Day 8 : Shell Scripting Challenge

Today we have some tasks where we will know about Shell Scripting. What is Comments, echo, variables, wildcards.

Tasks :

Task 1 : Comments : In bash scripts, comments are used to add explanatory notes or disable certain lines of code.
- Your task is to create a bash script with comments explaining what the script does.
Task 2 : Echo : The echo command is used to display messages on the terminal.
- Your task is to create a bash script that uses echo to print a message of your choice.
Task 3 : Variables : Variables in bash are used to store data and can be referenced by their name.
- Your task is to create a bash script that declares variables and assigns values to them.
Task 4 : Using Variables : Now that you have declared variables, let's use them to perform a simple task.
- Create a bash script that takes two variables (numbers) as input and prints their sum using those variables.
Task 5 : Using Built-in Variables : Bash provides several built-in variables that hold useful information.
- Your task is to create a bash script that utilizes at least three different built-in variables to display relevant information.
Task 6 : Wildcards : Wildcards are special characters used to perform pattern matching when working with files.
- Your task is to create a bash script that utilizes wildcards to list all the files with a specific extension in a directory.

Solutions :

All Solutions are in a sinle script, read the following script :

#!/bin/bash

# Task 1 Solution :
# In this script, We will know about Comments, Echo, Variables and Wildcards.
# First of all what is comments?
# You are reading this line after '#' is a single line comment.
<< note
This is a multi-line comment. We use this when we need to write so many lines
as a comment. We write '<<' in the beginning and give some name like 'note' and 
end it with the same name 'note'. In between these, whatever you write is a 
Multi-line comment.
Comments are non executable lines in a script/code.
note

# Task 2 Solution :
# Echo is a command that display/print something like for Eg.

echo "This script contains Basics of Shell Scripting."
echo ""
# This line will be display after you execute this script. That blank 'echo ""' will skip a
# line between two commands

# Task 3 Solution :
# Variables are the thing which stores some values, values can be Numbers, Characters, etc.

variable1="Hello!"

# 'variable1' is variable name, you can give name as per your choice. '=' is to assign 
# values to the varable. And "Hello!" is the value that is assigned to a variable.

# Task 4 Solution :
# Lets take two variables and get values from user

read -p "Enter 1st No : " num1
read -p "Enter 2nd No : " num2
sum=$((num1 + num2))
echo ""
echo "The Addition is : $sum"
echo ""

# 'read -p' accept value from user with displaying message and store in 'num1' 'num2' variable
# Then addition of both nums stored in 'sum' variable

# Task 5 Solution :
# Some built-in variables :

echo ""
echo "Logged in as : $USER"
echo "Home directory is : $HOME"
echo "Present working directory is : $PWD"
echo ""

# Task 6 Solution :
# Some common wildcards are  '*'  '?'  '[]'
# Suppose if I  want  to display details about all files which have '.txt' extension at end
# So we write

ls -l *.txt

# '*' means whatever name of file but with extension '.txt'
# Suppose we write 'file_name.*' it means 'file_name' file with whatever extension

After giving execute permission by sudo chmod +x and executing by ./Shell_Scripting_Basics.sh you will be able to see like this.

so here we completed our today’s task. Follow and keep learning with us.

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