1,234
edits
Changes
no edit summary
{{Admon/caution|DO NOT USE THIS VERSION OF THE LAB. This page will no longer be updated.|'''New version here:''' https://seneca-ictoer.github.io/ULI101/A-Tutorials/tutorial3<br />'''Andrew's students please go here:''' http://wiki.littlesvr.ca/wiki/OPS145_Lab_3}}=LEARNING ABOUT YOUR MATRIX SERVER ACCOUNTADVANCED UNIX / LINUX FILE MANAGEMENT=
===Main Objectives of this Practice Tutorial===
:* Understand the purpose of the difference between '''Matrix serverabsolute''' and the <u>, '''advantagesrelative'''</u> of combining Linux servers to form a and '''clusterrelative-to-home'''.pathnames
:* List Become productive at issuing Linux commands with the steps to connect to your Matrix server account in the <u>'''computer labs</u> at Seneca College'''.most appropriate pathname
:* List the steps to connect to your Matrix server account from a computer <u>Use '''outside</u> of Seneca CollegeFilename Expansion''' ('''FNE''') Symbols: '''*''' , '''?''' , '''[ ]''' , '''[! ]'''.
:* Working with the Linux Use '''Command Promptquotation''' (Linux treat special characters as just '''shelltext''')when issuing Linux commands.
:* Changing your Matrix Account Understand the quotation symbols: '''PasswordBackslash \''', '''single quotes ' '''' and '''double quotes " "'''<br><br>
|- valign===Purpose of Having a Matrix Account==="top"
|-| colspan="1" style="paddingfont-size:16px;font-weight:bold;border-bottom: thin solid black;border-leftspacing:0px;width:10%" |'''my.senecacollege.ca'''| style="padding-left:15px;width:65%" |Learning Content Management System (Student Grades / Notes / Online Quizzes)YouTube Videos<br>
|-| stylevalign="padding-left:0px;width:10%top" |'''ict.senecacollege.ca'''| style="padding-left:15px;width:65%" |Main ICT Webserver
|-| stylecolspan="padding-left:0px;1" width:10="22%" |'''Slides:'''<ul><li>Week 3 Lecture 1 Notes:<br> [https://wiki.cdot.senecacollege.ca'''/uli101/slides/ULI101-3.1.pdf PDF] | style="padding[https://wiki.cdot.senecacollege.ca/uli101/slides/ULI101-left3.1.pptx PPTX]</li><li>Week 3 Lecture 2 Notes:15px;width<br> [https:65%" //wiki.cdot.senecacollege.ca/uli101/slides/ULI101-3.2.pdf PDF] |Course WIKIs for Seneca College Students[https://wiki.cdot.senecacollege.ca/uli101/slides/ULI101-3.2.pptx PPTX] <br></li></ul>
| style="padding-left:15px;" |'''Pathname / Filename Expansion:'''* [https://www.cyberciti.biz/faq/understanding-absolute-pathnames/ Absolute]<br>* [https://www.oreilly.com/library/view/web-design-in/0596009879/ch04s02s02.html Relative]<br>* [https://stackoverflow.com/questions/24048533/unix-simple-what-is-a-relative-to-home-pathname Relative-to-home]<br>* [https://docstore.mik.ua/orelly/linux/run/ch04_08.htm#:~:text=Another%20way%20to%20save%20time,is%20sometimes%20called%20%22globbing.%22 Filename Expansion Symbols] | style="padding-left:0px15px;width:10%" |'''matrixQuoting Special Characters:'''* [http://tldp.senecacollegeorg/LDP/Bash-Beginners-Guide/html/sect_03_03.cahtml Backslash '''\''' , Single ''' ' ' ''' , Double '''" "''']<br>'''Linux Commands:'''* [https://man7.org/linux/man-pages/man1/echo.1.html echo] | colspan="1" style="padding-left:15px;" width:65="30%" |Linux Account for Student Practice '''Instructional Videos:'''<ul><li>[https://www.youtube.com/watch?v=ephId3mYu9o Pathname Types]</li> <li>[https://youtu.be/5FQnehwzwSM Filename Expansion Examples]</li><li>[https://youtu.be/3quKLqUFGHo Relative, Absolute, and Assignment submissionRelative-to-Home Filepaths]</li> <li>[https://www.youtube.com/watch?v=mzgfE6-ZtUY Quoting Special Characters]</li></ul>
|}
= KEY CONCEPTS =
===Pathname Types===
As previously mentioned, a '''pathname is a fully-specified location of a unique filename''' within a file system.<br>The concept of a pathname relates to every operating system including: ''Unix, Linux, MS-DOS, MS-Windows, Apple-Macintosh,'' etc.
Last week, we used a pathname from our home directory to create and manipulate directories and text files.<br>There are '''different types of file pathnames''' that we can use to access a directory or text file.
'''For Example:'''<br><span style="font-family:courier">/home/userid/uli101/cars.txt</span> ('''absolute pathname''')<br><span style="font-family:courier">samples/cars.txt</span> ('''relative pathname''')<br><span style="font-family:courier">~/cars.txt</span> ('''relative-to-home pathname''')
These types of file pathnames can make it more efficient (i.e. less keystrokes for users to type) when issuing Unix and Linux commands.
====Absolute Pathnames====
<table align="right"><tr><td>[[Image:absolute-path-2.png|thumb|right|250px|The directory in red displays the FULL path from the '''root''' directory to the '''bin''' directory (i.e. the absolute pathname: '''/bin'''.]]</td><td>[[Image:absolute-path-1.png|thumb|right|250px|Directories in red display the FULL path from the '''root''' directory to the '''examples''' directory (i.e. the absolute pathname: '''/home/your-user-id/uli101/examples'''.]]</td></tr></table>
An '''absolute pathname''' is a path to a file or directory always<br>'''beginning from the root directory (i.e. / )'''.
This type of pathname is referred to as '''absolute''' because the pathname always begins from the '''root directory''', regardless the location or your current directory. In other words, this type of pathname requires that you always provide the '''FULL''' pathname starting with the root directory.
''Advantages of using Absolute Pathnames:''
:* Useful if you do not know your current directory location
:* Understand the location of file within the filesystem.
''Examples:''<br><span style="color:blue;font-family:courier;">ls /bin<br>ls /home/your-user-id/uli101/examples</span>
<br><br>
====Relative Pathnames====
<table align="right"><tr><td>[[Image:relative-pathname-1.png|thumb|right|250px|Directories in red display the path from the current directory location (which is '''xyz100''') to the '''bin''' directory (i.e. the relative pathname: '''../../../bin'''.]]</td><td>[[Image:relative-pathname-2.png|thumb|right|250px|Directories in red display the path from the current directory location (which is '''uli101''') to the '''examples''' directory (i.e. the relative pathname: '''uli101/examples''' or ./uli101/examples]]</td></tr></table>
A '''relative pathname''' is a path to a file or directory that begins from your '''current''' directory. This is called relative because it is used to locate a specific file <u>relative</u> to your current directory.
'''NOTE:''' In order to use relative pathnames, it is <u>absolutely necessary</u> that you know the '''location''' of your '''current directory'''!
''Relative Pathname Symbols:''
:'''<span style="font-size:1.5em;">.</span> ''' A period symbol "." represents the '''current''' directory
:'''<span style="font-size:1.5em;">..</span>''' Two consecutive period symbols ".." represents the '''parent''' directory (i.e. one level up)
''Advantages of using Relative Pathnames:''
:* Possible shorter pathname (less typing)
Examples: <br><span style="color:blue;font-family:courier;">ls ../../../bin</span><br><span style="color:blue;font-family:courier;">ls examples<br>ls ./examples</span>
<br><br>
====Relative-to-home Pathnames====
<table align="right"><tr><td>[[Image:relative-to-home-1.png|thumb|right|250px|Directories in red display the path from the home directory of the current user (which is '''userid''') to the '''examples''' directory (i.e. the relative-to-home pathname: '''~/uli101/examples'''.]]</td><td>[[Image:relative-to-home-2.png|thumb|right|250px|Directories in red display the path from another user's home directory location to their '''notes''' directory (i.e. the relative-to-home pathname: '''~jane/uli101/notes''']]</td></tr></table>
A '''relative-to-home pathname''' begins with the tilde character ( i.e. ~) to represent the user’s home directory.<br><br>
The tilde character '''~''' stores the path of the user’s home directory<br>(i.e. '''~ = /home/current-user-id''')<br><br>You can immediately place a username after the tilde to represent another user’s home directory (e.g. <span style="font-family:courier">'''~jane = /home/jane'''</span>)
Examples:<br><span style="color:blue;font-family:courier">ls ~/uli101/examples<br>ls ~murray.saul/uli101/notes</span>
'''NOTE:''' Deciding which '''type of pathname''' to use depends on many factors including: '''knowledge of current directory''', '''knowledge of directory structure''',<br>'''currently directory location''', and '''type of file management command''' that is being used.
<br><br>
===Filename Expansion===
When issuing Linux commands, it may be '''more efficient''' (less typing) to use '''filename expansion symbols'''<br>to match files that share similar characteristics (e.g. same file extension) when issuing Linux commands.
=INVESTIGATION 1: ACCESSING YOUR MATRIX LINUX ACCOUNT==Quoting Special Characters===
As discussed in the above section, there are some special characters that the shell uses to perform<br>an operation; for example, the filename expansion symbols: '''*''' or '''?'''
There are '''3 methods''' to make those special characters '''act only like text characters'''<br>when issuing Linux commands (displayed in chart below):
<table cellpadding="5"><tr><th style="border-bottom: 1px solid black;text-align:left;">Quoting Method</th><th style="border-bottom: 1px solid black;text-align:left;">Example</th></tr><tr><td>Place the character '''\''' <u>before</u> a special character</td><td><span style="font-family:courier">'''echo \*'''</span></td></tr><tr valign="top"><td>Contain special characters within '''double-quotes'''<br>'''NOTE:''' Double quotes works for most special<br>characters, but not all special characters (such as $)<br></td><td><span style="font-family:courier">'''echo "* hello *"'''</span></td></tr><tr valign="top"><td>Contain Special character within single '''quotes'''<br>(Quotes out ALL special characters)</td><td><span style="font-family:courier">'''echo '* hello *''''</span></td></tr></table>
<span style="color:* From a workstation '''within'red;">'' a 'ATTENTION''Seneca College lab''':* From your <u>own</u> computer This online tutorial will be required to be completed by '''withinFriday in week 4 by midnight''' or to obtain a grade of '''outside''' '''Seneca College2%''' towards this course</span><br><br>
'''Perform the Following Steps:'''
# Start '''Login''' to your workstation matrix account.<br><br># Issue a command to '''confirm''' you are located in your lab home directory.<br><br>Let's create the following directory structure under your home directory by issuing the mkdir command using only absolute pathnames.<br><br># Issue the following Linux command to create the directory structure displayed to the right using '''absolute pathnames''':<br><br>'''NOTE:''' Just continue typing and login let the text continue of separate lines. Remeber to replace the text "youruserid" with your actual Seneca Windows account-id.<br><br><span style="color:blue;font-weight:bold;font-family:courier;">mkdir -p /home/youruserid/tutorial3/practice/commands /home/youruserid/tutorial3/practice/examples /home/youruserid/tutorial3/notes/lesson1 /home/youruserid/tutorial3/notes/lesson2</span><br><br># Make certain Issue the following Linux command to confirm that you properly created the MyApps browser is open (if notdirectory structure:<br><span style="color:blue;font-weight:bold;font-family:courier;">tree /home/youruserid/tutorial3</span><br><br>You should notice that using absolute pathnames with this Linux command '''requires a lot of typing'''.<br>Let's '''remove''' this directory structure, doubleand issue the same command using a ''relative-click on to-home'' pathname instead.<br><br># To remove this directory structure, issue the MyApps icon on the desktop following Linux command (enter "'''y'''" at each prompt to launchremove ALL contents):<br><span style="color:blue;font-weight:bold;font-family:courier;">rm -ri /home/youruserid/tutorial3</span><br><br># Issue a command tree command as you did in '''step #4''' to confirm that the directory structure has been removed.<br><br># In Issue the MyApps window, click on following Linux command to create the same directory structure using relative-to-home pathnames:<br><br>'''NOTE:''' You usually generate the search area ~ character by Holding down '''SHIFT''' and type press the button<br>to the <u>left</u> of the number '''1''' above the wordtext on your keyboard.<br><br><span style="color:blue;font-weight: sshbold;font-family:courier;">mkdir -p ~/tutorial3/practice/commands ~/tutorial3/practice/examples ~/tutorial3/notes/lesson1 ~/tutorial3/notes/lesson2</span><br><br>Did this command require less typing than the previous command using absolute pathnames?<br><br># Several SSH applications will appearIssue the '''tree''' command to confirm the directory structure was properly created.<br><br>Let's remove the '''tutorial3''' directory and its contents and issue the same command using '''relative pathnames'''. All of these applications allow <br><br># Issue the same command as you did in '''step #5''' to connect remove the '''tutorial3''' directory and its contents safely.<br><br># Issue a Linux command to your Matrix accountconfirm you removed the '''tutorial3''' directory and its contents. We will use <br><br># Issue the application called SSH Client for this following Linux command to create the same directory structure using relative pathnames:<br><br><span style="color:blue;font-weight:bold;font-family:courier;">mkdir -p tutorial3/practice/commands tutorial3/practice tutorial/examples tutorial3/notes/lesson1 tutorial3/notes/lesson2</span><br><br># Issue a command to verify that the proper directory structure was created.<br><br>'''QUESTION:''' Which '''mkdir''' command (pathname type) that you performed in steps '''3''' , '''7''' , and '''11''' required the <u>LEAST</u> number of keystrokes (i.e. characters)?<br><br>
:When performing the next series of steps, refer to the '''Perform the following steps:tree diagram'''# Select from on the installation menu: right. Learning to reference a tree diagram on a '''Install CentOS 7quiz'''.# Next, you will be prompted for a language. In the first screen, select language '''Englishmidterm''' with subselection or '''English-Canadafinal exam''' and then click the can help to '''Continueprevent errors and loss of marks!''' button on the bottom right-hand screen.<br>
=INVESTIGATION 2: FILENAME EXPANSION=
[[Image:dir12.png|right|350px|thumb|]]
:'''Perform the following steps:'''
# Open TerminalIssue a Linux command to move to the '''examples''' directory<br>(i.e. under ''practice'' directory as shown in diagram to the right).<br><br># Issue a Linux command to confirmed that you have moved to the '''examples''' directory.<br><br># Login as rootIssue the '''touch''' command to create the following empty text files in the ''examples'' directory:<br>(note ''upper'' and ''lowercase'' letters)<br><br><div style="font-family:courier;margin-left:50px;font-weight: bold;">abc.txt<bbr>def.text<codebr>hij.TxT<br>1a4.txt<br>123.TXT<br>456.txt<br>6u9.txt<br>ab2.html<br>1234.txt<br>abcdef.txt<br>abcde.txt<br><br></div><ol><li value="4">To verify that you properly created those files, issue the following:<br><span style="color:#3366CCblue;font-weight:bold;font-sizefamily:courier;">~uli101/week3-check-3</span><br><br>If you encounter errors, then make corrections (eg. '''viewing directory contents''', '''check for correct filename syntax''',<br>'''case sensitivity''', '''missing files''', '''files in the wrong location''', etc.) and then re-run the checking script<br>until you receive a congratulations message, and then continue with this investigation.<br><br><span style="color:red;">'''ATTENTION''':<br>Learning to '''fix your mistakes''' by issuing Linux commands may be required if you make mistakes<br>in your online tutorial. </span><br><br><li>Issue the '''ls''' command to get a listing of files in your ''examples'' directory.<br><br>The output should look identical to the diagram displayed below.<br>You can refer to this listing to see all files so you can then predict the output from Linux commands that use filename expansion symbols.<br><br>[[Image:listing-1.3empng|left|650px|thumb|]]<br><br><br><br></li><li>What do you think the output will be from the following Linux command?<br><span style="color:blue;font-weight:bold;font-family:courier;">su ls ???.txt</span><br>'''Write down the expected output''' on paper, then '''issue the command''' to check your answer.<br><br></li><li>What do you think the output will be from the following Linux command?<br><span style="color:blue;font-weight:bold;font-family:courier;">ls ?????.txt</span><br>'''Write down the expected output''' on paper, then '''issue the command''' to check your answer.<br><br></li><li>What do you think the output will be from the following Linux command?<br><spanstyle="color:blue;font-weight:bold;font-family:courier;">ls ??????.txt</codespan><br>'''Write down the expected output''' on paper, then '''issue the command''' to check your answer.<br><br></bli><li>What do you think the output will be from the following Linux command?<br># Type<span style="color:blue;font-weight:bold;font-family: courier;">ls [0-9].txt<b/span><codebr>'''Write down the expected output''' on paper, then '''issue the command''' to check your answer.br>Did the command work?<br>What does this teach you about the character class [ ] symbol?<br><br></li><li>What do you think the output will be from the following Linux command?<br><span style="color:#3366CCblue;font-weight:bold;font-sizefamily:1courier;">ls [0-9][0-9][0-9].txt</span><br>'''Write down the expected output''' on paper, then '''issue the command''' to check your answer.3em<br><br></li><li>What do you think the output will be from the following Linux command?<br><span style="color:blue;font-weight:bold;font-family:courier;">yum updatels [a-z][a-z][a-z].txt</span><br>'''Write down the expected output''' on paper, then '''issue the command''' to check your answer.<br><br></codeli><li>What do you think the output will be from the following Linux command (using character class with UPPERCASE letters)?:<br><span style="color:blue;font-weight:bold;font-family:courier;">ls [A-Z][A-Z][A-Z].txt</bspan># Follow <br>'''Write down the expected output''' on paper, then '''issue the promptscommand''' to check your answer.# If there is <br><br></li><li>What do you think the output will be from the following Linux command (using character class using alpha-numeric characters)?<br><span style="color:blue;font-weight:bold;font-family:courier;">ls [a-zA-Z0-9][a-zA-Z0-9][a kernel update-zA-Z0-9].txt</span><br>'''Write down the expected output''' on paper, then '''issue the command''' to check your answer.<br><br></li><li>What do you think the output will be from the following Linux command?<br><span style="color:blue;font-weight:bold;font-family:courier;">ls *.txt</span><br>'''Write down the expected output''' on paper, reboot then '''issue the command''' to check your systemanswer. Did ALL text files get listed? Why not?<br><br></li><li>What do you think the output will be from the following Linux command?<br><span style="color:blue;font-weight:bold;font-family:courier;">ls *.[tT][xX][tT]</span><br>'''Write down the expected output''' on paper, then '''issue the command''' to check your answer. Did ALL text files get listed this time? If so, why?<br><br></li><li>'''NOTE:''' We have just been using filename expansion symbols just with the ls command.<br>Filename expansion symbols can be used for ANY Linux file management command (There usually e.g. '''cat''', '''more''', '''less''', '''cp''', '''mv''', '''rm''', '''ls''', etc.).<br><br>Let's get some practice issuing these other Linux file management commands.<br><br></li><li>Issue the following Linux command: <span style="color:blue;font-weight:bold;font-family:courier;">file *.[tT][xX][tT]</span><br>What is the purpose of this command? Which files are contained in this output?<br><br><li>[[Image:dir12.png|right|350px|thumb|]]Change to the '''commands''' directory using an '''absolute''' pathname<br>(use the diagram on right-side for reference).<br><br></li><li>Issue a first update after OS installationLinux command to confirm that you are now in the '''commands''' directory.<br><br></li><li>Issue the following Linux command (lowercase "l" NOT the number "1"):<br><span style="color:blue;font-weight:bold;font-family:courier;">cp /bin/l* .</span><br>View the contents of the contents directory. What did this command do?<br><br></li><li>Issue the following Linux command: <span style="color:blue;font-weight:bold;font-family:courier;">rm *</span><br><br>View the contents of the contents directory. What did this command do?<br><br></li><li>Issue the following Linux command (lowercase "l" NOT the number "1"):<br> <span style="color:blue;font-weight:bold;font-family:courier;">cp /bin/l? .</span><br>View the contents of the contents directory.What did this command do?<br><br></li><li>Issue the following Linux command: <span style="color:blue;font-weight:bold;font-family:courier;">rm l[!s]</span><br>View the contents of the contents directory. What did this command do?<br><br></li><li>Use a text editor (nano or vi) to create the file called '''ab''' in the '''commands''' directory that contains the line of text below,<br>and then save editing changes to this file:<br><span style="font-family:courier;">This is file ab</span><br><br></li><li>Use a text editor (nano or vi)to create the file called '''cd''' in the '''commands''' directory that contains the line of text below,<br>and then save editing changes to this file:<br><span style="font-family:courier;">This is file cd</span><br><br></li><li>Use a text editor (nano or vi) to create the file called '''ef''' in the '''commands''' directory that contains the line of text below,<br>and then save editing changes to this file:<br><span style="font-family:courier;">This is file ef</span><br><br></li><li>Issue the following Linux command: <span style="color:blue;font-weight:bold;font-family:courier;">cat ??</span><br><br>View the contents of the contents directory. What did this command do? Why does the output look strange?<br><br>'''NOTE:''' Press the keys '''ctrl-c''' to return to the shell prompt.<br><br></li><li>Issue the following Linux command: <span style="color:blue;font-weight:bold;font-family:courier;">cat [!l][!s]</span><br><br>View the contents of the contents directory. What did this command do? Does the output look better? If so, why?<br><br></li></ol>
= INVESTIGATION 3: QUOTING SPECIAL CHARACTERS =
There is a method make the shell '''ignore the purpose of special characters''' and treat as '''regular text'''.
= LINUX PRACTICE QUESTIONS =
The purpose of this section is to obtain extra practice to help with your assignment #1, quizzes, your midterm, and your final ezamexam.
Here is a link to the MS Word Document of ALL of the questions displayed below but with extra room to answer on the document to
simulate a quiz:
https://ictwiki.cdot.senecacollege.ca/~murray.saululi101/uli101files/uli101_week1_practiceuli101_week3_practice.docx
Your instructor may take-up these questions during class. It is up to the student to attend classes in order to obtain the answers to the following questions. Your instructor will NOT provide these answers in any other form (eg. e-mail, etc).
'''Review Questions:'''
When answering Linux command questions on this side or the back side of this page, refer to the following Inverted Tree diagram. The week3 directory is contained in your home directory. Assume that you just logged into your Matrix account. Directories are underlined.
[[Image:week3-practice-question.png|left|300px|thumb|]]
<br><br><br><br><br><br><br><br><br><br><br><br><br><br>
# Write a single Linux command using relative pathnames to create the directory structure displayed in the diagram above.
# Write a single Linux command to create the empty files “.answers.txt” and “questions.txt” shown in the diagram above using absolute pathnames.
# Write a Linux command to display a listing of all hidden and non-hidden filenames in the directory called “final” using a relative-to-home pathname.
# Assuming you are in your home directory, write a Linux command to view the contents of the “.answers.txt” file using a relative pathname. You can assume this text file is very large and you want to see all of the contents.
# Write a Linux command to change to the “backup “directory using an absolute pathname.<br>Write a command to verify that you changed to that directory:<br><br>
# Assuming that you remain in the “backup” directory, write a Linux command to copy the “questions.txt file” to your current directory. You are required to only use relative pathnames.
# Assuming that you remain in the “backup” directory, write a Linux command to delete the “questions.txt” file that is in your “backup” directory. Use a relative-to-home pathname.
# Assuming that you are currently located in your “backup” directory, write a Linux command to safely remove the directory “week3” and all of its contents. Use an absolute pathname.<br>Will your command you wrote in question 8 work if you run it? (yes/no). Why?<br><br>
# Assuming you are still located in the “backup” directory. Write a Linux command using a relative-to-home pathname to remove all files that end with the extension “.txt” in the “final” directory.
# Write a Linux command using an absolute pathname to list all files that consist of just 4 consecutive characters that are contained in your home directory.
# Write a Linux command using a relative pathname to list all files that begin and end with a number.
# Write a Linux command using a relative-to-home pathname to list all files that begin with a number but ends with any character other than a number.
# Assuming you are in your home directory. Write a Linux command using a relative pathname to view the contents of regular files whose file names only consist of 5 consecutive numbers.<br><br>
# Write a Linux command to display the following message:<br>*** Hello ***
# Write a Linux command to display the following message (including quotation marks):<br>“This is my message”<br><br>
_________________________________________________________________________________
Author: Murray Saul
License: LGPL version 3
Link: https://www.gnu.org/licenses/lgpl.html
_________________________________________________________________________________
