Difference between revisions of "Linux/C3/The-grep-command/English-timed"

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|00:01
 
|00:01
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|Welcome to the spoken tutorial on '''grep''' command
+
|Welcome to the spoken tutorial on '''grep''' command.
  
 
|-
 
|-
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|-
 
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|00:15
 
|00:15
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|*'''Ubuntu Linux''' 12.04''' Operating System'''  
+
|'''Ubuntu Linux''' 12.04''' Operating System'''  
  
 
|-
 
|-
 
|00:20
 
|00:20
−
| and *'''GNU BASH''' version 4.2.24
+
| and '''GNU BASH''' version 4.2.24.
  
 
|-
 
|-
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|-
 
|-
 
|00:32
 
|00:32
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|As prerequisitesYou should know basics of '''Linux terminal'''
+
|As prerequisites you should know basics of '''Linux terminal'''.
  
 
|-
 
|-
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|-
 
|-
 
|00:41
 
|00:41
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|First let us know about regular expressions.
+
|First let us know about '''regular expressions'''.
  
 
|-
 
|-
 
|00:45
 
|00:45
−
|*Regular expressions are pattern matching techniques.
+
| Regular expressions are pattern matching techniques
  
 
|-
 
|-
 
|00:50
 
|00:50
−
|*When we have to find out whether a pattern exist in a line, paragraph or a file.
+
| when we have to find out whether a pattern exist in a line, paragraph or a file.
  
 
|-
 
|-
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|-
 
|-
 
| 01:02
 
| 01:02
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|  Or To find a keyword in a paragraph or a line, we use '''grep command'''
+
|  or to find a keyword in a paragraph or a line, we use '''grep command'''.Let us move on to '''grep'''.
−
  Let us move on to '''grep'''.
+
  
 
|-
 
|-
 
|01:11
 
|01:11
−
|'''grep''' searches for one or more patterns in one or more line, paragraph or a file.
+
|'''grep''' searches for one or more patterns in one or more lines, paragraphs or a file.
  
 
|-
 
|-
 
|01:17
 
|01:17
−
|If filename is not mentioned,''' grep''' search for the patterns in the standard input.
+
|If file name is not mentioned, '''grep''' searches for the patterns in the standard input.
  
 
|-
 
|-
 
|01:23
 
|01:23
−
|If filename is missing, '''grep''' searches for the patterns in the standard input.
+
|If file name is missing, '''grep''' searches for the patterns in the standard input.
  
 
|-
 
|-
 
|01:30
 
|01:30
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|I will demonstrate usage of '''grep''' using a demo file called '''grepdemo.txt'''
+
|I will demonstrate usage of '''grep''' using a demo file called '''grepdemo.txt'''.
  
 
|-
 
|-
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|-
 
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|01:44
 
|01:44
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|Each entry has 6 fields roll number, name, stream, marks, and stipend amount.  
+
|Each entry has 6 fields: roll number, name, stream, marks, and stipend amount.  
  
 
|-
 
|-
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|01:56
 
|01:56
 
|Let us see how '''grep''' works.
 
|Let us see how '''grep''' works.
−
 
  
 
|-
 
|-
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|-
 
|-
 
|02:10
 
|02:10
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|So press '''CTRL + ALT and T''' keys simultaneously on your keyboard.
+
|So press '''Ctrl + Alt''' and '''T''' keys simultaneously on your keyboard.
  
 
|-
 
|-
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|-
 
|-
 
|02:18
 
|02:18
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|'''grep space (within double quotes) computers after the double quotes space  grepdemo .txt'''
+
|'''grep space''' (within double quotes) '''computers''' after the double quotes '''space  grepdemo .txt'''
  
 
|-
 
|-
 
|02:27
 
|02:27
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|Press Enter
+
|Press Enter.This would enlist those entries where stream is '''computers'''.
−
 
+
−
|-
+
−
|02:28
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−
|This would enlist those entries where stream is '''computers'''.
+
  
 
|-
 
|-
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|-
 
|-
 
|02:45
 
|02:45
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|Why this is so?
+
|Why this is so? This is because '''grep''' searched for the pattern “computers” with small '''c'''.
−
 
+
−
 
+
−
|-
+
−
|02:46
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−
|This is because '''grep''' searched for the pattern '''“computers”''' with small '''c'''  
+
  
 
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|-
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|-
 
|-
 
|03:00
 
|03:00
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|To make it '''case''' insensitive, we need to use the '''minus i ''' option with '''grep'''.
+
|To make it '''case insensitive''', we need to use the '''minus i ''' (-i) option with '''grep'''.
  
 
|-
 
|-
 
|03:06
 
|03:06
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|From back to our terminal Now Type:
+
|Come back to our terminal, now type:'''grep space (minus) i space''' (within double quotes) '''“computers”''' after the double quotes '''space grepdemo.txt'''
−
'''grep space (minus) i space (within double quotes) “'''computers”''' after the '''double quotes space grepdemo.txt'''
+
  
 
|-
 
|-
 
|03:20
 
|03:20
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|Press ''' Enter.'''
+
|Press '''Enter'''. This will now enlist all the four entries.
−
 
+
−
|-
+
−
|03:21
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−
|This will now enlist all the four entries.
+
  
 
|-
 
|-
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|-
 
|-
 
|03:48
 
|03:48
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|We can also store this result in another file
+
|We can also store this result in another file.
−
 
+
  
 
|-
 
|-
 
|03:52
 
|03:52
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|For this type:
+
|For this type: '''grep space minus iv space''' within double quotes '''pass''' after the double quotes '''space grepdemo.txt space greater than sign space notpass.txt '''
−
'''grep space minus iv space''' Within double quotes '''pass after the double quotes space grepdemo.txt space greater than sign space notpass.txt '''
+
  
 
|-
 
|-
 
|04:11
 
|04:11
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|Press '''Enter.'''
+
|Press '''Enter.''' To see the content of file, type: '''cat space notpass.txt '''
−
 
+
−
|-
+
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|04:12
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−
|To see the content of file, type:
+
−
'''cat space notpass.txt '''
+
  
 
|-
 
|-
 
|04:20
 
|04:20
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|Press '''Enter'''.
+
|Press '''Enter'''.The output is displayed.
−
 
+
−
|-
+
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|04:21
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−
|The output is displayed.
+
  
 
|-
 
|-
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|-
 
|-
 
|04:37
 
|04:37
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|And Press '''Enter.'''
+
|And Press '''Enter.'''This is different.
−
 
+
−
|-
+
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|04:38
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−
|This is different.
+
 
    
 
    
 
|-
 
|-
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|-
 
|-
 
|04:54
 
|04:54
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|Let us clear the '''prompt'''.  
+
|Let us clear the prompt.  
  
 
|-
 
|-
 
|04:58
 
|04:58
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|  Now type "'''grep space -in space within double quote "fail" after the double quotes space grepdemo.txt'''
+
|  Now type '''grep space -in space''' within double quote "fail" after the double quotes '''space grepdemo.txt'''.
  
 
|-
 
|-
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|-
 
|-
 
|05:18
 
|05:18
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|We may have multiword patterns as well.  
+
|We may have multi-word patterns as well.  
  
 
|-
 
|-
 
|05:21
 
|05:21
−
|But the entire pattern must be within '''quotes'''.
+
|But the entire pattern must be within quotes.
  
 
|-
 
|-
 
|05:24
 
|05:24
−
|So type: '''grep space minus i space'''within double quotes '''ankit space saraf after the double quotes space grepdemo.txt '''
+
|So, type: '''grep space minus i space'''within double quotes '''ankit space saraf''' after the double quotes '''space grepdemo.txt '''
  
 
|-
 
|-
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|05:44
 
|05:44
 
|We can also find patterns in multiple files.
 
|We can also find patterns in multiple files.
−
 
−
 
−
 
−
 
−
 
  
 
|-
 
|-
 
|05:48
 
|05:48
−
|For this Type:
+
|For this, type: '''grep space minus i space''' within double quotes '''fail''' after double quotes space '''grepdemo.txt space notpass.txt'''  
−
'''grep space minus i space''' within double quotes '''fail after double quotes space grepdemo.txt space notpass.txt'''  
+
−
 
+
  
 
|-
 
|-
 
|06:03
 
|06:03
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|'''Press Enter'''.
+
|'''Press Enter'''. The output is displayed.
−
 
+
−
|-
+
−
|06:04
+
−
|The output is displayed.
+
−
 
+
  
 
|-
 
|-
 
|06:07
 
|06:07
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|With multiple files, '''grep''' will write the name of the file in which the entry was found.'''grepdemo.txt''' and '''notpass.txt'''
+
|With multiple files, '''grep''' will write the name of the file in which the entry was found. '''grepdemo.txt''' and '''notpass.txt'''.
  
 
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|06:26
 
|06:26
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|Suppose we may only want to know the '''number of matches '''or '''count''' .
+
|Suppose, we may only want to know the '''number of matches '''or '''count'''.
  
 
|-
 
|-
 
|06:31
 
|06:31
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|For that, we have the '''minus c''' option
+
|For that, we have the '''minus c''' option.
−
 
+
  
 
|-
 
|-
 
|06:35
 
|06:35
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| So Type: '''grep space minus c space'''within double quotes '''Fail  with a capital F after the quotes space grepdemo.txt'''
+
| So, type: '''grep space minus c space'''within double quotes '''Fail''' with a capital F after the quotes '''space grepdemo.txt'''
  
 
|-
 
|-
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|06:55
 
|06:55
 
|This brings us to the end of this tutorial.
 
|This brings us to the end of this tutorial.
−
 
  
 
|-
 
|-
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|-
 
|-
 
| 07:01
 
| 07:01
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| In this tutorial we learnt,
+
| In this tutorial we learnt:
  
 
|-
 
|-
 
|07:03
 
|07:03
−
|*To see the content of a file
+
|To see the contents of a file eg. '''cat filename'''
−
**eg. '''cat filename'''
+
 
 
|-
 
|-
 
|07:07
 
|07:07
−
|*To list the entries of a particular stream
+
| To list the entries of a particular stream eg. '''grep “computers” grepdemo.txt'''
−
**eg. '''grep “computers” grepdemo.txt'''
+
  
 
|-
 
|-
 
|07:14
 
|07:14
−
|*To ignore cases
+
|To ignore cases eg. '''grep -i “computers” grepdemo.txt'''
−
**eg. '''grep -i “computers” grepdemo.txt'''
+
  
 
|-
 
|-
 
|07:21
 
|07:21
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|*Lines that do not match the pattern
+
| Lines that do not match the pattern eg. '''grep -iv “pass” grepdemo.txt'''
−
**eg. '''grep -iv “pass” grepdemo.txt'''
+
  
 
|-
 
|-
 
|07:30
 
|07:30
−
|*To list the line numbers with the entries
+
|To list the line numbers with the entries eg.''' grep -in “fail” grepdemo.txt'''
−
**eg.''' grep -in “fail” grepdemo.txt'''
+
  
 
|-
 
|-
 
|07:38
 
|07:38
−
|*To store the result in another file
+
|To store the result in another file eg. '''grep -iv “pass” grepdemo.txt > notpass.txt'''
−
**eg. '''grep -iv “pass” grepdemo.txt > notpass.txt'''
+
  
 
|-
 
|-
 
|07:50
 
|07:50
−
|And*To know the count
+
|And To know the count eg.''' grep -c “Fail” grepdemo.txt'''.
−
**eg.''' grep -c “Fail” grepdemo.txt'''
+
  
 
|-
 
|-
 
|07:57
 
|07:57
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|As an assignment,
+
|As an assignment,Explore some other commands like '''-E, + and ?'''.
−
 
+
−
|-
+
−
|07:58
+
−
|Explore some other commands like '''-E, + and ?'''
+
−
 
+
  
 
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|08:06
 
|08:06
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|It summarises the Spoken Tutorial project.
+
|It summarizes the Spoken Tutorial project.
  
 
|-
 
|-
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|08:14
 
|08:14
−
|The Spoken Tutorial Project Team
+
|The Spoken Tutorial Project Team:
  
 
|-
 
|-
 
|08:16
 
|08:16
−
|*Conducts workshops using spoken tutorials
+
|Conducts workshops using spoken tutorials
  
 
|-
 
|-
 
|08:19
 
|08:19
−
|*Gives certificates to those who pass an online test
+
|Gives certificates to those who pass an online test.
  
 
|-
 
|-
 
|08:23
 
|08:23
−
|For more details, please write to
+
|For more details, please write to'''contact@spoken-tutorial.org'''
−
'''contact@spoken-tutorial.org'''
+
  
 
|-
 
|-
 
|08:30
 
|08:30
−
|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.
  
 
|-
 
|-
 
|08:33
 
|08:33
−
|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.
  
 
|-
 
|-
 
|08:40
 
|08:40
−
|More information on this Mission is available at: http://spoken-tutorial.org\NMEICT-Intro
+
|More information on this Mission is available at: http://spoken-tutorial.org\NMEICT-Intro.
  
 
|-
 
|-
 
|08:45
 
|08:45
−
|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 11:04, 17 October 2017

Time Narration
00:01 Welcome to the spoken tutorial on grep command.
00:05 In this tutorial we will learn grep command.
00:09 We will do this with the help of some examples.
00:11 To record this tutorial, I am using
00:15 Ubuntu Linux 12.04 Operating System
00:20 and GNU BASH version 4.2.24.
00:24 Please note, GNU bash version 4 or above is recommended to practice this tutorial.
00:32 As prerequisites you should know basics of Linux terminal.
00:36 For relevant tutorials, please visit our website which is as shown.
00:41 First let us know about regular expressions.
00:45 Regular expressions are pattern matching techniques
00:50 when we have to find out whether a pattern exist in a line, paragraph or a file.
00:56 For ex. If you want to search a phone number in the telephone directory
01:02 or to find a keyword in a paragraph or a line, we use grep command.Let us move on to grep.
01:11 grep searches for one or more patterns in one or more lines, paragraphs or a file.
01:17 If file name is not mentioned, grep searches for the patterns in the standard input.
01:23 If file name is missing, grep searches for the patterns in the standard input.
01:30 I will demonstrate usage of grep using a demo file called grepdemo.txt.
01:37 Let us see the content of the file.
01:40 This is a file that has 13 entries.
01:44 Each entry has 6 fields: roll number, name, stream, marks, and stipend amount.
01:52 The fields are separated by a bar, which is called a delimiter.
01:56 Let us see how grep works.
02:00 Say we want to use grep command, to see who are the students in the computers stream.
02:07 For this we have to open the terminal.
02:10 So press Ctrl + Alt and T keys simultaneously on your keyboard.
02:16 Now type on the terminal:
02:18 grep space (within double quotes) computers after the double quotes space grepdemo .txt
02:27 Press Enter.This would enlist those entries where stream is computers.
02:33 Now compare the result with the original file.
02:37 Come back to our text editor.
02:40 We see that the entry for Zubin is not enlisted.
02:45 Why this is so? This is because grep searched for the pattern “computers” with small c.
02:52 While for Zubin, the stream is “Computers” with a capital C.
02:57 The pattern matching is case sensitive.
03:00 To make it case insensitive, we need to use the minus i (-i) option with grep.
03:06 Come back to our terminal, now type:grep space (minus) i space (within double quotes) “computers” after the double quotes space grepdemo.txt
03:20 Press Enter. This will now enlist all the four entries.
03:25 So we saw, grep enlists only those lines of files that match a given pattern.
03:32 We may do the reverse.
03:34 It is possible to make grep enlist only those lines that do not match the pattern.
03:40 For that we have the minus v option.
03:43 Say, we want to enlist those entries of students who have not passed.
03:48 We can also store this result in another file.
03:52 For this type: grep space minus iv space within double quotes pass after the double quotes space grepdemo.txt space greater than sign space notpass.txt
04:11 Press Enter. To see the content of file, type: cat space notpass.txt
04:20 Press Enter.The output is displayed.
04:24 Now at the prompt type:
04:26 grep space minus i space' within double quotes fail after the double quotes space grepdemo.txt
04:37 And Press Enter.This is different.
04:41 This will include those students who are failed but their result is incomplete.
04:46 If we want to see the line number in the file at which the enlisted entries are, we have the minus n option
04:54 Let us clear the prompt.
04:58 Now type grep space -in space within double quote "fail" after the double quotes space grepdemo.txt.
05:09 Press Enter.
05:11 The line number is displayed.
05:15 The patterns so far have been of single word.
05:18 We may have multi-word patterns as well.
05:21 But the entire pattern must be within quotes.
05:24 So, type: grep space minus i spacewithin double quotes ankit space saraf after the double quotes space grepdemo.txt
05:38 Press Enter.
05:40 We see that Ankit Saraf's record is displayed.
05:44 We can also find patterns in multiple files.
05:48 For this, type: grep space minus i space within double quotes fail after double quotes space grepdemo.txt space notpass.txt
06:03 Press Enter. The output is displayed.
06:07 With multiple files, grep will write the name of the file in which the entry was found. grepdemo.txt and notpass.txt.
06:18 These are the records from notpass.txt file and these are the records from grepdemo.txt file.
06:26 Suppose, we may only want to know the number of matches or count.
06:31 For that, we have the minus c option.
06:35 So, type: grep space minus c spacewithin double quotes Fail with a capital F after the quotes space grepdemo.txt
06:48 Press Enter.
06:50 This will give us the count of number of lines matched.
06:55 This brings us to the end of this tutorial.
06:59 Let us summarize.
07:01 In this tutorial we learnt:
07:03 To see the contents of a file eg. cat filename
07:07 To list the entries of a particular stream eg. grep “computers” grepdemo.txt
07:14 To ignore cases eg. grep -i “computers” grepdemo.txt
07:21 Lines that do not match the pattern eg. grep -iv “pass” grepdemo.txt
07:30 To list the line numbers with the entries eg. grep -in “fail” grepdemo.txt
07:38 To store the result in another file eg. grep -iv “pass” grepdemo.txt > notpass.txt
07:50 And To know the count eg. grep -c “Fail” grepdemo.txt.
07:57 As an assignment,Explore some other commands like -E, + and ?.
08:04 Watch the video available at the link shown below.
08:06 It summarizes the Spoken Tutorial project.
08:10 If you do not have good bandwidth, you can download and watch it.
08:14 The Spoken Tutorial Project Team:
08:16 Conducts workshops using spoken tutorials
08:19 Gives certificates to those who pass an online test.
08:23 For more details, please write tocontact@spoken-tutorial.org
08:30 Spoken Tutorial Project is a part of the Talk to a Teacher project.
08:33 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
08:40 More information on this Mission is available at: http://spoken-tutorial.org\NMEICT-Intro.
08:45 This is Ashwini Patil from IIT Bombay, signing off. Thank you for joining.

Contributors and Content Editors

Madhurig, PoojaMoolya, Pratik kamble, Sandhya.np14

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