13,420
edits
Changes
→Part 1: Using the Linux Shell
[[Image:cli-prompt.png|thumb|right|120px|A '''shell''' is an interface / interpreter to allow a user to communicate with the Linux computer system. ]]
Although you need to study concepts (slides) throughout this course, you will also need to get '''hands-on practice running Linux commands as well as performing online tutorials and performing and submitting online course assignments'''.<br>This requires that you '''connect to a Linux server''' and become comfortable with '''issuing Linux commands'''.
In Unix/Linux, a '''shell''' is simply an '''interface''' to allow a user to communicate with the Linux computer system (server). Linux shells have evolved (improved) over a period of time. You will be using the '''Bash Shell''' which is considered to be ''user-friendly''. By understanding how to issue Linux commands, you can create a file that contains Linux commands (called a '''shell script''') later in this course to automate tasks to make you a more '''productive''' Linux user and system administrator.
===Layout of the Matrix Linux Server===
[[Image:matrix-layout.png|thumb|right|250px|The Matrix server consists of several Computers connected together to form a '''cluster'''. A '''Linux Cluster''' is a '''cost effective''' alternative to larger servers. ]]
The '''Matrix server''' consists of '''several computers connected together''' to form a '''cluster'''.<br>A '''Linux cluster ''' is a '''cost effective''' alternative to buying larger servers.
All registered students in this course should have an account on the Matrix server.<br>You will be using this account for the following reasons:
===Connecting to Your Matrix Account===
[[Image:cli-prompt.png|right|80px|]]
After connecting to the Seneca Global Portal, you can open a '''command terminal '''<br>in your '''Newer Windows 10''', '''Mac''' or '''Linux''' computer<br>and issue the following command:<br><br><span style="color:blue;font-weight:bold;">ssh senecauserid@matrix.senecacollege.ca</span><br><br>
[[Image:ssh-application-icon.png|right|80px|]]
You can also click on the following link to '''download''' and '''install''' a graphical SSH application for your Windows machine:<br>http://www.sfsu.edu/ftp/win/ssh/SSHSecureShellClient-3.2.9.exe<br><br>
</td>
<td>
*Launch Click ''Launchpad'Terminal'icon, type '' from the 'terminal''finder'<br>and press '''ENTER''' utility
*In the terminal, enter the following command:<br><span style="color:blue;font-weight:bold;font-size:.75em;">ssh senecausername@matrix.senecacollege.ca</span>
</td>
<td>
*From the menu, choose:<br>'''Applications''' > '''System Tools''' > '''Terminal'''.
*In the terminal, enter the following command:<br><span style="color:blue;font-weight:bold;font-size:.75em;">ssh senecausername@matrix.senecacollege.ca</span>
</td>
</tr>
</table>
<ol><li value="4">When connecting securely for the '''first time''', a dialog box will appear to share a "'''public key'''" with your Matrix account in order to make your interaction between your workstation and the remote Linux server secure within the network (i.e. encrypted to prevent unauthorized access by other users)<br><br>'''<b>FYI:''' </b> To make communications over a network secure, a computer generates '''two keys''': a '''private key''' that is kept on the computer, and a '''public key''', which can be shared with other computers. Transmissions from your computer uses the private key to encrypt ('''scramble''') transmission to the remote computer, which in turn, uses the public key to decrypt (unscramble) the transmission. Likewise, the remote computer uses the public key to encrypt (scramble) transmissions and your computer uses the private key to decrypt ('''unscramble''') those transmissions.''<br><br></li><li>Type '''yes''' and press '''ENTER''' to share your public key.<br><br>Next, a dialog box will appear prompting you for your Matrix account '''password''' in order to gain entry to your Matrix account. Your Matrix password is identical to your Seneca password. As you type the password, the text will be blocked-out or hidden to prevent others from viewing the screen to obtain your password<br><br></li><li>Enter your Seneca password and press '''ENTER'''<br><br></li>'''NOTE:''' If you encounter an '''error message''', this can occur for several reasons:<ol><li>You mis-spelled the '''name of the server'''</li><li>You mis-spelled your Matrix '''username''' (same username that you connect to ''my.senecacollege.ca'')</li><li>You have '''CAPS LOCK''' on by mistake (your username should be '''lowercase''' only).</li><li>You mis-spelled your '''password''' (same password that you connect to ''my.senecacollege.ca'')<br><br>If you continue to experience the same problems, click on the following link for IT service desk contact info: <br>[https://employees.senecacollege.ca/spaces/122/support/wiki/view/3524/contact-its '''IT service desk'''].<br><br></li></ol><li>If you entered your password correctly, the '''Matrix Linux shell''' should appear where you can enter Linux commands.<br><br>The '''Matrix''' server has been configured to allow users to '''only interact with the Linux OS by issuing commands'''.<br>The main reason for this is to '''force students to learn how to issue Linux commands'''.<br><br></li><li>To exit your Matrix session, type the command <span style="color:blue;font-weight:bold">exit</span> followed by '''ENTER'''<br><br>'''NOTE:''' You should notice that you are returned to the original command prompt where you issued the ''ssh'' command.<br><br></li><li>type Type the same command and the '''command terminal prompt''': <span style="color:blue;font-weight:bold">exit</span> followed by '''ENTER'''<br><br>
'''NOTE:''' You should notice that the you are disconnected and that the original terminal window has '''automatically closed'''.<br><br></li><li>Try accessing your Matrix account, and then exiting your Matrix account several times to become familiar with this process.<br><br>You will now learn an alternative method to access your Matrix account (if you have an MS Windows machine)<br>by downloading and running a graphical SSH application.</li></ol><br>
-->
# '''Click''' the following '''link''' to download and install the free SSH Secure Shell application on your Windows computer:<br>http://www.sfsu.edu/ftp/win/ssh/SSHSecureShellClient-3.2.9.exe<br><br>'''NOTE:''' If you can't download or run this link, check to see if you computer allows downloads from this site.<br><br><table align="right"><tr valign="top"><td>[[Image:ssh-application-icon.png|thumb|right|75px|Double-click SSH icon on desktop to launch application]]</td><td>[[Image:ssh-main-window.png|thumb|right|150px|SSH Client Application Window ]]</td></table># After the application has been installed, an application icon should appear on your desktop.<br>'''Double click''' the '''SSH Secure Shell Client''' application iconto run this application.<br><br>The main SSH Client window will appear. Let's learn how to connect to and login to our Matrix account<br>using this graphical SSH application.<br><br>
# Click the '''Quick Connect''' button.<br><br>'''NOTE:''' The Connect dialog box allows the user to specify the '''server name''' and your '''account name'''<br>to allow you to connect to the server.<br><br>[[Image:quick-connect-window.png|thumb|right|150px|Quick Connect Dialog Box ]]
# Click on the textbox labelled '''Hostname''' and type the text: <span style="color:blue;font-weight:bold">matrix.senecacollege.ca</span><br><br>'''NOTE:''' You can use the hostname '''matrix''' since you are located <u>'''inside'''</u> Seneca's network.<br>If you where located <u>outside</u> Seneca's network, then you would need to enter the full domain name: '''matrix.senecacollege.ca'''<br>You will be using the latter hostname since you will be connecting to your Matrix account remotely and not within the college.<br><br>[[Image:share-public-key.png|thumb|right|150px|Dialog Box to Share Public Key on Remote Server ]]
# Click the '''Connect''' button.<br><br>
# When connecting securely for the '''first time''', a dialog box will appear to share a "public key" with your Matrix account in order to make your interaction between your workstation and the remote Linux server secure within the network<br>(i.e. encrypted to prevent unauthorized access by other users).<br><br>
# Click the '''Yes''' button to share your public key.<br><br>'''NOTE:''' In subsequent logins to your Matrix account, you may experience a welcome dialog box - simply click '''OK''' to proceed.<br><br>
# Next, a dialog box will appear prompting you for your '''Matrix account password''' in order to gain entry to your Matrix account. Your Matrix password is identical to your Seneca password. As you type the password, the text will be blocked-out or hidden to prevent others from viewing the screen to obtain your password<br><br><table align="right"><tr valign="top"><td>[[Image:ssh-password-prompt.png|thumb|right|150px|Password Dialog Box ]]</td><td>[[Image:ssh-authentication-response.png|thumb|right|150px|Authentication Response Dialog Box ]]</td></table>
# '''Enter your password''' and click '''OK'''.<br><br>[[Image:ssh-login-error.png|thumb|right|150px|SSH Login Error ]]
# Try moving your mouse pointer to the bottom right-hand corner of the SSH application window,<br>then '''click and drag''' outwards to make the application window larger.<br><br>
# To exit your Matrix session, type the command <span style="color:blue;font-weight:bold">exit</span> followed by '''ENTER'''<br><br>'''NOTE:''' You should notice that the colour of the text changes slightly when disconnected<br>and you are unable to issue Linux commands from that window.<br><br>
# After you have disconnected from your account, '''close''' the SSH Secure Shell Client application window.<br><br>'''NOTE:''' You are '''STRONGLY ADVISED''' to use the '''exit''' command to properly terminate your Matrix session<br>as opposed '''<u>PRIOR</u>''' to closing the SSH or terminal application window!<br><br>In the next investigation, you will learn how to '''issue Linux commands''' and how to<br><u>setup</u> and <u>perform</u> the '''first two sections of the online ULI101 assignment #1'''.<br><br>
=INVESTIGATION 2: USING THE LINUX SHELL / ONLINE ASSIGNMENTS =
In this section, you will learn how to use the Linux Shell. Topics in the section include:
:* Learn the basic '''Linux command structure''' (''arguments'' and ''options''):* Learn how to get '''help''' for Linux commands with an via the '''online manual ''' (i.e. '''man''' command).:* Learn Perform '''Basic Shell Editing''':* Learn how to perform setup '''online assignmentsassignment 1'''.:* Perform the '''first two sections section''' and '''3 parts of the second section''' of online assignment #1'''.<br><br>
===Part 1: Using the Linux Shell ===
:* a series of characters (i.e. '''text''') that the command can use
An '''argument''' is <u>separated</u> from a command (or from other arguments) by a '''SPACE''', '''multiple spacesMULTIPLE SPACES''' or a '''TAB'''.<br><br>
'''Perform the Following Steps:'''
With the Linux OS containing over '''2500''' commands and utilities, it is good for a Linux user or sysadmin to learn about how to use commands “on-the-fly”.<br><br>
The '''man''' command can provide information on how to use a command<br>(i.e. '''command usage''', '''acceptable command arguments''', '''command options''', '''examples''').<br><br>
# Issue the following command: <span style="font-family:courier;color:blue;font-weight:bold">man man</span><br><br>You may notice that the online manual categories commands into sections or '''numbered volumes'''.<br><br># Type the '''SPACE''' key to move to the next screen.<br><br>How many volume '''volume numbers''' are contained in the man pages (like '''executable commands''',<br>'''games''', or '''system administrator commands''')?<br><br>'''TIP:''' You can use the following '''short-cut keys''' within the man command to <br>help navigate throughout this utility to get help with the ls command (refer to table below):<br><br><table cellpadding="3"><tr><th style="border-bottom: 1px solid black;">Keyboard Shortcut</th><th style="border-bottom: 1px solid black;">Purpose</th></tr><tr><td>'''ENTER'''</td><td>Move down one line</td></tr><tr><td>'''SPACEBAR'''</td><td>Move one screen down</td></tr><tr><td>'''<ctrl><b>'''</td><td>Move one screen up</td></tr><tr><td>'''/pattern/'''</td><td>Search for Pattern</td></tr><tr><td>'''q'''</td><td>quit man utility</td></tr></table><br>
# Press the letter <span style="font-family:courier;color:blue;font-weight:bold">q</span> to exit the man command.<br><br>
# Issue the following Linux command to get help with the ls command: <span style="font-family:courier;color:blue;font-weight:bold">man ls</span><br><br>
# Issue the '''ls''' command for <u>each</u> of those option letters you noted in '''step 4''' to see how this command differs for each option.<br><br>'''NOTE:''' The '''man''' utility can be used with the '''-k''' option to help list Linux commands that match a text pattern<br>that is contained within the help screen for a Linux command.<br><br>
# '''Pipeline commands''' can be used to filter-out unnecessary output. In the next command that you will be issuing,<br>the output from the '''man -k''' command, is sent into the '''grep''' command to ''filter'' (i.e. ''trap'') only output that matches the pattern "8"<br>(The number "8" refers to the category of type of command - in this case, administration commands).<br><br>We will learn more about pipeline commands later in this course.<br><br>
# Issue the following Linux pipeline command: <span style="font-family:courier;color:blue;font-weight:bold">man -k copy user | grep 8</span><br><br>How does this ''pipeline command'' make it easier to obtain information regarding man command?<br><br>
# If you wish to change your password, you can change it by issuing the command: <span style="font-family:courier;color:blue;font-weight:bold">passwd</span><br>What option for the passwd command can be used to change user info (such as name)?<br>'''Hint:''' use the '''man''' command for '''passwd'''.<br><br>
# Press the letter <span style="font-family:courier;color:blue;font-weight:bold">q</span> to exit the man command.<br><br>'''NOTE:''' Do '''NOT''' run the ''passwd'' command. Unique for this college, your Matrix password is changed automatically when you change your '''myseneca''' password.<br><br>You will now learn how to perform '''command line editing''' to correct syntax errors while typing Linux commands PRIOR to pressing the ENTER key.<br><br>
'''Perform the Following Steps:'''
[[Image:meta-key.png|thumb|right|370px|To make '''alt-f''' key work, select '''Edit''' -> '''Settings''' -> '''Keyboard''', and select the checkbox '''Use ALT as Meta key (and Escape)'''.]]
# Type the following Linux command, but DON’T press the ''ENTER'' key:<br><span style="font-family:courier;color:blue;font-weight:bold">cd /bin</span><br><br>
# Press the <span style="font-family:courier;color:blue;font-weight:bold">ctrl-a</span> key combination. What happens?<br><br>'''NOTE:''' To make '''alt-f''' key work when use the '''GRAPHICAL Windows SSH Client application''', select '''Edit''' -> '''Settings''' -> '''Keyboard''', and select the checkbox '''Use ALT as Meta key (and Escape)'''.<br><br># Press the <span style="font-family:courier;color:blue;font-weight:bold">alt-f</span> key combination '''two times'''<br>(OPTION+right-arrow for Mac OSx).<br><br>What happens?<br><br># Press the <span style="font-family:courier;color:blue;font-weight:bold">alt-b</span> key combination '''one time'''.<br>(OPTION+left-arrow for Mac OSx).<br><br>What happens?<br><br>'''NOTE:''' These short-cut keys should work if you issued the ssh command within a terminal. If you are using a '''graphical''' windows SSH application, would would need to configure the application to understand the ''META'' (alt) key for shortcut commands (i.e. not shortcuts for the ''application menu'').<br><br><table align="right"><tr valign="top"><td>[[Image:ctrl-b.png|thumb|right|150px|'''alt-b''' moves one word backwards for Windows OS]]</td><td>[[Image:ctrl-w.png|thumb|right|150px|'''ctrl-w''' deletes a word to <u>left</u> of the cursor.]]</td><td>[[Image:new-ls.png|thumb|right|150px|After command is deleted, then type new command and press '''ctrl-e''' to move to end of the command line.]]</td></tr></table># Use a combinate of the '''ctrl-a''' and '''alt-f''' keys (or Mac equivalent) until the cursor is to the '''<u>right</u>''' of the '''cd''' command<br><br>
# Press the <span style="font-family:courier;color:blue;font-weight:bold">ctrl-w</span> shortcut key. What happens?<br><br>
# Type the following command: <span style="font-family:courier;color:blue;font-weight:bold">ls</span><br><br>
In this section, you will learn to:
* '''Select the correct section''' for assignment submission
* Perform the '''first two sectionssection''' and '''3 parts of the second section''' of assignment #1
* '''Verify''' that you successfully completed both sections
* '''Exit''' your online assignment #1.
[[Image:Assn-initial-window3.png|thumb|right|250px|Initial Assignment Window to Allow Student to Select Correct Course Section. ]]
# In your Matrix account, issue the following command:<br><span style="color:blue;font-weight:bold;font-family:courier">~uli101/a1</span><br><br>
# Press '''ENTER''' at the "Notes" screen.<br><br>
# A screen similar to the one displayed on the right will appear.<br><br><span style="color:red;">'''WARNING''': You need to select the <u>CORRECT</u> section for the course which you belong to.<br>If you do <u>NOT</u> select your correct section, your assignment may not be recorded for marks!</span><br><br>
# Select the '''3 letter(s)code''' corresponding to the <u>correct</u> '''ULI101 <u>section</u>''' and '''professor''' and press <span style="color:blue;font-weight:bold">ENTER</span><br><br>
# After you have selected your course section, There will be a screen that provides several important notes before proceeding.<br>Please take a few moments to read those notes and press <span style="color:blue;font-weight:bold">ENTER</span> to proceed.<br><br>[[Image:assn-section-completion.png|thumb|right|250px|Main Assignment Window to View Which Sections Need to be Completed. ]]
# The assignment main menu will then be displayed.<br><br>'''NOTES:'''<ul><li>Near the bottom of the window, you will see '''"You are currently registered to"''' followed by the '''section letter''' and '''instructor name'''. Double-check your course timetable to confirm that this the correct section letter. If you have selected the WRONG section, type <span style="color:blue;font-weight:bold">C</span> in the menu selection area and press <span style="color:blue;font-weight:bold">ENTER</span>. You will return back to the original window to select your correct course section.<br><br></li><li>Near the top of the window displays the sections to complete in the assignment. You are NOT required to complete all sections at the same time. You can check the assignment #1 link on the ULI101 main WIKI page to note the due date for assignment #1. Sections that are NOT completed will be displayed in '''reverse text with a blue background'''. On the other hand, when you compete a section, then the section will appear as regular text<br>(i.e not in reverse text).<br><br>[[Image:assn-completed-window.png|thumb|right|250px|Main Assignment Window to Confirm Which Sections Have or Have Not Been Completed. ]]</li><li>If you want to verify that you have completed sections for the assignment, look for the text '''"Marks earned so far for ULI101 Assignment:"''' and it will show how many sections have been completed. When it shows all sections completed, then your assignment is finished and you should receive full marks provided that you have selected your correct course section.<br><br></li></ul>