BOSS-Linux/C3/Basics-of-awk/English-timed - Revision history

Pratik kamble at 07:12, 24 March 2017

2017-03-24T07:12:29Z

Pratik kamble at 11:48, 20 February 2017

2017-02-20T11:48:05Z

Sandhya.np14 at 14:43, 13 August 2015

2015-08-13T14:43:08Z

Sandhya.np14 at 12:54, 13 August 2015

2015-08-13T12:54:26Z

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PoojaMoolya at 07:38, 12 February 2015

2015-02-12T07:38:06Z

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PoojaMoolya at 07:37, 12 February 2015

2015-02-12T07:37:54Z

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PoojaMoolya at 07:28, 12 February 2015

2015-02-12T07:28:34Z

PoojaMoolya: Created page with "{| border=1 | '''Time''' | '''Narration''' |- | 00:01 | Welcome to the spoken tutorial on the '''awk''' command. |- |00:05 | In this tutorial we will learn, '''awk comman..."

2015-02-12T07:26:50Z

Created page with "{| border=1 | '''Time''' | '''Narration''' |- | 00:01 | Welcome to the spoken tutorial on the '''awk''' command. |- |00:05 | In this tutorial we will learn, '''awk comman..."

New page

{| border=1
| '''Time'''
| '''Narration'''

|-
| 00:01
| Welcome to the spoken tutorial on the '''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
* Linux Operating system
*GNU BASH v. 4.2.24

|-
| 00:21
| Please note, GNU Bash version 4 or above is recommended to practice this tutorial.

|-
| 00:29
| Let us start with an introduction to '''awk'''.

|-
| 00:32
| The''' awk''' command is a very powerful text manipulation tool.

|-
| 00:36
| It is named after its authors, '''Aho, Weinberger''' and '''Kernighan'''.

|-
| 00:42
| It can perform several functions.

|-
| 00:46
| It operates at the field level of a record.

|-
| 00:49
| So, it can easily access and edit the individual fields of the record.

|-
| 00:56
| Let us see some examples.

|-
| 00:58
| For demonstration purpose, we use the''' awkdemo.txt '''file.

|-
| 01:03
| Let us see the contents of '''awkdemo.txt''' file.

|-
| 01:07
| Now open the '''terminal''' window

|-
| 01:10
| Let us see how to print using '''awk command.'''

|-
| 01:15
| Type: '''awk space''' (within single quote) (front slash) ‘'''/Pass '''(front slash)'''/'''(opening curly bracket) '''{print (closing curly bracket)}''' (after the quotes) '''space awkdemo.txt'''

|-
| 01:32
| Press '''Enter'''

|-
| 01:34
|Here '''Pass''' is the selection criteria.

|-
| 01:38
| All the lines of the '''awkdemo''' where '''Pass''' occurs are printed.

|-
| 01:43
| The action here is print.

|-
| 01:46
| We can also use '''regular expressions''' in '''awk'''

|-
| 01:50
| Say we want to print records of students with name '''Mira.'''

|-
| 01:55
| We would type: '''awk space '/M opening square bracket ei closing square bracket asterisk sign ra asterisk sign front slash opening curly bracket print closing curly bracket after the quoates space awkdemo.txt'''

|-
| 02:20
| Press '''Enter.'''

|-
| 02:22
| '''"*(asterisk)"''' will give one or more occurrences of previous character.

|-
| 02:27
| Thus entries with more than one occurrence for '''i, e''' and '''a''' will be listed.

|-
| 02:34
| For example

|-
| 02:35
| Mira (with 'M' 'I' 'R' 'A')

|-
|02:38
| Meera(with 'M' 'E' 'E' 'R' 'A')

|-
| 02:41
| *Meeraa(with M E E R A A )

|-
| 02:45
| '''awk''' supports the '''extended regular expressions (ERE)'''.

|-
| 02:51
| Which means we can match multiple patterns separated by a '''PIPE'''.

|-
|02:56
|Let me clear the promt

|-
|02:59
|Now type:

|-
| 03:00
| '''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'''

|-
| 03:18
| Press '''Enter.'''

|-
| 03:19
| Now entries for both '''civil''' and '''electrical''' are given.

|-
| 03:24
| Let us go back to our slides.

|-
| 03:28
| Parameters '''awk''' has some special parameters to identify individual fields of a line.

|-
| 03:36
| '''$1(Dollar 1)''' would indicate the first field.

|-
| 03:40
| Similarly we can have '''$2, $3''' and so on for respective fields.

|-
| 03:47
| '''$0''' represents the entire line.

|-
|03:50
|come back to our terminal

|-
| 03:52
|Note that each word is separated by '''PIPE''' in the file '''awkdemo.txt.'''

|-
| 03:59
| In this case '''PIPE '''is called a '''delimiter.'''

|-
| 04:03
| A '''delimiter''' separates words from each other.

|-
| 04:06
| A '''delimiter''' can also be a single '''whitespace. '''

|-
| 04:11
| To specify a '''delimiter''', we have to give '''- capital F '''flag followed by a '''delimiter'''.

|-
|04:18
| Let us see

|-
| 04:19
| 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'''

|-
| 04:44
| Press '''Enter'''

|-
| 04:46
| This print the entire line since we have used '''$0.'''

|-
| 04:52
| Notice that, '''names''' and '''stream of students''' are the second and third fields.

|-
| 04:58
|Say we only want to print two fields.

|-
| 05:01
| We will replace '''$0''' with '''$2 and$3''' in the above command.

|-
| 05:09
| Press '''Enter '''

|-
| 05:11
| Only two fields are shown.

|-
| 05:14
| Though it gives the right result, the display is all jagged and unformatted.

|-
| 05:20
| We can provide formatted output by using the '''C''' style '''printf '''statement.

|-
| 05:26
| We can also provide a serial number by using a builtin variable '''NR'''.

|-
| 05:33
| We will see more about builtin variables later.

|-
| 05:37
| Now Type '''awk''' space '''minus capital F within double quotes |(Pipe)”''' after the double quotes space ''''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'''

|-
| 06:25
| Press '''Enter.'''

|-
| 06:28
| We see the difference.

|-
| 06:30
| Here the '''NR''' stands for number of records.

|-
| 06:33
| Records are '''integers''', hence we have written''' %d'''.

|-
| 06:37
| '''Name''' and '''Stream''' are '''strings'''. So we have used '''%s'''.

|-
| 06:43
| Here '''25s''' will reserve 25 spaces for '''Name''' field.

|-
| 06:48
| '''15s''' will reserve 15 spaces for '''Stream''' field.

|-
| 06:54
| The '''minus sign''' is used to left justify the output.

|-
| 06:58
| This brings us to the end of this tutorial.

|-
| 07:01
| Let us move back to our slides.

|-
| 07:04
| Let us summarize.

|-
| 07:05
| In this tutorial we learnt To print using '''awk'''

|-
| 07:10
| Regular expression in '''awk'''. To list the enteries for a paritcular stream

|-
| 07:15
| To list only the second and the third fileds

|-
| 07:18
| To display a formatted output

|-
| 07:19
| As an assignment

|-
|07:22
| Display roll no., stream and marks of Ankti Saraf

|-
| 07:27
| Watch the video available at the link shown below

|-
| 07:30
| It summarises the Spoken Tutorial project

|-
| 07:33
| If you do not have good bandwidth, you can download and watch it

|-
|07:37
|The Spoken Tutorial Project Team Conducts workshops using spoken tutorials

|-
| 07:42
| Gives certificates to those who pass an online test

|-
| 07:45
| For more details, please write to contact@spoken-tutorial.org

|-
| 07:51
|Spoken Tutorial Project is a part of the Talk to a Teacher project

|-
| 07:55
| It is supported by the National Mission on Education through ICT,MHRD,Government of India

|-
| 08:02
| More information on this Mission is available at: [http://spokentutorial.org\NMEICT-Intro]

|-
| 08:07
|This is Ashwini Patil from IIT Bombay signning off. Thank you for joining.

|}

@@ Line 115: / Line 115: @@
 |-
 | 02:34
-| For example-
+| For example- Mira (with 'M'  'I'  'R'  'A')
-−
-|-
-| 02:35
-| Mira (with 'M'  'I'  'R'  'A')
 |-
@@ Line 143: / Line 139: @@
 |-
 |02:59
-|Now, type:
+|Now, type: '''awk space within single quotes front slash civil PIPE (|) electrical front slash space opening curly bracket print closing curly bracket''' after the quotes '''space awkdemo.txt'''
-−
-|-
-| 03:00
-| '''awk space within single quotes front slash civil PIPE (|) electrical front slash space opening curly bracket print closing curly bracket''' after the quotes '''space awkdemo.txt'''
 |-
 | 03:18
-| Press '''Enter.'''
+| Press '''Enter.''' Now, entries for both '''civil''' and '''electrical''' are given.
-−
-|-
-| 03:19
-| Now, entries for both '''civil''' and '''electrical''' are given.
 |-
@@ Line 199: / Line 187: @@
 |-
 | 04:11
-| To specify a '''delimiter''', we have to give '-F' (capital F) '''flag''' followed by a delimiter.
+| To specify a '''delimiter''', we have to give '-F' (capital F) '''flag''' followed by a delimiter. Let us see.
-−
-|-
-|04:18
-| Let us see.
 |-
@@ Line 299: / Line 283: @@
 |-
 | 07:04
-| Let us summarize.
+| Let us summarize. In this tutorial, we learnt:  To print using '''awk'''
-−
-|-
-| 07:05
-| In this tutorial, we learnt:  To print using '''awk'''
 |-
@@ Line 315: / Line 295: @@
 |-
 |07:18
-| To display a formatted output.
+| To display a formatted output. As an assignment,
-−
-|-
-| 07:19
-| As an assignment,
 |-

@@ Line 17: / Line 17: @@
 |-
 | 00:12
-| To record this tutorial, I am using:
+|To record this tutorial, I am using:
-* Linux  Operating system
+Linux  Operating system
-*GNU BASH v. 4.2.24
+GNU BASH v. 4.2.24
 |-
@@ Line 107: / Line 107: @@
 |-
 | 02:22
-| '''*(asterisk)'''  will give one or more occurrences of previous character.
+| '''(asterisk)'''  will give one or more occurrences of previous character.
 |-
@@ Line 119: / Line 119: @@
 |-
 | 02:35
-|* Mira (with 'M'  'I'  'R'  'A')
+| Mira (with 'M'  'I'  'R'  'A')
 |-
 |02:38
-|* Meera(with 'M'  'E'  'E'  'R'  'A')
+| Meera(with 'M'  'E'  'E'  'R'  'A')
 |-
 | 02:41
-|* Meeraa(with M E E R A A )
+| Meeraa(with M E E R A A )
 |-
@@ Line 303: / Line 303: @@
 |-
 | 07:05
-| In this tutorial, we learnt: * To print using '''awk'''
+| In this tutorial, we learnt:  To print using '''awk'''
 |-
 | 07:10
-|* Regular expression in '''awk''' * To list the entries for a particular stream
+| Regular expression in '''awk''' To list the entries for a particular stream
 |-
 | 07:15
-|* To list only the second and the third fields
+| To list only the second and the third fields
 |-
-| 07:18
+|07:18
-|* To display a formatted output.
+| To display a formatted output.
 |-

@@ Line 67: / Line 67: @@
 |-
 | 01:10
-| Let us see how to print using '''awk command.'''
+| Let us see how to print using ''''awk' command.'''
 |-
 | 01:15
-| Type: '''awk space''' (within single quote) (front slash) ‘'''/Pass '''(front slash)'''/'''(opening curly bracket) '''{print (closing curly bracket)}''' (after the  quotes) '''space awkdemo.txt'''
+| Type: '''awk space''' within single quote front-slash '''Pass ''' front- slash opening curly bracket '''print''' closing curly bracket (after the  quotes) '''space awkdemo.txt'''
 |-
@@ Line 99: / Line 99: @@
 |-
 | 01:55
-| We would type: '''awk space''' within single quotes '''/M (front-slash capital M) opening square-bracket  ei closing square-bracket asterisk-sign ra asterisk-sign front-slash space opening curly-bracket  print closing-curly bracket''' after the quotes '''space awkdemo.txt'''
+| We would type: '''awk space''' within single quotes front-slash capital '''M''' (/M) opening square-bracket ''' ei''' closing square-bracket asterisk-sign '''ra''' asterisk-sign front-slash space opening curly-bracket  '''print''' closing-curly bracket after the quotes '''space awkdemo.txt'''
 |-

@@ Line 255: / Line 255: @@
 |-
 | 05:37
-| Now Type '''awk''' space '''minus capital F within double quotes |(Pipe)”''' after the double quotes space ''''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'''
+| Now Type '''awk''' space '''minus capital F within double quotes (Pipe)”''' after the double quotes space ''''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'''
 |-