Day-4 DevOps 90 days challenge

**Tasks**

 - Explain in your own words and examples, what is Shell Scripting for DevOps.
 - What is `#!/bin/bash?` can we write `#!/bin/sh` as well?
 - Write a Shell Script which prints `I will complete #90DaysOofDevOps challenge`
 - Write a Shell Script to take user input, input from arguments and print the variables.
 - Write an Example of If else in Shell Scripting by comparing 2 numbers

- Explain in your own words and examples, what is Shell Scripting for DevOps.

To interact with Kernal Shell Used.

Line by line Execution of a task/process is called a script(Top to bottom ).

Shell Script is an set of commands written in a single file. commands in Shell scripting line by line.

The Shell script has the extension.SH

Steps to create Shell Script -

1 Go to terminal --> Create a file with extension. SH

Vim script1(Filename).SH ---> This will create a shell file for you now inside it you have to write script for your Automation.

What is #!/bin/bash? can we write #!/bin/sh as well?

▪ #!/bin/bash is known as shebang in Unix. Shebang is a collection of characters or letters that consist of a number sign and exclamation mark, that is (#!) at the beginning of a script.

can we write #!/bin/sh as well?

as I mentioned #!/bin/ will remain same in first line of all shell script

^{There are different type of shell present there}

1 #!/bin/Bash ---> Bash

2 #!/bin/sh ---> sh bourne

3 #!/bin/ksh ---> Korn shell

4 #!/bin/csh ---> C shell

So according to our requirements, we can use different commands. Nowadays generally we all prefer #!/bin/Bash.

Write a Shell Script that prints I will complete the #90DaysOofDevOps challenge

#!/bin/bash
echo " I will complete my 90 days of challenge "

Write a Shell Script to take user input, input from arguments and print the variables

#!/bin/bash

# user inuput
read -p "Enter your name: "name

#Print the variables
echo "Hello $name! welcome to my shell script!"

Write an Example of If else in Shell Scripting by comparing 2 numbers

Let take an example N1 = 5 & N2 = 6

num1=5
num2=6
if [$num1 -gt $num2 ];
then echo "$num1 is greater than $num2"
else 
echo "$num2 is greater to $num1"
fi