Quiz Module 4 - Process Management

Instructions

This quiz contains 30 multiple-choice questions to validate your understanding of Module 4.

Tip: Answer each question before revealing the answer. The answers are hidden just after each question.

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Question 1

What is a process in Linux?

1. An executable file

2. An instance of a running program with its own PID

3. A system directory

4. A user

See explanation

Correct answer: An instance of a running program with its own PID

Explanation: A process is an instance of a running program. Each process has a unique PID (Process ID), its own memory, and its own resources.

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Question 2

What is the PID of the init (or systemd) process?

1. 0

2. 1

3. 2

4. 100

See explanation

Correct answer: 1

Explanation: The init process (or systemd on modern systems) always has PID 1. It is the first process launched at startup and the parent of all other processes.

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Question 3

Which command allows you to see the running processes?

1. ps

2. proc

3. process

4. list

See explanation

Correct answer: ps

Explanation: ps (process status) displays running processes. Common options: ps aux (all processes), ps -ef (extended format), ps -e (all processes).

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Question 4

Which command displays processes in real-time with CPU and memory usage?

1. ps

2. top or htop

3. process

4. monitor

See explanation

Correct answer: top or htop

Explanation: top displays processes in real-time with CPU and memory usage. htop is an improved and more interactive version. You can also use vmstat or iostat.

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Question 5

What is a PID?

1. Process Information Data

2. Process ID - Unique identifier of a process

3. Program Installation Directory

4. Personal Identification Document

See explanation

Correct answer: Process ID - Unique identifier of a process

Explanation: The PID (Process ID) is a unique number assigned to each process upon creation. It allows identifying and managing processes.

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Question 6

What is a PPID?

1. Process Priority ID

2. Parent Process ID - PID of the parent process

3. Process Performance ID

4. Process Permission ID

See explanation

Correct answer: Parent Process ID - PID of the parent process

Explanation: The PPID (Parent Process ID) is the PID of the process that created this process. Processes form a tree hierarchy with init (PID 1) as the root.

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Question 7

Which command allows you to kill a process?

1. stop

2. kill

3. terminate

4. remove

See explanation

Correct answer: kill

Explanation: kill sends a signal to a process. Syntax: kill PID (TERM by default), kill -9 PID (KILL, forced), kill -15 PID (TERM, graceful).

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Question 8

Which signal forces the termination of a non-responsive process?

1. SIGTERM (15)

2. SIGKILL (9)

3. SIGINT (2)

4. SIGHUP (1)

See explanation

Correct answer: SIGKILL (9)

Explanation: SIGKILL (signal 9) forces the immediate termination of a process and cannot be ignored or intercepted. Use it as a last resort: kill -9 PID or kill -KILL PID.

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Question 9

Which command allows you to kill a process by its name?

1. killname

2. killall or pkill

3. terminate

4. stop

See explanation

Correct answer: killall or pkill

Explanation: killall process_name kills all processes with that name. pkill pattern kills processes matching the pattern. Examples: killall firefox, pkill -9 python.

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Question 10

Which command displays the process tree?

1. tree

2. pstree

3. proctree

4. ps -tree

See explanation

Correct answer: pstree

Explanation: pstree displays processes in a tree format, showing parent-child relationships. Options: pstree -p (with PIDs), pstree -u (with users).

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Question 11

What is a zombie process in Linux?

1. A process that consumes a lot of memory

2. A terminated process whose parent has not yet read its exit status

3. A malicious process

4. A sleeping process

See explanation

Correct answer: A terminated process whose parent has not yet read its exit status

Explanation: A zombie process (state "Z") is a process that has terminated but whose entry in the process table has not yet been cleaned up because the parent process has not called wait() to read its exit status.

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Question 12

What is an orphan process in Linux?

1. A malicious process

2. A process whose parent process has terminated before it

3. A process without permissions

4. An isolated process

See explanation

Correct answer: A process whose parent process has terminated before it

Explanation: An orphan process is adopted by init (PID 1) when its parent terminates. Init becomes its new parent and reaps the zombie process when it terminates.

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Question 13

How to launch a process in the background?

1. command -bg

2. command &

3. command background

4. bg command

See explanation

Correct answer: command &

Explanation: Adding & at the end of a command launches it in the background. Example: sleep 60 &. The shell displays the process PID and immediately returns to the prompt.

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Question 14

Which command allows you to see background jobs?

1. processes

2. jobs

3. background

4. list

See explanation

Correct answer: jobs

Explanation: jobs displays the background jobs of the current shell. Options: jobs -l (with PIDs), jobs -a (including completed). Jobs are numbered: [1], [2], etc.

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Question 15

Which command brings a job to the foreground?

1. foreground

2. fg

3. bring

4. front

See explanation

Correct answer: fg

Explanation: fg brings a job to the foreground. Syntax: fg (last job), fg %1 (job number 1), fg %name (job by name). Use bg to send to the background.

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Question 16

Which command allows you to launch a process that continues after disconnection?

1. keep

2. nohup

3. persist

4. continue

See explanation

Correct answer: nohup

Explanation: nohup (no hang up) allows a process to continue after terminal disconnection. Syntax: nohup command &. Output is redirected to nohup.out by default.

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Question 17

Which command allows you to change the priority of a process?

1. priority

2. nice and renice

3. setpriority

4. chpriority

See explanation

Correct answer: nice and renice

Explanation: nice launches a process with a modified priority: nice -n 10 command (priority +10). renice changes the priority of an existing process: renice 10 PID (priority +10). Values range from -20 (high priority) to +19 (low priority).

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Question 18

What is the range of nice values in Linux?

1. 0 to 100

2. -20 to +19

3. 1 to 10

4. 0 to 20

See explanation

Correct answer: -20 to +19

Explanation: Nice values range from -20 (highest priority) to +19 (lowest priority). By default, processes have a priority of 0. Only root can use negative values (higher priority).

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Question 19

Which signal is sent by default with Ctrl+C in the terminal?

1. SIGKILL

2. SIGINT

3. SIGTERM

4. SIGHUP

See explanation

Correct answer: SIGINT

Explanation: Ctrl+C sends SIGINT (signal 2) to the foreground process. It is an interrupt signal that can be intercepted by the process. To force termination, use Ctrl+\ (SIGQUIT) or kill -9.

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Question 20

Which signal is sent by Ctrl+Z in the terminal?

1. SIGINT

2. SIGSTOP

3. SIGTERM

4. SIGKILL

See explanation

Correct answer: SIGSTOP

Explanation: Ctrl+Z sends SIGSTOP (signal 19) to the foreground process, suspending it. The process can be resumed with fg (SIGCONT) or bg (in the background).

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Question 21

Which command allows you to suspend a process?

1. suspend

2. kill -STOP or kill -19

3. pause

4. stop

See explanation

Correct answer: kill -STOP or kill -19

Explanation: kill -STOP PID or kill -19 PID suspends a process (SIGSTOP). The process can be resumed with kill -CONT PID or kill -18 PID (SIGCONT).

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Question 22

Which command allows you to resume a suspended process?

1. resume

2. kill -CONT or kill -18

3. continue

4. start

See explanation

Correct answer: kill -CONT or kill -18

Explanation: kill -CONT PID or kill -18 PID resumes a suspended process (SIGCONT). You can also use fg to bring a suspended job to the foreground or bg to send it to the background.

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Question 23

Which ps option displays all processes with full details?

1. ps -a

2. ps aux

3. ps -l

4. ps -e

See explanation

Correct answer: ps aux

Explanation: ps aux displays all processes (a = all users, u = user-oriented format, x = processes without controlling terminal) with full details: PID, CPU, memory, command, etc.

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Question 24

Which command allows you to see the processes of a specific user?

1. ps -user

2. ps -u username or ps aux | grep username

3. ps --user

4. ps user

See explanation

Correct answer: ps -u username or ps aux | grep username

Explanation: ps -u username displays the processes of a specific user. You can also use ps aux | grep username to filter by user. ps -u $USER displays the processes of the current user.

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Question 25

Which command in top allows you to kill a process?

1. t

2. k

3. x

4. d

See explanation

Correct answer: k

Explanation: In top, pressing k allows you to kill a process. It will ask for the PID and the signal (default SIGTERM). Other useful commands: q (quit), r (renice), M (sort by memory), P (sort by CPU).

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Question 26

Which command in top allows you to sort by CPU usage?

1. C

2. P

3. U

4. T

See explanation

Correct answer: P

Explanation: In top, pressing P sorts processes by CPU usage (from highest to lowest). M sorts by memory, T by CPU time, N by PID.

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Question 27

Which command allows you to see processes sorted by memory usage?

1. ps aux --sort=cpu

2. ps aux --sort=-%mem

3. ps aux --sort=mem

4. ps aux --sort=memory

See explanation

Correct answer: ps aux --sort=-%mem

Explanation: ps aux --sort=-%mem sorts processes by decreasing memory usage (the - indicates descending). ps aux --sort=%cpu sorts by CPU. You can also use ps aux | sort -k4 -rn to sort by column.

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Question 28

What is htop compared to top?

1. An older version

2. An improved and more interactive version with a graphical interface

3. An alias of top

4. A different tool for something else

See explanation

Correct answer: An improved and more interactive version with a graphical interface

Explanation: htop is an improved version of top with a more user-friendly interface, mouse navigation, colors, and better visualization. It is not always installed by default: sudo apt install htop on Ubuntu.

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Question 29

Which command allows you to see processes with their parent-child relationships?

1. ps -tree

2. ps auxf or pstree

3. ps -hierarchy

4. ps --tree

See explanation

Correct answer: ps auxf or pstree

Explanation: ps auxf displays processes in a tree format. pstree is specifically designed to display the process tree. Options: pstree -p (with PIDs), pstree -u (with users), pstree -h (highlight the current process).

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Question 30

What is the difference between kill and killall?

1. No difference

2. kill uses a PID, killall uses a process name

3. killall is safer

4. kill only works for system processes

See explanation

Correct answer: kill uses a PID, killall uses a process name

Explanation: kill PID kills a specific process by its PID. killall process_name kills all processes with that name. Examples: kill 1234, killall firefox. Be careful: killall can kill multiple processes at once!

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Quiz Result

Congratulations on completing the Module 4 quiz!

Score:

• 25-30 correct answers: Excellent! You master Linux process management.
• 20-24 correct answers: Very good! Review the concepts where you had difficulties.
• 15-19 correct answers: Good! Review the chapters on process management.
• Less than 15: Recommended to review the module before continuing.

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Next Steps

Now that you have validated your knowledge:

Module 5: User and Permissions Management
Practical Labs: Practice process management with Module 4 labs

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Quiz created on: December 2024 - Tested on Ubuntu 24.04