102-500 Exam Preparation Material | LPI Level 1

Explanation:
The chage command can change the following parameters related to user password expiry and aging:
The last password change date (-d or --lastday option)
The password expiry date (-E or --expiredate option)
The minimum number of days between password changes (-m or --mindays option)
The maximum number of days during which a password is valid (-M or --maxdays option)
The number of days of warning before password expires (-W or --warndays option)
The chage command cannot change the number of days of inactivity after a password has expired before the account is locked. This parameter is controlled by the -I or --inactive option of the usermod command, which modifies the user account information. The chage command only displays the current value of this parameter, but does not allow changing it.
Reference: chage command in Linux with examples - GeeksforGeeks
10 chage command examples in Linux [Cheat Sheet] - GoLinuxCloud How to Use the Chage Command in Linux C TecAdmin
How to Manage User Password Expiration and Aging in Linux - Tecmint

Explanation:
The groupadd command creates a new group using the options specified on the command line and the default values from the /etc/login.defs file. It adds an entry for the new group to the /etc/group and /etc/gshadow files. Only the root user or a user with sudo privileges can create new groups using this command. The general syntax for the groupadd command is as follows: groupadd [OPTIONS] GROUPNAME
Some of the common options for the groupadd command are:
-g, --gid GID: Specify the numeric group ID for the new group. If not given, the system will assign the next available GID from the range of group IDs specified in the login.defs file.
-r, --system: Create a system group with a GID chosen from the range of system group IDs specified in the login.defs file. System groups are usually used for some special system operation purposes, like creating backups or doing system maintenance.
-f, --force: Suppress the error message if the group already exists and exit successfully. This option is useful for scripts that need to ensure the existence of a group.
-K, --key KEY=VALUE: Override the default values from the /etc/login.defs file. The valid keys are GROUP_MIN_ID, GROUP_MAX_ID, SYS_GROUP_MIN_ID, SYS_GROUP_MAX_ID, and GID_INCREMENT.
Reference:
https://www.makeuseof.com/linux-file-ownership-groups-guide/
https://linuxize.com/post/how-to-create-groups-in-linux/ https://linuxhandbook.com/groupadd-command/

Explanation:
The $? variable in bash is a special parameter that holds the exit status of the last command executed in the current shell. The exit status is a numerical value that indicates whether the command was successful (zero) or failed (non-zero). The echo command simply prints its arguments to the standard output. Therefore, when the command echo $? outputs 1, it means that the previous command failed with an exit status of 1.
Reference: [LPI Linux Essentials - Topic 103: Command Line Basics]
[Bash Special Parameters]
[Exit status - Wikipedia]

Explanation:
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.
Reference: 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