LPI Updated 102-500 Exam Questions and Answers by milena

The usermod, passwd, and chage commands can be used to change a user’s account aging information. These commands can modify the password expiry date, the last password change date, the minimum and maximum number of days between password changes, the number of days of warning before password expiration, and the number of days of inactivity after password expiration. The usermod command is mainly used for modifying a user account, but it also has options for changing the password expiry and aging information, such as -e, -f, -p, and -L1. The passwd command is mainly used for changing the user password, but it also has options for changing the password expiry and aging information, such as -e, -i, -n, -w, and -x2. The chage command is specifically used for changing the user password expiry and aging information, and it has options such as -d, -E, -I, -m, -M, and -W3.

The other options, chattr and chsh, are not related to changing the user’s account aging information. The chattr command is used to change the file attributes on a Linux file system4. The chsh command is used to change the user’s login shell5.

References:

usermod(8) — Linux manual page

passwd(1) — Linux manual page

chage(1) — Linux manual page

chattr(1) — Linux manual page

chsh(1) — Linux manual page

The command userdel --force --remove bob is used to delete the user account named bob and all its associated files. The --force option forces the removal of the user account, even if the user is still logged in. The --remove option forces userdel to remove the user’s home directory and mail spool, even if another user uses the same home directory or if the mail spool is not owned by the specified user12. Therefore, options A and B are true regarding this command.

The other options are not true because:

Option C is false because the locate database is not updated by the userdel command. The locate database is updated by the updatedb command, which is usually run by cron as a scheduled job3.

Option D is false because the userdel command does not remove all files owned by bob from all mounted filesystems. The userdel command only removes the user’s home directory and mail spool, and it does not search for and delete the user files located in other file systems. You have to search for and delete the files manually1.

Option E is false because the userdel command does not delete the group with the same name as the user, unless the USERGROUPS_ENAB parameter is set to yes in the /etc/login.defs file and the group has no other members14.

References:

How to Delete/Remove Users in Linux (userdel Command) | Linuxize

userdel(8) — Linux manual page

updatedb(8) — Linux manual page

Understanding the /etc/login.defs File | Linuxize

Linux UIDs (user identifiers) are numbers that are used to identify users and groups on a Linux system. Each user and group has a unique UID and GID (group identifier) respectively. The UID 0 is always reserved for the root or superuser account, which has full privileges to access and modify the system. The UIDs lower than 100 (or 1000 on some modern systems) are typically reserved for system accounts, which are used by various services and daemons that run on the system. These accounts are not meant for human users, but for specific purposes such as managing files, processes, network, security, etc. For example, some common system accounts are bin, daemon, mail, sshd, etc. The UIDs higher than 100 (or 1000) are usually allocated for regular user accounts, which have limited privileges and can be created and deleted by the system administrator. The system accounts are defined in the /etc/passwd file, which contains the username, UID, GID, home directory, shell, and other information for each account12345. References: 1: Linux User Management - Tecmint 2: What are the well-known UIDs? - Stack Overflow 3: user ID less than 1000 on CentOS 7 - Unix & Linux Stack Exchange 4: Recommended GID for users group in Linux (100 or 1000)? - Unix & Linux Stack Exchange 5: What is the conventional purpose of Linux UIDs that are lower than 100? - VCE Guide

The commands that can be used to change a user’s account aging information are:

usermod: this command can modify various user account properties, including the password expiration date, the account expiration date, the minimum and maximum password age, the password warning period, and the password inactivity period. To use this command, you need to specify the option and the value for the property you want to change, followed by the username. For example, to set the password expiration date for the user test to February 11, 2022, you can run:

usermod -e 2022-02-11 test

To view the current account aging information for a user, you can use the -l option with the usermod command. For example, to view the information for the user test, you can run:

usermod -l test

passwd: this command can change the password of a user account, as well as some password aging options. To use this command, you need to specify the username and the option for the property you want to change. For example, to change the password of the user test, you can run:

passwd test

To set the maximum password age for the user test to 90 days, you can run:

passwd -x 90 test

To view the current password aging information for a user, you can use the -S option with the passwd command. For example, to view the information for the user test, you can run:

passwd -S test

chage: this command can change the user password expiry and aging information, such as the password expiration date, the account expiration date, the minimum and maximum password age, the password warning period, and the password inactivity period. To use this command, you need to specify the option and the value for the property you want to change, followed by the username. For example, to set the account expiration date for the user test to February 11, 2022, you can run:

chage -E 2022-02-11 test

To view the current account aging information for a user, you can use the -l option with the chage command. For example, to view the information for the user test, you can run:

chage -l test

The other options are incorrect because:

chattr: this command can change the file attributes on a Linux file system, such as making a file immutable, append-only, or undeletable. It has nothing to do with user account aging information.

chsh: this command can change the login shell of a user account, such as bash, zsh, or ksh. It has nothing to do with user account aging information.

References:

How to Manage User Password Expiration and Aging in Linux - Tecmint

Use the Chage Command in Linux

How to set user password expirations on Linux | Enable Sysadmin

How to change password and account expiry options on Linux using chage - Linux Tutorials - Learn Linux Configuration

3 ways to change user password expiration date in Linux - howtouselinux