Nancyvarkey at 06:17, 7 January 2014

2014-01-07T06:17:34Z

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Ashwini at 07:46, 30 December 2013

2013-12-30T07:46:04Z

Ashwini at 07:44, 30 December 2013

2013-12-30T07:44:02Z

Ashwini at 07:37, 30 December 2013

2013-12-30T07:37:44Z

Ashwini at 07:37, 30 December 2013

2013-12-30T07:37:15Z

Ashwini: Created page with ''''Title of script:''' '''Nested loop in Bash''' '''Author:''' Ashwini Patil '''Keywords: video tutorial, for loop''' {| style="border-spacing:0;" ! Visual Cue
2013-12-20T07:45:47Z

Created page with ''''Title of script:''' '''Nested loop in Bash''' '''Author:''' Ashwini Patil '''Keywords: video tutorial, for loop''' {| style="border-spacing:0;" ! <center>Visual Cue</cent…'

New page
'''Title of script:''' '''Nested loop in Bash'''

'''Author:''' Ashwini Patil

'''Keywords: video tutorial, for loop'''

{| style="border-spacing:0;"
! <center>Visual Cue</center>
! <center>Narration</center>

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display Slide 1
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Dear friends, Welcome to the spoken tutorial on

'''Nested for loop in BASH'''

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display Slide 2
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| In this tutorial, we will learn

* '''Nested for loop'''
* With the help of an example

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display Slide 3
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| For this tutorial I am using''' '''

* '''Ubuntu Linux''' 12.04 '''Operating System '''and
* '''GNU BASH''' version 4.1.10

Please note,''' GNU Bash''' version 4 or above is recommended to practise this tutorial.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display slide 4

| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| To learn this tutorial,

you should be familiar with '''arrays''' and '''loops''' in '''Bash'''.

For relevant tutorials, please visit our website:

[http://spoken-tutorial.org/ http://spoken-tutorial.org]

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display Slide 5

| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Let us start with an introduction.

A loop within a loop is known as '''nested loop.'''

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display Slide 6
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Let us start with''' for loop''' first.

Syntax:

'''for ((exp1; exp2; exp3))'''
'''do'''
'''for ((exp1; exp2; exp3))'''
'''do'''
'''statement1'''
'''statement1'''
'''done'''
'''done'''

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Open the file for-new.sh
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Let us see an example on '''for''' loop

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Show the folder structure

Double-click to open '''simple-nested-for '''directory
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| First let us go through the directory structure.

Here is a directory on the '''Desktop''' named '''simple-nested-for. Let's open it.'''

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Open '''test '''directory to show the text files.
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| We have subdirectories '''test''', '''test2''' and '''test3''' and a bash script'''.'''

In each sub-directory there are multiple text files.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Now we will move on to our code.

This program displays all the files within each subdirectory.

Please note that the same can be acheived with a single line command

'''ls -1 -R test'''

But we will do it using a '''for-loop'''.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Point to the filename.
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Note that the name of our bash script is''' nested-for.sh'''

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Highlight

'''<nowiki>#!/usr/bin/env bash</nowiki>'''
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| This is our shebang line.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Highlight

'''for dir in test; do '''

'''echo "Files in $dir directory:" '''

'''echo " " '''

| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| This is the outer '''for loop'''.

This '''for loop''' will check for directories starting with the name '''test '''.

First 'echo' line will display the sub-directories name.

The second 'echo' line will create a blank line.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| '''for file in $(ls -1 $dir); do '''

| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| This is the inner '''for''' '''loop'''.

It will check for files present within the directories.

'''ls '''displays the directory content.

'''-1''' is used to list one file per line.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| '''echo $file '''

'''done '''

'''echo "------------------------" '''

'''done'''
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Here we list the files.

'done' ends the inner '''for loop'''.

This command prints a vertical line after completion of every cycle of '''outer for-loop.'''

'done' ends the '''outer for loop'''.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Open terminal

'''Ctrl+alt+t'''
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Let us execute the program.

Open the '''terminal '''by pressing '''ctrl+alt+t''' keys simultaneously on your keyboard.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| '''Type:'''

'''chmod +x nested-for.sh'''

'''./nested-forsh'''
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| Type:

'''chmod +x nested-for.sh'''

Type:

'''./nested-for.sh'''

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Highlight

Output
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| The output is displayed.

It shows

* Files in '''test''' directory.
* Files in '''test2''' directory.
* And files in '''test3''' directory.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| This brings us to the end of this tutorial.

Let us summarize.

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display Slide 7

'''Summary'''
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| '''Summary'''

In this tutorial we learnt,

Nested for loop

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display Slide 8

Assignment
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| As an assignment

Retype the above program using '''nested while loop.'''

Save your program with the name ''''nested-while.sh''''

|-
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display Slide 9

http://spoken-tutorial.org /What\_is\_a\_Spoken\_Tutorial

About the Spoken Tutorial Project
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| 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-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display Slide 10

Spoken Tutorial Workshops
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| 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-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"| Display Slide 11

Acknowledgement
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| 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-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:none;padding:0.097cm;"|
| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"| The script has been contributed by FOSSEE and Spoken-tutorial team.

This is Ashwini Patil from IIT Bombay

Thank You for joining.

|}

← Older revision		Revision as of 07:44, 30 December 2013
Line 191:		Line 191:

	Open the '''terminal '''by pressing '''ctrl+alt+t''' keys simultaneously on your keyboard.		Open the '''terminal '''by pressing '''ctrl+alt+t''' keys simultaneously on your keyboard.
		+
		+	Now let us go to the directory where our bash script is.
		+
		+	That is on the desktop.
		+
		+	Type cd desktop
		+
		+	Let us go in the folder
		+
		+	simple-nested-for
		+
		+	'''Press Enter'''

	\|-		\|-

@@ Line 74: / Line 74: @@
 Outer for loop
 expression 1, 2, 3
 Inner for loop
 expression 1, 2, 3
 statement 1
 statement 2
 Closing inner for loop
 Closing outer for loop

← Older revision		Revision as of 07:46, 30 December 2013
Line 188:		Line 188:

	'''Ctrl+alt+t'''		'''Ctrl+alt+t'''
		+
		+	Type:
		+
		+	cd Desktop/simple-nested-for
		+
		+
	\| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"\| Let us execute the program.		\| style="border-top:none;border-bottom:1pt solid #000000;border-left:1pt solid #000000;border-right:1pt solid #000000;padding:0.097cm;"\| Let us execute the program.

@@ Line 72: / Line 72: @@
   '''done'''
   '''done'''
 |-

BASH/C2/More-on-Loops/English - Revision history

Nancyvarkey at 06:17, 7 January 2014

Ashwini at 07:46, 30 December 2013

Ashwini at 07:44, 30 December 2013

Ashwini at 07:37, 30 December 2013

Ashwini at 07:37, 30 December 2013