
    $ echo hi there >foo                    # redirect the echo output into file foo
    $ cat foo                               # display contents of file foo on your screen
    hi there
    $ ls                                    # list all the files on your screen
    foo
    $ rm foo                                # delete (remove) the file foo

    Looking at the above command line that uses output redirection, type a new echo command line that uses only the second argument (not both arguments) from that command line, and redirect the output (just the second argument from above) into a file named second_argument.txt. The output file should contain only one word.

In the following tasks you will be asked to use echo to echo specific arguments from previous command lines into output files.

Run the Checking Program to verify your work so far.

4.5 Using a relative pathnameIndexup to index

You need to understand File System and Pathnames and the two Worksheets to do this task.

  1. Make the Assignments directory that you created above your current directory. Do not change directories during this task.

  2. Run the command that shows your current working directory. One line should display on your screen that looks similar to this:

    /home/abcd0001/CST8207-17F/Assignments

cwdir.txt

  1. Redo the previous command, and this time redirect the output of the command into the file cwdir.txt in the current directory (just as you did in Assignment #02).

    Hint: Recall that you can redirect into a file any output that appears on your terminal screen. You did this output redirection using the date command to create the file date.txt in Assignment #02.

Re-read the part at the start of this assignment about drawing file system diagrams on paper so you know what you are doing. Do it now.

  1. Move (rename) the cwdir.txt file from the current directory (Assignments) down into your Base Directory using the shortest relative pathname to do the move. (You did work similar to this in Section 4 of Worksheet #03 HTML.)

  2. Remember the “shortest relative pathname” you just used in the last command line. You will need to use that pathname later.

  3. Use a command that shows file names to confirm that there are no files left in the current Assignments directory. (You should only see the directory basename of the Base Directory in the current directory. That is all you should see.)

  4. Use the echo command to display on your terminal screen the “shortest relative pathname” that you remembered and just used as the second argument to the previous move command. Echo just this one pathname onto your screen.

    Hint: If you want to be lazy and not re-type the pathname, you can do this: Use UP-ARROW to recall and then and edit the move command line you used. Remove the first argument from the command line, and then replace the move command name by the echo command name so that only the second pathname echoes to the terminal screen. Do not include the first pathname.

relecho.txt

  1. Without changing directories, redo the previous echo command, and this time redirect the output of the command (the relative pathname) into the file relecho.txt in your Base Directory (not in the current directory).

    Hint: For the redirection output file pathname, you must use a relative pathname that leads from your current directory Assignments down into the Base Directory. The relative pathname will contain one embedded slash separating two name components. The basename of the relative pathname must be the destination file name relecho.txt

  2. Use a command to confirm that the Base Directory contains the new relecho.txt file. The current directory should not contain any files.

Run the Checking Program to verify your work so far.

4.6 Using find to list all the pathnamesIndexup to index

  1. From the current Assignments directory, change directories and make the CST8207-17F directory that you created above your current directory, using the shortest relative pathname to change from Assignments to CST8207-17F. Do not change directories during this task.

  2. Remember the “shortest relative pathname” you just used in the last command line. You will need to use that pathname later.

  3. There should be no files in this CST8207-17F directory. Use a command to verify that there are no files here. The only name here should be the directory named Assignments. If there are files in this CST8207-17F directory, delete the files before continuing. (Don’t delete the Assignments directory!)

relpath.txt

  1. Without changing directories, use the echo command with output redirection to save the “shortest relative pathname” argument that you remembered and just used, into file relpath.txt in your Base Directory (not in the current directory).

    Hint: For the redirection output file pathname, you must use a relative pathname that leads from your current directory CST8207-17F down into the Base Directory. The relative pathname will contain two embedded slashes separating three name components. The basename of the relative pathname must be the destination file name relpath.txt

  2. Still in the current CST8207-17F directory, use the command from the worksheet to recursively walk the current directory and 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.

f0und.txt

  1. Repeat the same recursive command you just used and redirect the output of the command into file f0und.txt in your Base Directory (not in your current directory). Note the strange spelling of the file name.

    Hint: For the redirection output file pathname, you must use a relative pathname that leads from your current directory CST8207-17F down into the Base Directory, as you did above. See the previous Hints.

  2. Use a command that shows file names to confirm that the relpath.txt and f0und.txt files are located only in the Base Directory and not in the current directory or anywhere else.

Run the Checking Program to verify your work so far.

4.7 Creating new files and directoriesIndexup to index

You may find it easier to type pathnames in this task if you make the Base Directory you created above (assignment03) 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 spelling of the names used.

calnew,txt

  1. Copy the 1752 cal.txt file you created in Assignment #02 HTML into the Base Directory using the new name calnew,txt for the file. (Note carefully the punctuation character used in this new name.)

1Idlr

  1. Create the following directory structure starting in the Base Directory and record (for study purposes) the series of commands you used to create it. Spelling and capitalization must be exactly as shown:
    1. Create the 1Idlr directory in the Base Directory. Pay careful attention to the name; every letter in the name is a different character.
    2. Under directory 1Idlr create two new directories named aOo0 and b0oO (four letters each).
    3. Under directory aOo0 create new directory Oo0sub (six characters, including one digit).
    4. Under directory b0oO create new directory 0oOsub (six characters, including one digit).

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.

  1. 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 of each name must be exactly as shown.

    1Idlr
    |-- aOo0
    |   `-- Oo0sub
    `-- b0oO
        `-- 0oOsub

l1dIr

  1. Copy the directory 1Idlr to new directory l1dIr using the correct directory copy option, as you did in Section 3 of Worksheet #03 HTML. Pay careful attention to the name; every letter in the new directory name is a different character.

    Hint: The new directory l1dIr must not exist before you do this copy! If it already exists, recursively remove it before you do the copy, or else you will get a spurious incorrect extra level of directory such as l1dIr/1Idlr

  2. Check that the tree structure of l1dIr is exactly the same as the tree structure of the 1Idlr directory from which you copied it.

Run the Checking Program to verify your work so far.

4.8 Generating a recursive pathname listIndexup to index

  1. Make the Base Directory your current directory.

  2. Use a command to recursively generate a list of all pathnames using your 1Idlr directory as the starting directory. (You used this recursive command above, and many times in the Section 8 in the end of Worksheet #02 HTML. Do not use the tree or ls commands. Use the 1Idlr directory as your starting directory.)

    The recursive output of all pathnames under your 1Idlr directory will be exactly five lines long and will contain this exact line in the output somewhere (along with another four lines):

    1Idlr/aOo0/Oo0sub

    Make sure the exact line above appears as one of the five lines!

myPaths.txt

  1. When the five lines of recursive output above on your screen looks correct, redirect the output of the command into the file named myPaths.txt in the Oo0sub directory that you created earlier under the l1dIr directory.

    Hint: Draw a file system tree diagram so that you know what relative pathname to use. Don’t try to invent the pathname in your head! Don’t redirect the output into the current directory!

    Hint: For the output redirection file, use a relative path from your current directory down into the Oo0sub directory under l1dIr. The relative pathname will contain three embedded slashes separating four name components. The basename of the relative pathname is the destination file name myPaths.txt

  2. Make the Oo0sub directory under l1dIr your current directory. (Make sure you get the right one under l1dIr and not 1Idlr! Display your current working directory and make sure.)

    Hint: Draw a file system tree diagram so that you know what relative pathname to use. Don’t try to invent the pathname in your head!

  3. Use a command to list the files in the current (Oo0sub) directory to confirm that the myPaths.txt file is here. Use another command to display the contents of the myPaths.txt file, and make sure it contains exactly five lines of pathnames from under the 1Idlr directory, including the sample line showsn earlier.

myPaths.txt.copy

  1. From in the Oo0sub directory, copy the myPaths.txt file (from the current directory) into the 0oOsub directory that is also under the l1dIr directory, giving it the new name myPaths.txt.copy as the destination file name for the copy. Use relative pathnames to do the copy.

    Hint: 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 b0oO directory. The relative pathname will contain four embedded slashes separating five name components. The basename of the relative pathname should be the destination file name.

copycmnd.txt

  1. Save a copy of the command line you just used into a file as follows:
    1. Use the Up-Arrow key to retrieve the copy command you just typed.
    2. Use the Left-Arrow key to move all the way left and then prefix the copy command line you just typed with the word echo; type the word echo followed by a space at the start of the command line, in front of the copy command name.
    3. Push the [Enter] key and confirm that the copy command name and its two relative pathname arguments echo onto the screen.
    4. Again use the Up-Arrow key to retrieve the echo command you just typed.
    5. To the right end of the echo command line, add redirection to redirect the echo output into file copycmnd.txt in the Base Directory. No output should appear on screen.

    The copycmnd.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 copycmnd.txt output file must be located in the Base Directory, not in the current Oo0sub 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 and many parent directories. The basename of the relative pathname is the destination file name copycmnd.txt

    You will need to use the echo command to create another file later in this assignment. Remember how you used it here.

Run the Checking Program to verify your work so far.

4.9 Working with existing directories and files: mydirIndexup to index

  1. Execute this exact command line in your account on the CLS:

    ~idallen/cst8207/17f/assignment03/create_mydir.sh

mydir

  • The command will create a directory named mydir in your Base Directory. The directory will contain some sub-directories and files.

  • 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.) Make sure you use the correct command to recursively show all the files and directories, not just the first layer.

  • You can re-execute the above create_mydir.sh command line to start this task over from scratch, if you make errors in this part of the assignment, but you will have to rename or remove the existing mydir first.

  • You will be asked to make some changes to this existing set of files and directories. You must not make any changes other than the changes asked. If you accidentally create or delete files not required, you may change the modify time of sub-directories and you will have to erase the whole directory and start over.

All the following commands in this task section apply to files and directories under the new mydir directory. You will have to use commands to find some of the file names mentioned here; they may be located under sub-directories; see Finding Files. Some of these tasks may require more than one command to complete.

  1. Find and read the file named README.txt (located somewhere under some directory under mydir). You have to find this file.

  2. 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.)

bar.old

  1. Move (rename) the only file named bar to be bar.old

    Hints: This is a move, not a copy; it renames the file. Make sure you rename the file, not any decoy directories with the same name. You know a command that can find names that are files (and not directories) by using the -type f expression from Finding Files along with the -name expression that you already know from Section 8 in Worksheet #02 HTML.

bar

  1. Directly under the mydir directory, create a new empty directory named bar (three letters). (Make sure you create bar under mydir, not in your HOME or any other directory.)

    Hints: If this command fails with the message File exists, you need to re-read the Hints on the previous item.

stuff.old

  1. Find the file named stuff (not the directory with the same name) and move (rename) that stuff file to be named stuff.old under the new directory bar that you just created. (This is a move/rename, not a copy.) Make sure you move the file, not any directory with the same name.

Run the Checking Program to verify your work so far.

4.10 Working with new directories and files: top1bIndexup to index

You may find it easier to type pathnames in this task if you make the Base Directory your current directory for the next few sections.

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. echo hi mom | wc should print 1 2 7 (one line, two words, seven characters (counting the space character and the invisible newline character at the end of the line).

top1b

  1. Create the following directory structure starting in the Base Directory and record (for study purposes) the series of commands you used to create it. Spelling and capitalization must be exactly as shown:
    1. Create a directory named top1b in your Base Directory.
    2. Under directory top1b create two new directories named dir1b and dir2b (four letters and one digit each).
    3. Under directory dir1b create new directory dir1b-1 (four letters, two digits, and one dash).
    4. Under directory dir2b create new directory dir2b-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.

  1. Verify that the directory tree under top1b looks similar to the ASCII tree diagram below. The spelling and capitalization must be exactly as shown:

    top1b
    |-- dir1b
    |   `-- dir1b-1
    `-- dir2b
        `-- dir2b-1
  2. Make the above directory top1b (in your Base Directory) your current directory.

  3. Use a command to recursively generate a list of all pathnames in the current 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):

    ./dir2b/dir2b-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 50 and if the count is wrong, re-read all the words in ths step.

top1bfind.txt

  1. When the recursive output above on your screen looks correct, redirect the five lines of output of the command into the file named top1bfind.txt up in the Base Directory (not in the current directory). (That file name has one digit in it.) The word count of this file must also be: 5 5 50.

    Hints: If the file has six lines in it, remove the file and re-read the words “not in the current directory”. You need to use a output redirection pathname that goes from the current directory up to the Base Directory. Don’t create the file in the current directory!

Run the Checking Program to verify your work so far.

4.11 Working with new directories and files: top2bIndexup to index

top2b

  1. RTFM in the Manual 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.

  2. Choose the appropriate current directory before you do this task: Under your Base Directory create another directory top2b that contains a copy of everything you created under directory top1b, with the timestamps preserved.

    Hints: 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. Do not create the top2b directory before you copy. The new directory top2b must not exist before you do this copy! If it already exists, recursively remove it before you do the copy, or else you will get a spurious incorrect extra level of directory such as top2b/top2b

Make sure the time stamps have been preserved in the copy, before you continue, or else you will have to redo this whole section.

emt

  1. Use a command to create an empty file named emt in each of the five directories from top2b down. You will create five empty files, one in each of five directories.

    Hints: You can do this with one single command name and five relative pathnames. If you’re using the cd command to do this, you’re wasting time.

  2. Make the directory top2b (in your Base Directory) your current directory.

  3. 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):

    ./dir2b/dir2b-1/emt

    Make sure the exact line above appears as one of the ten lines! The word count of this command output must be: 10 10 120 and if the count is wrong, re-read all the words in this step.

top2bfind.txt

  1. When the recursive output above on your screen looks correct, redirect the ten lines of output of the command into the file named top2bfind.txt in the Base Directory (not in the current directory). The word count of this file must also be: 10 10 120.

    Hints: If the file has 11 lines in it, remove the file and re-read the previous task’s Hints about “not in the current directory”.

Run the Checking Program to verify your work so far.

4.12 Working with new directories and files: top3bIndexup to index

top3b

  1. Under your Base Directory create another directory top3b that contains a copy of everything that you created under top2b, with timestamps preserved. Hints: See the previous task Hints!

Make sure the time stamps have been preserved in the copy, before you continue, or else you will have to redo this whole section.

emt3b, emt2b-1 etc.

  1. Under top3b rename each of the emt files to have the suffix of the immediate parent directory that contains it, e.g. rename top3b/emt to be top3b/emt3b and dir2b-1/emt to be dir2b-1/emt2b-1, etc. You don’t know enough scripting yet to do this with a script; do each of the five files manually.

    Hint: The -type f expression may again be useful here to generate a recursive list of only file names and not show directory names; see Finding Files and Section 8 in Worksheet #02 HTML.

  2. Make the directory top3b (in your Base Directory) your current directory.

  3. 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):

    ./dir2b/dir2b-1/emt2b-1

    Make sure the exact line above appears as one of the ten lines! The word count of this command output must be: 10 10 134 and if the count is wrong, re-read all the words in this step.

top3bfind.txt

  1. When the recursive output above on your screen looks correct, redirect the ten lines of output of the command into the file named top3bfind.txt in the Base Directory (not in the current directory). The word count of this file must also be: 10 10 134

    Hints: If the file has 11 lines in it, remove the file and re-read the previous task’s Hints about “not in the current directory”.

Run the Checking Program to verify your work so far.

4.13 Finding files in a large mazeIndexup to index

You need to know Finding Files to do this task.

mymaze

  1. Create a new directory named mymaze in your Base Directory.

  2. 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 23,390 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.

    Hints:
    1. Review the definition of basename in the File System and Pathnames class notes.
    2. Recall that you do not have permission to list the names of all the files in the Source Directory, but you can access the maze directory there because you know its name.
    3. This maze directory contains many hidden sub-directories; you need a special option to see hidden files and directories.
    4. Do not try to use cd or ls to find the file in the maze; the maze is very big. Use the correct command to recursively search the maze directory for the file name.
    5. You must use a single command that recursively finds files by basename to find your 12-character file name. You have previously seen the command you will need in the first item b. of Section 8 of Worksheet #02 HTML.
    6. Read the file when you find it. The file content will tell you clearly that you have found the right file. If you see XXX in the file, it is not the right file.
    7. Pay careful attention to the exact spelling of the 12-character basename of the required file.

mazepath.txt

  1. When the above command has found your personal abcd0001-txt file in the maze and outputs exactly one line, put the absolute pathname of your personal file (one line) into a file named mazepath.txt in the mymaze directory that you created in step 1 above.

    Hint: It must be the absolute pathname. You will have to draw a file system diagram and figure out what that pathname is; no command will show it to you. You can test your absolute pathname by giving it as an argument to a command that reads pathnames, e.g. to ls, wc, cat, sum, etc. and make sure you get no error message.

    Hint: You can use the echo command with output redirection to put one line of text into any file. (You used the echo comand in a similar way to create the one-line copycmnd.txt file, earlier.) When you know the absolute pathname, give the echo command one argument that is the absolute pathname of your personal file in the maze. Make sure the pathname echoes onto your screen. Then, add output redirection to this echo command so that the echo output goes into the mazepath.txt file and not onto your screen. The mazepath.txt file should contain one line that is the absolute pathname of the found file in the maze.

treasure.txt

  1. Copy only your one personal file from the maze into your mymaze 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 mymaze directory; the file content will tell you clearly that you have found the right file. If you see XXX in the file, it is not the right file.

    Hint: Be careful not to copy the entire maze directory! Copy only the contents of one file into mymaze.

Run the Checking Program to verify your work so far.

4.14 Tidy up your HOME directoryIndexup to index

  1. Create a directory named assignment02 under Assignments to store all your Assignment #02 files and move all your Assignment 2 files down into that directory.

  2. Re-run the Assignment 2 checking program to make sure it can find all your Assignment 2 files in their new location.

Run the Assignment 3 Checking Program to verify your work so far.

4.15 When you are doneIndexup to index

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.

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

Nothing seriously bad will happen if you forget to log out, but you may leave behind an empty, “ghost” login session that may take some days to time out and disappear. Always exit before you close your laptop, PuTTY, or Terminal session.

5 Checking, Marking, and Submitting your WorkIndexup to index

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 assignment03check 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/cst8207/17f/assignment03/assignment03check

    Note the leading tilde ~ character on the command name. You will learn of ways to make this long line shorter in future assignments.

  2. When you are done, 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 assignment03.txt in your Base Directory on the CLS, like this:

    $ ~idallen/cst8207/17f/assignment03/assignment03check >assignment03.txt
    • Use standard output redirection with that exact assignment03.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; the format is fixed.

    You can view the output file one-page-at-a-time using the less program (use the space bar to page forward and use the letter q to quit):

    $ less assignment03.txt
    • 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 assignment03.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 or open and save this file on your local computer! 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 assignment03.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 assignment03 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 assignment03.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 assignment03.txt file for upload. Do not attach any other file names.
    5. After you have attached the assignment03.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 assignment03.txt file to Blackboard.
    6. Submit the file exactly as uploaded from the CLS.
    7. Do not submit an empty file. Do not submit any other file names.

    Use only Attach File, Browse My Computer on the Upload Assignment page. Do not enter any text into the Write Submission or 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.

  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 assignment03.txt 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. Click on the Download button to open and view the file you just uploaded. MAKE SURE THE FILE YOU JUST UPLOADED HAS YOUR MARKS IN IT!
    5. 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.)
    6. Make sure you have used Submit and not Save as Draft. I cannot mark draft assignments. Make sure you Submit.

    You will also see the Review Submission History page any time you already have an assignment attempt uploaded and you click on the underlined assignment03 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, BA, MMath - 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/

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