[Linux] Bash passwd uso: Change user passwords

Overview

The passwd command in Linux is used to change user passwords. It allows users to update their own passwords or, if executed by a superuser, to change passwords for other users. This command is essential for maintaining security by ensuring that user accounts have strong, unique passwords.

Usage

The basic syntax of the passwd command is as follows:

passwd [options] [username]

If no username is specified, the command will change the password for the currently logged-in user.

Common Options

-d: Delete the password for the specified user, allowing login without a password.
-e: Expire the password immediately, forcing the user to change it upon next login.
-l: Lock the specified user’s password, preventing them from logging in.
-u: Unlock a previously locked user account.
-S: Display the password status of the specified user.

Common Examples

Change your own password:
```
passwd
```
Change another user’s password (requires superuser privileges):
```
sudo passwd username
```
Delete a user’s password:
```
sudo passwd -d username
```
Expire a user’s password immediately:
```
sudo passwd -e username
```
Lock a user’s account:
```
sudo passwd -l username
```
Unlock a user’s account:
```
sudo passwd -u username
```
Check the password status of a user:
```
passwd -S username
```

Tips

Always use strong passwords that combine letters, numbers, and special characters to enhance security.
Regularly update passwords to minimize the risk of unauthorized access.
If you are changing another user’s password, ensure you have the necessary permissions to avoid errors.