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Taking inputs from user in a script

Here we will see how to take input from user in a script with the help of read command. #!/bin/bash Lets try multiplication of two numbers which the user enters. What read does is ? It takes values by user on stdin. It prompt the user to input any value on stdin. -p is used to display a prompt. read -p "First number:" value1 This will give a prompt as " First number " and store the value in variable " value1 " echo Will display a blank line. read -p "Second number:" value2 This will give a prompt as " Second number " and store the value in variable " value2 " echo Will display a blank line. read -sn1 -p "Press any key to see the answer..." Just to make it bit more interactive lets add one more thing. -s means silent mode that is if any value is pressed it will not be displayed on the screen like as in the password. -nX means how many characters. X here is one that is any ...
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BASH?

BASH is a Unix shell, which is a command line interface for interacting with the operating system. Also it is the default shell on many linux distributions including Max OS X.

It was created in late 1980's by Brian Fox (FSF). It was basically an alertnative to the Bourne SHell and it stands for Bourne Again SHell. It has all the features of shell as well as new features such as regex/airthmetic operations etc.

Its location is /bin/bash

How to know on which shell are you working? as in if it is a bash,sh,ksh,csh etc

 [root@sunny-workstation ~]$ echo $SHELL
/bin/bash
[root@sunny-workstation ~]$
[root@sunny-workstation ~]$ echo $0
bash
[root@sunny-workstation ~]$

Either by checking the value of $SHELL variable or $0 variable.

If you remember when we wrote a sample script, the first line was #!/bin/bash this particular line is used to let the operating system know under which interpreter the script will run.

In this case its bash, so what will happen is the specified interpreter program will run instead of default one. This particular line is known as she-bang. 

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