This LFCS practice question tests your understanding of essential commands. 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.
To compress a file while preserving the original file, which command should be used?
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.
gzip file.txt
Why wrong: This compresses but removes the original.
gzip -d file.txt.gz
Why wrong: This decompresses the file, not compresses.
gzip -1 file.txt
Why wrong: This compresses with level 1, but still removes the original unless -k is also used.
gzip -k file.txt
The -k option keeps the original file after compression.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
gzip -k file.txt
Option D is correct because the `-k` (or `--keep`) flag in `gzip` instructs the utility to compress the file while retaining the original uncompressed file. By default, `gzip` replaces the original file with a compressed version (appending `.gz`), so `-k` is the explicit option to preserve the source file.
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.
gzip file.txt
Why it's wrong here
This compresses but removes the original.
gzip -d file.txt.gz
Why it's wrong here
This decompresses the file, not compresses.
gzip -1 file.txt
Why it's wrong here
This compresses with level 1, but still removes the original unless -k is also used.
gzip -k file.txt
Why this is correct
The -k option keeps the original file after compression.
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
Linux Foundation often tests the default behavior of `gzip` (which deletes the original) versus the `-k` flag, trapping candidates who assume compression always preserves the source file without an explicit option.
Detailed technical explanation
The `gzip` command uses Lempel-Ziv coding (LZ77) to reduce file size. The `-k` flag was introduced in GNU gzip 1.6 (2013) to comply with POSIX conventions for preserving input files. In scripts or automated backups, using `gzip -k` ensures the original remains intact, which is critical when the source file must be retained for further processing or auditing.
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 exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Essential Commands — study guide chapter
Learn the concepts, then practise the questions
Essential Commands practice questions
Targeted practice on this topic area only
All LFCS questions
513 questions across all exam domains
Linux Foundation Certified System Administrator LFCS study guide
Full concept coverage aligned to exam objectives
LFCS practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise LFCS questions linked to User and Group Management.
Practise LFCS questions linked to Operation of Running Systems.
Practise LFCS questions linked to Essential Commands.
Practise LFCS questions linked to Networking.
Practise LFCS questions linked to Service Configuration.
Practise LFCS questions linked to Storage Management.
Practise LFCS questions linked to LFCS fundamentals.
Practise LFCS questions linked to LFCS scenario.
Practise LFCS questions linked to LFCS troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Essential Commands — This question tests Essential Commands — Read the scenario before looking for a memorised answer..
The correct answer is: gzip -k file.txt — Option D is correct because the `-k` (or `--keep`) flag in `gzip` instructs the utility to compress the file while retaining the original uncompressed file. By default, `gzip` replaces the original file with a compressed version (appending `.gz`), so `-k` is the explicit option to preserve the source file.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jun 30, 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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.