- A
sed 's/oldhost/newhost/g' /etc/hosts
Why wrong: This prints the result to stdout but does not modify the file.
- B
awk '{gsub(/oldhost/,"newhost")}1' /etc/hosts
Why wrong: This prints to stdout but does not modify the file.
- C
grep -r 'oldhost' /etc/hosts | sed 's/oldhost/newhost/g'
Why wrong: This does not modify the file and is incorrect syntax.
- D
sed -i 's/oldhost/newhost/g' /etc/hosts
Correct: -i edits file in-place, s/oldhost/newhost/g replaces all occurrences.
Question 972 of 981
XK0-005 System Management Practice Question
This XK0-005 practice question tests your understanding of system management. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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.
An administrator needs to replace all occurrences of 'oldhost' with 'newhost' in the configuration file /etc/hosts. Which command will perform the replacement and save the changes directly to the file?
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.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
sed -i 's/oldhost/newhost/g' /etc/hosts
Option D is correct because the `-i` flag (in-place editing) tells `sed` to write the changes directly back to the file specified. Without `-i`, `sed` only prints the modified output to stdout and does not alter the original file. The substitution command `s/oldhost/newhost/g` performs a global replacement of all occurrences of 'oldhost' with 'newhost' on each line.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
sed 's/oldhost/newhost/g' /etc/hosts
Why it's wrong here
This prints the result to stdout but does not modify the file.
- ✗
awk '{gsub(/oldhost/,"newhost")}1' /etc/hosts
Why it's wrong here
This prints to stdout but does not modify the file.
- ✗
grep -r 'oldhost' /etc/hosts | sed 's/oldhost/newhost/g'
Why it's wrong here
This does not modify the file and is incorrect syntax.
- ✓
sed -i 's/oldhost/newhost/g' /etc/hosts
Why this is correct
Correct: -i edits file in-place, s/oldhost/newhost/g replaces all occurrences.
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.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often forget the `-i` flag for in-place editing, assuming `sed` modifies the file by default, or they confuse `sed`'s stream behavior with editors like `vim` that directly change the file.
Detailed technical explanation
How to think about this question
The `sed -i` option creates a temporary file, applies the edits, and then replaces the original file atomically, which is critical for system files like /etc/hosts to avoid corruption during concurrent access. Some implementations (e.g., BSD `sed`) require a backup extension argument (e.g., `-i .bak`), but GNU `sed` (common on Linux) allows `-i` alone. The `g` flag ensures all occurrences on a line are replaced, not just the first, which is important if 'oldhost' appears multiple times in an alias list.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the XK0-005 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
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
System Management — study guide chapter
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System Management practice questions
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FAQ
Questions learners often ask
What does this XK0-005 question test?
System Management — This question tests System Management — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: sed -i 's/oldhost/newhost/g' /etc/hosts — Option D is correct because the `-i` flag (in-place editing) tells `sed` to write the changes directly back to the file specified. Without `-i`, `sed` only prints the modified output to stdout and does not alter the original file. The substitution command `s/oldhost/newhost/g` performs a global replacement of all occurrences of 'oldhost' with 'newhost' on each line.
What should I do if I get this XK0-005 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
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.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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Last reviewed: Jul 4, 2026
This XK0-005 practice question is part of Courseiva's free CompTIA 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 XK0-005 exam.
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