Changes

:* List and understand explain several '''addresses''' and '''instructions''' associated with the '''sed''' command.

|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:'''

|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>

'''NoteHow it Works:'''

*The sed command reads '''all reads all lines in the input file''' and file and will be exposed to the expression <br>(i.e. area contained in 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 '''address–n''', then it will perform the option is used to suppress default display<br>'''instructionAddress:'''.

* Can use a line number, to select a specific line (for example: '''5''Address')* 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|thumb|right|500px|'''Common instructions''' to take action if text matches an address.]]

*Refer to table on right-side for list of some <br>'''common instructions'''<br>and their purpose  '''Examples:''' <span style="font-family:courier;">'''sed -n '3 p' text.txt''' (print 3rd line)<br>'''sed -n '1-5 p' text.txt''' (print lines 1 to 5)<br>'''sed -n '4,7 p' text.txt''' (print only lines 4 and 7)<br>'''sed -n'/^Therefore/ p' text.txt''' (print lines that begin with the patterh "Therefore")<br><br>'''sed '/^#/ d' myscript.bash''' (remove comments at beginning of line)<br>'''sed '/exit/ q' text.txt''' (print all lines until line containing pattern: "exit")<br>'''sed 's/this/that/' text.txt''' (replace first occurrence of pattern "this" with "that")<br>'''sed 's/this/that/' text.txt''' (replace ALL occurrences of pattern "this" with "that")<br><br></span>

<span style="color:blue;font-weight:bold;font-family:courier;">awk options [-F] 'selection _criteria -criteria {action }’ file-name</span>

'''NoteHow It Works:'''

*The '''awk command reads '''command reads all lines in the input file''' and will be exposed to the expression (contained within quotes) for processing.*Expression The '''expression''' (contained in quotes) represents '''selection criteria''', and '''action ''' to execute (contained within braces) '''{}'''* if selection criteria is matched , then action (between braces) is executed.*If no pattern is specified, The '''–F''' option can be used to specify the default '''field delimiter''' (separator) character<br>eg. '''awk selects all lines in the –F”;”''' (would indicate a semi-colon delimited inputfile).<br>*If no action is specified, awk copies the selected lines to standard output'''Selection Criteria'''

* Action to be executed is contained within braces '''Patterns{}'''* The '''print''' command can be used to display text (fields).* You can use parameters which represent fields within records (lines) within the expression of the awk utility.* The parameter '''$0''' represents all of the fields contained in the record (line).* The parameters '''$1''', '''$2''', '''$3''' … '''$9''' represent the first, second and third to the 9th fields contained within the record. * Parameters greater than nine requires the value of the parameter to be placed within braces (for example: Regular Expressions '''${10}''','''${11}''','''${12}''', etc.)* You can use built-in '''variables''' (such as '''NR''' or "record number" representing line number)<br>eg. '''{print NR,$0}''' (will print record number, then entire record).

*You can use a '''regular expression''', enclosed within slashes, as a pattern. *The '''~'''' operator tests whether a field or variable matches a regular expression *The '''!~''' operator tests for no match.*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  [[Image=INVESTIGATION 1:awk.png|thumb|right|300px|'''Comparison operators''' used with the '''awk''' command.]]'''Patterns: Relational Operators'''USING THE SED UTILITY=

*The following operators (in the table on the right<span style="color:red;">'''ATTENTION''': Effective '''May 9, 2022''' -side) can this online tutorial will be required to be used with the awk utility completed by '''Friday in week 11 by midnight'''<br>to pattern searching. *Since those symbols are used within the expression, they are NOT confused with redirection symbols.obtain a grade of '''2%''' towards this course</span><br><br>

 '''Examples:''' <span style="font-family:courier;">'''x''' (x)<br>'''x''' (x)<br>'''x''' (x)<br>'''x''' (x)<br><br>'''x''' (x)<br>'''x''' (x)<br>'''x''' (x)<br>'''x''' (x)<br><br></span> =INVESTIGATION 1: USING THE SED UTILITY= <br>In this sectioninvestigation, you will learn how to manipulate text using the '''sed''' utility.

# '''Login''' to your matrix accountand confirm you are located in your '''home''' directory.<br><br># Issue a Linux command to create a directory called '''sed'''<br><br># Issue a Linux command to <u>change</u> to the '''confirmsed''' directory and confirm that you are located in your home 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>[[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 in sed is used to <br>'''print or ''' (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>'''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 of 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 pattern'''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 ''' to display lines using the sed utility<br>(eg. ''line #'', '''line #s ''' or range of '''line #s''') when using the sed utility.<br><br># Issue the following linux Linux pipeline command:<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><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:<br><span style="color:blue;font-weight:bold;font-family:courier;">sed -n '2,5 p' data.txt | tee sed-3.txt</span><br><br>What do you think is displayed? (in another SSH session, compare with contents in How would you modify the sed command to display the data.txt text file line range 10 to confirm).50?<br><br>The '''s''' command 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''' command instruction terminates or '''quits ''' the execution of the sed utility as soon as 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. In fact,<br>the sed command was one of the <u>first</u> Linux commands that used regular expression.<br><br>The rules remain the same for using regular expressions as demonstrated in lab8 '''tutorial 9'''<br>except the regular expression must be contained within delimiters such as the '''forward slash slashes'''<br>(eg. <span style="font-family:courier;font-weight:bold;">/" when using the sed utilityregexp/</span> ).<br><br>[[Image:sed-4.png|thumb|right|400px|Using the sed command using regular expressions with '''anchors'''.]]# Issue the following linux Linux pipeline command:<br><span style="color:blue;font-weight:bold;font-family:courier;">sed -n '/^The/ p' data.txt | tee sed-6.txt</span><br><br>What do you notice?<br><br># Issue the following linux Linux pipeline command:<br><span style="color:blue;font-weight:bold;font-family:courier;">sed -n '/d$/ p' data.txt | tee sed-7.txt</span><br><br>What do you notice?<br><br>The '''sed''' utility can also be used as a '''filter ''' to manipulate text that <br>was generated from linux Linux commands.<br><br>[[Image:sed-5.png|thumb|right|400px|Using the sed command with '''pipeline''' commands.]]# Issue the following linux Linux pipeline command:<br><span style="color:blue;font-weight:bold;font-family:courier;">ls who | sed -n '/txt$^[a-m]/ p'| tee sed-8.txt | more</span><br><br>What did you notice?<br><br># Issue the following linux Linux pipeline command:<br><span style="color:blue;font-weight:bold;font-family:courier;">who ls | sed -n '/^[a-m]txt$/ p' | moretee 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>until you 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>

In this sectioninvestigation, you will learn how to use the awk utility to manipulate text and generate reports. 

# Issue Change to your '''home''' directory and issue a command to '''confirm''' <br>you are located 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 '''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 "print" action is the default action of awk to print all selected all selected lines that match a '''pattern'''.<br><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># Issue [[Image:awk-1.png|thumb|right|400px|Using the following linux awk command all to display records in matches of the "carspattern '''ford'''.txt" database that contain ]]# Issue the make "fordfollowing linux command all to display all lines (i.e. records) in the '''cars.txt''' database that matches the pattern (or "make":<) called '''ford''':<br><span style="color:blue;font-weight:bold;font-family:courier;">wget awk '/ford/ {print}' cars.txt</span><br><br># Issue the following linux command all We will use '''pipeline commands''' to both display records in stdout to the "cars.txt" database that contain the make "ford":screen and save to files for <bru>confirmation<span style="color:blue;font/u> of running these pipeline commands when run a '''checking-weight:bold;font-family:courier;">awk script''/ford/' carslater in this investigation.txt</spanbr><br># Issue the following linux pipeline command all to display records<br>What do you notice?<br>in the '''cars.txt''' database that contain the pattern (i.e. make) '''ford''':<br>You can use variables with the <span style="printcolor:blue;font-weight:bold;font-family:courier;" action for further processing. We will discuss the following variables in this tutorial:>awk '/ford/' cars.txt | tee awk-1.txt</span><br><br>'''$0''' - Current record (entire line)What do you notice? You should notice ALL lines displayed <u>without<br/u>using '''$1search criteria''' - First field in record.<br><br>You can use ''builtin''$n''' - nth field in record<br>variables'''NRwith the ''' - Record Number (order in database)<br> print'''NF''' - Number of fields in current recordcommand for further processing.<br><br>For a listing of more We will discuss the following variables, please consult your course notes.in this tutorial:<br><br>The tilde ''[[Image:awk-2.png|thumb|right|400px|Using the awk command to print search results by '~''field number'''.]]''' character is used to search for a pattern or display standard output for a particular field.$0''' - Current record (entire line)<br><br># Issue the following linux command to display the model, year, quantity and price '''$1''' - First field in the "cars.txt" database for makes of "chevy":record<br>'''$n''' - nth field in record<br><span style="color:blue;font'''NR''' -weight:bold;font-family:courier;"Record Number (order in database)<br>awk '/chevy/ {print $2,$3,$4,$5}' cars.txt</span>'NF''' - Number of fields in current record<br><br>Notice that For a space " " is the delimiter for the fields that appear as standard outputlisting of more variables, please consult your course notes.<br><br># Issue the following linux pipeline command to display all plymouths (plyms) by the '''model name''', price and quantity:'''year''', '''quantity''' and price<br><span style="color:in the '''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>You can also use comparison operators to specify conditions Notice that a '''space''' is the delimiter for processing with matched patterns when using the awk commandthe fields that appear as standard output. Since they are used WITHIN the awk expression, they are not confused with redirection symbols<br><br> Comparison Operators:<br><br><br><br>The '''tilde character''<''' &nbsp;&nbsp;&nbsp;&nbsp;Less than<br>'~''<=''' &nbsp;&nbsp;Less than is used to search for a pattern or equaldisplay standard output for a particular field.<br><br># Issue the following linux pipeline command to display all '''>plymouths''' ('''plym''' &nbsp;&nbsp;&nbsp;&nbsp;Greater than)<br>by '''>=model name''' &nbsp;&nbsp;Greater than or equal<br>, '''==price''' &nbsp;&nbsp;Equal<br>and '''!=quantity''' &nbsp;&nbsp;&nbsp;Not equal:<br><br># Issue the following linux command to display display the car make, model number, quantity and price of all vehicles that are prices less than span style="color:blue;font-weight:bold;font-family:courier;">awk '$1 ~ /plym/ {print $2,$3,$54,000:<br$5}' cars.txt | tee awk-3.txt</span><br><span style="color:blue;font-weight:bold;font-family:courier;"br>awk You can also use '''comparison operators''$5 < 5000 {print $1,$2,$4,$5}' cars.txt</span>to specify conditions for processing with matched patterns<br><when using the awk command. Since they are used WITHIN the awk expression,<br>What do you notice?they are not confused with redirection symbols<br><br># Issue [[Image:awk-3.png|thumb|right|400px|Using the following linux awk command to display display the car make, model number, quantity and price of all vehicles that are prices less than $5,000:results based on '''comparison operators'''.]]'''<br><span style="color:blue''' &nbsp;&nbsp;font-weight:bold&nbsp;font-family:courier&nbsp;">awk Less than<br>'''$5 < 5000 {print $1,$2,$4,$5}='' cars.txt</span>' &nbsp;&nbsp;Less than or equal<br><br>The symbol tilde '''~>''' is used to match a pattern for a particular field number.&nbsp;&nbsp;&nbsp;&nbsp;Greater than<br><br'''># Issue the following linux command to display the car make, year and quantity of all car makes that begin with the letter ='''f':&nbsp;&nbsp;Greater than or equal<br><span style'''=="color:blue''' &nbsp;font-weight:bold&nbsp;font-family:courier;"Equal<br>awk '$1 ~ /^f/ {print $1,$2,$4}' cars.txt</span>'!=''' &nbsp;&nbsp;&nbsp;Not equal<br><br>Compound criteria symbols can be used # Issue the following linux pipeline command to join search statements together<br><br>Compound Operators:<br><br>display display the '''&&car make''' &nbsp;&nbsp;&nbsp;&nbsp;(and)<br>, '''model'''||, ''' &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(or)quantity''' and '''price''' of all vehicles whose '''prices are less than $5,000''':<br><br># Issue the following linux 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:boldbold;font-family:courier;">awk '$1 ~ /ford/ && $5 > 10000 < 5000 {print $01,$2,$4,$5}' cars.txt | tee awk-4.txt</span><br><br>What do you notice?<br><br># After you complete Issue the Review Questions sections following linux pipeline command to get additional practice, then work on your display display '''online assignment 3,price''',<br>'''sections 4 to 6quantity''' labelled: , '''More Scripting (add)model''', and '''Yet More Scripting (oldfiles)car make''', and of vehicles whose '''sed And awkprices are less than $5,000''':<br><span style="color:blue;font-weight:bold;font-family:courier;">awk '$5 < 5000 {print $5,$4,$2,$1}' cars.txt | tee awk-5.txt</span><br><br># Issue the following linux pipeline command to display the '''car make''',<br>'''year''' and '''quantity''' of cars that '''begin''' with the '''letter 'f'''':<br><span style="color:blue;font-weight:bold;font-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>'''&&''' &nbsp;&nbsp;&nbsp;&nbsp;(and)<br>'''||''' &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;(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.<br><br>

# <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 '4 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>

# <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>