How to use the “passwd” command In Linux

1. Steps to Lock User Accounts:

In Linux, we can use the “passwd” command with the “-l” option to lock a user account. This option locks a user account, preventing the user from logging in.

Step 1: Open the terminal and run the following command as the root user or with superuser privileges.

passwd -l  username

Step 2: Just replace “username” with the name of the user account you want to lock.

Output:

The user will no longer be able to log in, and the account will now be locked. They will be prompted for their password, but access will be denied, as shown in the screenshot below.

Output:

2. Checking the Status of User Account:

Step 1: Fire up the terminal.

Step 2: To check the status of the user account whether it is locked or unlocked type the following command.

passwd -S  username

Output:

Here “kaal-el” is the username and “L” stands for Locked status.

3. Steps to Unlock User Accounts:

In Linux, we can use the “passwd” command with the “-u” option to unlock a user account.

Step 1: Open the terminal.

Step 2: Run the following command as the root user or with superuser privileges.

passwd -u username

Step 3: Just replace “username” with the name of the user account you want to unlock.

Output:

Step 4: A prompt to change the user’s password will now show up. We have two options:

• Create a new password.
• Hit the Enter key to save the current one.

The user account should be unlocked, and the user should be able to log in again after executing this command.

To regulate access and maintain security, Linux/Unix systems must have the ability to lock and unlock user accounts. It offers the adaptability required to handle a range of security and operational scenarios while making sure that only authorized users have access. Some of the reasons why locking and unlocking user accounts is essential for system security are mentioned below.

• Security: A user account can be locked to stop someone from using it without authorization. Access that is not authorized may result in security events like data loss or breaches.
• Account Management: Proper account management may include locking accounts. For instance, to ensure that someone who leaves the company, no longer has access to company resources, the account should be closed. When a new employee wants access, unlocking may be done.
• Temporary Suspension: User access can be temporarily suspended for maintenance or system updates by locking accounts. The accounts can be unlocked after the maintenance is finished.
• Multiple Failed Attempts: Multiple failed login attempts can be detected by a system, and the account can then be immediately locked to prevent brute-force attacks.

In this article we will discuss some of the common methods to lock and unlock user accounts in Linux/Unix-based OS: