BASH/C2/Introduction-to-BASH-Shell-Scripting/English-timed
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Time | Narration |
00:01 | Dear friends, welcome to the Spoken tutorial on Introduction to BASH shell scripting. |
00:08 | In this tutorial, we will learn: |
00:10 | About different types of Shells |
00:13 | To write a Bash Shell script and |
00:16 | To execute it. |
00:18 | To follow this tutorial, you should be familiar with Linux Operating System. |
00:25 | If not, then for relevant Linux tutorials, please visit our website which is as shown. |
00:32 | For this tutorial, I am using: |
00:35 | * Ubuntu Linux 12.04 OS and |
00:39 | GNU Bash version 4.1.10. |
00:43 | Please note, GNU bash version 4 or above is recommended for practice. |
00:50 | Let us start with an introduction. |
00:53 | We will see what a Bash Shell is. |
00:56 | * Bash Shell is a Command language interpreter that executes commands. |
01:02 | * These commands are read from the standard input device. |
01:07 | * The input device can be- |
01:09 | your keyboard |
01:11 | or a simple text file. |
01:14 | Let me show you what is a Bash Shell. |
01:16 | Open the terminal window by pressing Ctrl+Alt+T keys simultaneously on your keyboard . |
01:24 | This will open the Gnome terminal. |
01:27 | To check which type of shell we are using, type: echo space dollar sign SHELL (in capital). |
01:38 | Press Enter. |
01:40 | You will see the output printed on the next line as slash bin slash bash. |
01:47 | This indicates that we are using the Bash Shell. |
01:51 | Now, let us know different types of Shells available. |
01:56 | Let us switch back to our slides Bourne Shell. |
02:00 | * This was original UNIX shell written by Stephen Bourne. |
02:06 | * It lacked interactivity provided by most modern shells today. |
02:11 | C Shell- |
02:12 | It provides features lacking in Bourne Shell . |
02:16 | K Shell- |
02:17 | It was created by David Korn. |
02:20 | It has features of both, B Shell and C Shell along with some additional features. |
02:27 | Bash Shell- |
02:30 | * The Bash Shell was developed by GNU Project |
02:32 | * It is based on B Shell language. |
02:35 | * It has features of C and K Shells. |
02:40 | TC Shell- |
02:41 | * It is the default Shell of FreeBSD and its descendants. |
02:46 | Z shell- |
02:49 | * It is a Shell designed for interactive use. |
02:52 | * It has many useful features of ksh, bash and tcsh. |
02:58 | Now let us see what a Bash Shell script is. |
03:02 | The Bash Shell script contains a series of Bash commands in plain text file. |
03:08 | * It tells the Shell to execute this text file instead of typing the commands. |
03:15 | Let us see how to write a simple Bash script. |
03:20 | We will test the echo command which will print Hello World on the terminal. |
03:25 | Go back to the terminal. |
03:29 | Now, type: echo space within double quotes Hello world |
03:35 | and press Enter. |
03:37 | This prints Hello World on the terminal. |
03:40 | The command worked as expected. |
03:43 | Now, what if we want to use this command in a file? |
03:47 | Just put this command in a file and execute that file. |
03:52 | I will use gedit text-editor for this purpose. |
03:57 | You are free to use your favorite text-editor. |
04:00 | I want to create my file on the Desktop. |
04:03 | So, type: cd space Desktop |
04:07 | Press Enter. |
04:09 | Now type: gedit space hello underscore world dot sh space &(ampersand sign). |
04:20 | Gedit is the text editor. 'Hello underscore world dot sh' is the file name and |
04:27 | we use the & (ampersand) to free up the prompt. |
04:32 | Now press Enter. |
04:33 | We have opened a new file named hello_world.sh using gedit. |
04:40 | Now, type: hash exclamation mark front slash bin front slash bash |
04:47 | This is the first line of every bash script. |
04:51 | It is called as shebang or bang line. |
04:55 | Press Enter. |
04:57 | Now, let's add a comment to the file by typing: |
05:00 | hash space my first Bash script |
05:06 | Remember that any line after hash is treated as a comment. |
05:11 | And comments are ignored by the Bash interpreter. |
05:15 | Now we can add the command which we used earlier. |
05:19 | Press Enter |
05:20 | and type: echo space within double quotes Hello world |
05:27 | press Enter. |
05:28 | Type: echo space dollar sign SHELL (in Capital) |
05:34 | press Enter. |
05:35 | Type: echo space backtick date backtick |
05:41 | backtick symbol is present on the key which has tilde character. |
05:47 | Now, click on Save to save the file. |
05:50 | Let us execute. Come back to our terminal. |
05:55 | First, we have to make the file executable. |
05:58 | For this, type: chmod space plus x space hello underscore world dot sh |
06:09 | and press Enter. |
06:12 | Now, type: |
06:14 | dot slash hello underscore world dot sh |
06:19 | Press Enter. |
06:22 | You can see Hello World is displayed on the terminal. |
06:27 | The shell type is displayed on the next line. i.e slash bin slash bash |
06:32 | and day, month, time, time zone and year are displayed. |
06:38 | The output may vary depending on the system. |
06:43 | Let us go back to our slide and summarize. |
06:46 | In this tutorial, we have learnt about: |
06:48 | * Different types of Shells |
06:50 | * Bash Shell |
06:51 | *Bash Shell script. |
06:52 | To write a simple Shell script and to execute the script. |
06:57 | As an assignment- write a simple script to display the message -
“Welcome to Bash learning” |
07:03 | and “***************” (asterisks) on separate lines. |
07:06 | Watch the video available at the link shown below. |
07:10 | It summarizes the Spoken-Tutorial project. |
07:13 | If you do not have good bandwidth, you can download and watch it. |
07:17 | The Spoken-Tutorial Project team: |
07:20 | Conducts workshops using spoken tutorials. |
07:22 | Gives certificates to those who pass an online test. |
07:26 | For more details, please write to contact@spoken-tutorial.org |
07:34 | Spoken Tutorial Project is a part of the "Talk to a Teacher" project. |
07:39 | It is supported by the National Mission on Education through ICT, MHRD, Government of India. |
07:45 | More information on this Mission is available at the link shown below. http://spoken tutorial.org\NMEICT-Intro |
07:51 | The script has been contributed by FOSSEE and Spoken-Tutorial teams, IIT Bombay. |
07:56 | This is Ashwini Patil from IIT Bombay, signing off. Thank you for joining. |