# Shell Scripting

DAY 04 Q. What is a shell script?

Ans : In the simplest terms, a shell script is a file containing a series of commands.The shell reads this file and carries out the commands as though they have been entered directly on the command line. Normally the shell scripts has the file [extensions. sh](http://extensions.sh) nano devops\_first.sh

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

Ans : Yes, #!/bin/bash and #!/bin/sh are both called shebangs, and they are used at the beginning of a script file to specify the interpreter that should be used to execute the script. #!/bin/bash: This shebang specifies that the script should be executed using the Bash shell. Bash (short for Bourne Again SHell) is a popular and powerful shell that is available on most Unix-like operating systems, including Linux. #!/bin/sh: This shebang specifies that the script should be executed using the system's default Bourne shell or a compatible shell.

Q. Write a Shell Script which prints I will complete #90DaysofDevOps challenge

Ans : nano devops\_first.sh (create file with sh extension )

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

Ans : #!/bin/bash

echo " I will complete #90DaysofDevops challenge"

./ devops\_first.sh

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

Ans : ==> #!/bin/bash

Taking user input echo "Enter a value user want to print: "

read userInput

Taking input from arguments arg1="$1"

Printing variables echo "User input is: $userInput"

echo "Argument is: $arg1"

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

Ans : ==> #!/bin/bash Define two numbers for comparison

number1=10

number2=20

Compare the two numbers

if \[ $number1 -eq $number2 \] then

echo "The numbers are equal."

elif \[ $number1 -lt $number2 \]

then

echo "Number 1 is less than Number 2." else echo "Number 1 is greater than Number 2."

fi