LFCS Practice Test 15 — 15 Questions

Question 1

Refer to the exhibit. The administrator attempted to create a user 'newuser' but received an error. Which command should be used to check if the user already exists?

Accepted Answer

cat /etc/passwd | grep newuser. The simplest way is to check /etc/passwd; the 'id' command can also verify existence.

Answer

passwd -S newuser

Answer

usermod -c newuser

Answer

userdel -v newuser

Question 2

Refer to the exhibit. Assuming today is Feb 20, 2025, what happens when 'bob' attempts to log in today?

Accepted Answer

Login is successful without warnings. Option D is correct. Account expiration is Mar 01, 2025, which is in the future, so account is not yet expired. Password expires on Apr 15, also future. Warning period started after Jan 15+81 days? Actually warning starts 7 days before expiration, which would be around Apr 8, not yet. So login should succeed. Option A: Account expires Mar 01, not yet. Option B and C are incorrect because conditions are not met.

Answer

Login is denied because the password has expired

Answer

Login is successful, but a warning message is displayed that password will expire soon

Answer

Login is denied because the account expired on Mar 01

Question 3

A user reports that they cannot execute a file even though they are in the file's group. The file has permissions 644 and group ownership 'staff'. The user is a member of 'staff'. What is the likely issue?

Accepted Answer

The file lacks execute permission for the group. The file permissions 644 (rw-r--r--) do not include execute for group, so the user cannot execute it.

Answer

The file does not have the setgid bit

Answer

The user's primary group is not 'staff'

Answer

The user is not the owner of the file

Question 4

A junior administrator issued the command 'usermod -L alice' to lock the account of user alice. However, alice is still able to log in via SSH using a public key. What is the most likely reason?

Accepted Answer

The usermod -L command only locks the password but does not prevent SSH key-based authentication.. Option A is correct because usermod -L locks the password by adding a '!' to the password hash, but SSH key authentication bypasses password verification. Option B is wrong because usermod changes take effect immediately; SSH restart is not required for account locking. Option C is wrong because changing shell is not part of -L. Option D is wrong because UID doesn't affect locking.

Answer

The usermod -L command only changes the user's shell to /sbin/nologin.

Answer

The usermod -L command requires a restart of the SSH service to take effect.

Answer

The usermod -L command is not effective on accounts with a UID less than 1000.

Question 5

Which THREE of the following are valid methods to temporarily switch to a different user account without logging out entirely? (Choose three.)

Accepted Answer

sudo -u username -s. Options A, B, and D are correct. su - username starts a login shell as that user. sudo -u username -s launches a shell as that user. runuser is a command that runs a program as another user (used in scripts). Option C (newgrp) changes the group, not user. Option E (login) requires a full login.

Answer

newgrp groupname

Answer

login username

Question 6

A temporary contractor 'contractor1' has left the company. The administrator needs to remove the user account and all associated files in the home directory. Which command accomplishes this?

Accepted Answer

userdel -r contractor1. userdel -r removes the user and their home directory and mail spool.

Answer

userdel contractor1

Answer

passwd -d contractor1

Answer

deluser --remove-home contractor1

Question 7

A security policy requires that all users in the 'admin' group must have a umask of 027 set automatically upon login. An administrator adds 'umask 027' to /etc/profile. However, users report that the umask is still 022. What is a likely cause?

Accepted Answer

The umask in /etc/profile is overridden by user-specific .bash_profile or .bashrc files.. Option A is correct because user-specific startup files (like .bash_profile) can override /etc/profile. Option B is wrong because /etc/profile is sourced automatically for login shells. Option C is possible but less likely since syntax is correct. Option D is wrong because /etc/profile executes before user files; any reset would be in user files.

Answer

The umask command in /etc/profile has a syntax error that is silently ignored.

Answer

The admin placed the umask command after the call to /etc/bash.bashrc which resets it.

Answer

The admin forgot to run 'source /etc/profile' on each user's session.

Question 8

Refer to the exhibit. An administrator adds user 'frank' to the group 'projectx' by editing /etc/group directly and changing the line to 'projectx:x:500:carol,dave,frank'. After saving, the administrator runs 'groups frank' and sees only 'frank' in the output. Why does frank not appear in the group 'projectx'?

Accepted Answer

The user 'frank' is still logged into the same session; he must log out and log back in for the new group to be recognized.. Option D is correct. Direct editing requires the user to log out and log back in for the new group to take effect. Option A is wrong because the GID is fine. Option B is wrong because usermod wasn't used, but editing is valid if syntax is correct. Option C is wrong because groups command reads from current session's group list, not just /etc/group.

Answer

Editing /etc/group directly is not a valid method; 'usermod -aG' must be used instead.

Answer

The group 'projectx' has a GID conflict with another group.

Answer

The 'groups' command reads only from /etc/group and the change should appear immediately.

Question 9

After running 'chage -l bob', the output shows: 'Last password change: Apr 01, 2023', 'Password expires: May 31, 2023', 'Account expires: Jul 15, 2023'. What will happen on May 31, 2023?

Accepted Answer

Bob can still log in but will be forced to change his password.. Option A is correct. On the password expiration date, the user is forced to change password at next login; the account remains active until the account expiry date.

Answer

Bob's account will be locked.

Answer

Bob's password will be disabled.

Answer

Bob will receive a warning message only.

Question 10

An administrator needs to view a list of users who have logged in recently. Which command provides this information?

Accepted Answer

last. The 'last' command displays a list of last logged-in users from /var/log/wtmp.

Answer

users

Answer

who

Answer

finger

Question 11

An administrator wants to change the primary group of user 'jane' from 'staff' to 'developers'. Which command accomplishes this?

Accepted Answer

usermod -g developers jane. Option A is correct because usermod -g changes the primary group. Option B adds a secondary group. Option C changes the group name, not user's group. Option D is a non-existent command.

Answer

usermod -G developers jane

Answer

groupmod -g developers jane

Answer

chgrp developers jane

Question 12

Refer to the exhibit. The shadow entry for user 'carol' shows 18000 in the third field. What does the value 18000 represent?

Accepted Answer

The number of days since the password was last changed.. Option B is correct. The third field in /etc/shadow is the date of last password change (in days since epoch). 18000 corresponds to about April 2025 (as of 2025). Option A is the first field (last change). Option C is the minimum days field (fourth field, which is 0). Option D is the warning days field (seventh field, which is 7).

Answer

The number of days until the account expires.

Answer

The minimum number of days required between password changes.

Answer

The number of days before password expiration that the user is warned.

Question 13

Which two commands can be used to set password expiration policies for a user?

Accepted Answer

passwd. chage is the dedicated tool for password aging; passwd can also set expiration with -x (max days), -n (min days), etc.

Answer

usermod

Answer

expiry

Answer

pwconv

Question 14

A user's account needs to be set to expire on a specific date. Which command should the administrator use?

Accepted Answer

chage -E 2025-01-01 username. Option B is correct: chage -E sets the account expiration date. Option A sets GECOS, not expiration. Option C sets password expiration, not account. Option D is invalid.

Answer

usermod -e 2025-01-01 username

Answer

usermod -c 'expire=2025-01-01' username

Answer

passwd -x 90 username

Question 15

Refer to the exhibit. What is the primary group ID of user 'charlie'?

Accepted Answer

1005 (the same as UID). Option B is correct. In /etc/passwd, the fourth field (after the second colon) is the primary group GID. Here it is 1005. Option A is the UID (third field). Option C is the GECOS field (fifth field). Option D is not directly listed.

Answer

1000

Answer

Charlie Brown

Answer

1005

LFCS Practice Test 15 — 15 Questions

Exhibit

LFCS Practice Test 15 — 15 Questions

Exhibit