Bash/Linux

Question 1

ls -la

Answer 1

for listing permission

Question 2

Get-LocalGroup

Answer 2

Get default local groups listed w descriptions

Question 3

Get-LocalUser

Answer 3

gives the names of users, if they are enabled or not, with description

Question 4

Get-LocalGroupMember

Answer 4

can see which users are in the group

Question 5

sudo su -

Answer 5

you become the root user, but not recommended if a mistake has been made

Question 6

sudo cat /etc/group file

Answer 6

shows which groups or users have sudo accessibility to run commands/unrestricted access

Question 7

cat /etc/group

Answer 7

shows each group, group password (x means the pw is encrypted), group ID, list of users in the group

Question 8

cat etc/password

Answer 8

first field is username, password, UID (user ID),

Question 9

How to reset password in GUI

Answer 9

computer management, local users and groups, select account, properties, then you can ask to reset PW or set it manually for them by selecting set PW

Question 10

net user cindy ‘some_password’ OR * to then ask for PW for user

OR /logonpasswordchg:yes

Answer 10

to change a users password, set it hidden from sight, or for next login they will have to change it

Question 11

passwd cindy

Answer 11

changing password for cindy in Linux, you need current PW, then entering a new one

Question 12

sudo passwd -e cindy

Answer 12

set the password to expire and require a new one in Linux

Question 13

new -localuser in windows

Answer 13

creates a new user in windows

Question 14

net user cindy * /add

Answer 14

adds a new user called cindy and asks for the password/hidden in Windows

Question 15

net user cindy /logonpasswordchg:yes

Answer 15

next login cindy will need to change her password in Windows

Question 16

net user cindy /del

Answer 16

delete cindy command in Windows

Question 17

Remove-LocalUser Cindy

Answer 17

removes a local user in Windows

Question 18

sudo useradd cindy

Answer 18

adding a user in Linux

Question 19

sudo userdel cindy

Answer 19

deletes a user in Linux

Question 20

ls -l ~/my_file

Answer 20

listing it using the long flag to see the permissions on the file

• at the beginning is a normal file, D is for directory, the next 9 bits are the permissions grouped in sets of 3

first set is permission of owner,
second set is permission of group,
last is permission of all other users
- means its disabled, otherwise it has rwx (read, write, execute)

Question 21

chmod u+x my_cool_file

chmod u-x my_cool_file

chmod ugo+r my_cool_file

Answer 21

change the permission by giving executable or x access to the owner or you.

remove a permission with -

add read permissions to our owner, the group that the file belongs to, and to all users and groups

Question 22

numerical equivalent for rwx (read, write, execute)

Answer 22

4 for read,
2 for write,
1 for execute

chmod 754 my_cool_file

stands for 4+2+1 meaning rwx for the owner,
5 is 4+1 for read and execute for g

Question 23

if you ls -l /usr/bin/passwd, you get

-rwsr-xr-x 1 root root 54256 May 16 19:35

what does the S in the permissions stand for?

Answer 23

S stands for set UID, you can run permissions as if you were the owner of the file

Question 24

sudo chmod +t my_folder/

OR

sudo chmod 1755 my_folder/

Answer 24

sticky bit aka this means everyone can add and modify files in the /tmp directory, but only root or the owner can delete the /tmp directory.

Question 25

sudo apt install gimp

Answer 25

open source graphical editor named Gimp

Question 26

where are repository source files saved on Ubuntu?

Answer 26

/etc/APT/sources.list

Question 27

sudo apt update

sudo apt upgrade

Answer 27

updates the list of packages in your repos but wont upgrade them.

to upgrade packages, it will then install any outdated packages for you automatically. before installing new software, its good to run apt update

Question 28

orca.exe

Question 29

uname -r

Answer 29

gives us system information on the kernal for the microchip installed and what version it is

Question 30

sudo apt update

sudo apt full-grade

Answer 30

this will update for a new kernal version for microchip

Question 31

FAT32

Answer 31

file system that support reading and writing data to all 3 major OS, linux, windows, Mac OS

files cant be larger than 4 GB
size of file system cant be bigger than 32 GB
mainly for USB

Question 32

Partition

Answer 32

splitting up the hard drive into another section that can be used.

if a different OS is on the partition, it is called a volume

disks can have 4 partitions, with extended, and logical as additional partitions within

Question 33

GPT

Answer 33

GUID Partition Table

2 TB or greater size volume that has 1 type of partition, but has unlimited partitions

Question 34

MBR and GPT partitioning

Answer 34

MBR is an interactive program and GPT is from command line

sudo parted -l (disk named /dev/sda will be partitioned into /dev/sda 1)

sudo parted /dev/sdb
there was error as unrecognized disk lable

mklabel gpt
print

sudo mkfs -t ext4 /dev/sdb1

sudo parted -l

then mount it

Question 35

sudo mount /dev/sdb1 /my_usb/

Answer 35

mounting the usb

Question 36

/etc/fstab

Answer 36

to permanently mount a disk

cat /etc/fstab
sudo blkid (will show UUID for block device ID's)

Question 37

mkpart primary linux-swap 5GiB 100%

sudo mkswap /dev/sdb2
sudo swapon /dev/sdb2

Answer 37

virtual memory is known as swap space

to automatically mount the swap space everytime, just add

swapentry /etc/fstab file like earlier

Question 38

inode

Answer 38

stores everything about a file except for the filename and data

Question 39

df -h

Answer 39

disk free space in human readable form

Linux generally doesnt need disk defrag

Question 40

sudo fsck /dev/sda

Answer 40

checks the filesystem to repair

Question 41

ps -x -ef (more details of where it is located)

ps -ef | grep Chrome (to find chrome)

cat /proc/1805 to look at more info on process state

Answer 41

shows processes running

PID
PPID
C is children processes
TTY is terminal associated with the process,
STAT stands for R running, T stopped, S interruptible sleep,
TIME the time the process has been running

Question 42

kill 10235

kill -KILL 10235

kill -CONT 10235

Answer 42

kills a firefox process or something else using PID

killed without it cleaning up processes, may lead to corruption

process turned from a T to an S (stop to a suspended)
SIGTERM, SIGKILL, SIGSTP are most common signals

Question 43

top

uptime

lsof

Answer 43

top processes being used

shows current time, up for X time, how many users, and load averages

lists open files and what processes are using them, good for showing processes that are holding open files

Question 44

ls -l /

ls -la /

Answer 44

gives detailed info about our directory and the files and folders in them

shows all files aka hidden files

Question 45

cp -r ‘cat pics’ ~/Desktop

Answer 45

will copy the directory of cat pics and all contents recursively for all contents

Question 46

less mytext.txt

head mytext.txt (or tail

Answer 46

interactive shell,

first 10 lines of file or last 10

keys for up and down
g at beginning of file,
G goes to end of file,
/word find_thisword
q to quit

Question 47

grep cow *.txt

Answer 47

find strings of cow in all .txt files

Question 48

less /var/log/syslog 2> /dev/null/

Answer 48

filtered from error messages, is a redirector or STDER or standard error

Question 49

scp /home/drdoo/Desktop/myfile.txt drdoo@104.131.122.215:

Answer 49

will copy a file with the path of the file

Question 50

unmount /dev/sdd

dd if=/dev/sdd of=~/Desktop/myusbimage.img bs=100M

Answer 50

how to disk clone in linux, first make sure to unmount the disk, then copy it over using a USB flash image