Difference between revisions of "Linux-AWK/C2/Basics-of-awk/English-timed"

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|-
 
|-
 
|  00:01
 
|  00:01
| Welcome to the spoken tutorial on the '''awk''' command.
+
| Welcome to the '''spoken tutorial''' on ''''awk' command'''.
  
 
|-
 
|-
 
|00:05  
 
|00:05  
|  In this tutorial we will learn, '''awk command.'''
+
|  In this tutorial, we will learn '''awk command.'''
  
 
|-
 
|-
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|-
 
|-
 
| 00:12
 
| 00:12
| To record this tutorial, I am using
+
| To record this tutorial, I am using:
*Ubuntu Linux 12.04 OS
+
'''Ubuntu Linux''' version '''12.04 OS''',
*GNU BASH v. 4.2.24
+
 
 +
'''GNU BASH''' version '''4.2.24'''
  
 
|-
 
|-
 
| 00:23
 
| 00:23
| Please note, GNU Bash version 4 or above is recommended to practice this tutorial.
+
| Please note, '''GNU Bash''' version 4 or above is recommended to practice this tutorial.
  
 
|-
 
|-
Line 35: Line 36:
 
|-
 
|-
 
| 00:38
 
| 00:38
| It is named after its authors, '''Aho, Weinberger''' and '''Kernighan'''.
+
| It is named after its authors- Aho, Weinberger and Kernighan.
  
 
|-
 
|-
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|-
 
|-
 
| 00:46
 
| 00:46
| It operates at the field level of a record.  
+
| It operates at the '''field''' level of a '''record.'''
  
 
|-
 
|-
 
| 00:51
 
| 00:51
| So, it can easily access and edit the individual fields of the record.
+
| So, it can easily access and '''edit''' the individual '''field'''s of the '''record'''.
  
 
|-
 
|-
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|-
 
|-
 
| 00:59
 
| 00:59
| For demonstration purpose, we use the''' awkdemo.txt '''file.  
+
| For demonstration purpose, we use the '''awkdemo.txt''' file.  
  
 
|-
 
|-
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|-
 
|-
 
| 01:09
 
| 01:09
| Now open the '''terminal''' by pressing  
+
| Now, open the '''terminal''' window by pressing '''Ctrl + Alt''' and '''T''' keys simultaneously on your keyboard.
'''CTRL + ALT''' and '''T''' keys simultaneosuly on your keyboard.
+
  
 
|-
 
|-
 
| 01:17
 
| 01:17
| Let us see how to print using '''awk command.'''  
+
| Let us see how to '''print''' using '''awk command.'''  
  
 
|-
 
|-
 
| 01:22
 
| 01:22
| Type:
+
| Type: '''awk space''' (within single quote) (front slash) ''' '/Pass '''(front slash)'''/'''(opening curly bracket) '''{print (closing curly bracket)}''' (after the  quotes) '''space awkdemo.txt'''  
'''awk space''' (within single quote) (front slash) '''/Pass '''(front slash)'''/'''(opening curly bracket) '''{print (closing curly bracket)}''' (after the  quotes) '''space awkdemo.txt'''  
+
  
 
|-
 
|-
 
| 01:38
 
| 01:38
| Press '''Enter'''
+
| Press '''Enter'''.
  
 
|-
 
|-
 
| 01:40
 
| 01:40
|Here '''Pass''' is the selection criteria.  
+
|Here, '''Pass''' is the selection criteria.  
  
 
|-
 
|-
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|-
 
|-
 
| 01:49
 
| 01:49
| The action here is print.  
+
| The action here is '''print'''.  
  
 
|-
 
|-
 
| 01:52
 
| 01:52
| We can also use '''regular expressions''' in '''awk'''
+
| We can also use '''regular expressions''' in '''awk'''.
  
 
|-
 
|-
 
| 01:56
 
| 01:56
| Say we want to print records of students with name '''Mira.'''
+
| Say, we want to '''print record'''s of students with name "Mira."
  
 
|-
 
|-
 
| 02:01
 
| 02:01
 
| We would type:
 
| We would type:
'''awk space '/M opening square bracket [ ei closing square bracket ]*ra */{ print}' space awkdemo.txt'''
+
'''awk space '/M (opening square bracket) [ ei (closing square bracket) ]*ra */{print}' space awkdemo.txt'''
  
 
|-
 
|-
Line 110: Line 109:
 
|-
 
|-
 
| 02:29
 
| 02:29
| '''"*"'''  will give one or more occurrences of previous character.
+
| ''' "*" '''  will give one or more occurrences of previous character.
  
 
|-
 
|-
 
| 02:33
 
| 02:33
| Thus entries with more than one occurrence for '''i, e''' and '''a''' will be listed.
+
| Thus, entries with more than one occurrence for '''i, e''' and '''a''' will be listed.
  
 
|-
 
|-
 
| 02:40
 
| 02:40
| For example  
+
| For example-
  
 
|-
 
|-
 
| 02:42
 
| 02:42
| *Mira
+
| Mira with M I R A,
  
 
|-
 
|-
 
|02:45  
 
|02:45  
| *Meera
+
| Meera with M double E R A
  
 
|-
 
|-
 
| 02:47
 
| 02:47
| *Meeraa
+
| and Meeraa with M double E R double A.
  
 
|-
 
|-
 
| 02:52
 
| 02:52
| '''awk''' supports the '''extended regular expressions (ERE)'''.
+
| '''awk''' supports the '''extended regular expressions (ERE)'''
  
 
|-
 
|-
 
| 02:58
 
| 02:58
| Which means we can match multiple patterns separated by a '''PIPE'''.
+
| which means we can match multiple patterns separated by a '''PIPE'''.
 
|-
 
|-
 
|03:03
 
|03:03
|Let me clear the promt
+
|Let me clear the '''prompt'''.
  
 
|-
 
|-
 
|03:05
 
|03:05
|Now type:
+
|Now, type: '''awk space (within single quotes)(front slash) ‘/civil(PIPE) |electrical'''(front slash)'''space (opening curly brackets)/{print}(closing curly brackets)''' after the quotes space'''awkdemo.txt'''
 
+
|-
+
| 03:06
+
| '''awk space (in single quotes)(front slash) ‘/civil(PIPE) '''|electrical '''(front slash)'''space (open curly brackets)/{print}(close curly brackets) after the quotes space'''awkdemo.txt'''
+
  
 
|-
 
|-
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|-
 
|-
 
| 03:26
 
| 03:26
| Now entries for both '''civil''' and '''electrical''' are given.
+
| Now entries for both "civil" and "electrical" are given.
  
 
|-
 
|-
 
| 03:31
 
| 03:31
|  Let us go back to our slides.  
+
|  Let us go back to our '''slide'''s.  
  
 
|-
 
|-
 
| 03:34
 
| 03:34
| Parameters '''awk''' has some special parameters to identify individual fields of a line.  
+
| '''Parameter'''s: '''awk''' has some special parameters to identify individual '''field'''s of a line.  
  
 
|-
 
|-
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|-
 
|-
 
| 03:45
 
| 03:45
| Similarly we can have '''$2, $3''' and so on for respective fields.  
+
| Similarly, we can have '''$2, $3''' and so on for respective fields.  
  
 
|-
 
|-
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|-
 
|-
 
|03:56
 
|03:56
|come back to our terminal
+
|Come back to our '''terminal'''.
  
 
|-
 
|-
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|-
 
|-
 
| 04:05
 
| 04:05
| In this case '''PIPE '''is called a '''delimiter.'''
+
| In this case, '''PIPE '''is called a '''delimiter.'''
  
 
|-
 
|-
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|-
 
|-
 
| 04:13
 
| 04:13
| A '''delimiter''' can also be a single '''whitespace. '''
+
| A '''delimiter''' can also be a single white '''space.'''
  
 
|-
 
|-
 
| 04:16
 
| 04:16
| To specify a '''delimiter''', we have to give '''- capital F '''flag followed by a '''delimiter'''.
+
| To specify a '''delimiter''', we have to give '''- capital F flag''' followed by a '''delimiter'''.
  
 
|-
 
|-
 
|04:24
 
|04:24
| Let us see  
+
| Let us see.  Type: '''awk space minus capital F space''' within double quotes ''' PIPE space''' within single quote '''front-slash civil PIPE electrical front-slash''' opening curly bracket '''print space dollar0 closing curly bracket after the quotes space awkdemo.txt'''
 
+
|-
+
| 04:25
+
| Type '''awk space minus capital F space''' within double quotes''' PIPE space''' within single quote '''front slash civil PIPE electrical front slash ''' opening curly bracket''' print space dollar0 closing curly braket after the quotes space awkdemo.txt'''
+
  
 
|-
 
|-
 
| 04:51
 
| 04:51
| Press '''Enter'''
+
| Press '''Enter'''.
  
 
|-
 
|-
 
| 04:53
 
| 04:53
| This print the entire line since we have used '''$0.'''
+
| This prints the entire line since we have used '''$0.'''
  
 
|-
 
|-
 
| 04:58
 
| 04:58
| Notice that, '''names''' and '''stream of students''' are the second and third fields.
+
| Notice that '''names''' and '''stream of students''' are the second and third fields.
  
 
|-
 
|-
 
| 05:04
 
| 05:04
|Say we only want to print two fields.
+
|Say, we only want to print two fields.
  
 
|-
 
|-
 
| 05:08
 
| 05:08
| We will replace '''$0''' with '''$2 and$3''' in the above command.
+
| We will replace '''$0''' with '''$2 and $3''' in the above command.
  
 
|-
 
|-
 
| 05:15
 
| 05:15
| Press '''Enter '''
+
| Press '''Enter '''.
  
 
|-
 
|-
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|-
 
|-
 
| 05:21
 
| 05:21
| Though it gives the right result, the display is all jagged and unformatted.  
+
| Though it gives the right result, the display is all jagged and un-formatted.  
  
 
|-
 
|-
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|-
 
|-
 
| 05:32
 
| 05:32
| We can also provide a serial number by using a builtin variable '''NR'''.  
+
| We can also provide a serial number by using a '''built-in variable 'NR''''.  
  
 
|-
 
|-
 
| 05:40
 
| 05:40
| We will see more about builtin variables later.
+
| We will see more about '''built-in variable'''s later.
  
 
|-
 
|-
 
| 05:44
 
| 05:44
| Now Type
+
| Now, type '''awk''' space '''minus capital F within double quotes (Pipe)''' after the double quotes space now within single quotes ''' front-slash  Pass front slash opening curly bracket printf (within double quotes)  "percentage sign 4d space percentage sign -25s space percentage sign  minus 15s space backslash n”,''' after the double quotes  '''NR, $2, $3 closing curly bracket' ''' after the single quote space '''awkdemo.txt'''
'''awk''' space '''-F”|”''' space ''''/Pass/{printf “%4d %-25s %-15s \n”,''' '''NR,$2,$3 }'''' space '''awkdemo.txt'''  
+
  
 
|-
 
|-
 
| 06:33
 
| 06:33
| '''Press Enter.'''
+
| Press '''Enter.''' We see the difference.
 
+
|-
+
| 06:34
+
| We see the difference.
+
  
 
|-
 
|-
 
| 06:37
 
| 06:37
| Here the '''NR''' stands for number of records.  
+
| Here'''NR''' stands for number of '''record'''s.  
  
 
|-
 
|-
 
| 06:41
 
| 06:41
| Records are '''integers''', hence we have written''' %d'''.  
+
| Records are '''integers''', hence we have written '''%d'''.  
  
 
|-
 
|-
 
| 06:45
 
| 06:45
| '''Name''' and '''Stream''' are '''strings'''. So we have used '''%s'''.  
+
| '''Name''' and '''Stream''' are '''strings'''. So, we have used '''%s'''.  
  
 
|-
 
|-
 
| 06:50
 
| 06:50
| Here '''25s''' will reserve 25 spaces for '''Name''' field.
+
| Here, '''25s''' will reserve 25 '''space'''s for '''Name''' field.
  
 
|-
 
|-
 
| 06:55
 
| 06:55
| '''15s''' will reserve 15 spaces for '''Stream''' field.
+
| '''15s''' will reserve 15 '''space'''s for '''Stream''' field.
  
 
|-
 
|-
 
| 07:01
 
| 07:01
| The '''minus sign''' is used to left justify the output.
+
| The '''minus sign''' is used to '''left justify''' the output.
  
 
|-
 
|-
Line 298: Line 284:
 
|-
 
|-
 
| 07:08
 
| 07:08
| Let us move back to our slides.
+
| Let us move back to our '''slide'''s.
  
 
|-
 
|-
 
| 07:10
 
| 07:10
| Let us summarize.
+
| Let us summarize. In this tutorial, we learnt:  to '''print''' using '''awk''',
 
+
|-
+
| 07:11
+
| In this tutorial we learnt To print using awk
+
  
 
|-
 
|-
 
| 07:16
 
| 07:16
| Regular expression in awk To list the enteries for a paritcular stream
+
| '''regular expression''' in '''awk''', 
 +
to list the entries for a particular '''stream''',
  
 
|-
 
|-
 
| 07:21
 
| 07:21
| To list only the second and the third fileds
+
| to list only the second and the third '''field'''s,
  
 
|-
 
|-
 
| 07:24
 
| 07:24
| To display a formatted output
+
| to display a formatted '''output'''.
  
 
|-
 
|-
 
| 07:28
 
| 07:28
| As an assignment  
+
| As an assignment,  display '''roll no., stream''' and '''marks''' of Ankit Saraf.
 
+
|-
+
|07:29
+
| Display roll no., stream and marks of Ankti Saraf
+
  
 
|-
 
|-
 
| 07:34
 
| 07:34
|  Watch the video available at the link shown below
+
|  Watch the video available at the '''link''' shown below.
  
 
|-
 
|-
 
| 07:37
 
| 07:37
| It summarises the Spoken Tutorial project
+
| It summarizes the '''Spoken Tutorial''' project.
  
 
|-
 
|-
 
| 07:40
 
| 07:40
| If you do not have good bandwidth, you can download and watch it
+
| If you do not have good bandwidth, you can download and watch it.
  
 
|-
 
|-
 
|07:45
 
|07:45
|The Spoken Tutorial Project Team Conducts workshops using spoken tutorials
+
|The Spoken Tutorial Project Team: conducts workshops using spoken tutorials,
  
 
|-
 
|-
 
| 07:48
 
| 07:48
| Gives certificates to those who pass an online test
+
| gives certificates to those who pass an online test.
  
 
|-
 
|-
 
| 07:52
 
| 07:52
| For more details, please write to contact@spoken-tutorial.org
+
| For more details, please write to '''contact@spoken-tutorial.org'''
  
 
|-
 
|-
 
| 07:58
 
| 07:58
|Spoken Tutorial Project is a part of the Talk to a Teacher project
+
|'''Spoken Tutorial Project''' is a part of the '''Talk to a Teacher project'''.
  
 
|-
 
|-
 
| 08:01
 
| 08:01
| It is supported by the National Mission on Education through ICT,MHRD,Government of India
+
| It is supported by the National Mission on Education through '''ICT, MHRD,''' Government of India.
  
 
|-
 
|-
 
| 08:07
 
| 08:07
| More information on this Mission is available at:  [http://spokentutorial.org\NMEICT-Intro]
+
| More information on this mission is available at:  [http://spokentutorial.org\NMEICT-Intro]
  
 
|-
 
|-
 
| 08:12
 
| 08:12
|This is Ashwini Patil from IIT Bombay signning off. Thank you for joining.
+
|This is Ashwini Patil from '''IIT Bombay''', signing off. Thank you for joining.
  
 
|}
 
|}

Latest revision as of 16:41, 5 September 2019

Time Narration
00:01 Welcome to the spoken tutorial on 'awk' command.
00:05 In this tutorial, we will learn awk command.
00:09 We will do this through some examples.
00:12 To record this tutorial, I am using:

Ubuntu Linux version 12.04 OS,

GNU BASH version 4.2.24

00:23 Please note, GNU Bash version 4 or above is recommended to practice this tutorial.
00:29 Let us start with an introduction to awk.
00:33 The awk command is a very powerful text manipulation tool.
00:38 It is named after its authors- Aho, Weinberger and Kernighan.
00:44 It can perform several functions.
00:46 It operates at the field level of a record.
00:51 So, it can easily access and edit the individual fields of the record.
00:56 Let us see some examples.
00:59 For demonstration purpose, we use the awkdemo.txt file.
01:04 Let us see the contents of awkdemo.txt file.
01:09 Now, open the terminal window by pressing Ctrl + Alt and T keys simultaneously on your keyboard.
01:17 Let us see how to print using awk command.
01:22 Type: awk space (within single quote) (front slash) '/Pass (front slash)/(opening curly bracket) {print (closing curly bracket)} (after the quotes) space awkdemo.txt
01:38 Press Enter.
01:40 Here, Pass is the selection criteria.
01:44 All the lines of the awkdemo where Pass occurs are printed.
01:49 The action here is print.
01:52 We can also use regular expressions in awk.
01:56 Say, we want to print records of students with name "Mira."
02:01 We would type:

awk space '/M (opening square bracket) [ ei (closing square bracket) ]*ra */{print}' space awkdemo.txt

02:27 Press Enter.
02:29 "*" will give one or more occurrences of previous character.
02:33 Thus, entries with more than one occurrence for i, e and a will be listed.
02:40 For example-
02:42 Mira with M I R A,
02:45 Meera with M double E R A
02:47 and Meeraa with M double E R double A.
02:52 awk supports the extended regular expressions (ERE)
02:58 which means we can match multiple patterns separated by a PIPE.
03:03 Let me clear the prompt.
03:05 electrical(front slash)space (opening curly brackets)/{print}(closing curly brackets) after the quotes spaceawkdemo.txt
03:23 Press Enter.
03:26 Now entries for both "civil" and "electrical" are given.
03:31 Let us go back to our slides.
03:34 Parameters: awk has some special parameters to identify individual fields of a line.
03:41 $1(Dollar 1) would indicate the first field.
03:45 Similarly, we can have $2, $3 and so on for respective fields.
03:53 $0 represents the entire line.
03:56 Come back to our terminal.
03:59 Note that each word is separated by PIPE in the file awkdemo.txt.
04:05 In this case, PIPE is called a delimiter.
04:09 A delimiter separates words from each other.
04:13 A delimiter can also be a single white space.
04:16 To specify a delimiter, we have to give - capital F flag followed by a delimiter.
04:24 Let us see. Type: awk space minus capital F space within double quotes PIPE space within single quote front-slash civil PIPE electrical front-slash opening curly bracket print space dollar0 closing curly bracket after the quotes space awkdemo.txt
04:51 Press Enter.
04:53 This prints the entire line since we have used $0.
04:58 Notice that names and stream of students are the second and third fields.
05:04 Say, we only want to print two fields.
05:08 We will replace $0 with $2 and $3 in the above command.
05:15 Press Enter .
05:18 Only two fields are shown.
05:21 Though it gives the right result, the display is all jagged and un-formatted.
05:26 We can provide formatted output by using the C style printf statement.
05:32 We can also provide a serial number by using a built-in variable 'NR'.
05:40 We will see more about built-in variables later.
05:44 Now, type awk space minus capital F within double quotes (Pipe) after the double quotes space now within single quotes front-slash Pass front slash opening curly bracket printf (within double quotes) "percentage sign 4d space percentage sign -25s space percentage sign minus 15s space backslash n”, after the double quotes NR, $2, $3 closing curly bracket' after the single quote space awkdemo.txt
06:33 Press Enter. We see the difference.
06:37 Here, NR stands for number of records.
06:41 Records are integers, hence we have written %d.
06:45 Name and Stream are strings. So, we have used %s.
06:50 Here, 25s will reserve 25 spaces for Name field.
06:55 15s will reserve 15 spaces for Stream field.
07:01 The minus sign is used to left justify the output.
07:05 This brings us to the end of this tutorial.
07:08 Let us move back to our slides.
07:10 Let us summarize. In this tutorial, we learnt: to print using awk,
07:16 regular expression in awk,

to list the entries for a particular stream,

07:21 to list only the second and the third fields,
07:24 to display a formatted output.
07:28 As an assignment, display roll no., stream and marks of Ankit Saraf.
07:34 Watch the video available at the link shown below.
07:37 It summarizes the Spoken Tutorial project.
07:40 If you do not have good bandwidth, you can download and watch it.
07:45 The Spoken Tutorial Project Team: conducts workshops using spoken tutorials,
07:48 gives certificates to those who pass an online test.
07:52 For more details, please write to contact@spoken-tutorial.org
07:58 Spoken Tutorial Project is a part of the Talk to a Teacher project.
08:01 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
08:07 More information on this mission is available at: [1]
08:12 This is Ashwini Patil from IIT Bombay, signing off. Thank you for joining.

Contributors and Content Editors

Nancyvarkey, PoojaMoolya, Pratik kamble, Ranjana, Sandhya.np14