PERL/C3/Including-files-or-modules/English-timed - Revision history

PoojaMoolya at 12:53, 20 February 2017

2017-02-20T12:53:07Z

Sandhya.np14 at 07:05, 2 March 2016

2016-03-02T07:05:44Z

Sandhya.np14 at 12:02, 18 February 2016

2016-02-18T12:02:59Z

Sandhya.np14 at 07:33, 18 February 2016

2016-02-18T07:33:10Z

Sandhya.np14 at 12:38, 17 February 2016

2016-02-17T12:38:46Z

Sandhya.np14 at 07:39, 17 February 2016

2016-02-17T07:39:25Z

Sandhya.np14 at 06:35, 29 December 2015

2015-12-29T06:35:24Z

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PoojaMoolya at 10:23, 26 November 2015

2015-11-26T10:23:56Z

PoojaMoolya: Created page with "{| Border = 1 |'''Time ''' |'''Narration''' |- |00:01 |Welcome to the''' Spoken Tutorial''' on''' Including files or modules in a PERL program''' |- |00:08 |In this tutorial..."

2015-11-24T10:22:31Z

Created page with "{| Border = 1 |'''Time ''' |'''Narration''' |- |00:01 |Welcome to the''' Spoken Tutorial''' on''' Including files or modules in a PERL program''' |- |00:08 |In this tutorial..."

New page

{| Border = 1
|'''Time '''
|'''Narration'''

|-
|00:01
|Welcome to the''' Spoken Tutorial''' on''' Including files or modules in a PERL program'''

|-
|00:08
|In this tutorial we will learn to use
* '''do'''
* '''use '''and
* '''require'''
methods in''' PERL''' programming.

|-
|00:16
|For this tutorial, I am using
* '''Ubuntu Linux 12.04''' operating system
* '''Perl 5.14.2 and'''
* '''gedit''' Text Editor

|-
|00:28
|You can use any text editor of your choice.

|-
|00:32
| To follow this tutorial, you should have working knowledge of''' Perl''' programming.

|-
|00:37
|If not, then go through the relevant''' Perl''' spoken tutorials on the''' spoken tutorial''' website.

|-
|00:44
|Do Method: These are simple ways to include the source code from other files into the current script file.

|-
|00:53
|Let us understand how to use '''do()''' method.

|-
|00:57
|Open a new file in your text editor and name it as '''datetime.pl'''

|-
|01:03
|In the''' datetime dot pl''' file, type the following code as displayed on the screen.

|-
|01:09
|From here onwards, remember to press the '''Enter key '''after every command on the '''terminal'''.

|-
|01:15
|Let us understand the code now.

|-
|01:18
|The current date and time is stored in a variable''' dollar datestring.'''

|-
|01:23
|Here, I have a''' function''' by name''' msgThanks,''' which returns a “'''Thank you'''” message.

|-
|01:31
|Now, press''' Ctrl+S''' to save the file.

|-
|01:35
|Next let us look at another '''Perl '''program which will make use of this file''' datetime dot pl'''

|-
|01:43
|Open a new file in your text editor and name it as '''main dot pl'''

|-
|01:49
|In the''' main dot pl''' file, type the following code as displayed on the screen.

|-
|01:55
|Let me explain the code now.

|-
|01:58
|Here, the first line prints the welcome message.

|-
|02:03
|'''do()''' method is called with the filename from where we want to use the code.

|-
|02:09
|Current date and time is stored in the''' $datestring''' variable of''' datetime dot pl file.'''

|-
|02:16
|And at the end, we call the''' msgThanks()''' function from the same file.

|-
|02:21
|Now, press''' Ctrl+S''' to save the file.

|-
|02:25
|Let us execute the program.

|-
|02:27
|Switch back to the''' terminal''' and type '''perl main dot pl '''and press''' Enter'''

|-
|02:34
|Observe the output on the '''terminal.'''

|-
|02:37
|Next we will learn how to use''' require method''' and''' use method''' in a '''Perl''' program.

|-
|02:44
|These '''methods''' are used - when we have collections of '''subroutines ''' that can be used in multiple '''Perl '''programs.

|-
|02:52
| '''use''' method is used only for the '''modules'''.

|-
|02:56
| It is verified at the time of '''compilation'''

|-
|02:59
|There is no need to give the '''file extension'''

|-
| 03:03
| '''require '''method is used for both '''Perl''' '''programs '''and '''modules'''

|-
|03:08
| It is verified at the '''run time'''

|-
|03:10
| One needs to give the '''file extension'''.

|-
|03:14
| The syntax of '''use method '''is '''use module name semicolon'''

|-
|03:20
| '''Perl modules''' are the files which end with '''.pm''' extension.

|-
|03:25
| Reusability of code is implemented through '''modules'''.

|-
|03:30
| These are similar to libraries in other languages.

|-
|03:35
|Now I will show a simple program with the''' use method''' to include a''' module''' in '''Perl''' code.

|-
|03:43
|Open a new file In your '''text editor '''and name it as '''sum dot pm.'''

|-
|03:49
|In the''' sum dot pm''' file, type the following code as displayed on the screen.

|-
|03:55
|Here, I have a simple '''function''' which will calculate the sum of a given set of numbers.

|-
|04:01
|Now, press''' Ctrl+S''' to save the file

|-
|04:05
|We will write another '''Perl''' script where we’ll use this''' sum.pm''' file.

|-
| 04:11
| Let me open the sample program app dot pl file which I have saved already

|-
|04:17
|In the''' app dot pl''' file, type the following code as displayed on the screen.

|-
|04:22
|Let me explain the code now.

|-
|04:25
|The first line shows the use method with the '''module '''name.

|-
|04:29
|In our case, the '''module '''name is '''sum'''.

|-
|04:33
|We are passing 1,7,5,4,9 as '''input parameters '''to the function '''total''' in '''sum dot pm '''file.

|-
|04:44
|Again, in the next line, we are passing 1 to 10 as '''input parameters '''to the same '''function'''.

|-
|04:52
|Now, press''' Ctrl+S''' to save the file.

|-
|04:56
|Let us execute the program.

|-
|04:59
|Switch back to the''' terminal''' and type '''perl app dot pl''' and Press '''Enter'''

|-
|05:06
|Observe the output displayed on the '''terminal.'''

|-
|05:10
|Let us see few more options in''' use method'''. Switch back to''' sum.pm '''in the '''text editor.'''

|-
|05:18
|At the beginning of the source code, add the lines '''use strict semicolon''' '''use warnings semicolon'''

|-
|05:27
|'''use strict''' and''' use warnings''' are '''compiler flags '''that instruct''' Perl''' to behave in a stricter way.

|-
|05:35
|These are used to avoid common programming mistakes.

|-
|05:39
|'''use strict''' forces the user to declare all the '''variables''' used in the program.

|-
|05:45
|If there are '''errors''', '''use strict''' will abort the execution.

|-
|05:50
|'''use warnings''' will only provide warnings but continue with the execution.

|-
|05:56
|Assume that we forgot to declare the '''variable $sum '''as''' my'''.

|-
|06:02
|Let us now see how the same program is executed.

|-
|06:06
|Press''' Ctrl+S''' to save the file.

|-
|06:09
|Switch back to the''' terminal''' and type '''perl app dot pl'''

|-
|06:15
|We can see that the program is aborted without executing the result.

|-
|06:21
|The first set of lines displayed on the '''terminal''' are '''error messages''' generated by “'''use strict'''”.

|-
|06:29
|The last two are the abort messages.

|-
|06:32
|So, this is how the '''use method '''options work.

|-
|06:36
|Next let us see a '''Perl program '''where we use the''' require''' method.

|-
|06:41
|Let me open the sample program''' commonfunctions.pl''' which I have already saved.

|-
|06:48
|Type the following code as displayed on the screen in your '''commonfunctions dot pl''' file.
Let us understand the code now.

|-
|06:57
|Here we can see a collection of commonly used '''functions'''.

|-
|07:01
|The first '''function square()''' returns the square of a number.

|-
|07:06
|The second '''function square underscore root()''' returns the square root of a given number.

|-
|07:12
|Next '''function random underscore number()''' generates a random number.

|-
|07:18
|The last '''function random underscore range()''' generates a random number between a lower range and upper range of numbers.

|-
|07:26
|Note that we need the '''1 semicolon''' at the end of the file.

|-
|07:31
|This is because''' Perl''' needs the last expression in the file to return a '''true value'''.

|-
|07:37
|Now, press''' Ctrl+S''' to save the file.

|-
|07:41
|Next we will write a''' Perl''' program in which we’ll call these '''subroutines '''using''' require''' method.

|-
|07:48
|Let me open the sample program''' callprogram dot pl''' which I have already saved.

|-
|07:54
|Type the following code as displayed on the screen in your file. Let me explain the code now.

|-
|08:02
|'''require''' reads the''' commonfunctions.pl''' file containing '''Perl''' code and compiles it.

|-
|08:09
|This program gives 4 options to the user. The user has to choose one option at a time.

|-
|08:17
|One is to find the square of a number.

|-
|08:20
|Two is for square root of a number.

|-
|08:23
|Three is for a random number in the given range. Four is to quit the program.

|-
|08:29
|If option one is typed, it will ask the user to enter a number.

|-
|08:34
|The value is stored in''' $number.''' This is passed to the function''' square''' in''' commonfunctions.pl''' file.

|-
|08:44
|The '''function''' returns the square of a number.

|-
|08:47'
|The '''print statement''' prints the square of a number as output.

|-
|08:52
|If option two is typed, the square root of a number is displayed as output.

|-
|08:58
|The execution is followed as explained in the previous '''function square'''.

|-
|09:03
|If option three is typed, a random number is displayed as output in the given range.

|-
|09:09
|Else if option is four, the program exits. If any option other than the ones specified is given, the '''print statement '''says “Incorrect option”.

|-
|09:20
|Note that in this program we have called only three functions out of four from '''commonfunctions.pl'''.
|-
|09:28
|Now, press''' Ctrl+S''' to save the file

|-
|09:31
|Let us execute the program.

|-
|09:34
|Switch back to the''' terminal''' and type '''perl callprogram dot pl'''

|-
|09:41
|Observe the output

|-
|09:44
|I'll execute the program once again with a different option.

|-
|09:49
|Type''' perl callprogram dot pl'''

|-
|09:53
|Now, '''Enter the Option''' as 3.

|-
|09:56
|'''Enter a lower range''' as 50.

|-
|09:59
|'''Enter a upper range''' as 99.

|-
|10:02
|We can see the random number is generated in the given range of numbers.

|-
|10:08
|Try other options on your own.

|-
|10:11
|This brings us to the end of this tutorial. Let us summarise.

|-
|10:16
|In this tutorial we learnt to use
* '''do'''
* '''use'''
* '''require methods '''in''' PERL''' programming.

|-
|10:24
|'''Note''': "'''use Module'''" is recommended over "'''require Module'''", because it determines '''module availability '''at '''compile time'''.
|-
|10:33
|Here is an assignment for you.
Write a''' Perl''' program''' reminder.pl''' where you will write a letter to the participants.

|-
|10:41
|Prompt the user to enter''' To''' and''' From''' name

|-
|10:45
|Call the subroutines from''' Letter.pm''' using '''‘use’''' method.

|-
|10:50
| Write the below functions in''' Letter.pm '''file.

|-
|10:54
| LetterDate() function returns the current date and time

|-
|10:58
|To() function returns the name of the participants

|-
|11:02
| From() function returns the sender name

|-
|11:05
| Lettermsg() function returns the content of the letter

|-
|11:09
|Thanksmsg() function returns thanks and regards.

|-
|11:13
|The output should be displayed as shown here.

|-
| 11:20
|The video at the following link summarize the spoken tutotial project. Please download and watch it

|-
|11:27
|The''' Spoken Tutorial Project''' Team

* conducts workshops using spoken tutorials and
* gives certificates on passing online tests.

|-
|11:36
|For more details, please write to us.

|-
|11:40
|Spoken Tutorial project is funded by NMEICT, MHRD, Government of India.

More information on this mission is available at this link.

|-
|11:51
|This is Nirmala Venkat from IIT Bombay, signing off. Thanks for watching.

|}

@@ Line 353: / Line 353: @@
 |-
 |08:02
-|'''require''' reads the''' commonfunctions dot pl''' file containing Perl code and compiles it.
+|'''require''' reads the''' commonfunctions dot pl''' file, containing Perl code, and compiles it.
 |-

@@ Line 10: / Line 10: @@
 |00:08
 |In this tutorial, we will learn to use:
-* '''do'''
+'''do'''
-* '''use '''and
+'''use '''and
-* '''require'''
+'''require'''
 '''method'''s in PERL programming.
@@ Line 18: / Line 18: @@
 |00:16
 |For this tutorial, I am using:
-* '''Ubuntu Linux 12.04''' operating system
+'''Ubuntu Linux 12.04''' operating system
-* '''Perl 5.14.2''' and
+'''Perl 5.14.2''' and
-* '''gedit''' Text Editor.
+'''gedit''' Text Editor.
 |-
@@ Line 304: / Line 304: @@
 |-
 |06:48
-|Type the following code as displayed on the screen in your '''commonfunctions dot pl''' file.
+|Type the following code as displayed on the screen in your '''commonfunctions dot pl''' file. Let us understand the code now.
 Let us understand the code now.
 |-
@@ Line 457: / Line 456: @@
 |10:16
 |In this tutorial, we learnt to use:
-* '''do'''
+'''do'''
-* '''use'''
+'''use'''
-* '''require methods '''in PERL programming.
+'''require methods '''in PERL programming.
 |-
@@ Line 511: / Line 510: @@
 |11:27
 |The''' Spoken Tutorial Project''' team:
-* conducts workshops using spoken tutorials and
+conducts workshops using spoken tutorials and
-* gives certificates on passing online tests.
+gives certificates on passing online tests.
 |-

@@ Line 313: / Line 313: @@
 |-
 |07:01
-|The first function '''square()''', returns the square of a number.
+|The first function, '''square()''', returns the square of a number.
 |-
@@ Line 321: / Line 321: @@
 |-
 |07:12
-|Next function '''random underscore number()''', generates a random number.
+|Next function, '''random underscore number()''', generates a random number.
 |-

@@ Line 204: / Line 204: @@
 |-
 |04:25
-|The first line shows the '''use method''' with the module name.
+|The first line shows the '''use''' method with the module name.
 |-
@@ Line 212: / Line 212: @@
 |-
 |04:33
-|We are passing 1, 7, 5, 4,9 as '''input parameters '''to the function '''total()''' in '''sum dot pm '''file.
+|We are passing 1, 7, 5, 4, 9 as '''input parameters '''to the function '''total()''' in '''sum dot pm '''file.
 |-
@@ Line 329: / Line 329: @@
 |-
 |07:26
-|Note that we need the '''1 semicolon''' at the end of the file.
+|Note that we need the '''1 semicolon''' (1;) at the end of the file.
 |-
@@ Line 341: / Line 341: @@
 |-
 |07:41
-|Next, we will write a Perl program in which we’ll call these '''subroutines '''using''' require''' method.
+|Next, we will write a Perl program in which we’ll '''call''' these '''subroutines '''using "require" method.
 |-
@@ Line 377: / Line 377: @@
 |-
 |08:34
-|The value is stored in''' $number.''' The value is  passed to the function  '''square()''' in''' commonfunctions dot pl''' file.
+|The value is stored in''' $number.''' The value is passed to the function  '''square()''' in''' commonfunctions dot pl''' file.
 |-

@@ Line 120: / Line 120: @@
 |-
 |02:37
-|Next, we will learn how to use''' require() method''' and''' use() method''' in a '''Perl''' program.
+|Next, we will learn how to use''' require()''' method and''' use()''' method in a '''Perl''' program.
 |-
@@ Line 140: / Line 140: @@
 |-
 | 03:03
-|  '''require() method''' is used for both '''Perl program'''s and '''modules'''.
+|  '''require()''' method is used for both Perl programs and '''modules'''.
 |-
 |03:08
-| It is verified at the '''run time'''.
+| It is verified at the '''run''' time.
 |-
 |03:10
-| One needs to give the file extension.
+| One needs to give the '''file extension'''.
 |-
 |03:14
-| The syntax of '''use() method '''is: '''use module name semicolon'''.
+| The syntax of '''use''' method is: '''use module name semicolon'''.
 |-
@@ Line 164: / Line 164: @@
 |-
 |03:30
-| These are similar to '''libraries''' in other languages.
+| These are similar to '''libraries''' in other (computer) languages.
 |-
@@ Line 188: / Line 188: @@
 |-
 |04:05
-|We will write another '''Perl''' script where we’ll use this''' sum dot pm''' file.
+|We will write another '''Perl script''' where we’ll use this''' sum dot pm''' file.
 |-
@@ Line 463: / Line 463: @@
 |-
 |10:24
-|Note: "use" '''module''' is recommended over "require" module, because it determines '''module availability '''at '''compile time'''.
+|Note: "use" '''module''' is recommended over "require" module, because it determines module availability at '''compile time'''.
 |-
 |10:33

@@ Line 60: / Line 60: @@
 |-
 |01:18
-|The current date and time is stored in a variable''' dollar datestring.'''
+|The current date and time are stored in a variable''' dollar datestring.'''
 |-
@@ Line 92: / Line 92: @@
 |-
 |02:03
-|'do()' '''method''' is called with the filename from where we want to use the code.
+|'do()' method is called with the filename from where we want to use the code.
 |-
 |02:09
-|Current date and time is stored in the''' $datestring''' variable of''' datetime dot pl file.'''
+|Current date and time are stored in the''' $datestring''' variable of''' datetime dot pl file.'''
 |-
@@ Line 486: / Line 486: @@
 |-
 |10:58
-|'''To()''' function returns the name of the participants.
+|'''To()''' function returns the names of the participants.
 |-

@@ Line 36: / Line 36: @@
 |-
 |00:44
-|Do Method: These are simple ways to include the source code from other files into the current script file.
+|'''Do Method''': These are simple ways to include the source code from other files into the current script file.
 |-
@@ Line 44: / Line 44: @@
 |-
 |00:57
-|Open a new file in your text editor and name it as '''datetime.pl'''
+|Open a new file in your text editor and name it as '''datetime dot pl'''
 |-
@@ Line 188: / Line 188: @@
 |-
 |04:05
-|We will write another '''Perl''' script where we’ll use this''' sum.pm''' file.
+|We will write another '''Perl''' script where we’ll use this''' sum dot pm''' file.
 |-
 | 04:11
-| Let me open the sample program app dot pl file which I have saved already
+| Let me open the sample program '''app dot pl''' file which I have saved already
 |-
@@ Line 236: / Line 236: @@
 |-
 |05:10
-|Let us see few more options in''' use method'''. Switch back to''' sum.pm '''in the '''text editor.'''
+|Let us see few more options in''' use method'''. Switch back to''' sum dot pm '''in the '''text editor.'''
 |-
@@ Line 300: / Line 300: @@
 |-
 |06:41
-|Let me open the sample program''' commonfunctions.pl''' which I have already saved.
+|Let me open the sample program''' commonfunctions dot pl''' which I have already saved.
 |-
@@ Line 353: / Line 353: @@
 |-
 |08:02
-|'''require''' reads the''' commonfunctions.pl''' file containing '''Perl''' code and compiles it.
+|'''require''' reads the''' commonfunctions dot pl''' file containing '''Perl''' code and compiles it.
 |-
@@ Line 377: / Line 377: @@
 |-
 |08:34
-|The value is stored in''' $number.''' This is passed to the function''' square''' in''' commonfunctions.pl''' file.
+|The value is stored in''' $number.''' The value is to passed to the function''' square''' in''' commonfunctions dot pl''' file.
 |-
@@ Line 384: / Line 384: @@
 |-
-|08:47'
+|08:47
 |The '''print statement''' prints the square of a number as output.
@@ Line 405: / Line 405: @@
 |-
 |09:20
-|Note that in this program we have called only three functions out of four from '''commonfunctions.pl'''.
+|Note that in this program we have called only three functions out of four from '''commonfunctions dot pl'''.
 |-
 |09:28
@@ Line 466: / Line 466: @@
 |-
 |10:33
-|Here is an assignment for you.
+|Here is an assignment for you. Write a''' Perl''' program''' reminder.pl''' where you will write a letter to the participants.
- Write a''' Perl''' program''' reminder.pl''' where you will write a letter to the participants.
 |-
@@ Line 475: / Line 474: @@
 |-
 |10:45
-|Call the subroutines from''' Letter.pm''' using '''‘use’''' method.
+|Call the subroutines from''' Letter dot pm''' using '''‘use’''' method.
 |-
 |10:50
-| Write the below functions in''' Letter.pm '''file.
+| Write the below functions in''' Letter dot pm '''file.
 |-
 |10:54
-| LetterDate() function returns the current date and time
+| '''LetterDate()''' function returns the current date and time
 |-
 |10:58
-|To() function returns the name of the participants
+|'''To()''' function returns the name of the participants
 |-
 |11:02
-| From() function returns the sender name
+| '''From()''' function returns the sender name
 |-
 |11:05
-| Lettermsg() function returns the content of the letter
+|''' Lettermsg()''' function returns the content of the letter
 |-
 |11:09
-|Thanksmsg() function returns thanks and regards.
+|'''Thanksmsg()''' function returns thanks and regards.
 |-