Difference between revisions of "BASH/C2/Arithmetic-Comparison/English-timed"

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|-
 
|-
 
|  00:01   
 
|  00:01   
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|  Welcome to the spoken tutorial on '''Arithmetic Comparison in BASH'''
+
|  Welcome to the '''spoken tutorial''' on '''Arithmetic Comparison''' in '''BASH'''
  
 
|-
 
|-
 
|  00:07
 
|  00:07
−
| In this tutorial, we will learn
+
| In this tutorial, we will learn:
  
 
|-
 
|-
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|-
 
|-
 
|  00:10
 
|  00:10
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| '''not equal to'''
+
| * '''not equal to'''
 
   
 
   
 
|-
 
|-
 
|  00:12
 
|  00:12
−
| '''less than'''
+
|* '''less than'''
  
 
|-
 
|-
 
|  00:13
 
|  00:13
−
|'''less than equal to'''
+
|* '''less than equal to'''
  
 
|-
 
|-
 
|  00:15
 
|  00:15
−
| '''greater than''' and
+
|* '''greater than''' and
  
 
|-
 
|-
 
|  00:16
 
|  00:16
−
| '''greater than equal to''' commands
+
|* '''greater than equal to''' '''commands'''.
  
 
|-
 
|-
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|-
 
|-
 
| 00:23  
 
| 00:23  
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|  For this tutorial I am using  
+
|  For this tutorial, I am using:
  
 
|-
 
|-
 
| 00:26  
 
| 00:26  
−
| *'''Ubuntu Linux 12.04''' Operating System   
+
| * '''Ubuntu Linux 12.04''' Operating System   
  
 
|-
 
|-
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|-
 
|-
 
| 00:34  
 
| 00:34  
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| '''GNU Bash''' version '''4''' or above, is recommended for practice .
+
| '''GNU Bash''' version '''4''' or above is recommended for practice.
  
 
|-
 
|-
 
| 00:39
 
| 00:39
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| I already have a working example of arithmetic operators.  
+
| I already have a working example of '''arithmetic operators'''.  
  
 
|-
 
|-
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|-
 
|-
 
| 00:45
 
| 00:45
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| I have named the file '''example1.sh'''
+
| I have named the file '''example1.sh'''.
  
 
|-
 
|-
 
|  00:50   
 
|  00:50   
−
|  Open a file in any editor of your choice and type the code as shown.
+
|  Open a file in any '''editor''' of your choice and type the '''code''' as shown.
  
 
|-
 
|-
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|-
 
|-
 
| 01:06   
 
| 01:06   
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|  Let me explain the code.
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|  Let me explain the '''code'''.
  
 
|-
 
|-
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|-
 
|-
 
|  01:15
 
|  01:15
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| '''read''' command reads  one line of data from the '''standard input.'''
+
| '''read''' '''command''' reads  one line of data from the '''standard input.'''
  
 
|-
 
|-
 
|  01:20  
 
|  01:20  
−
|  This command is enclosed within '''backticks.'''
+
|  This '''command''' is enclosed within '''backticks.'''
  
 
|-
 
|-
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|-
 
|-
 
|  01:37  
 
|  01:37  
−
| '''wc''' will print newline, word, and byte counts, for each file.
+
| '''wc''' will print newline, word and byte counts for each file.
  
 
|-
 
|-
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|-
 
|-
 
|  01:49  
 
|  01:49  
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| * First the '''cat''' command will read the file.  
+
| First the '''cat''' command will read the file.  
  
 
|-
 
|-
 
|  01:53  
 
|  01:53  
−
| This is the input file.
+
| This is the '''input file'''
  
 
|-
 
|-
 
|  01:55  
 
|  01:55  
−
| * Which is then piped or sent to the '''wc''' command.
+
| which is then '''piped''' or sent to the '''wc''' command.
  
 
|-
 
|-
 
|  02:00  
 
|  02:00  
−
| * So, this statement counts the words in a given file.
+
| So, this '''statement''' counts the words in a given file.
  
 
|-
 
|-
 
|  02:05  
 
|  02:05  
−
| * The output is stored in variable '''x.'''
+
| The '''output''' is stored in '''variable  x.'''
  
 
|-
 
|-
 
|  02:08   
 
|  02:08   
−
|  This is the '''if statement'''  
+
|  This is the '''if''' statement.
  
 
|-
 
|-
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|-
 
|-
 
|  02:16   
 
|  02:16   
−
| If the condition is '''true,''' we will print a message '''“File has zero words”.'''
+
| If the condition is '''True,''' we will print a message '''“File has zero words”.'''
  
 
|-
 
|-
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|-
 
|-
 
|  02:35
 
|  02:35
−
| If the condition is '''true,''' we print '''“File has so-and-so words”'''.
+
| If the condition is '''True,''' we print '''“File has so-and-so words”'''.
  
 
|-
 
|-
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|-
 
|-
 
|  02:46
 
|  02:46
−
|  Save your '''program''' file.
+
|  '''Save''' your '''program''' file.
  
 
|-
 
|-
 
|  02:48
 
|  02:48
−
| let us execute our '''program.'''
+
| Let us '''execute''' our '''program.'''
  
 
|-
 
|-
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|-
 
|-
 
|  02:53
 
|  02:53
−
|  First let's create a file '''list.txt'''
+
|  First let's create a file '''list.txt'''.
  
 
|-
 
|-
 
|  02:57
 
|  02:57
−
| Type: '''touch list.txt'''
+
| Type: '''touch list.txt'''.
  
 
|-
 
|-
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| 03:04   
 
| 03:04   
 
| Type:
 
| Type:
−
'''echo within double quotes “How are you” after the double quotes greater than sign list.txt'''
+
'''echo within double quotes “How are you” after the double quotes greater than sign list.txt'''.
  
 
|-
 
|-
 
|  03:13  
 
|  03:13  
−
| Now let's make our script executable.
+
| Now let's make our '''script''' executable.
  
 
|-
 
|-
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|-
 
|-
 
| 03:21  
 
| 03:21  
−
| Now type '''dot slash example1.sh'''
+
| Now, type: '''dot slash example1.sh'''
  
 
|-
 
|-
 
| 03:26  
 
| 03:26  
−
| '''Enter filename ''' is displayed.
+
| '''Enter filename: ''' is displayed.
  
 
|-
 
|-
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|-
 
|-
 
| 03:31  
 
| 03:31  
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| The output is displayed as: '''list.txt has 3 words'''
+
| The output is displayed as: '''list.txt has 3 words'''.
  
 
|-
 
|-
 
|  03:36
 
|  03:36
−
|  Now let's learn about another set of operators.
+
|  Now let's learn about another set of '''operator'''s.
  
 
|-
 
|-
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|-
 
|-
 
| 03:46  
 
| 03:46  
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|  Please open a file in your editor and name it as '''example2.sh'''
+
|  Please open a file in your '''editor''' and name it as '''example2.sh'''
  
 
|-
 
|-
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|-
 
|-
 
|  04:00
 
|  04:00
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|  This program will check whether the word count is  
+
|  This program will check whether the word count is-
  
 
|-
 
|-
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|-
 
|-
 
| 04:07
 
| 04:07
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| * Between one and hundred Or above hundred.
+
| * Between one and hundred or above hundred.
  
 
|-
 
|-
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|-
 
|-
 
|  04:19
 
|  04:19
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|  Here, '''- (hyphen) c''' command is used to print the byte counts.
+
|  Here, '''- (hyphen) c''' command is used to print the '''byte''' counts.
  
 
|-
 
|-
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|-
 
|-
 
|  04:31
 
|  04:31
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| If the condition is '''true,''' then we print '''“No characters present in the file”.'''
+
| If the condition is '''True''' then we print '''“No characters present in the file”.'''
  
 
|-
 
|-
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|-
 
|-
 
|  04:45
 
|  04:45
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| First the '''- (hyphen) gt''' command checks whether word count is greater than one.
+
| First, the '''- (hyphen) gt''' command checks whether word count is greater than one.
  
 
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|-
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|-
 
|-
 
| 05:01
 
| 05:01
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| Here, in this '''if'''
+
| Here, in this '''if''':
−
* '''- (hyphen) ge '''command checks whether word count is greater than or equal to one  
+
* '''- (hyphen) ge '''command checks whether word count is greater than or equal to one and
  
 
|-
 
|-
 
| 05:09
 
| 05:09
−
| * and '''- (hyphen) le '''command checks whether word count is less than or equal to hundred.
+
|* '''- (hyphen) le '''command checks whether word count is less than or equal to hundred.
  
 
|-
 
|-
 
| 05:17
 
| 05:17
−
| If both the conditions are satisfied, then it prints:
+
| If both the conditions are satisfied then it prints:
  
 
|-
 
|-
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|-
 
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| 05:25
 
| 05:25
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| Please note that both conditions should be true to satisfy the entire '''if condition'''.  
+
| Please note that both '''conditions''' should be true to satisfy the entire '''if condition'''.  
  
 
|-
 
|-
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|  06:10   
 
|  06:10   
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| Let us execute the program.
+
| Let us '''execute''' the program.
  
 
|-
 
|-
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|-
 
|-
 
|  06:22
 
|  06:22
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|  Type '''list.txt '''
+
|  Type '''list.txt '''.
  
 
|-
 
|-
 
|  06:25  
 
|  06:25  
−
|  The output is displayed as '''list.txt''' has more than one character.
+
|  The '''output''' is displayed as '''list.txt has more than one character'''.
  
 
|-
 
|-
 
| 06:31  
 
| 06:31  
−
| '''Number of characters ranges between one and hundred '''''
+
| '''Number of characters ranges between one and hundred'''.
  
 
|-
 
|-
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|-
 
|-
 
| 06:51
 
| 06:51
−
|  In this tutorial we learnt,
+
|  In this tutorial we learnt:
 
* '''equal to'''
 
* '''equal to'''
 
* '''not equal to'''
 
* '''not equal to'''
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* '''less than equal to'''
 
* '''less than equal to'''
 
* '''greater than''' and
 
* '''greater than''' and
−
* '''greater than equal to''' commands
+
* '''greater than equal to''' '''commands'''.
  
 
|-
 
|-
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|-
 
|-
 
|  07:12
 
|  07:12
−
|  Watch the video available at the link shown below
+
|  Watch the video available at the link shown below.
  
 
|-
 
|-
 
|  07:15
 
|  07:15
−
| It summarises the Spoken Tutorial project  
+
| It summarizes the Spoken-Tutorial project.
  
 
|-
 
|-
 
|  07:18
 
|  07:18
−
| 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.
  
 
|-
 
|-
 
|  07:23   
 
|  07:23   
−
|  The Spoken Tutorial Project Team
+
|  The Spoken Tutorial Project team:
  
 
|-
 
|-
 
|  07:25   
 
|  07:25   
−
| Conducts workshops using spoken tutorials  
+
| Conducts workshops using spoken tutorials.
  
 
|-
 
|-
 
|  07:28
 
|  07:28
−
| Gives certificates to those who pass an online test  
+
| Gives certificates to those who pass an online test.
  
 
|-
 
|-
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|-
 
|-
 
|  07:40
 
|  07:40
−
|  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.
  
 
|-
 
|-
 
|  07:43
 
|  07:43
−
| 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.
  
 
|-
 
|-
 
|  07:51
 
|  07:51
−
| More information on this Mission is available at the link shown below.
+
| More information on this mission is available at the link shown below.
  
 
|-
 
|-
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|-
 
|-
 
|  08:02
 
|  08:02
−
| This is Ashwini Patil from IIT Bombay signing off.
+
| This is Ashwini Patil from IIT Bombay, signing off.
  
 
|-
 
|-

Revision as of 16:25, 3 July 2015

Title of script: Arithmetic comparison in BASH

Author: Ashwini Patil

Keywords: video tutorial, Bash shell, -eq, -ne, -gt, -ge, -lt, -le


Time Narration
00:01 Welcome to the spoken tutorial on Arithmetic Comparison in BASH
00:07 In this tutorial, we will learn:
00:09 * equal to
00:10 * not equal to
00:12 * less than
00:13 * less than equal to
00:15 * greater than and
00:16 * greater than equal to commands.
00:19 We will do this with the help of some examples.
00:23 For this tutorial, I am using:
00:26 * Ubuntu Linux 12.04 Operating System
00:30 *GNU BASH version 4.1.10
00:34 GNU Bash version 4 or above is recommended for practice.
00:39 I already have a working example of arithmetic operators.
00:43 Let me switch to it.
00:45 I have named the file example1.sh.
00:50 Open a file in any editor of your choice and type the code as shown.
00:56 You must be familiar how to do so, by now.
01:00 In this program, we will check whether a given file is empty or not.
01:06 Let me explain the code.
01:08 This is the shebang line.
01:10 First of all, “Enter filename” will be printed on the console.
01:15 read command reads one line of data from the standard input.
01:20 This command is enclosed within backticks.
01:24 Backtick has a very special meaning.
01:27 Everything you type between backtick is evaluated.
01:32 cat command will display the content of the file.
01:37 wc will print newline, word and byte counts for each file.
01:43 - (hyphen) w will print the word count.
01:47 What will happen is -
01:49 First the cat command will read the file.
01:53 This is the input file
01:55 which is then piped or sent to the wc command.
02:00 So, this statement counts the words in a given file.
02:05 The output is stored in variable x.
02:08 This is the if statement.
02:10 - (hyphen) eq command checks whether word count is equal to zero.
02:16 If the condition is True, we will print a message “File has zero words”.
02:22 fi is the end of first if condition.
02:26 Here is another if condition.
02:28 Here, - (hyphen) ne command checks whether word count is not equal to zero.
02:35 If the condition is True, we print “File has so-and-so words”.
02:40 $ (dollar) x will give the word count.
02:43 This is the end of 2nd if condition.
02:46 Save your program file.
02:48 Let us execute our program.
02:51 Open the terminal.
02:53 First let's create a file list.txt.
02:57 Type: touch list.txt.
03:01 Now, let's add a line in the file.
03:04 Type:

echo within double quotes “How are you” after the double quotes greater than sign list.txt.

03:13 Now let's make our script executable.
03:16 Type:

chmod plus x example1 dot sh

03:21 Now, type: dot slash example1.sh
03:26 Enter filename: is displayed.
03:28 Type:

list.txt

03:31 The output is displayed as: list.txt has 3 words.
03:36 Now let's learn about another set of operators.
03:40 Let me switch to another file.
03:43 This is example2.sh .
03:46 Please open a file in your editor and name it as example2.sh
03:52 Now type the code as shown here in your example2.sh file.
03:58 Let me explain the code.
04:00 This program will check whether the word count is-
04:04 * greater or less than one
04:07 * Between one and hundred or above hundred.
04:11 We have our shebang line here.
04:14 read statement takes input as filename from the user.
04:19 Here, - (hyphen) c command is used to print the byte counts.
04:24 In the if statement, - (hyphen) lt command checks whether word count is less than one.
04:31 If the condition is True then we print “No characters present in the file”.
04:37 fi ends the if condition.
04:40 The next if statement contains a nested if statement.
04:45 First, the - (hyphen) gt command checks whether word count is greater than one.
04:51 If yes, then this echo statement will be executed.
04:56 There are multiple conditions within this if statement.
05:01 Here, in this if:
  • - (hyphen) ge command checks whether word count is greater than or equal to one and
05:09 * - (hyphen) le command checks whether word count is less than or equal to hundred.
05:17 If both the conditions are satisfied then it prints:
05:21 Number of characters ranges between 1 and 100.
05:25 Please note that both conditions should be true to satisfy the entire if condition.
05:33 This is because we have included ampersand in-between both the conditions.
05:39 fi is the end of this if statement.
05:43 Then the next if statement will be evaluated.
05:47 - (hyphen) gt command checks whether word count is greater than hundred.
05:53 If the condition is satisfied, we print Number of characters is above hundred.
06:00 fi is the end of if statement.
06:04 Here we end the 2nd if statement.
06:07 Now come back to our terminal.
06:10 Let us execute the program.
06:13 chmod plus x example2 dot sh
06:18 dot slash example2 dot sh
06:22 Type list.txt .
06:25 The output is displayed as list.txt has more than one character.
06:31 Number of characters ranges between one and hundred.
06:36 Now, add or remove characters to the list.txt file.
06:40 Then observe which if statement gets executed.
06:46 This brings us to the end of this tutorial.
06:49 Let us summarize.
06:51 In this tutorial we learnt:
  • equal to
  • not equal to
  • less than
  • less than equal to
  • greater than and
  • greater than equal to commands.
07:03 As an assignment, write a program to demonstrate the use of not equal to operator.
07:09 Hint: - (hyphen) ne
07:12 Watch the video available at the link shown below.
07:15 It summarizes the Spoken-Tutorial project.
07:18 If you do not have good bandwidth, you can download and watch it.
07:23 The Spoken Tutorial Project team:
07:25 Conducts workshops using spoken tutorials.
07:28 Gives certificates to those who pass an online test.
07:32 For more details, please write to contact@spoken-tutorial.org
07:40 Spoken Tutorial project is a part of the Talk to a Teacher project.
07:43 It is supported by the National Mission on Education through ICT, MHRD, Government of India.
07:51 More information on this mission is available at the link shown below.
07:56 The script has been contributed by FOSSEE and spoken-tutorial team.
08:02 This is Ashwini Patil from IIT Bombay, signing off.
08:06 Thank you for joining.

Contributors and Content Editors

PoojaMoolya, Pratik kamble, Ranjana, Sandhya.np14

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