This LFCS practice question tests your understanding of user and group management. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Refer to the exhibit. # useradd -u 1005 -G wheel,dbadmin -m -k /etc/skel newuser useradd: user 'newuser' already exists #
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?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "which command"
Why it matters: Tests specific CLI syntax. Recall the exact command and its required context — near-synonyms and partial matches are common distractors.
Refer to the exhibit. # useradd -u 1005 -G wheel,dbadmin -m -k /etc/skel newuser useradd: user 'newuser' already exists #
cat /etc/passwd | grep newuser
Looks for the user in the password file.
passwd -S newuser
Why wrong: Shows password status, but requires user to exist; if not, error.
usermod -c newuser
Why wrong: usermod -c changes comment, not lookup.
userdel -v newuser
Why wrong: userdel has no -v option.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
cat /etc/passwd | grep newuser
The simplest way is to check /etc/passwd; the 'id' command can also verify existence.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
cat /etc/passwd | grep newuser
Why this is correct
Looks for the user in the password file.
Clue confirmation
The clue word "which command" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
passwd -S newuser
Why it's wrong here
Shows password status, but requires user to exist; if not, error.
usermod -c newuser
Why it's wrong here
usermod -c changes comment, not lookup.
userdel -v newuser
Why it's wrong here
userdel has no -v option.
Common exam traps
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Trap categories for this question
Command / output trap
Shows password status, but requires user to exist; if not, error.
Detailed technical explanation
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A practitioner preparing for the LFCS exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Identify which LFCS exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
User and Group Management — study guide chapter
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FAQ
User and Group Management — This question tests User and Group Management — Read the scenario before looking for a memorised answer..
The correct answer is: cat /etc/passwd | grep newuser — The simplest way is to check /etc/passwd; the 'id' command can also verify existence.
Identify which LFCS exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Yes — watch for: "which command". Tests specific CLI syntax. Recall the exact command and its required context — near-synonyms and partial matches are common distractors.
Read the scenario before looking for a memorised answer.
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Last reviewed: Jun 24, 2026
This LFCS practice question is part of Courseiva's free Linux Foundation certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the LFCS exam.
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