Branching on several string patterns | LPIC-1 102-500 Exam original practice question

105.2Standard

Run start for $1=start, stop for $1=stop, and usage for any other value.

Which case statement is appropriate?

Hint 1: Focus on shell semantics

Separate command substitution, parameter and arithmetic expansion, condition operators, and exit-status flow before comparing the choices.

Hint 2: Key terms

Review the short definitions of shell expansion, condition operators, and command status.

case: A shell construct that compares one value with multiple patterns.
pattern matching: Comparing text with rules that may include shell wildcards.
;;: The marker that ends one case branch and prevents fall-through to the next branch.
default pattern: The final branch used for values that match no earlier pattern.

Detailed explanation

Incorrectcase $1 { start: run_start; stop: run_stop; *: usage; }

Incorrect. C-style braces and colons are not shell case syntax.

Correctcase "$1" in start) run_start ;; stop) run_stop ;; *) usage ;; esac

Correct. It uses in, pattern parentheses, ;;, and esac correctly.

Incorrectif "$1" in start|stop; then run; fi

Incorrect. if does not use in in this form and the branches are not separated.

Incorrectcase "$1" then start run_start else usage fi

Incorrect. It mixes case and if keywords into invalid syntax.

An example you can run in a temporary verification environment.

bash --noprofile --norc -c 'case "$1" in start) printf start ;; stop) printf stop ;; *) printf usage ;; esac' demo stop

stop

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 IDKP-105-631

EnvironmentGNU Bash 5.2 / 短命シェル

Last technical review2026-08-13

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