Added Day 1 - 3 solutions in separate branch

Challenges/Day_1/Day_1_Basics.sh

@@ -0,0 +1,46 @@
+#!/bin/bash
+
+# Welcome to Day 1 of the Bash Scripting Challenge! Today, we will cover the basics of bash scripting to get you started. Let's dive in:
+
+# Task 1: You can add comments by adding '#' before any sentence to make it a comment. Usually it is a best practice to add comments before the program/ code to let reader know what next line will do.
+# or we can add comments along with code line for better understading of that particular line of code.
+
+# Task 2: Echo. The echo command is used to display messages on the terminal. 
+# Let's print a message of our choice.
+echo "Welcome to the World of Bash Scripting!"
+echo ''
+
+# Task 3: Variables. Variables in bash are used to store data and can be referenced by their name. 
+# Let's create two variables 'num1' and 'num2' and assigns some integer values to them.
+# CAUTION! : DO NOT ADD SPACES WHILE ASSIGNING VALUES TO VARIABLES.
+var1=5
+var2=10
+
+name='Randhawa Verma'     # You can assign string as well to the variables just like we added integers above.
+
+
+# Task 4: Using Variables.
+# Let's Create a bash script that takes above created two numbers as input and prints their sum using those variables.
+# First we will create a new variable called sum and add the two numbers. INFO - Use $ sign before variable name to use the variable.
+sum=$(( $var1 + $var2 ))    #$(()) will evaluate the expression we provided in it.
+echo 'Total of the two variables'  $var1  'and'  $var2 'is:' $sum
+echo ''
+
+
+# Task 5: Using Built-in Variables. Bash provides several built-in variables that hold useful information. 
+# Let's Use following three built-in - $#, $@ & $?. When running script, we need to provide arguments like this ./Day1_script.sh 1 2 3 4
+echo 'Using $#, Numbers you entered total are:' $#
+echo 'Using $@, You entered following numbers:' $@
+echo 'Using $?, Let us confirm if last command was successful or not. (0 is for Yes)' $?
+echo ''
+
+# $# = Tells number of arguments passed. 
+# $@ = What parameters were passed to the command line. 
+# $? = Was last command successful. If Answer is 0 that means 'yes'.
+
+
+# Task 6: Wildcards. Wildcards are special characters used to perform pattern matching when working with files. 
+# Let's create a bash script that lists all the files with a specific extension in a directory.
+# let's print all script files i.e. to print files with .sh extension.
+echo "Listing all scripts in the current directory- "
+ls *.sh

Challenges/Day_2/backup_with_rotation.sh

@@ -1,41 +1,37 @@
 #!/bin/bash
 
-# Function to display usage information and available options
-function display_usage {
-    echo "Usage: $0 /path/to/source_directory"
-}
-
-# Check if a valid directory path is provided as a command-line argument
-if [ $# -eq 0 ] || [ ! -d "$1" ]; then
-    echo "Error: Please provide a valid directory path as a command-line argument."
-    display_usage
-    exit 1
+# Asking user to provide the directory path to take backup of
+read -p "Please provide path to take back up of: " src_dir
+echo $src_dir
+
+# Creating back up folder
+echo "Creating back up..."
+
+# Setting Current Time using date command
+current_time=$(date "+%Y-%m-%d_%H-%M-%S")
+# echo "Current Time : $current_time"
+
+# Creating back up folder by appending current time with backup_
+backup_folder=$src_dir/backup_$current_time
+
+# Getting count of back up folders
+file_count=$(ls -l $src_dir | awk '/backup_/' | wc -l)
+# echo $file_count
+
+# Getting the name of oldest file
+oldest_file=$(ls -l $src_dir | awk '/backup_/ {print $9}' | head -1)
+# echo $oldest_file
+
+# Using condition to check if there are 3 back up folders already present then remove the oldest one and add the new.
+if [ $file_count -eq 3 ]
+then
+    echo "Removing Oldest File: $oldest_file"
+    rm -r "$src_dir/$oldest_file"
 fi
 
-# Directory path of the source directory to be backed up
-source_dir="$1"
-
-# Function to create a timestamped backup folder
-function create_backup {
-    local timestamp=$(date '+%Y-%m-%d_%H-%M-%S')  # Get the current timestamp
-    local backup_dir="${source_dir}/backup_${timestamp}"
-
-    # Create the backup folder with the timestamped name
-    mkdir "$backup_dir"
-    echo "Backup created successfully: $backup_dir"
-}
-
-# Function to perform the rotation and keep only the last 3 backups
-function perform_rotation {
-    local backups=($(ls -t "${source_dir}/backup_"* 2>/dev/null))  # List existing backups sorted by timestamp
-
-    # Check if there are more than 3 backups
-    if [ "${#backups[@]}" -gt 3 ]; then
-        local backups_to_remove="${backups[@]:3}"  # Get backups beyond the last 3
-        rm -rf "${backups_to_remove[@]}"  # Remove the oldest backups
-    fi
-}
-
-# Main script logic
-create_backup
-perform_rotation
+# using rysnc to copy src folder and copying it into backup folder. rsync helped in excluding older back up folders.
+rsync -ar $src_dir/. $backup_folder --exclude /backup*
+
+echo "Backup created: $backup_folder"
+
+

Challenges/Day_2/explorer.sh

@@ -1,23 +1,29 @@
 #!/bin/bash
 
-# Part 1: File and Directory Exploration
-echo "Welcome to the Interactive File and Directory Explorer!"
+# Welcome Message for the user
+echo 'Welcome to the Interactive File and Directory Explorer!'
+echo ''
+echo 'Files and Directories in the Current Path:'
+# echo ''
 
-while true; do
-    # List all files and directories in the current path
-    echo "Files and Directories in the Current Path:"
-    ls -lh
+# Using ls command to list all the content in current path. 
+# -lhR flags with print items in listing format showing size in human readable format recursively.
+# awk command will filter out only file or folder name and their size.
+# sed will delete the lines with blank () in the output.
+ls -lhR | awk 'NF>0 {print $9 "("$5")"}' | sed '/()/d'
 
-    # Part 2: Character Counting
-    read -p "Enter a line of text (Press Enter without text to exit): " input
 
-    # Exit if the user enters an empty string
-    if [ -z "$input" ]; then
-        echo "Exiting the Interactive Explorer. Goodbye!"
-        break
+# Creating a while loop which will ask user to provide any line of text and as show total characters in that line as output.
+# Pressing Enter key will exit out of the program.
+while true
+do
+    read -p "Enter a line of text (Press Enter without text to exit): " line_of_text
+    if [[ $line_of_text = "" ]]; 
+    then echo "Exiting the Interactive Explorer. Goodbye!" 
+    break
+    else
+    echo "No. of characters: ${#line_of_text}"
     fi
-
-    # Calculate and print the character count for the input line
-    char_count=$(echo -n "$input" | wc -m)
-    echo "Character Count: $char_count"
 done
+
+

Challenges/Day_3/user_management.sh

@@ -1,94 +1,73 @@
 #!/bin/bash
 
-# Function to display usage information and available options
-function display_usage {
-    echo "Usage: $0 [OPTIONS]"
-    echo "Options:"
-    echo "  -c, --create     Create a new user account."
-    echo "  -d, --delete     Delete an existing user account."
-    echo "  -r, --reset      Reset password for an existing user account."
-    echo "  -l, --list       List all user accounts on the system."
-    echo "  -h, --help       Display this help and exit."
+############################################################
+# Help                                                     #
+############################################################
+Help()
+{
+   # Display Help
+   echo "Usage: ./user_management.sh [OPTIONS]"
+   echo
+   echo "Options:"
+   echo "-c, --create	Create a new user account."
+   echo "-d, --delete	Delete an existing user account."
+   echo "-r, --reset	Reset password for an existing user account."
+   echo "-l, --list	List all user accounts on the system."
+   echo "-h, --help	Display this help and exit."
+   echo "-i, --info	Display Extra User Info."
+   echo "-u, --uname	Change username."
 }
 
-# Function to create a new user account
-function create_user {
-    read -p "Enter the new username: " username
 
-    # Check if the username already exists
-    if id "$username" &>/dev/null; then
-        echo "Error: The username '$username' already exists. Please choose a different username."
-    else
-        # Prompt for password (Note: You might want to use 'read -s' to hide the password input)
-        read -p "Enter the password for $username: " password
+############################################################
+# Main program                                             #
+############################################################
 
-        # Create the user account
-        useradd -m -p "$password" "$username"
-        echo "User account '$username' created successfully."
-    fi
-}
-
-# Function to delete an existing user account
-function delete_user {
-    read -p "Enter the username to delete: " username
-
-    # Check if the username exists
-    if id "$username" &>/dev/null; then
-        userdel -r "$username"  # -r flag removes the user's home directory
-        echo "User account '$username' deleted successfully."
-    else
-        echo "Error: The username '$username' does not exist. Please enter a valid username."
-    fi
-}
-
-# Function to reset the password for an existing user account
-function reset_password {
-    read -p "Enter the username to reset password: " username
-
-    # Check if the username exists
-    if id "$username" &>/dev/null; then
-        # Prompt for password (Note: You might want to use 'read -s' to hide the password input)
-        read -p "Enter the new password for $username: " password
-
-        # Set the new password
-        echo "$username:$password" | chpasswd
-        echo "Password for user '$username' reset successfully."
-    else
-        echo "Error: The username '$username' does not exist. Please enter a valid username."
-    fi
-}
-
-# Function to list all user accounts on the system
-function list_users {
-    echo "User accounts on the system:"
-    cat /etc/passwd | awk -F: '{ print "- " $1 " (UID: " $3 ")" }'
-}
-
-# Check if no arguments are provided or if the -h or --help option is given
-if [ $# -eq 0 ] || [ "$1" = "-h" ] || [ "$1" = "--help" ]; then
-    display_usage
-    exit 0
-fi
-
-# Command-line argument parsing
-while [ $# -gt 0 ]; do
-    case "$1" in
-        -c|--create)
-            create_user
-            ;;
-        -d|--delete)
-            delete_user
-            ;;
-        -r|--reset)
-            reset_password
-            ;;
-        -l|--list)
-            list_users
-            ;;
-        *)
-            echo "Error: Invalid option '$1'. Use '--help' to see available options."
-            exit 1
-            ;;
-    esac
-    shift
-done
+	if [ "$1" = "--create" -o "$1" = "-c" ]; then
+	   read -p "Enter username: " username
+	   read -p "Enter password: " userpass
+	   if id "$username" >/dev/null 2>&1; then
+	   echo "ERROR: User already present. Please choose a different username."
+	   else
+	   sudo useradd $username
+	   echo "SUCCESS: User account for $username created Successfully."
+	   fi
+	elif [ "$1" = "--delete" -o "$1" = "-d" ]; then
+	    read -p "Enter username to delete: " username
+	    read -p "Please confirm (y/n): " option
+	    if [ $option = 'y' ]; then
+	    	if id "$username" >/dev/null 2>&1; then
+	        sudo userdel $username
+	    	echo "SUCCESS: User deleted Successfully."
+	        else
+	    	echo 'ERROR: User not present. Please Check.'
+		fi
+	    else echo 'Cancelling User Deletion Process.'
+	    fi
+	elif [ "$1" = "--reset" -o "$1" = "-r" ]; then
+	    read -p "Enter the username to reset password: " username
+		if id "$username" >/dev/null 2>&1; then
+		read -p 'Enter new password: ' userpass
+		sudo chpasswd <<< "$username:$userpass"
+		echo 'SUCCESS: Password reset successfully.'
+		else echo 'ERROR: User not present'
+		fi 
+	elif [ "$1" = "--list" -o "$1" = "-l" ]; then
+	cat /etc/passwd | awk -F':' '{print $1 " (ID: "$3")"}'
+	elif [ "$1" = "--info" -o "$1" = "-i" ]; then
+	read -p "Enter the username to get additional info: " username
+                if id "$username" >/dev/null 2>&1; then
+		echo '====== USER INFO ======'
+                lslogins -u $username
+                else echo 'ERROR: User not present'
+                fi
+	elif [ "$1" = "--uname" -o "$1" = "-u" ]; then
+        read -p "Enter the username to change: " username
+                if id "$username" >/dev/null 2>&1; then
+		read -p "Enter new username: " newuser
+		echo 'SUCCESS: Username updated successfully.'
+		sudo usermod -l $newuser $username
+                else echo 'ERROR: User not present'
+                fi
+	elif [ "$1" = "" -o "$1" = "--help" -o "$1" = "-h" ]; then Help
+	fi