System administration involves numerous tasks, including managing users and groups and under-user management. Some of the minor tasks involved are adding, modifying, suspending, or deactivating user accounts, among many others.
This article will explain one of the critical user account management functions: how to set or change user password expiration and aging in Linux using the change command.
The change command is used to modify user password expiration information. It enables you to view user account aging information and change the number of days between password changes and the date of the last password change.
Once you have set password expiry and aging information, this information is used by the system to determine when a user must change his or her password. Normally, companies or organizations have certain security policies that demand users change passwords regularly; this can be a simple way to enforce such policies as we explained below.
To view a user account aging information, use the -l flag as shown.
# chage -l ravi
View User Password Aging Information
To set the date or number of days (since January 1, 1970) when the password was last changed, use the -d flag as follows.
# chage -d 2018-02-11 ravi
Next, you can also set the date or number of days (since January 1, 1970) on which the user’s account will no longer be accessible by using the -E switch as shown in the following command.
In this case, once a user’s account is locked, he/she is required to contact the system administrator before being able to use the system again.
# chage -E 2018-02-16 ravi
Then, the -W option allows you to set the number of days of warning before a password change is required. Considering the command below, the user ravi will be warned 10 days before his password expires.
# chage -W 10 ravi
In addition, you can set the number of days of inactivity after a password has expired before the account is locked. This example means that after user ravi’s password expires, his account will be inactive for 2 days before it is locked.
When the account becomes inactive, he must contact the system administrator before being able to use the system again.
# chage -I 2 ravi
For more information, refer to the change man page.
# man chage
Note that you can also change a user’s password expiration and aging information using the usermod command, which is intended for modifying a user account.
That’s it for now. Hoping you find this article informative and useful.
