Passing a variable to child processes | LPIC-1 102-500 Exam original practice question

105.1Standard

APP_MODE=staging is already a shell variable.

Pass the value to subsequently started child processes.

Which command should be added?

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.

set APP_MODE: Incorrect. set does not mark APP_MODE for export.
export APP_MODE: Correct. export APP_MODE adds the export attribute so child processes receive the value.
unset APP_MODE: Incorrect. unset deletes the variable.
alias APP_MODE: Incorrect. alias defines command substitution, not an environment variable.

Detailed explanation

Incorrectset APP_MODE

Incorrect. set does not mark APP_MODE for export.

Correctexport APP_MODE

Correct. export APP_MODE adds the export attribute so child processes receive the value.

Incorrectunset APP_MODE

Incorrect. unset deletes the variable.

Incorrectalias APP_MODE

Incorrect. alias defines command substitution, not an environment variable.

An example you can run in a temporary verification environment.

bash --noprofile --norc -c 'APP_MODE=staging; export APP_MODE; bash -c '\''printf "%s\n" "$APP_MODE"'\'''

staging

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-105-605

EnvironmentGNU Bash 5.2 / 一時子シェル

Last technical review2026-08-13