LFCS Certification Process and Job Scheduling 3

Question 1

Which command displays the real-time CPU and memory usage of processes, updating every few seconds?

Accepted Answer

top

Answer

`top` provides an interactive, continuously refreshing view of system processes and resource utilization.

Question 2

What does `at now + 2 hours` do when entered in an `at` session?

Accepted Answer

Schedules the subsequent commands to run 2 hours from the current time

Answer

`at now + 2 hours` opens an at-job prompt; commands typed are queued to execute once, 2 hours later.

Question 3

Which signal number corresponds to SIGKILL?

Accepted Answer

9

Answer

SIGKILL is signal number 9; it immediately terminates a process and cannot be caught or blocked.

Question 4

How do you list all pending `at` jobs for the current user?

Accepted Answer

atq

Answer

`atq` lists all pending at jobs, showing job number, execution time, and queue for the current user.

Question 5

What is the purpose of the `/proc/[PID]/status` file?

Accepted Answer

It provides detailed status information about a specific process including memory, UID, and signal masks

Answer

`/proc/[PID]/status` exposes human-readable process metadata including state, memory usage, and signal handling info.

LFCS Certification Practice Test