Saving output and errors separately | LinuC Level 1 101 Exam original practice question

1.03.3Basic

Save build stdout to build.out and stderr to build.err, overwriting both files.

Which command is appropriate?

Hint 1: Focus on the requirement

Assign descriptors 1 and 2 to different files.

Hint 2: Key terms

Review the short stream and redirection definitions before comparing the choices.

Output stream: The process stream carrying ordinary results.
Error stream: The process stream carrying diagnostics.
Separate destinations: A configuration that stores the two streams in different files.
File descriptor 1: The conventional number for standard output.

Detailed explanation

Incorrectbuild > build.out 2>&1

Incorrect. Both streams are combined into build.out.

Incorrectbuild 2> build.out > build.err

Incorrect. The requested stdout and stderr destinations are reversed.

Correctbuild > build.out 2> build.err

Correct. build > build.out 2> build.err assigns separate files.

Incorrectbuild < build.out 2< build.err

Incorrect. These redirections attempt to use the files as input.

An example you can run in a temporary verification environment.

tmp=$(mktemp -d); sh -c 'echo out; echo err >&2' >"$tmp/o" 2>"$tmp/e"; printf '%s/%s\n' "$(cat "$tmp/o")" "$(cat "$tmp/e")"; rm -rf "$tmp"

out/err

Environment: POSIX shell / 一時ディレクトリ
Use temporary files and harmless commands for stream experiments.
Shell redirection syntax and xargs behavior should be checked on the target shell implementation.

Foundation review

Keeping streams separate makes normal results and diagnostics independently reviewable.

Use temporary files and confirm each receives only its intended stream.

Question IDKL-101-472

EnvironmentPOSIX shell / 一時ディレクトリ

Last technical review2026-08-13

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