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=INTRODUCTION TO SHELL SCRIPTINGUSING SED & AWK UTILTIES=
<br>
===Main Objectives of this Practice Tutorial===
:* Understand Use the process for planning prior '''sed''' command to writing '''manipulate text''' contained in a shell scriptfile.
:* Understand List and explain several '''addresses''' and '''instructions''' associated with the purpose of a she-bang line contained at the top of a shell script'''sed''' command.
:* Setting permissions for Use the '''sed''' command as a shell script and properly execute a shell script'''filter''' with Linux pipeline commands.
:* Understand and use environment and user-defined variables within Use the '''awk''' command to '''manipulate text''' contained in a shell scriptfile.
:* Understand List and explain '''comparison operators''', '''variables''' and '''actions''' associated with the purpose of control flow statements used with shell scripts'''awk''' command.
:* Use the test '''awk''' command to test various conditionsas a '''filter''' with Linux pipeline commands. :* Use the if logic statement and the for loop statement within shell scripts.<br><br>
===Tutorial Reference Material===
|- valign="top" style="padding-left:15px;"
|colspan="2" |Course Notes'''Slides''':<ul><li>Week 11 Lecture 1 Notes:<br> [[Media:ULI101-Week11.1.pdf | PDF]] | [https://ictmatrix.senecacollege.ca/~murraychris.sauljohnson/uli101ULI101/ULI101-Week11.1.pptx PPTX]</li><li>Week 11 Lecture 2 Notes:<br> [[Media:ULI101-Week10Week11.2.pdf | PDF]] | [https://ictmatrix.senecacollege.ca/~murrayjason.saulcarman/uli101slides/ULI101-Week10Week11.2.pptx PPTX]<br></li></ul>
| style="padding-left:15px;" |'''Text Manipulation:'''
* [https://www.digitalocean.com/community/tutorials/the-basics-of-using-the-sed-stream-editor-to-manipulate-text-in-linux Purpose of using the sed utility]
* [https://www.digitalocean.com/community/tutorials/how-to-use-the-awk-language-to-manipulate-text-in-linux Purpose of using the awk utility]
| style="padding-left:15px;" |Shell Scripting* [https'''Commands://searchdatacenter.techtarget.com/definition/shell-script Purpose]'''* [https://wwwman7.youtube.comorg/watch?v=cQepf9fY6cE Creating and Running a Shell Script]<br>Variables* [https:linux//opensource.com/article/19/8/whatman-are-environment-variables Environment]* [https:pages/man1/wwwsed.linuxtechi.com/variables-in-shell-scripting/#:~:text=User%20Defined%20Variables%3A,like%20a%20real%20computer%20program. User Defined]Commands* [http://linuxcommand.org/lc3_man_pages/readh1p.html readsed]* [https://man7.org/linux/man-pages/man1/readonlyawk.1p.html readonlyawk]
|colspan="1" style="padding-left:15px;" width="30%"|'''Brauer Instructional Videos:'''<ul><li>[https://www.youtube.com/watch?v=kxEP-KUhOSgnpU6S61AIko&list=PLU1b1f-2Oe90TuYfifnWulINjMv_Wr16N&index=5 Introduction to Shell Scripting14 Using the sed Utility]</li><li>[https://www.youtube.com/watch?v=XVTwbINXnk4OV3XzjDYgJo&list=PLU1b1f-2Oe90TuYfifnWulINjMv_Wr16N&index=6 13 Using Variables and Control Flow Statements in Shell Scriptingthe awk Utility]</ul>
|}
= KEY CONCEPTS =
'''Using a Shebang LineHow it Works:'''
* Can use a line number, to select a specific line (for example: '''5''')
* Can specify a range of line numbers (for example: '''5,7''')
* Regular expressions are contained within forward slashes (e.g. /regular-expression/)
* Can specify a regular expression to select all lines that match a pattern (e.g '''/^[0-9].*[0-9]$/''')
* If NO address is present, the instruction will apply to ALL lines
[[Image:sed.png|right|500px|]]'''Instruction:'''*'''Action''' to take for matched line(s)*Refer to the diagram to the table on right -side for examples using positional list of some<br>'''common instructions''' and special parameters.their purpose<br><br>
===Using Control Flow Statements in Shell Scriptsthe awk Utility===
* You can use a regular expression, enclosed within slashes, as a pattern. For example: '''Logic Statements/pattern/'''* The ~ operator tests whether a field or variable matches a regular expression. For example: '''$1 ~ /^[0-9]/'''* The '''!~''' operator tests for no match. For example: '''$2 !~ /line/'''* You can perform both numeric and string comparisons using relational operators ( '''>''' , '''>=''' , '''<''' , '''<=''' , '''==''' , '''!=''' ).* You can combine any of the patterns using the Boolean operators '''||''' (OR) and '''&&''' (AND).* You can use built-in variables (like NR or "record number" representing line number) with comparison operators.<br>For example: '''NR >=1 && NR <= 5''' <br>'''Action (execution):'''
'''Perform the Following Steps:'''
# '''Login''' to your matrix accountand confirm you are located in your '''home''' directory.<br><br># Issue a Linux command to create a directory called '''confirmsed''' you are located in your home directory.<br><br>We want # Issue a Linux command to create a Bash Shell script <u>change</u> to welcome the user by their username. Let's first provide some useful tips ''sed''' directory and confirm that you are located in terms<br>of selecting an appropriate name for the shell script'''sed''' directory.<br><br># Issue the following linux Linux command to check if your intended shell script namedownload the data.txt file<br>is already exists ('''copy and paste''' to be run automatically from the Bash shellsave time):<br><span style="color:blue;font-weight:bold;font-family:courier;">which hellowget <nowiki>https://ict.senecacollege.ca/~murray.saul/uli101/data.txt</nowiki></span><br><br>You should notice that there is no output and therefore, this shell script name can be used# Issue the '''more''' command to quickly view the contents of the '''data.txt''' file.<br>On When finished, exit the other hand, if you wanted more command by pressing the letter <span style="color:blue;font-weight:bold;font-family:courier;">q</span>[[Image:sed-1.png|thumb|right|300px|Issuing the '''p''' instruction without using the '''-n''' option (to create a file called sed, then suppress original output) will display lines twice.]]<br><br>The '''p''' instruction with the '''which sed''' commandis used to<br>would indicate it is already being used by the shell and that '''sedprint''' (i.e. ''display' wouldn't be an appropriate shell script name to use) the contents of a text file.<br><br># Use a text editor like vi or nano to create Issue the text file called hello (eg. following Linux command:<br><span style="color:blue;font-weight:bold;font-family:courier;">vi hellosed 'p' data.txt</span><br><br>'''NOTE: You should notice that each line appears twice'''.<br><br>The reason why standard output appears twice is that the sed command<br>(without the '''-n option''')displays all lines regardless of an address used.<br><br>If you are using We will use '''pipeline commands''' to both display stdout to the nano text editor, refer screen and save to notes on text editing in files<br>for <u>confirmation</u> of running these pipeline commands when run a previous week '''checking-script''' later in the course schedulethis investigation.<br><br># Enter Issue the following two lines in your shell script, replacing "your-username" with your actual nameLinux pipeline command:<br><span style="color:blue;font-weight:bold;font-family:courier;">clear<br>echo "Hello yoursed -n 'p' data.txt | tee sed-username"1.txt</span><br><br># Save your editing session and exit What do you notice? You should see only one line.<br><br>You can specify an '''address''' to display lines using the text editor sed utility<br>(eg. with vi: press '''ESC'line #'', then type ''':wxline #s''' followed by or range of '''ENTERline #s''').<br><br># Issue the following linux Linux pipeline command to run your shell script in your current directory:<br><span style="color:blue;font-weight:bold;font-family:courier;">sed -n '1 p' data./hellotxt | tee sed-2.txt</span><br><br>You should notice an error indicating you don't have permissions to run see the first line of the text filedisplayed.<br>You need What other command is used to only display the first add execute permissions prior to running the shell script.line in a file?<br><br>[[Image:sed-2.png|thumb|right|500px|Using the sed command to display a '''range''' of lines.]]# Issue the following linux Linux pipeline command to add execute permissions for your shell script:<br><span style="color:blue;font-weight:bold;font-family:courier;">chmod u+x hellosed -n '2,5 p' data.txt | tee sed-3.txt</span><br><br>What is displayed? How would you modify the sed command to display the line range 10 to 50?<br><br>The '''s''' instruction is used to '''substitute''' text<br>(a similar to method was demonstrated in the vi editor in tutorial 9).<br><br># Re-run your shell scriptIssue the following Linux pipeline command: <br><span style="color:blue;font-weight:bold;font-family:courier;">sed '2,5 s/TUTORIAL/LESSON/g' data./hellotxt | tee sed-4.txt | more</span><br><br>Although your shell script should work, it is recommended What do you notice? View the original contents of lines 2 to force your shell script to run 5 in a specific shellthe '''data. This helps prevent your txt''' file<br>in another shell script encountering errors when run in to confirm that the incorrect shell (isubstitution occurred.<br><br>[[Image:sed-3.epng|thumb|right|500px|Using the sed command with the '''-q''' option to display up to a line number, then quit. syntax not recognized ]]The '''q''' instruction terminates or '''quits''' the execution of the sed utility as soon as it is read in a specific shell)particular line or matching pattern.<br><br># Edit your Issue the following Linux pipeline command:<br><span style="color:blue;font-weight:bold;font-family:courier;">sed '11 q' data.txt | tee sed-5.txt</span><br><br>What did you notice? How many lines were displayed<br>before the sed command exited?<br><br>You can use '''helloregular expressions''' shell script using to select lines that match a text editorpattern. In fact,<br>the sed command was one of the <u>first</u> Linux commands that used regular expression.<br><br># Insert the following line at The rules remain the same for using regular expressions as demonstrated in '''beginningtutorial 9''' of <br>except the regular expression must be contained within '''firstforward slashes''' line of your hello file:<br>(eg. <span style="font-family:courier;font-weight:bold;">#!/binregexp/bash</span>).<br><br>This is referred to as a she[[Image:sed-bang line4. It forces png|thumb|right|400px|Using the script to be run in sed command using regular expressions with '''anchors'''.]]# Issue the Bash Shellfollowing Linux pipeline command:<br><span style="color:blue;font-weight:bold;font-family:courier;">sed -n '/^The/ p' data. When your Bash Shell script finishes execution, txt | tee sed-6.txt</span><br><br>What do you are returned to your current shell that you are using (which in our case in Matrix, is still the Bash shell).notice?<br><br># Save your editing changes and exit your text editorIssue the following Linux pipeline command:<br><span style="color:blue;font-weight:bold;font-family:courier;">sed -n '/d$/ p' data.txt | tee sed-7.txt</span><br><br># It is What do you notice?<br><br>The '''sed''' utility can also be used as a good idea '''filter''' to rename your shell script to include an extension to indicate manipulate text that <br>was generated from Linux commands.<br><br>[[Image:sed-5.png|thumb|right|400px|Using the file is a Bash Shell script filesed command with '''pipeline''' commands. ]]# Issue the following linux Linux pipeline command to rename your shell script file:<br><span style="color:blue;font-weight:bold;font-family:courier;">mv hello hellowho | sed -n '/^[a-m]/ p' | tee sed-8.bashtxt | more</span><br><br>What did you notice?<br><br># Run your renamed shell script by issuingIssue the following Linux pipeline command:<br><span style="color:blue;font-weight:bold;font-family:courier;">.ls | sed -n '/txt$/hellop' | tee sed-9.bashtxt</span><br><br>What did you notice?<br><br> # Issue the following to run a checking script:<br><span style="color:blue;font-weight:bold;font-family:In the next investigationcourier;">~uli101/week11-check-1</span><br><br>If you encounter errors, you will learn to create make corrections and '''re-run shell scripts that''' the checking script<br>use variablesuntil you receive a congratulations message, positional and special parametersthen you can proceed.<br><br> =INVESTIGATION 2: USING VARIABLES IN SHELL SCRIPTS =
:In this sectionthe next investigation, you will learn how to use variables, positional and special parameters to assist you in creating adaptable shell scriptsmanipulate text using the '''awk''' utility.<br><br>
=INVESTIGATION 2: USING THE AWK UTILITY =
In this investigation, you will learn how to use the awk utility to manipulate text and generate reports.
'''Perform the Following Steps:'''
# Use Change to your '''home''' directory and issue a text editor command to edit the shell script called '''hello.bashconfirm'''<br><br># Add the following line to the bottom of the file:you are located in your ''home'' directory.<br><span style="font-family:courier;"br># Issue a Linux command to create a directory called '''awk'''<br><br>echo "The current shell you are using is: $SHELL"# Issue a Linux command to </spanu>change<br/u><br># Save your editing changes to the '''awk''' directory and exit your text editorconfirm you are located in the '''awk''' directory.<br><br># Issue the Let's download a database file that contains information regarding classic cars.<br><br># Issue the following linux command to change to the c-shell (a different shell than the default Bash):<'''copy and paste''' to save time):<br><span style="color:blue;font-weight:bold;font-family:courier;">cshwget <nowiki>https://ict.senecacollege.ca/~murray.saul/uli101/cars.txt</nowiki></span><br><br># Issue the following linux '''cat''' command to confirm you are in quickly view the contents of the c-shell:<br'''cars.txt''' file.<br><span style="color:blue;font-weight:bold;font-family:courier;br>The "'''print'''"action (command) is the <u>echo $SHELLdefault</spanu>action of awk to print<br><br>You should see the output of the command that you are located in the c-shellall selected lines that match a '''pattern'''.<br><br># Run your This '''hello.bashaction''' shell script.(contained in braces) can provide more options<br>such as printing '''specific fields''' of selected lines (or records) from a database.<br>What shell does the shell script indicate is running?<br><br>This is because of [[Image:awk-1.png|thumb|right|400px|Using the shebang line indicating awk command to run display matches of the shell script in pattern '''ford'''.]]# Issue the Bash shell although you ran this script within the c-shell.<br><br># Enter the following following linux command all to return to your Bash shell: <span style=display all lines (i.e. records) in the '''cars.txt''' database that matches the pattern (or "make"color) called '''ford''':blue;<br><span style="color:blue;font-weight:bold;font-family:courier;">exitawk '/ford/ {print}' cars.txt</span><br><br># Use a text editor to edit the shell script called We will use '''hello.bashpipeline commands'''<br><br># Add to both display stdout to the following lines screen and save to the bottom of the file:files for <bru>confirmation<span style="font/u> of running these pipeline commands when run a '''checking-family:courier;">echo "The current username is: $USER"script''' later in this investigation.<br>echo "The current directory location is: $PWD"<br>echo "The current user# Issue the following linux pipeline command all to display records<br>in the '''cars.txt''' database that contain the pattern (i.e. make) '''ford'''s home directory is: $HOME</span><br><brspan style="color:blue;font-weight:bold;font-family:courier;"># Save your editing changes and exit your text editorawk '/ford/' cars.txt | tee awk-1.txt<br/span><br># Run your '''hello.bash''' shell script.<br>What do you notice? You should notice ALL lines displayed <br>Take time to view the output and the values of the environment variables.<bru>without<br/u># Issue the following linux command to add your current directory to the PATH environment variable:using '''search criteria'''.<br><span style="color:blue;font-weight:bold;font-family:courier;">PATH=$PATH:br>You can use ''builtin'' '''variables''' with the '''print''' command for further processing.</spanbr>We will discuss the following variables in this tutorial:<br><br># Issue [[Image:awk-2.png|thumb|right|400px|Using the following linux awk command to confirm that the current directory "print search results by '''field number'''." has been added to the PATH environment variable:<]]'''$0''' - Current record (entire line)<br>'''$1''' - First field in record<span style="color:blue;fontbr>'''$n''' -weight:bold;font-family:courier;">echo $PATH</span>nth field in record<br><br># Run the '''hello.bash'NR''' by just shell script name - Record Number (i.e. to not use ./ prior to shell script nameorder in database).<br>'''NF''' - Number of fields in current record<br>The shell script should run just by name.<br><br># Exit your Matrix sessionFor a listing of more variables, and log back into please consult your Matrix sessioncourse notes.<br><br># Re-run Issue the hello.bash shell script by just using following linux pipeline command to display the name.<br><br>What did you notice?'''model''', '''year''', '''quantity''' and price<br><br>The setting of the PATH variable only worked in the current session only'''cars. If exit the current Matrix session, then the recently changed settings txt''' database for environment variables are lost. You will learned in Week 12 how to set environment variables in startup files.<makes of '''chevy''':<br><brspan style="color:blue;font-weight:bold;font-family:courier;"># Use a text editor to create a file called awk '/chevy/ {print $2,$3,$4,$5}''usercars.txt | tee awk-variables2.bash'''txt</span><br><br># Add Notice that a '''space''' is the following lines to delimiter for the bottom of the file:fields that appear as standard output.<br><span style="font-family:courier;"br>#!/bin/bash<br>age=25The '''tilde character''' '''~''' is used to search for a pattern or display standard output for a particular field.<br>readonly age<br>read -p "Enter your Full Name" name<br>read -p "Enter your age # Issue the following linux pipeline command to display all '''plymouths''' (in years'''plym'''): " age<br>echo "Hello $by '''model name - You are $age years old"</span>''', '''price''' and '''quantity''':<br><brspan style="color:blue;font-weight:bold;font-family:courier;"># Save your editing changes and exit your text editorawk '$1 ~ /plym/ {print $2,$3,$4,$5}' cars.txt | tee awk-3.txt</span><br><br># Issue the following You can also use '''comparison operators''' to run specify conditions for processing with matched patterns<br>when using the user-variablesawk command.bash Bash shell script:Since they are used WITHIN the awk expression,<br>they are not confused with redirection symbols<span style="colorbr><br>[[Image:blue;fontawk-weight:bold;font-family:courier;">3./user-variablespng|thumb|right|400px|Using the awk command to display results based on '''comparison operators'''.bash]]'''</span>''' Less than<br>'''<br>What do you notice when you try to change the age variable? Why?<br>=''' Less than or equal<br># Use a text editor to create a file called '''parameters.bash>''' Greater than<br>'''<br>=''' Greater than or equal<br># Add the following lines to the bottom of the file:'''==''' Equal<br><span style'''!="font-family:courier''' ">#!/bin/bashNot equal<br>echo \$0: $0<br>echo \$2: $2<br>echo \$3: $3<br><br>echo \$#: $#<br>echo \$*# Issue the following linux pipeline command to display display the '''car make''', '''model''', '''quantity''' and '''price''' of all vehicles whose '''prices are less than $5,000''': $*<br><br>echo shift 2<brspan style="color:blue;font-weight:bold;font-family:courier;">echo \awk '$#: $#5 <br>echo \5000 {print $*: 1,$2,$4,$*5}' cars.txt | tee awk-4.txt</span><br><br># Save your editing changes and exit your text editor.What do you notice?<br><br># Issue the following linux pipeline command to run the user-variables.bash Bash shell script:display display '''price''',<br><span style="color'''quantity''', '''model''' and '''car make''' of vehicles whose '''prices are less than $5,000''':blue<br><span style="color:blue;font-weight:bold;font-family:courier;">./parameters.bashawk '$5 </span><br>5000 {print $5,$4,$2,$1}' cars.txt | tee awk-5.txt<br/span>What happened?<br><br>You shouldn't see any values for # Issue the parameters since you did NOT provide any arguments when running following linux pipeline command to display the shell script.'''car make''',<br><br># Issue the following to run '''year''' and '''quantity''' of cars that '''begin''' with the user-variables.bash Bash shell script with arguments'''letter 'f'''':<br><span style="color:blue;font-weight:bold;font-family:courier;">./parametersfont-family:courier;">awk '$1 ~ /^f/ {print $1,$2,$4}' cars.txt | tee awk-6.txt</span><br><br>[[Image:awk-4.png|thumb|right|400px|Using the awk command to display combined search results based on '''compound operators'''.]]Combined pattern searches can be made<br>by using '''compound operator''' symbols:<br><br>'''&&''' (and)<br>'''||''' (or)<br><br># Issue the following linux pipeline command to list all '''fords'''<br>whose '''price is greater than $10,000''':<br><span style="color:blue;font-weight:bold;font-family:courier;">awk '$1 ~ /ford/ && $5 > 10000 {print $0}' cars.txt | tee awk-7.txt</span><br><br># Issue the following linux command ('''copy and paste''' to save time):<br><span style="color:blue;font-weight:bold;font-family:courier;">wget <nowiki>https://ict.senecacollege.ca/~murray.saul/uli101/cars2.txt</nowiki></span><br><br># Issue the '''cat''' command to quickly view the contents of the '''cars2.txt''' file.<br><br># Issue the following linux pipeline command to display the '''year'''<br>and '''quantity''' of cars that '''begin''' with the '''letter 'f'''' for the '''cars2.txt''' database:<br><span style="color:blue;font-weight:bold;font-family:courier;">awk '$1 ~ /^f/ {print $2,$4}' cars2.txt | tee awk-8.txt</span><br><br>What did you notice?<br><br>The problem is that the '''cars2.txt''' database separates each field by a semi-colon (''';''') <u>instead</u> of '''TAB'''.<br>Therefore, it does not recognize the second and fourth fields.<br><br>You need to issue awk with the -F option to indicate that this file's fields are separated (delimited) by a semi-colorn.<br><br># Issue the following linux pipeline command to display the '''year'''<br>and '''quantity''' of cars that '''begin''' with the '''letter 'f'''' for the '''cars2.txt''' database:<br><span style="color:blue;font-weight:bold;font-family:courier;">awk -F";" '$1 ~ /^f/ {print $2,$4}' cars2.txt | tee awk-9.txt</span><br><br>What did you notice this time?<br><br># Issue the following to run a checking script:<br><span style="color:blue;font-weight:bold;font-family:courier;">~uli101/week11-check-2</span><br><br>If you encounter errors, make corrections and '''re-run''' the checking script until you<br>receive a congratulations message, then you can proceed.bash 1 2 3 4 5 6 7 8</span><br><br>What do you notice?
https://ict.senecacollege.ca/~murray.saul/uli101/uli101_week11_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).
# <span style="font-family:courier;font-weight:bold">sed -n '3,6 p'~murray.saul/uli101/stuff.txt</span><br><br># <span style="font-family:courier;font-weight:bold">sed 'Review Questions4 q' ~murray.saul/uli101/stuff.txt</span><br><br># <span style="font-family:courier;font-weight:bold">sed '/the/ d'~murray.saul/uli101/stuff.txt</span><br><br># <span style="font-family:courier;font-weight:bold">sed 's/line/NUMBER/g'~murray.saul/uli101/stuff.txt</span>
'''PART APart B: WRITE BASH SHELL SCRIPT CODEWriting Linux Commands Using the sed Utility'''
# Write a Bash shell script that clears Linux sed command to display only lines 5 to 9 for the screen and displays the text Hello World on the screenfile: '''~murray.saul/uli101/stuff.<br><br><br><br><br>What permissions are required to run this Bash shell script?<br><br><br>What are the different ways that you can run this Bash shell script from the command line?<br>txt'''<br><br># Write a Bash shell script that clears Linux sed command to display only lines the screen, prompts begin the user pattern “and” for their '''full name''' and then prompts the user for their file: '''age~murray.saul/uli101/stuff.txt''',<br>then clears the screen again and welcomes the user by their name and tells them their age.<br> <br><br><br><br><br><br><br>What comments would you add # Write a Linux sed command to display only lines that end with a digit for the above script’s contents to properly document this Bash shell script to be understood<br>for those users that would read file: '''~murray.saul/uli101/ edit this Bash shell script’s contents?<br> stuff.txt'''<br><br># Write a Bash shell script Linux sed command to save lines that will first set match the pattern “line” (upper or lowercase) for the value of a variable called file: '''number~murray.saul/uli101/stuff.txt''' and save results (overwriting previous contents) to : '''23''' and make this variable '''read-only~/results.txt'''.<br>Then the script will clear the screen and prompt the user to enter a value for that variable called number to another value.<br>Have the script display the value of the variable called number to prove that it is a read-only variable.<br><br><br><br><br>When you ran this Bash shell script, did you encounter an error message?<br>How would you run this Bash shell script, so the error message was NOT displayed?<br><br><br># Write a Bash shell script that will clear the screen and then display all arguments that were entered after your Bash shell script when it was run. Also have the Bash shell script display the number of arguments that were entered after your Bash shell script.<br><br><br><br><br><br><br><br>
'''Write Part C: Writing Linux Commands Using the expected output from running each of the following Bash shell scripts You can assume that these Bash shell script files have execute permissions. Show your work.awk Utility'''
<pre>
</pre>
'''Write the results of each of the following Linux commands for the above-mentioned file:'''
# <span style="font-family:courier;font-weight:bold">awk ‘NR == 3 {print}’ ~murray.saul/uli101/stuff.txt</span><br><br>
# <span style="font-family:courier;font-weight:bold">awk ‘NR >= 2 && NR <= 5 {print}’ ~murray.saul/uli101/stuff.txt</span><br><br>
# <span style="font-family:courier;font-weight:bold">awk ‘$1 ~ /This/ {print $2}’ ~murray.saul/uli101/stuff.txt</span><br><br>
# <span style="font-family:courier;font-weight:bold">awk ‘$1 ~ /This/ {print $3,$2}’ ~murray.saul/uli101/stuff.txt</span><br><br>
'''Part D: Writing Linux Commands Using the awk Utility'''
Write a single Linux command to perform the specified tasks for each of the following questions.
# Write a Linux awk command to display all records for the file: '''~/cars''' whose fifth field is greater than 10000.<br><br># Write a Linux awk command to display the first and fourth fields for the file:'''Walkthru ~/cars''' whose fifth field begins with a number.<br><br>#2Write a Linux awk command to display the second and third fields for the file:'''~/cars''' for records that match the pattern “chevy”.<br><br># Write a Linux awk command to display the first and second fields for all the records contained in the file: '''~/cars'''<br><br>
[[Category:ULI101]]