Removing carriage-return characters | LinuC Level 1 101 Exam original practice question

1.03.2Basic

Remove CR (carriage return, \r) from CRLF input.

Keep LF (\n) line breaks and write the result to standard output.

Which tr command is appropriate?

Hint 1: Focus on the requirement

Identify what must change and what must remain unchanged. Then choose the command whose scope matches that requirement.

Hint 2: Check each command's role

Separate commands that display information, change state, remove data, or affect a child process.

tr '\r' '\n': Incorrect. Replacing CR with LF would add an extra line break.
tr -d '\n': Incorrect. Deleting LF would remove the line separators.
tr -s '\r': Incorrect. -s squeezes repeated characters but does not remove CR.
tr -d '\r': Correct. tr -d '\r' deletes CR while preserving LF.

Detailed explanation

Incorrecttr '\r' '\n'

Incorrect. Replacing CR with LF would add an extra line break.

Incorrecttr -d '\n'

Incorrect. Deleting LF would remove the line separators.

Incorrecttr -s '\r'

Incorrect. -s squeezes repeated characters but does not remove CR.

Correcttr -d '\r'

Correct. tr -d '\r' deletes CR while preserving LF.

An example you can run in a temporary verification environment.

printf 'one\r\ntwo\r\n' | tr -d '\r' | od -An -tx1

各行末が0aだけで、0dを含まない16進列

Foundation review

Check whether the command acts on the current shell, a new process, an existing process, or a file.

Use the supplied command and compare the output with the expected result.

Question IDKL-101-463

EnvironmentGNU coreutils 9.x / 標準入力

Last technical review2026-08-13