BASH/C2/Globbing-and-Export-statement/Gujarati

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Title of script: Globbing and Export Statement

Author: FOSSEE and spoken-tutorial team

Keywords: Video tutorial, Globbing, Export statement


Time Narration
00:01 Welcome to this spoken tutorial on Globbing and Export command
00:06 In this tutorial, we will learn about
00:08 * Globbing
00:09 * export command


00:11 To follow this tutorial, You should be familiar with Linux Operating System
00:18 If not, for relevant tutorials please visit our website which is are shown.
00:24 For this tutorial I am using
00:27 * Ubuntu Linux 12.04 OS and
00:31 * GNU Bash version 4.1.10
00:35 Please note GNU Bash 'version 4' or above is recommended to practise this tutorial.
00:43 Let us start with an introduction to globbing.
00:46 * Filename or pathname expansion carried by BASH is known as Globbing.
00:52 * Globbing recognizes and expands wildcards.
00:57 * It also interprets standard wildcard characters like
01:02 # * (asterix) and
01:04 # ? (Question mark)


01:05 Let us understand this with the help of an example.
01:09 Open the terminal window by pressing Ctrl+Alt and T keys simultaneously on your keyboard.
01:18 On the Terminal type,ls space asterix dot sh press Enter.
01:27 It matches all the files having .sh extension in the present directory.


01:34 Here we can see that all the sh files are listed.
01:40 Let me clear the prompt,Now type, ls space s asterix dot sh press Enter.
01:51 We can see that s asterix dot sh matches all the files starting with character s and having sh as extension.
02:02 Lets move on ,
02:04 Now type, ls space opening square bracket a hyphen c closing square bracket asterix dot sh press Enter.
02:19 This will match and display the files starting with letter a or b or c.


02:26 Observe the output.
02:28 We see a list of all files starting with character a or b or c.
02:35 And these files have sh extension.
02:39 Now, let's go ahead and type ls space opening square bracket caret sign a hyphen c closing square bracket asterix dot sh press Enter.
02:55 This will match all the filenames with extension sh.
03:00 But will omit those starting with character as 'a' OR 'b' OR 'c'


03:07 Observe the output. You will notice that the filenames are not starting with character 'a' , 'b' or 'c'.
03:16 Let me clear the prompt,
03:19 Now type, ls space opening square bracket capital 'A' small 'a' closing square bracket asterix sign dot sh press Enter.
03:34 This will match filenames starting with upper and lower case of letter 'A'.
03:40 See the output.All filenames starting with upper and lower case 'A and extension sh are listed.
03:49 Now let's see the Export command in BASH.
03:53 Switch to the slides.
03:55 In Bash, variables are local to their own Shell.
04:00 * Local variables can be used by same Shell or by the current Shell.
04:06 Export command Exports a variable or a function to the environment of all child processes.
04:15 * Can also change a local variable to a global variable.
04:20 We will try to understand this with an example.
04:24 Switch to the Terminal type, myvar equal to sign lion press Enter.


04:34 Now type, echo space dollar sign myvar press Enter.
04:41 lion is printed.
04:44 This is the value assigned to the variable myvar.
04:48 Now, let's navigate to a new Shell.
04:51 To go to a new Shell, we can either open a new Terminal or type, slash bin slash bash press Enter.


05:03 Now let's check the value in the variable myvar.
05:07 Type, echo space dollar sign myvar press Enter.
05:15 An empty line is printed.
05:17 This means that the value assigned to variable myvar was not transferred to this Shell.
05:24 Also, the variable myvar is local only to the previous Shell and not to current Shell.
05:32 We will type exit to get back to our previous Shell.
05:36 So, to declare variables globally, we have to use the export command.
05:43 Let's learn how.
05:46 Type, export space myvar equal to sign lion press Enter.
05:55 Now type, echo space dollar sign myvar press Enter.
06:02 lion is displayed.
06:05 Let's navigate to another Shell, type, slash bin slash bash press Enter.
06:13 Let me clear the prompt.
06:15 Now type,echo space dollar sign myvar.
06:22 lion is displayed
06:25 This is because we have declared the variable myvar globally using the export command.
06:33 This brings us to the end of this tutorial.
06:36 Let us summarize. Come back to our slides.
06:39 In this tutorial we learnt,
06:41 * Globbing
06:42 * Export command
06:44 As an assignment.
06:45 Write a Bash script to do all the operations discussed under globbing.
06:51 Watch the video available at the link shown below
06:54 It summarises the Spoken Tutorial project
06:57 If you do not have good bandwidth, you can download and watch it
07:02 The Spoken Tutorial Project Team
07:05 Conducts workshops using spoken tutorials
07:08 Gives certificates to those who pass an online test
07:12 For more details, please write to contact@spoken-tutorial.org
07:20 Spoken Tutorial Project is a part of the Talk to a Teacher project
07:24 It is supported by the National Mission on Education through ICT, MHRD, Government of India
07:31 More information on this Mission is available at the link shown below.
07:37 The script has been contributed by FOSSEE and Spoken-Tutorial team.
07:42 This is Ashwini from IIT Bombay Signning off.
07:47 Thank you for joining.

Contributors and Content Editors

Gaurav, Jyotisolanki, PoojaMoolya