Bash Script to Create User Account with Output

Use the Bash command sudo useradd username inside a script to create a user account, for example: sudo useradd newuser creates a user named 'newuser'.

Examples

Inputnewuser

OutputUser 'newuser' created successfully.

Inputtest123

OutputUser 'test123' created successfully.

Inputadmin

OutputUser 'admin' created successfully.

How to Think About It

To create a user account with a Bash script, first get the username from the user or as an argument. Then run the system command useradd with that username. Finally, check if the command succeeded and print a message.

Algorithm

1

Get the username input from the user or script argument.

2

Run the command <code>sudo useradd username</code> to create the user.

3

Check if the command was successful.

4

Print a success or error message.

Code

bash

#!/bin/bash

read -p "Enter username to create: " username

if sudo useradd "$username"; then
  echo "User '$username' created successfully."
else
  echo "Failed to create user '$username'."
fi

Output

Enter username to create: newuser
User 'newuser' created successfully.

Dry Run

Let's trace creating user 'newuser' through the script

1

Input username

User types 'newuser' when prompted.

2

Run useradd command

Script runs: sudo useradd newuser

3

Check command result

Command succeeds, script prints success message.

Step	Action	Value
1	Input username	newuser
2	Run command	sudo useradd newuser
3	Output message	User 'newuser' created successfully.

Why This Works

Step 1: Get username input

The script uses read to get the username from the user.

Step 2: Create user with useradd

The useradd command creates the new user account on the system.

Step 3: Check success and print message

The script checks if useradd ran without error and prints a message accordingly.

Alternative Approaches

Using adduser command

bash

#!/bin/bash

read -p "Enter username to create: " username

if sudo adduser --disabled-password --gecos "" "$username"; then
  echo "User '$username' created successfully with adduser."
else
  echo "Failed to create user '$username'."
fi

adduser is more interactive and user-friendly but may not be available on all systems.

Passing username as script argument

bash

#!/bin/bash

username="$1"

if [ -z "$username" ]; then
  echo "Usage: $0 username"
  exit 1
fi

if sudo useradd "$username"; then
  echo "User '$username' created successfully."
else
  echo "Failed to create user '$username'."
fi

This method allows automation by passing the username directly when running the script.

Complexity: O(1) time, O(1) space

Time Complexity

Creating a user is a single system command, so it runs in constant time regardless of input size.

Space Complexity

The script uses minimal memory, only storing the username string and command status.

Which Approach is Fastest?

Using useradd directly is fastest and simplest; adduser adds convenience but may be slower.

Approach	Time	Space	Best For
useradd command	O(1)	O(1)	Simple, fast user creation
adduser command	O(1)	O(1)	User-friendly, interactive creation
Script argument input	O(1)	O(1)	Automation and scripting