Choosing POSIX function syntax | LinuC Level 1 102 Exam original practice question

1.06.2Basic

Define cleanup in a script run by /bin/sh.

Do not depend on Bash's function keyword.

Which definition is appropriate?

Hint 1: Focus on the input model

Separate word-list iteration, condition-controlled loops, field splitting, and literal input handling before comparing the choices.

Hint 2: Key terms

Review the short definitions of the shell syntax, parameters, permissions, and control flow involved.

POSIX function syntax: The portable name() { ...; } form for defining a shell function.
function keyword: A Bash extension that can introduce a function definition.
Function body: The commands grouped for execution when a function is called.
Shell portability: The property that a script uses syntax understood by its target shell implementations.

Detailed explanation

Incorrectfunction cleanup() { rm -f -- "$tmp"; }

Incorrect. Combining function and () is not the portable POSIX form.

Correctcleanup() { rm -f -- "$tmp"; }

Correct. cleanup() { ...; } is valid POSIX shell syntax.

Incorrectcleanup = () { rm -f -- "$tmp"; }

Incorrect. The assignment operator does not belong in a function definition.

Incorrectcleanup: { rm -f -- "$tmp"; }

Incorrect. A colon does not define a shell function.

An example you can run in a temporary verification environment.

sh -c 'cleanup() { printf "cleaned\n"; }; cleanup'

cleaned

Foundation review

A reusable group of commands that runs in the caller's shell context.

A numbered argument or special value supplied to a script or function.

Conditions, loops, and exit statuses determine which shell commands run.

Question IDKL-102-914

EnvironmentPOSIX sh / 状態変更なし

Last technical review2026-08-13

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