Based on the Linux Master 2 exam syllabusReport an error
| Category | Part 1 | Part 2 |
|---|---|---|
| Subjects | Linux General | Linux Operation and Management + Linux Usage |
| Weeks in this track | W1-W3 | W4-W7 + W8-W11 |
| Questions · time | 50 questions · 60 minutes | 80 questions · 100 minutes |
| Format | Online exam, four choices | Written, four choices |
| Passing criteria | 60 points or more | 60 points or more, and a score below 40% in any subject is a fail |
W1 What is Linux Torvalds 1991 · GPL · distribution lineages (Red Hat/Debian/Slackware)
kernel versions · open-source licenses
W2 Install and boot partitions · swap · file systems (ext2/3/4, xfs) · inode
boot order BIOS → bootloader (GRUB) → kernel → init/systemd
runlevel 3 text · 5 graphical
W3 Basic commands pwd cd ls · cp(-r) mv(-r not needed) rm(-r) · ln(-s)
cat less head tail(-f) · find (path first) grep (contents) · wc -l
/etc/passwd 7 fields · UID 0 root · su vs sudo
W4 Permissions rwx = 4/2/1 · 644 file · 755 directory
umask is subtracted (base 666 for files · 777 for directories)
special permissions 4 SetUID · 2 SetGID · 1 Sticky · /tmp 1777
FHS · mount/umount · df (file system) vs du (path) · fsck
W5 Shell Bourne (sh ksh bash zsh dash) vs C (csh tcsh)
shell variables (set) vs environment variables (env, export) · PATH colon
login .bash_profile / non-login .bashrc · source
FD 0/1/2 · > >> 2> &> · pipe · alias/unalias · history
W6 Editor, process vi 3 modes · dd yy p · :wq :q! · :%s/A/B/g · nano (Ctrl+O)
PID 1 systemd · orphan vs zombie · fg/bg/Ctrl+Z
ps -ef / ps aux · signal 9 force, 15 default · nice -20 to 19
cron 5 fields (min hour day month weekday) · at once
W7 Software, devices RPM (Red Hat, SUSE) vs DEB (Debian, Ubuntu)
low-level rpm/dpkg (no dependencies) vs high-level yum/apt (dependencies)
apt update (list) vs upgrade (actual) · tar -c/-x -z/-j/-J
block b / character c · udev · CUPS 631 · ALSA · SANE| Value | What it is |
|---|---|
| 4 / 2 / 1 | r/w/x, SetUID/SetGID/Sticky |
| 644 / 755 / 1777 | File / directory / /tmp |
| 666 / 777 | umask base values (file / directory) |
| 7 / 0 | Number of /etc/passwd fields / root's UID |
| 9 / 15 | Force-kill / default termination signal |
| 5 | Number of crontab fields |
| 3 / 5 | Text / graphical runlevel |
| 631 | CUPS port |
Numbers that did not get confused when memorized week by week get mixed up once they come together on one exam paper. Here they are organized in reverse, by number.
| Number | Permissions (W4) | Editor and process (W6) | Install and boot (W2) | Account and shell (W3, W5) |
|---|---|---|---|---|
| 0 | No permission --- | nice default | Shutdown | root's UID · standard input · $? success |
| 1 | x · Sticky | PID 1 (systemd) · SIGHUP | Single-user (recovery) | Standard output |
| 2 | w · SetGID | SIGINT (Ctrl+C) | — | Standard error |
| 3 | -wx | Number of vi modes | Text | — |
| 4 | r · SetUID | — | Maximum number of MBR primary partitions | Number of /etc/group fields |
| 5 | r-x | Number of crontab time fields | Graphical · starting number of logical partitions | — |
| 6 | rw- | — | Reboot · number of /etc/fstab fields | — |
| 7 | rwx | Sunday in the crontab weekday field (same as 0) | — | Number of /etc/passwd fields |
| 9 | — | SIGKILL | — | Number of /etc/shadow fields |
| 15 | — | SIGTERM (kill default) | — | — |
x), special permission 1 (Sticky). A question asks about only one of these, but the others are laid out as wrong choices.This is the table we collected once in week 3, widened to cover W4-W7 commands. Memorizing only the letter gets you wrong answers; you have to memorize it together with the command.
| Letter | Meaning per command |
|---|---|
-r | cp -r, rm -r include subdirectories / ls -r reverse order / userdel -r also deletes the home directory / dpkg -r remove package / crontab -r delete everything / uname -r kernel version |
-l | ls -l detailed / wc -l line count / fdisk -l, crontab -l, kill -l, dpkg -l list / usermod -l rename |
-i | cp -i confirm before overwriting / grep -i ignore case / rpm -i, dpkg -i install / df -i, ls -i inode |
-e | ps -e all processes / rpm -e erase / crontab -e edit |
-f | rm -f force / tail -f follow / ps -f detailed / tar -f specify file name |
-a | ls -a include hidden / uname -a everything / mount -a all of fstab / usermod -aG append |
-u | useradd -u specify UID / crontab -u, top -u specify user |
-U | rpm -U upgrade (uppercase) |
-p | mkdir -p including intermediate paths / cp -p preserve attributes / renice -p, top -p specify PID |
-h | df -h, du -h human-readable units / the h in rpm -ivh is the progress display (#) |
rpm -e, dpkg -r (-P to include configuration), crontab -r, userdel, atrm. The single word "delete" maps to five different notations.-l. The exceptions are rpm -qa (all installed packages) and atq.A passage saying "I ran the command but it disappeared after reboot (or after logging in again)" has the same structure regardless of the week. A command lasts only for now; it must be written to a file to persist.
| Just now (command) | Next time too (file) | Week |
|---|---|---|
mount /dev/sdb1 /data | One line in /etc/fstab | W2, W4 |
systemctl isolate multi-user.target | systemctl set-default multi-user.target | W2 |
init 3 | /etc/inittab | W2 |
umask 027 | ~/.bashrc (/etc/profile for all users) | W4 |
export EDITOR=vi | ~/.bash_profile | W5 |
alias ll='ls -l' | ~/.bashrc | W5 |
:set nu inside vi | ~/.vimrc | W6 |
at 22:00 (runs once and disappears) | crontab -e (repeating) | W6 |
source, /etc/fstab with mount -a, and /etc/default/grub requires regenerating grub.cfg with grub2-mkconfig. Only schedules edited with crontab -e take effect as soon as you save.| Task | Regular user | root |
|---|---|---|
Change permissions of own files (chmod) | O | O |
Change a file's owner (chown) | X | O |
Change own password (passwd) | O | Can also change others' |
Create/delete accounts (useradd, userdel) | X | O |
Read /etc/passwd | O | O |
Read /etc/shadow | X | O |
Send signals to own processes (kill) | O | All processes |
| Raise the nice value (yield) | O | O |
| Lower the nice value (specify negative) | X | O |
View another user's crontab (crontab -u) | X | O |
/etc/shadow that only root can write, is the SetUID from week 4. Because /usr/bin/passwd is 4755, it borrows the owner's (root's) privileges only while running. It is the classic case where the permission, account, and special-permission units overlap in a single question.Exam questions come by week, but real work crosses weeks. Following the process of creating one collaboration directory, we point out which unit each line belongs to.
groupadd -g 1500 dev # W3 create group → one line in /etc/group
useradd -m -u 1001 -G dev alice # W3 create account → /etc/passwd, home directory
passwd alice # W3 password → /etc/shadow
id alice
# uid=1001(alice) gid=1001(alice) groups=1001(alice),1500(dev)
mkdir /project # W3
chgrp dev /project # W4 set the owning group to dev
chmod 2770 /project # W4 SetGID(2) + rwxrwx---
ls -ld /project
# drwxrws--- 2 root dev 4096 Oct 14 10:00 /project
su - alice # W3, W5 switch to a login shell
umask 027 # W4
touch /project/plan.txt
ls -l /project/plan.txt
# -rw-r----- 1 alice dev 0 Oct 14 10:05 /project/plan.txt| What to read in the output | Why | Unit |
|---|---|---|
groups=...,1500(dev) | -G is a supplementary group. The primary group (gid=) is alice, created separately with the same name as the account (default behavior on Red Hat and Debian families) | W3 |
The s in drwxrws--- | The x spot of the group field is s → SetGID | W4 |
plan.txt's group is dev | It inherited the directory's group rather than alice's primary group (alice) | W4 |
plan.txt's permission 640 | umask 027 was subtracted from the file base 666 | W4 |
The hyphen in su - | The hyphen makes it a login shell that reads even alice's .bash_profile | W5 |
The process and package units tack on to this.
crontab -l # W6 root's schedule list
# 0 3 * * 0 tar -czf /backup/project.tar.gz /project* · month * · weekday 0, so it means "every Sunday at exactly 3 o'clock" (W6).tar -czf is c bundle · z gzip compression · f file name. Without z, it only bundles and does not compress (W7).>> /var/log/backup.log 2>&1 at the end of the line (W5).These are sentences mixing several weeks. Decide for yourself first, then look at the right side.
| Sentence | Verdict | Reason |
|---|---|---|
The seventh field of /etc/passwd and the value changed by chsh -s are the same thing | ○ | Both are the login shell |
In ps -ef, every process with PPID 1 is a zombie | ✗ | It only means the parent is systemd. A zombie is seen by state Z |
The -e in rpm -e and crontab -e means the same thing | ✗ | Erase versus edit |
After apt update finishes, newer-version packages are installed | ✗ | It only refreshes the list. Installation is apt upgrade |
Runlevel 5 and graphical.target point to the same state | ○ | 3 is multi-user.target |
kill 1234 and kill -15 1234 are the same command | ○ | The default signal is 15 |
A file made with tar -cvf a.tar dir is compressed | ✗ | It was only bundled. Compression is -z, -j, -J |
An alias written in ~/.bashrc can be used in the current shell as soon as it is saved | ✗ | You must run source ~/.bashrc |
/dev/sda5 on an MBR disk is a logical partition | ○ | Logical partitions always start from 5 |
find / -name core 2> /dev/null removes error messages from the screen | ○ | Channel 2 was sent to the discard location |
SUSE uses .rpm, so it is managed with yum | ✗ | The format is RPM, but the tool is zypper |
An executable with chmod 4755 runs with the permissions of the person who runs it | ✗ | It runs with the file owner's permissions |
The -i in df -i and ls -i both relate to inodes | ○ | inode usage / inode number |
| A file created under umask 000 has permission 777 | ✗ | The file base value is 666, so 666 |
| Type | Marker in the passage | Where mistakes happen |
|---|---|---|
| Pick the correct one | "which is correct" | If the first choice looks plausible, you don't read to the end |
| Pick the incorrect one | "which is not correct", "wrong", "furthest from" | You mark a correct choice as the answer as soon as you see it |
| The odd one out | "different from the other three" | You must first find what the three have in common (shell families, package families, editor types) |
| Order | "the correct order" | Boot order, ./configure → make → make install, new disk fdisk → mkfs → mount |
| Calculation | Four numeric choices | Octal permissions, umask (files 666, directories 777), reading crontab |
| Matching | "correctly paired" | Choices with reversed order get mixed in, such as df - du, low-level - high-level tools |
rwxr-x--x to octal the moment I see it/etc/passwd fields (name, x, UID, GID, description, home, shell)export that is passed on to child processes.rpm and dpkg.Click a choice to reveal the answer and explanation.
Question 1
Which of the following is the license applied when the Linux kernel is distributed?
Question 2
Which of the following is responsible for loading the kernel into memory during the Linux boot process?
Question 3
Which of the following is the permission state after running the command chmod 640 report.txt?
Question 4
With the umask value set to 002, which of the following is the permission of a newly created directory?
Question 5
Which of the following is the command that uses find to find files larger than 100MB under /home?
Question 6
Which of the following is the special permission, and its value, that when set on a directory makes files created inside it inherit the directory's group?
Question 7
Which of the following is the command used last when you have asked a running process to terminate normally but got no response?
Question 8
Which of the following is the range symbol specified in the vi editor to replace a string across the whole file?
Question 9
Which of the following is the command that installs packages on the Debian family while handling dependencies automatically?
Question 10
Which of the following correctly pairs the command that shows the total capacity and usage rate per file system with the command that shows the total usage of a specific directory?