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{{Admon/caution|DO NOT USE THIS VERSION OF THE LAB. LOOK FOR LAB 10: SED & AWK|'''This is an archive version.'''}}
=USING SED & AWK UTILTIES=
<br>
:* Use the '''sed''' command to '''manipulate text''' contained in a file.
:* List and explain several '''addresses''' and '''instructions''' associated with the '''sed''' command.
:* Use the '''sed''' command as a '''filter''' with Linux pipeline commands.
:* Use the '''awk''' command to '''manipulate text''' contained in a file.
:* List and explain several '''comparison operators''', '''variables''' and variables '''actions''' associated with the '''awk''' command.
:* Use the '''awk''' command as a '''filter''' with Linux pipeline commands.
|- 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/ULI101/uli101ULI101-Week11.1.pptx PPTX]</li><li>Week 11 Lecture 2 Notes:<br> [[Media:ULI101-Week11.2.pdf | PDF]] | [https://ictmatrix.senecacollege.ca/~murrayjason.saulcarman/uli101slides/ULI101-Week11.2.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;" |Man Pages'''Commands:'''
* [https://man7.org/linux/man-pages/man1/sed.1p.html sed]
* [https://man7.org/linux/man-pages/man1/awk.1p.html awk]
|colspan="1" style="padding-left:15px;" width="30%"|'''Brauer Instructional Videos:'''<ul><li>[https://www.youtube.com/watch?v=npU6S61AIko&list=PLU1b1f-2Oe90TuYfifnWulINjMv_Wr16N&index=14 Using the sed Utility]</li><li>[https://www.youtube.com/watch?v=OV3XzjDYgJo&list=PLU1b1f-2Oe90TuYfifnWulINjMv_Wr16N&index=13 Using the awk Utility]</ul>
|}
'''How it Works:'''
* The sed command reads all lines in the input file and will be exposed to the expression <br>(i.e. area contained within quotes) one line at a time.
* The expression can be within single quotes or double quotes.
* The expression contains an address (match condition) and an instruction (operation).
* If the line matches the address, then it will perform the instruction.
* Lines will display be default unless the '''–n''' option is used to suppress default display<br>
'''Address:'''
* 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]$/''') * When using regular expressions, you must use forward slash(es) /
* If NO address is present, the instruction will apply to ALL lines
[[Image:sed.png|thumb|right|500px|'''Common instructions''' to take action if text matches an address.]]
'''Instruction:'''
*'''Action''' to take for matched line(s)
*Refer to table on right-side for list of some <br>'''common instructions''' and their purpose
<br><br>
'''Usage:'''
<span style="color:blue;font-weight:bold;font-family:courier;">awk options [-F] 'selection-criteria {action}’ file-name</span>
'''How It Works:'''
* The '''awk ''' command reads all lines in the input file and will be exposed to the expression (contained within quotes) for processing.* The '''expression ''' (contained in quotes) represents '''selection criteria''', and '''action ''' to execute contained within braces '''{}'''* If if selection criteria is matched, then action (between braces) is executed.* The '''–F''' option can be used to specify the default '''field delimiter''' (separator) character<br>eg. '''awk –F”;”''' (would indicate a semi-colon delimited input file).<br>
'''Selection Criteria'''
* 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):'''
* The parameters '''$1''', '''$2''', '''$3''' … '''$9''' represent the first, second and third to the 9th fields contained within the record.
* Parameters greater than nine requires the value of the parameter to be placed within braces (for example: '''${10}''','''${11}''','''${12}''', etc.)
* There are builtYou can use built-in variables that can be used in the awk expression (for example: '''NRvariables''', (such as '''NFNR''', or "record number" representing line number)<br>eg. '''FILENAME{print NR,$0}''' (will print record number, etc.then entire record)* You can use the '''-F''' option with the awk command to specify the field delimiter.
=INVESTIGATION 1: USING THE SED UTILITY=
<span style="color:red;">'''ATTENTION''': Effective '''May 9, 2022''' - this online tutorial will be required to be completed by '''Friday in week 11 by midnight'''<br>to obtain a grade of '''2%''' towards this course</span><br><br> In this sectioninvestigation, you will learn how to manipulate text using the '''sed''' utility.
# Issue a Linux command to create a directory called '''sed'''<br><br>
# Issue a Linux command to <u>change</u> to the '''sed''' directory and confirm that you are located in the '''sed''' directory.<br><br>
# Issue the following linux Linux command to download the data.txt file<br>('''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/data.txt</nowiki></span><br><br># Issue the '''more''' command to quickly view the contents of the '''data.txt''' file.<br>When finished, exit the more command by pressing the letter <span style="color:blue;font-weight:bold;font-family:courier;">q</span><br><br>[[Image:sed-1.png|thumb|right|300px|Issuing the '''p''' instruction without using the '''-n''' option (to suppress original output) will display lines twice.]]# <br><br>The '''p''' instruction with the '''sed''' command is used to print or <br>'''print''' (i.e. ''display '') the contents of a text file. <br><br># Issue the following linux Linux command:<br><span style="color:blue;font-weight:bold;font-family:courier;">sed 'p' data.txt</span><br><br>You '''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 if they had been specified as a patternof an address used.<br><br>We will use '''pipeline commands''' to both display stdout to the screen and save to files<br>for <u>confirmation</u> of running these pipeline commands when run a '''checking-script''' later in this investigation.<br><br># Issue the following linux Linux pipeline command:<br><span style="color:blue;font-weight:bold;font-family:courier;">sed -n 'p' data.txt | tee sed-1.txt</span><br><br>What do you notice?You should see only one line.<br><br>You can specify an address (''line #'address', '' to display lines using the sed utility<br>(eg. ''line #'', '''line #s''' or range of '''line #s''') when using the sed utility.<br><br>[[Image:sed-2.png|thumb|right|500px|Using # Issue the sed following Linux pipeline command to display a '''range''' of lines.]]# Issue the following linux pipeline command:<br><:<br><span style="color:blue;font-weight:bold;font-family:courier;">sed -n '1 p' data.txt | tee sed-2.txt</span><br><br>You should see the first line of the text file displayed.<br>What other command is used to only display the first line in a file?<br># Issue the following linux pipeline command:<br><span style="color:blue;font-weight[[Image:bold;font-family:courier;">sed -n '2,5 p' data.txt png|thumb|right|500px| tee Using the sed-3command to display a '''range''' of lines.txt</span>]]# Issue the following Linux pipeline command:<br><br>What is displayed? How would you modify the span style="color:blue;font-weight:bold;font-family:courier;">sed command to display the line range 2 to -n '2,5?p' data.txt | tee sed-3.txt</span><br><br>The '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 patterns ''' text<br>(a similar to method demonstratedin was demonstrated in the vi editorin tutorial 9).<br><br># Issue the following linux Linux pipeline command:<br><span style="color:blue;font-weight:bold;font-family:courier;">sed '2,5 s/TUTORIAL/LESSON/g' data.txt | tee sed-4.txt| more</span><br><br>What do you notice? View the original contents of lines 2 to 5 in the '''data.txt''' file<br>in another shell to confirm that the substitution occurred.<br><br>[[Image:sed-3.png|thumb|right|500px|Using the sed command with the '''-q''' option to display up to a line number, then quit.]]The '''q''' instruction terminates or '''quits''' the execution of the sed utility as soon as<br>it is read in a particular line or matching pattern.<br><br># Issue the following linux 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 '''regular expressions ''' to select lines that match a pattern. The rules remain the same for using regular expressions as demonstrated in lab8 except In fact,<br>the sed command was one of the <u>first</u> Linux commands that used regular expression must be contained within delimiters such as the forward slash "/" when .<br><br>The rules remain the same for using the sed utility.regular expressions as demonstrated in '''tutorial 9'''<br><br># Issue except the following linux pipeline command:regular expression must be contained within '''forward slashes'''<br>(eg. <span style="colorfont-family:bluecourier;font-weight:bold;font-family:courier;">sed -n '/^Theregexp/</ p' dataspan> ).txt | tee sed-6.txt</span><<br><br>What do you notice?<br><br># Issue [[Image:sed-4.png|thumb|right|400px|Using the following linux pipeline sed command:<br>using regular expressions with '''anchors'''.]]# Issue the following Linux pipeline command:<br><span style="color:blue;font-weight:bold;font-family:courier;">sed -n '/d$^The/ p' data.txt | tee sed-76.txt</span><br><br>What do you notice?<br><br>The '''sed''' utility can also be used as a filter to manipulate text that was generated from linux commands.<br><br># Issue the following linux pipeline command# Issue the following Linux pipeline command:<br><span style="color:<br><span style="color:blueblue;font-weight:bold;font-family:courier;">ls | sed -n '/txtd$/ p' data.txt | tee sed-87.txt</span><br><br>What did do you notice?<br><br># Issue the following linux pipeline command:<br><span style="color:blue;font-weight:bold;font-family:courier;">who | sed -n The '''sed''' utility can also be used as a '''filter''/^[a-m]/ p' | tee sed-9.txt | more</span>to manipulate text that<br>was generated from Linux commands.<br>What did you notice?<br><br># Issue the following to run a checking script[[Image:<br><span style="color:blue;fontsed-weight:bold;font-family:courier;">bash /home/murray5.png|thumb|right|400px|Using the sed command with '''pipeline''' commands.saul/scripts/week11-check-1]]# Issue the following Linux pipeline command:<br></span><br>style="color:blue;font-weight:bold;font-family:courier;">who | sed -n '/^[a-m]/ p' | tee sed-8.txt | more</span><br><br>What did you notice?<br><br># Issue the following Linux pipeline command:<br><span style="color:blue;font-weight:bold;font-family:courier;">ls | sed -n '/txt$/ p' | tee sed-9.txt</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:courier;">~uli101/week11-check-1</span><br><br>If you encounter errors, make corrections and '''re-run''' the checking script<br>If you encounter errors, make corrections and '''re-run''' the checking script until you<br>receive a congratulations message, then you can proceed.<br><br>
:In the next investigation, you will learn how to manipulate text using the '''awk''' utility.<br><br>
=INVESTIGATION 2: USING THE AWK UTILITY =
In this sectioninvestigation, you will learn how to use the awk utility to manipulate text and generate reports.
'''Perform the Following Steps:'''
# Change to your '''home''' directory and issue a command to '''confirm''' <br>you are located<br>in your ''home'' directory.<br><br>
# Issue a Linux command to create a directory called '''awk'''<br><br>
# Issue a Linux command to <u>change</u> to the '''awk''' directory and confirm you are located in the '''awk''' directory.<br><br>Let's download a database file that contains information regarding classic cars.<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/cars.txt</nowiki></span><br><br>
# Issue the '''morecat''' command to quickly view the contents of the '''cars.txt''' file.<br>When finished, exit the more <br>The "'''print'''" action (command by pressing ) is the letter <span style="color:blue;font-weight:bold;font-family:courier;">q<u>default</spanu>action of awk to print<br><br>The "all selected lines that match a '''printpattern'''" action (command) is the .<ubr>default</ubr> This '''action of awk to print all selected lines that match a pattern.<br>This action ''' (contained in braces) can provide more options <br>such as printing '''specific fields ''' of selected lines (or records) from a database.<br><br>[[Image:awk-1.png|thumb|right|400px|Using the awk command to display matches of the pattern '''ford'''.]]# Issue the following linux command all to display all lines (i.e. records ) in the "'''cars.txt" ''' database that contain matches the pattern (or "make ") called '''ford"''':<br><span style="color:blue;font-weight:bold;font-family:courier;">awk '/ford/ {print}' cars.txt</span><br><br>We will use '''pipeline commands''' to both display stdout to the screen and save to files<br>for <u>confirmation</u> of running these pipeline commands when run a '''checking-script''' later in this investigation.<br><br># Issue the following linux pipeline command all to display records <br>in the "'''cars.txt" ''' database that contain the pattern (i.e. make ") '''ford"''':<br><span style="color:blue;font-weight:bold;font-family:courier;">awk '/ford/' cars.txt | tee awk-1.txt</span><br><br>What do you notice? You should notice ALL lines displayed <u>without </u> using a '''search criteria.'''.<br><br>You can use ''builtin'' '''variables ''' with the "'''print" action ''' command for further processing. <br>We will discuss the following variables in this tutorial:<br><br>[[Image:awk-2.png|thumb|right|400px|Using the awk command to print search results by '''field number'''.]]''''$0''' - Current record (entire line)<br>'''$1''' - First field in record<br>'''$n''' - nth field in record<br>'''NR''' - Record Number (order in database)<br> '''NF''' - Number of fields in current record<br><br>For a listing of more variables, please consult your course notes.<br><br>The ''# Issue the following linux pipeline command to display the '''model''', 'tilde character''year' '', '~''quantity' is used to search for a pattern or display standard output for a particular field.'' and price<br><br># Issue in the following linux pipeline command to display the model, year, quantity and price in the "cars.txt" '''cars.txt''' database for makes of "'''chevy"''':<br><span style="color:blue;font-weight:bold;font-family:courier;">awk '/chevy/ {print $2,$3,$4,$5}' cars.txt | tee awk-2.txt</span><br><br>Notice that a '''space " " ''' is the delimiter for the fields that appear as standard output.<br><br># Issue the following linux pipeline command to display all plymouths (plyms) by model name, price and quantity:The '''tilde character''' '''~''' is used to search for a pattern or display standard output for a particular field.<br><span style="color:blue;font-weight:bold;font-family:courier;"br>awk '/chevy/ {print $2,$3,$4,$5}# Issue the following linux pipeline command to display all '''plymouths'' cars.txt | tee awk-3.txt</span>' ('''plym''')<br><br>You can also use comparison operators to specify conditions for processing with matched patterns when using the awk command. Since they are used WITHIN the awk expressionby '''model name''', they are not confused with redirection symbols<br><br> Comparison Operators:<br><br>'''<price''' and '''quantity' Less than'':<br>'''<span style='''  "color:blue; font-weight:bold;font-family:courier;Less than or equal<br">awk '$1 ~ /plym/ {print $2,$3,$4,$5}''>''' Greater thancars.txt | tee awk-3.txt</span><br><br>You can also use '''>=comparison operators''' Greater than or equalto specify conditions for processing with matched patterns<br>'''==''' Equalwhen using the awk command. Since they are used WITHIN the awk expression,<br>they are not confused with redirection symbols<br>'''!=''' Not equal<br><br># Issue [[Image:awk-3.png|thumb|right|400px|Using the following linux pipeline awk command to display display the car make, model number, quantity and price of all vehicles that are prices less results based on '''comparison operators'''.]]'''<''' Less than $5,000:<br>'''<span style="color:blue''' font-weight:bold font-family:courier;"Less than or equal<br>awk '$5 < 5000 {print $1,$2,$4,$5}' cars.txt | tee awk-4.txt</span'>''' Greater than<br><br'''>What do you notice?=''' Greater than or equal<br>'''==''' Equal<br># '''!=''' Not equal<br><br># Issue the following linux pipeline command to display display the '''car make, ''', '''model number''', '''quantity ''' and '''price ''' of all vehicles that whose '''prices are prices less than $5,000:''':<br><span style="color:blue;font-weight:bold;font-family:courier;">awk '$5 < 5000 {print $1,$2,$4,$5}' cars.txt | tee awk-54.txt</span><br><br>The symbol tilde What do you notice?<br><br># Issue the following linux pipeline command to display display '''~price''' is used to match a pattern for a particular field number.,<br><br># Issue the following linux pipeline command to display the '''quantity''', '''model''' and '''car make, year and quantity ''' of all car makes that begin with the letter vehicles whose '''prices are less than $5,000''f':<br><span style="color:blue;font-weight:bold;font-family:courier;">awk '$1 ~ /^f/ 5 < 5000 {print $15,$4,$2,$41}' cars.txt | tee awk-65.txt</span><br><br>Compound criteria symbols can be used # Issue the following linux pipeline command to join search statements together<br><br>Compound Operators:<br>display the '''car make''',<br>'''&&year''' and '''quantity''' (and)<br>of cars that '''begin'''with the '||''letter ' (or)f'''':<br><br># Issue the following linux pipeline command to list all "fords" that are greater than $10,000 in pricespan style="color:blue;font-weight:<br><span style="color:blue;font-weight:bold;bold;font-family:courier;">awk '$1 ~ /ford^f/ && $5 > 10000 {print $01,$2,$4}' cars.txt | tee awk-76.txt</span><br><br># Issue [[Image:awk-4.png|thumb|right|400px|Using the following awk command to run a checking scriptdisplay combined search results based on '''compound operators'''.]]Combined pattern searches can be made<br>by using '''compound operator''' symbols:<br><span style="color:bluebr>'''&&''' font-weight:bold font-family:courier ">bash /home/murray.saul/scripts/week11-check-2</span>(and)<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.'||''' (or)<br><br>:: After you complete # Issue the Review Questions sections following linux pipeline command to get additional practice,list all '''fords'''<br>then work on your whose '''online assignment 3price is greater than $10, section 2: Awk & Sed000''':<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.<br><br>
= LINUX PRACTICE QUESTIONS =
