HW02: The Linux CLI due Sat 07 Sep 23:59

\begin{purpose} In this assignment we will learn how to navigate a Linux command... ...actical skill that will serve you well in this course and in life. \end{purpose}

Overview

Unless noted otherwise, you should perform the instructions below using your own virtual instance of Kali.

Linux Tutorial

Visit https://ryanstutorials.net/linuxtutorial/ and work through these sections: Basic Navigation, More About Files, Manual Pages, File Manipulation, Wildcards, Permissions, Filters, Grep and Regular Expressions, Piping and Redirection, Process Management, and Cheat Sheet. Be sure to do the Activities section in each tutorial.

Choose a Text Editor

Based on our discussion of text editors in the online video, decide which text editor you would like to use: vim or nano. Then follow the instructions for the editor of your choice below:
vim
Make sure you have the cheat sheet(s) handy as a reference. See: https://josephus.sergeantservices.com/classes/all/docs/vi-ref.pdf and https://josephus.sergeantservices.com/classes/all/docs/vi-back.pdf. At the command-line enter the command: vimtutor and read and follow the instructions for lessons 1 and 2 (each lesson has quite a few parts so this will take about an hour).
nano
Read and follow the tutorial found at:

https://www.howtogeek.com/42980/the-beginners-guide-to-nano-the-linux-command-line-text-editor/

Exercises in Kali

You'll need to jot down some things in a text editor as you go. In the instructions that follow there will be several times the instructions say “(Save)” which is your cue to record what you learned in a text file (named stats.txt) along with a description. Some of the commands may be new to you. Feel free to use the man command to get a quick description if you are not sure how to proceed.

Using the command-line complete these tasks:

  1. You will get a copy of all files (including subdirectories) from the josephus.sergeantservices.com server. The files are currently combined and compressed into a single document with a .tgz extension ... which is to say the documents have been “tarred and zipped”. The file is located here: https://josephus.sergeantservices.com/classes/cy/source/data.tgz

    The easiest way to get it to your Kali VM is to use wget: 

    wget https://josephus.sergeantservices.com/classes/cy/source/data.tgz

  2. In your Kali instance, untar/zip the data.tgz file you just downloaded: 
    tar xvzf data.tgz

  3. Change into your newly created directory called data and do the remainder of the steps from there.
  4. Delete the gotthought directory and everything in it.
  5. Make a copy of alice.txt called greenalice.txt.
  6. Use a text editor to open greenalice.txt and find the line number of the first mention of “Cheshire”. (Save the line number to your text file)
  7. In the same file replace all occurrences of “Cheshire” with “Green”. Save and exit the file.
  8. Use the diff command to compare alice.txt with greenalice.txt. How many lines differ between the two files? (Save)
  9. Take moment to play around with the wc command (which counts lines, words, and characters in a file).
  10. Use ls, wc and the pipe to count how many .txt files are in the current directory. (Save)
  11. Use find, wc and the pipe to count how many .txt files are in the current directory and all of its subdirectories. (Save)
  12. Create a subdirectory called fun and copy zip1999.zip into it and then make it your working directory.
  13. Use unzip to unzip zip1999.zip. Take note of the size of zip1999.zip and of the files that were extracted from it (zipnov99.DBF and zipcodes.doc). (Save sizes) Then use a calculator to determine the space savings as a percentage. (Save calculated percentage).
  14. Remove all the files from the fun directory (but remain inside it). Then copy the file named p1source.tgz from the parent directory to fun.
  15. Use the tar command to extract the files from p1source.tgz inside fun. You may need to look up how to use this command. How many files were extracted from p1source.tgz? (Save)
  16. Without leaving the fun directory, copy the file pc.txt from the games directory to it.
  17. Return to the parent directory and delete fun and all the files in it.
  18. Use an editor to modify Indent.java so that it is properly indented. Instead of indenting each line one at a time look up how to indent a block of lines using your chosen text editor and indent accordingly. Save your changes.
  19. Don't delete this working directory yet ... we'll be using it in future steps.

Regex's

Start the Firefox web browser in Kali (Kali Icon -> Web Browser). Use the interactive lessons at https://regexone.com to learn/practice writing regular expressions. When you reach the screen with the graduation cap you can stop. Make a screen capture of the final screen and save it under the name cap.jpg. NOTE: This site has a section of additional exercises that you do not need to work through unless you just want extra practice.

Using sed

The program sed is a stream editor that will apply editing commands to whatever is fed into it. This can be done by piping output from another command to it or it can be applied to an existing file in place. Often you will want to use a regular expression to match a pattern and then insert new text after the pattern, delete the pattern, or replace the pattern. There are a number of decent sed tutorials online but not a single one that to me seemed the go-to tutorial. Take some time to play around with various sed commands and then proceed to the instructions below when you are ready to use it.

  1. Return to the data directory you created using the steps above.
  2. Use the wget utility to download this document into data: https://josephus.sergeantservices.com/classes/ds/source/melville.txt. The following exercises should be applied to melville.txt in place so that the file is modified. (If you accidently destroy the file you can download a fresh copy.
  3. Use sed to remove the leading spaces on each line. Once you have a command that works save the command to stats.txt along with a description.
  4. Use sed to replace all lines that begin with a hypen with a blank line. (Save)

What to Turn In

Use the tar command to create a .tgz file that contains these files:
stats.txt
Contains notes you took of various values and command along with descriptions of the the meaning of those values and commands.
greenalice.txt
Contains text of Alice in Wonderland with all instances of “Cheshire” replaced with “Green”.
Ident.java
Contains properly indented Java program.
cap.jpg
Is the screen capture of your completed regex tutorial.

Transfer your newly-created .tgz file from Kali to your host operating system by clicking Machine->File Manager in the VirtualBox menu of the window containing the running Kali machine. Initially you'll see a message that says: “No Guest Session found!”. To create a guest session enter your Kali username and password in the boxes to the left and then click the “Create Session” button. Once a connection has been made you can transfer a file from Kali to your local computer by simply dragging from the left panel to the right panel. Once you have transfered the file to your local computer you are ready to upload the .tgz file in Canvas. Once you have turned in your work you can/should remove the data directory in Kali in which you've been working.

Be sure to perform a proper shutdown of you Kali instance (File->Close) and save the results of the current session for future logins. NOTE: This may take a few minutes because of the many changes we made to the Kali file system.

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