Linux/C3/More-on-sed-command/English - Revision history

Nancyvarkey at 10:11, 16 December 2013

2013-12-16T10:11:54Z

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Ashwini at 10:01, 14 December 2013

2013-12-14T10:01:25Z

Ashwini at 12:51, 13 December 2013

2013-12-13T12:51:09Z

Ashwini: Created page with ''''Title of script''': sed - The stream editor '''Author: Sachin Patil''' '''Keywords: sed, substitute, insert, delete''' {| style="border-spacing:0;" | style="border:1pt so…'

2013-07-01T09:52:45Z

Created page with ''''Title of script''': sed - The stream editor '''Author: Sachin Patil''' '''Keywords: sed, substitute, insert, delete''' {| style="border-spacing:0;" | style="border:1pt so…'

New page

'''Title of script''': sed - The stream editor

'''Author: Sachin Patil'''

'''Keywords: sed, substitute, insert, delete'''

{| style="border-spacing:0;"
| style="border:1pt solid #000000;padding:0.106cm;"| '''Visual Cue'''
| style="border:1pt solid #000000;padding:0.106cm;"| '''Narration'''

|-
| style="border:1pt solid #000000;padding:0.106cm;"| Display slide 1

| style="border:1pt solid #000000;padding:0.106cm;"| Welcome to this spoken tutorial on some more on sed.

|-
| style="border:1pt solid #000000;padding:0.106cm;"| Display slide 2

Learning objectives
| style="border:1pt solid #000000;padding:0.106cm;"| In this tutorial we tutorial we will learn some more '''sed '''commands.

|-
| style="border:1pt solid #000000;padding:0.106cm;"| Display slide 3

System Requirement

| style="border:1pt solid #000000;padding:0.106cm;"| To record this tutorial, I am using

'''Ubuntu Linux''' 12.04''' Operating System''' and

'''GNU BASH''' version 4.2.24(1)

Please note,''' GNU bash''' version 4 or above is recommended to practice this tutorial.

|-
| style="border:1pt solid #000000;padding:0.106cm;"| Display slide 4

Prerequisites

| style="border:1pt solid #000000;padding:0.106cm;"| To practice this tutorial,

You should know Basics of linux terminal.

You should be aware of sed tool.

For relevant tutorials please visit our website:

http://spoken-tutorial.org

|-
| style="border:1pt solid #000000;padding:0.106cm;"|
| style="border:1pt solid #000000;padding:0.106cm;"| The major use of sed is substitution.

ie replacing some pattern in the input with something else.

|-
| style="border:1pt solid #000000;padding:0.106cm;"| Type

'''cat seddemo.tx'''t

<nowiki>[</nowiki>enter]

<nowiki>[ </nowiki>Point to the fourth and sixth line ]
| style="border:1pt solid #000000;padding:0.106cm;"| Lets first look at the original file '''seddemo.txt'''

|-
| style="border:1pt solid #000000;padding:0.106cm;"| Type

'''sed 's<nowiki>/[</nowiki>kK]umar/Roy/' seddemo.txt'''

<nowiki>[</nowiki>enter]
| style="border:1pt solid #000000;padding:0.106cm;"| Notice the word '''Kumar''' occurs two times in the fourth and once in the sixth line.

If you want to replace all occurrences of the '''‘kumar’''' with '''‘Roy’'''

Type

'''sed''' space ''''s<nowiki>/[</nowiki>kK]umar/Roy/'''' space '''seddemo.txt'''

'''Press Enter'''

|-
| style="border:1pt solid #000000;padding:0.106cm;"| Show the output

Show the file

'''cat seddemo.txt'''

<nowiki>[</nowiki>point to 4th line of both output and file]
| style="border:1pt solid #000000;padding:0.106cm;"| Notice the fourth line.

Only the first occurrence of '''kumar''' is changed to '''Roy''', not the second one.

Sixth line had one occurrence of the word '''kumar''' and this is replaced now.

So, we see only the first entry of the lines has been changed.

This is because, by default, the first matched entry of any line is substituted.

To substitute all the matched entries we need to use the flag''' g'''

|-
| style="border:1pt solid #000000;padding:0.106cm;"| Type

'''sed 's<nowiki>/[</nowiki>kK]umar/Roy/g' seddemo.txt'''

<nowiki>[</nowiki>enter]
| style="border:1pt solid #000000;padding:0.106cm;"| Type

'''sed''' space ''''s<nowiki>/[</nowiki>kK]umar/Roy/g'''' space '''seddemo.txt'''

And p'''ress Enter'''

Now, both entries of the fourth line are replaced.

We can make multiple substitutions in one go as well.

|-
| style="border:1pt solid #000000;padding:0.106cm;"|
| style="border:1pt solid #000000;padding:0.106cm;"| Say we want to replace the words '''electronics''' with the word '''electrical'''

And '''civil''' with '''metallurgy''' in the file '''seddemo.txt'''

|-
| style="border:1pt solid #000000;padding:0.106cm;"| Type

'''sed -e 's/electronics/electrical/g’ '''

'''-e ‘s/civil/metallurgy/g' seddemo.txt'''

<nowiki>[</nowiki>enter]

| style="border:1pt solid #000000;padding:0.106cm;"| Type:

'''sed''' space '''-e ‘s/electronics/electrical/g’ -e''' '''‘s/civil/metallurgy/g’''' space '''seddemo.txt'''

And '''press Enter.'''

|-
| style="border:1pt solid #000000;padding:0.106cm;"| Type

'''sed '/Anirban/s/computers/mathematics/' seddemo.txt'''

<nowiki>[</nowiki>enter]
| style="border:1pt solid #000000;padding:0.106cm;"| Now we want to change the stream of '''Anirban '''from '''computers''' to '''mathematics.'''

In such case we would need to type:

'''sed''' space ''''/Anirban/s/computers/mathematics/g' '''space '''seddemo.txt'''

Press '''Enter.'''

|-
| style="border:1pt solid #000000;padding:0.106cm;"| <nowiki>[</nowiki>highlight text inside single quotes]

<nowiki>[</nowiki>highlight ‘Anirban’]

<nowiki>[</nowiki>highlight ‘s’]

<nowiki>[</nowiki>highlight ‘computers’]

<nowiki>[</nowiki>highlight ‘mathematics’]
| style="border:1pt solid #000000;padding:0.106cm;"| Let us understand what this is.

First we write sed then in single quotes we write the pattern to be matched.

This is Anirban, now after the slash comes the operation.

This is s that stands for substitution as we have already seen.

Then we mention the pattern to be replaced which is computers

Then the new word that would be substituted which is mathematics.

|-
| style="border:1pt solid #000000;padding:0.106cm;"|
| style="border:1pt solid #000000;padding:0.106cm;"| We can also use sed to add , or delete lines in the file.

Say we want to select those lines which do not have stream as '''electronics.'''

|-
| style="border:1pt solid #000000;padding:0.106cm;"| Type

'''sed '/electronics/d' seddemo.txt > nonelectronics.txt'''

<nowiki>[</nowiki>enter]

| style="border:1pt solid #000000;padding:0.106cm;"| For that we have the '''d '''flag.

We would type:

'''sed''' space (in single quotes) (front slash) /electronics/d space '''seddemo.txt''' space greater than sign space '''nonelectronics.txt'''

'''Press Enter'''

|-
| style="border:1pt solid #000000;padding:0.106cm;"| '''cat nonelectronics.txt'''

<nowiki>[</nowiki>enter]
| style="border:1pt solid #000000;padding:0.106cm;"| To see the contents type:

cat space '''nonelectronics.txt'''

and press enter.

|-
| style="border:1pt solid #000000;padding:0.106cm;"| Type

'''sed '1i Student Information' seddemo.txt'''

<nowiki>[</nowiki>enter]
| style="border:1pt solid #000000;padding:0.106cm;"| Say at the start of the file we want to add a line Student Information.

For that we have the i action.

We need to type:

sed space in single quotes 1i space''' '''Student Information' '''seddemo.txt '''

And '''press''' '''Enter.'''

|-
| style="border:1pt solid #000000;padding:0.106cm;"|
| style="border:1pt solid #000000;padding:0.106cm;"| Infact we can enter multiple lines like this.

Say we want to add the two lines we would do it in a similar way.

Along with student information we also want to add academics in the next year.

|-
| style="border:1pt solid #000000;padding:0.106cm;"| Type

'''sed '1i Student Information\n2011' seddemo.txt'''

<nowiki>[</nowiki>enter]
| style="border:1pt solid #000000;padding:0.106cm;"| So in that case we would write

sed space in single quotes 1i space Student Information'''\n'''2011' seddemo.txt

'''Press Enter'''

Notice '''\n '''between the string ‘Information’ and ‘2011’.

'''\n '''prints 2011 in the next line after ‘Student Information’

|-
| style="border:1pt solid #000000;padding:0.106cm;"|
| style="border:1pt solid #000000;padding:0.106cm;"| This brings me to the end of this tutorial.

|-
| style="border:1pt solid #000000;padding:0.106cm;"| Summary
| style="border:1pt solid #000000;padding:0.106cm;"| Let us summarize,

In this tutorial we learnt,

Substitution

Replacement

Insertion

|-
| style="border:1pt solid #000000;padding:0.106cm;"| Assignment
| style="border:1pt solid #000000;padding:0.106cm;"| As an assignment,

Take the same text file '''seddemo.txt'''

And try to replace or substitute name '''Ankit''' with '''Ashish'''

|-
| style="border:1pt solid #000000;padding:0.106cm;"| Display Slide 8

Acknowledgement Slide

| style="border:1pt solid #000000;padding:0.106cm;"| Watch the video available at the link shown below

It summarises the Spoken Tutorial project

If you do not have good bandwidth, you can download and watch it

|-
| style="border:1pt solid #000000;padding:0.106cm;"| Display Slide 9

Spoken Tutorial Workshops

| style="border:1pt solid #000000;padding:0.106cm;"| The Spoken Tutorial Project Team

Conducts workshops using spoken tutorials

Gives certificates to those who pass an online test

For more details, please write to

contact@spoken-tutorial.org

|-
| style="border:1pt solid #000000;padding:0.106cm;"| Display Slide 10

Acknowledgement

| style="border:1pt solid #000000;padding:0.106cm;"| Spoken Tutorial Project is a part of the Talk to a Teacher project

It is supported by the National Mission on Education through ICT, MHRD, Government of India

More information on this Mission is available at: http://spoken-tutorial.org\NMEICT-Intro

|-
| style="border:1pt solid #000000;padding:0.106cm;"| No Last Slide for tutorials created at IITB

Display the previous slide only and narrate this line.
| style="border:1pt solid #000000;padding:0.106cm;"| The script has been contributed by Sachin Patil.

This is Ashwini PAtil from IIT bombay sighning off.

Thank you for joining.

|}

← Older revision		Revision as of 12:51, 13 December 2013
Line 46:		Line 46:


−	\| style="border:1pt solid #000000;padding:0.106cm;"\| ~~To practice this tutorial,~~	+	\| style="border:1pt solid #000000;padding:0.106cm;"\| As prerequisites

	You should know Basics of linux terminal.		You should know Basics of linux terminal.

@@ Line 1: / Line 1: @@
-'''Title of script''': sed - The stream editor
+'''Title of script''': More on sed
-'''Author: Sachin Patil'''
+'''Author: Sachin Patil and Anirban'''
 '''Keywords: sed, substitute, insert, delete'''
@@ Line 16: / Line 16: @@
-| style="border:1pt solid #000000;padding:0.106cm;"| Welcome to this spoken tutorial on some more on sed.
+| style="border:1pt solid #000000;padding:0.106cm;"| Welcome to the spoken tutorial on more on sed.
 |-
@@ Line 22: / Line 22: @@
 Learning objectives
-| style="border:1pt solid #000000;padding:0.106cm;"| In this tutorial we tutorial we will learn some more '''sed '''commands.
+| style="border:1pt solid #000000;padding:0.106cm;"| In this tutorial we tutorial we will learn some more on '''sed '''commands.
 |-
@@ Line 35: / Line 37: @@
 '''Ubuntu Linux''' 12.04''' Operating System''' and
-'''GNU BASH''' version 4.2.24(1)
+'''GNU BASH''' version 4.2.24
 Please note,''' GNU bash''' version 4 or above is recommended to practice this tutorial.
@@ Line 60: / Line 62: @@
 | style="border:1pt solid #000000;padding:0.106cm;"| The major use of sed is substitution.
-ie replacing some pattern in the input with something else.
+Replacing some pattern in the input with something else.
 |-
 | style="border:1pt solid #000000;padding:0.106cm;"| Type
-'''cat seddemo.tx'''t
+'''cat seddemo.txt'''
@@ Line 72: / Line 74: @@
 <nowiki>[ </nowiki>Point to the fourth and sixth line ]
-| style="border:1pt solid #000000;padding:0.106cm;"| Lets first look at the original file '''seddemo.txt'''
+| style="border:1pt solid #000000;padding:0.106cm;"| Let's first look at the original file '''seddemo.txt'''
@@ Line 90: / Line 92: @@
 If you want to replace all occurrences of the '''‘kumar’''' with '''‘Roy’'''
-Type
+Type on the terminal
-'''sed''' space ''''s<nowiki>/[</nowiki>kK]umar/Roy/'''' space '''seddemo.txt'''
+'''sed''' space within single quote ''''s<nowiki>front slash / opening square bracket [</nowiki>k capital K closing square bracket ]umar slash/ Roy slash/'''' after the quotes space '''seddemo.txt'''
 '''Press Enter'''
@@ Line 98: / Line 100: @@
 |-
 | style="border:1pt solid #000000;padding:0.106cm;"| Show the output
@@ Line 117: / Line 113: @@
 This is because, by default, the first matched entry of any line is substituted.
-To substitute all the matched entries we need to use the flag''' g'''
+To substitute all the matched entries we need to use the flag ''' g''' option.
 |-
@@ Line 129: / Line 125: @@
 | style="border:1pt solid #000000;padding:0.106cm;"| Type
-'''sed''' space ''''s<nowiki>/[</nowiki>kK]umar/Roy/g'''' space '''seddemo.txt'''
+'''sed''' space within single quotes ''''s<nowiki>/[</nowiki>kK]umar/Roy/g'''' after the single quote space '''seddemo.txt'''
-And p'''ress Enter'''
+And '''press Enter'''
 Now, both entries of the fourth line are replaced.
@@ Line 147: / Line 143: @@
-'''sed -e 's/electronics/electrical/g’ '''
+'''sed -e  's/electronics/electrical/g’ '''
-'''-e ‘s/civil/metallurgy/g' seddemo.txt'''
+'''-e ‘s/civil/metallurgy/g' after the single quote space seddemo.txt'''
@@ Line 158: / Line 154: @@
 | style="border:1pt solid #000000;padding:0.106cm;"| Type:
-'''sed''' space '''-e ‘s/electronics/electrical/g’ -e''' '''‘s/civil/metallurgy/g’''' space '''seddemo.txt'''
+'''sed''' space '''-e space within single quotes ‘s/electronics/electrical/g’ -e''' '''‘s/civil/metallurgy/g’''' after the single quote space '''seddemo.txt'''
 And '''press Enter.'''
 |-
@@ Line 175: / Line 173: @@
 In such case we would need to type:
-'''sed''' space ''''/Anirban/s/computers/mathematics/g' '''space '''seddemo.txt'''
+'''sed''' space within single quotes ''''/Anirban/s/computers/mathematics/g' ''' after the single quotes space '''seddemo.txt'''
 Press '''Enter.'''
 |-
@@ Line 208: / Line 209: @@
 |-
 | style="border:1pt solid #000000;padding:0.106cm;"|
-| style="border:1pt solid #000000;padding:0.106cm;"| We can also use sed to add , or delete lines in the file.
+| style="border:1pt solid #000000;padding:0.106cm;"| We can also use sed to add  or delete lines in the file.
 Say we want to select those lines which do not have stream as '''electronics.'''
@@ Line 226: / Line 227: @@
-We would type:
+type:
-'''sed''' space (in single quotes) (front slash) /electronics/d space '''seddemo.txt''' space greater than sign space '''nonelectronics.txt'''
+'''sed''' space (within single quotes) (front slash) /electronics/d after the single quotes space '''seddemo.txt''' space greater than sign space '''nonelectronics.txt'''
 '''Press Enter'''
 |-
@@ Line 253: / Line 256: @@
 | style="border:1pt solid #000000;padding:0.106cm;"| Say at the start of the file we want to add a line Student Information.
-For that we have the i action.
+For that we have the '''i''' action.
 We need to type:
@@ Line 260: / Line 263: @@
 And '''press''' '''Enter.'''
 |-
@@ Line 268: / Line 273: @@
 Along with student information we also want to add academics in the next year.
 |-
@@ Line 280: / Line 286: @@
-sed space in single quotes 1i space Student Information'''\n'''2011' seddemo.txt
+sed space within single quotes 1i space Student Information'''\n'''2013' after the quotes space seddemo.txt
 '''Press Enter'''
-Notice '''\n '''between the string ‘Information’ and ‘2011’.
+Notice '''\n '''between the string ‘Information’ and ‘2013’.
-'''\n '''prints 2011 in the next line after ‘Student Information’
+'''\n '''prints 2013 in the next line after ‘Student Information’
 |-