Building a Password Manager with Shell Scripting

Are you tired of manually managing your passwords in a text file? Do you want to automate the process and make it more secure? In this tutorial, we'll build a simple password manager using shell scripting.

Before we start, make sure that you have a basic understanding of shell scripting and have access to a Linux terminal. We'll be using the Bash shell for this tutorial.

Step 1: Set up the user data file

The first step is to set up the file that will store the user's data. Create a file called user-data.csv in your home directory and give it read and write permissions:

touch ~/user-data.csv
chmod 600 ~/user-data.csv

Step 2: Add a function to add passwords

The next step is to add a function that will allow the user to add passwords to the user-data.csv file. Here's the code for the function:

add_password() {
        read -p "Enter account name : " account_id
        read -p "Password: " password
        echo
        echo "$account_id,$password" >> "$user_data_file"
        echo
        echo "Data Saved"
}

This function prompts the user to enter an account name and password. Once the user has entered the information, it is appended to the user-data.csv file.

Step 3: Add a function to retrieve passwords

The next step is to add a function that will allow the user to retrieve passwords from the user-data.csv file. Here's the code for the function:

get_password() {
        read -p "Enter account name : " account_id
        if [ -n "$password" ]; then
                echo "Your password is : $password"
        else
                echo "User Id is not found"
        fi
}

This function prompts the user to enter an account name. It then uses grep to search the user-data.csv file for lines that start with the entered account name.The awk command is used to extract the password from the matching line.If a password is found, it is displayed to the user. If not, the function displays a message indicating that the account was not found.

Step 4: Add functions to update and delete passwords

To make the password manager more versatile, we can also add functions to update and delete passwords. Here's the code for the update function:

update_password() {
    read -p "Enter account id : " account_id
    if grep -q "^$account_id," "$user_data_file"; then
        read  -p "Enter new password : " password
        echo
        sed -i "s/^\($account_id,\).*/\1$p/" "$user_data_file"
        echo "password is updated for $account_id"
    else
        echo "account Id not found"
    fi
}

delete_data() {
    read -p "Enter account id : " account_id
    if grep -q "^$account_id," "$user_data_file"; then
        sed -i "/^$account_id,/d" "$user_data_file"
        echo "user details with $account_id is deleted"
    else
        echo "account not found"
    fi

}

This function update_password prompts the user to enter an account name and a new password. It then uses sed to search the user-data.csv file for lines that start with the entered account name and replaces the existing password with the new password. If the account is not found, the function does nothing.

The function delete_data prompts the user to enter an account name. It then uses sed to search the user-data.csv file for lines that start with the entered account name and delete them.

Overall, this script provides a simple and efficient way to manage passwords for multiple accounts. The script is easy to use and does not require any special software or tools. You can simply run the script from the command line and follow the prompts to add, retrieve, update, or delete data.

Here is full code :

#!/bin/bash
# author : Ajay Patel
# date : 18- april -2023
# version : 1.0

#path for file to store data
user_data_file="/home/ubuntu/scripts/user-data.csv"

#function for add user data
add_password() {
        read -p "Enter account name : " account_id
        read -p "Password: " password
        echo
        echo "$account_id,$password" >> "$user_data_file"
    echo
        echo "Data Saved"
}

#function for retrieve data
get_password() {
    read -p "Enter account name : " account_id
    password=$(grep "^$account_id" $user_data_file | awk -F ',' '{print $2}' )
    if [ -n "$password" ]; then
        echo "Your password is : $password"
    else
        echo "User Id is not found"
    fi
}

#function for delete data
delete_data() {
    read -p "Enter account id : " account_id
    if grep -q "^$account_id," "$user_data_file"; then
        sed -i "/^$account_id,/d" "$user_data_file"
        echo "user details with $account_id is deleted"
    else
        echo "account not found"
    fi

}

#function for update password
update_password() {
    read -p "Enter account id : " account_id
    if grep -q "^$account_id," "$user_data_file"; then
        read  -p "Enter new password : " password
        echo
        sed -i "s/^\($account_id,\).*/\1$p/" "$user_data_file"
        echo "password is updated for $account_id"
    else
        echo "account Id not found"
    fi
}

#to get input from user
read -p "Enter action (add/get/update/delete):" action

#check user action
if [ "$action" == "add" ]; then
    add_password
elif [ "$action" == "get" ]; then
    get_password
elif [ "$action" == "delete" ]; then
    delete_data
elif [ "$action" == "update" ]; then
    update_password
else
    echo "invalid selection"
fi

I hope this blog post has been helpful in understanding how to manage passwords using a Bash script. If you have any questions or feedback, please feel free to leave a comment below.

Happy coding!

#bashscripting #passwordmanager #linux #automation #security #scripting #csv #commandline #devops