Basic Linux Shell Scripting for DevOps Engineers.

• What is Linux Shell Scripting?

  A shell script is a computer program designed to be run by a linux shell, a command-line interpreter. The various dialects of shell scripts are considered to be scripting languages. Typical operations performed by shell scripts include file manipulation, program execution, and printing text.

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

A shell script is a text file that contains a sequence of commands for a UNIX- based operating system. It is called a shell script because it combines a sequence of commands, that would otherwise have to be typed into the keyboard one at a time, into a single script.

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

#! is called a SHEBANG.This represents which interpreter a script should be interpreted with .

#!/bin/bash This is a header command which represents it is a bash/shell script #!/bin/bash is this is not provided it often considers #!/bin/ sh which would be same in most cases. When you put #!/bin/bash in your script, even if you run the script in a different shell, the kernel will know which shell to interpret it with

Yes, we can use #!/bin/sh in our shell script should be executed by the default shell on the system.

• Write a Shell Script which prints I will complete #90DaysOofDevOps challenge :-

#!/bin/bash

echo "I will complete #90DaysOofDevOps challenge"

Output :-

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

#!/bin/bash

echo "Please Enter Your Name"
read name
echo "Please Enter Your Age"
read age
echo "Please Enter your Address"
read addr
echo "$name is a $age year and $name is from $addr"

Output:-

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

#!/bin/bash

echo "Please Enter FirstNumber"
read num1

echo "Please Enter SecondNumber"
read num2

if [ $num1 -gt $num2 ]
then
echo "$num1 is greater than $num2"
else
echo "$num2 is greater than $num1"
fi

Output:-

Devops#devops,#90daysofDevOps

Thank you for reading!! I hope you find this article helpful!!

if any query or if any correction to be done in this blog please let me know.

Happy Learning!!

Saikat Mukherjee