Using a fixed command search path | LinuC Level 1 102 Exam original practice question

1.06.2Basic

At the start of an administrative script, search only known directories.

Use /usr/local/bin, /usr/bin, and /bin in that order.

Which setting 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.

PATH=/usr/local/bin:/usr/bin:/bin; export PATH: Correct. It fixes the trusted directories and exports the chosen order to child commands.
PATH=$PATH:/usr/local/bin: Incorrect. It keeps an untrusted user-supplied PATH.
PATH=.:$PATH: Incorrect. Putting . first makes execution depend on the current directory.
unset PATH: Incorrect. Removing PATH makes command lookup depend on defaults or absolute paths.

Detailed explanation

CorrectPATH=/usr/local/bin:/usr/bin:/bin; export PATH

Correct. It fixes the trusted directories and exports the chosen order to child commands.

IncorrectPATH=$PATH:/usr/local/bin

Incorrect. It keeps an untrusted user-supplied PATH.

IncorrectPATH=.:$PATH

Incorrect. Putting . first makes execution depend on the current directory.

Incorrectunset PATH

Incorrect. Removing PATH makes command lookup depend on defaults or absolute paths.

An example you can run in a temporary verification environment.

sh -c 'PATH=/usr/local/bin:/usr/bin:/bin; export PATH; printf "%s\n" "$PATH"'

/usr/local/bin:/usr/bin:/bin

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-102-937

EnvironmentPOSIX sh / 短命プロセス

Last technical review2026-08-13