Displaying the process parent tree | LinuC Level 1 101 Exam original practice question

1.01.4Basic

Find which service process created worker processes.

Display the process hierarchy with PIDs.

Which 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.

ps -p tree: Incorrect. ps -p expects a PID list; tree is not the process-tree option in this form.
pstree -p: Correct. pstree -p shows the process hierarchy and PIDs.
pgrep --parent-all: Incorrect. pgrep has no --parent-all option for this display.
uptime -p: Incorrect. uptime reports system uptime and load.

Detailed explanation

Incorrectps -p tree

Incorrect. ps -p expects a PID list; tree is not the process-tree option in this form.

Correctpstree -p

Correct. pstree -p shows the process hierarchy and PIDs.

Incorrectpgrep --parent-all

Incorrect. pgrep has no --parent-all option for this display.

Incorrectuptime -p

Incorrect. uptime reports system uptime and load.

An example you can run in a temporary verification environment.

pstree -p $$ | head

現在shellを起点としたprocess tree

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-101-362

Environmentpsmisc系pstree

Last technical review2026-08-13