Copying only a newer source | LinuC Level 1 101 Exam original practice question

1.02.2Basic

Copy src/report.csv to dest/report.csv.

If the destination exists and is newer than the source, do not overwrite it.

Which GNU cp command is appropriate?

Hint 1: Focus on the requirement

Distinguish an existence-only no-clobber rule from a source-versus-destination time comparison.

Hint 2: Key terms

Review the short command and filesystem definitions before comparing the choices.

cp -u: A copy mode that updates when the destination is missing or older than the source.
cp -n: A copy mode that leaves an existing destination unchanged.
cp -i: A copy mode that asks before overwriting.
Modification time: The timestamp associated with the last content change.

Detailed explanation

Incorrectcp -f src/report.csv dest/report.csv

Incorrect. -f forces overwriting and is the opposite of the requirement.

Incorrectcp -i src/report.csv dest/report.csv

Incorrect. -i prompts but does not compare timestamps automatically.

Incorrectcp -n src/report.csv dest/report.csv

Incorrect. -n skips an existing destination regardless of age.

Correctcp -u src/report.csv dest/report.csv

Correct. cp -u copies only a missing or older destination.

An example you can run in a temporary verification environment.

tmp=$(mktemp -d); printf old >"$tmp/src"; sleep 1; printf newer >"$tmp/dst"; cp -u "$tmp/src" "$tmp/dst"; cat "$tmp/dst"; rm -rf "$tmp"

newer

Environment: GNU coreutils 9.x / 一時ファイル
Use disposable files and directories for destructive or timestamp-related checks.
Command details can vary slightly between GNU and non-GNU implementations.

Foundation review

The update option makes a one-way freshness decision; it is not a complete bidirectional synchronization tool.

Set known timestamps on temporary files and verify which destination content remains.

Question IDKL-101-393

EnvironmentGNU coreutils 9.x / 一時ファイル

Last technical review2026-08-13

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