Beginners Guide for Passwd Command in Linux

The passwd command is used to modify the user’s password and its properties, like deleting the password, expiring the password, deactivating the account, and many more.

• Change user account password information using chage command

The owner of an account only has permission to modify its password properties, except for the root user, who can easily modify any user account password.

If you are a sudo user, you are also able to modify other users’ password properties by placing sudo in front of each command.

Tutorial Details

Description	Passwd
Difficulty Level	Moderate
Root or Sudo Privileges	Yes
Host System and Architecture	Ubuntu 22.10 (x64)
OS Compatibility	Ubuntu, Manjaro, Fedora, etc.
Prerequisites	passwd
Internet Required	No

Syntax of the Passwd Command

The passwd command takes two arguments: one is the option (optional), and the other is the username (if you want to modify the password information for the current user, you do not need to specify this).

$ passwd [OPTION] [USERNAME]

The following is the list of valid options for the passwd command.

Options	Description
-a, --all	It is used with the “-S” flag to show status for all users
-d, --delete	It will remove the password from the user’s account (empty password)
-e, --expire	Immediately expire the specified user password. On their next login, the user must be forced to change their password
-i, --inactive	It will disable the user account after the password has expired for a number of days
-l, --lock	It will lock the user account, making it inaccessible
-u, --unlock	It will unlock the user account, making it accessible
-n, --mindays	Set the password change days (the default is 0)
-q, --quiet	Quiet mode
-r, --repository	Change the password in the repository
-R, --root	Apply changes to the CHROOT_DIR directory and use the configuration files from the CHROOT_DIR directory
-s, --status	Display account status information
-w, --warndays	It will show a warning on the number of days prior to the password expiring
-x, --maxdays	Set the maximum number of days the password remains valid; after that, the password is required to be changed

Changing the Current Logged-in User Password

The following command will change the current user password (if you are already using a password, you would need to specify your current password).

$ passwd

Output:

To maintain privacy, the typed password will not be visible on screen.

Changing the Other User Account Password

To change another user’s account password, you must be a root or sudo user; in this example, I will use the sudo user to change the account password for the newly created user “pt1“.

$ sudo passwd pt1

Output:

From now on, we will only use the “pt1” user account to show examples of the passwd command.

Display the Current Status of the User

The “-S” flag is used to display the “pt1” user account status as shown.

$ sudo passwd -S pt1

Output:

The following is a list of user account information.

Username	Status	Last Changed Password	Minimum Age	Maximum Age	Warning Period	Password Inactivity Period
pt1	P	09/11/2023	0	99999	7	-1

There are 3 types of status, as shown:

Status	Description
P	Password is set
L	Account is locked
NP	No password

The special numbers are reserved for setting parameters for password rules.

Special Numbers for Age	Description
0	Never expires
99999	Can be changed at anytime
1	Not active

Deleting the Account Password

The following command will remove the target account password, making it less meaningful (an empty password).

$ sudo passwd -d pt1

Output:

Now anyone can easily switch to the “pt1” user account without requiring any password (unsafe).

• How to Force User to Change Their Password on Next Login in Linux

Expire the Account Password

The following command will expire the password before its expiration date, requiring the target to set up a new password on their next login.

$ sudo passwd -e pt1

Output:

If you check the user account information, the password expiry date is set to 1970, and the status is “NP” (no password).

$ sudo passwd -S pt1

Output:

If “pt1” logs in again, he will be forced to set up a new password.

Disable Account After Password Expires

The following command will disable access to the target account after the password has expired for a certain number of days (ex: “6 days”).

$ sudo passwd -i 6 pt1

Output:

Minimum Days to Force Users to Update Their Passwords

The following command is used to specify the minimum number of days between password changes to the specified days (ex: 16 days), after which the user will be required to change their password again.

$ sudo passwd -n 16 pt1

Output:

After 16 days, the user will be forced to change their password again.

$ sudo passwd -S pt1

Output:

Maximum Days for Password Validation

The following command will set the maximum number of days before your account password is valid. After the specified number of days (ex: 26 days) has passed, the password is required to be changed.

$ sudo passwd -x 26 pt1

Output:

Check the user account information to verify the status.

$ sudo passwd -S pt1

Output:

Setup Warning Message Before Password Change is Required

The following command will prompt the user with a warning message the specified number of days (ex: 10 days) prior to their password expiring.

$ sudo passwd -w 10 pt1

Output:

Check the account status using the following command.

$ sudo passwd -S pt1

Output:

Lock or Unlock the User Account

The following command will lock the user account, and no one will be able to login to that particular user account via password.

$ sudo passwd -l pt1

Output:

It will change the account status from “P” (for password) to “L” (locked account), as shown.

$ sudo passwd -S pt1

Output:

Use the “-u” flag to unlock the target user account.

$ sudo passwd -u pt1

Output:

Verify the user status using the following command.

$ passwd -S pt1

Output:

And that was the end of the passwd command examples.

If you have a query regarding this topic, feel free to ask in the comment section.