Linux Commands

Question 1

ls

Answer 1

List the contents of the directory you want

Question 2

alias

Answer 2

Let’s you define temporary aliases in your shell session

Replace a word with a series of commands

Question 3

unalias

Answer 3

Remove alias

Question 4

pwd

Answer 4

print working directory

Ex: /home/john/Documents

Question 5

cd

Answer 5

Change directory

Question 6

cd ..

Answer 6

Move up a level

Question 7

cd -

Answer 7

Return to previous directory

Question 8

cp

Answer 8

Copy files and folder

Just add source and destination

Ex:
cp file_to_copy.txt new_file.txt

Question 9

rm

Answer 9

Remove files and directories

Question 10

cp -r

Answer 10

Copy entire directories

In Linux, files end with forward slash

Question 11

rm -r

Answer 11

Delete empty dorectory

Question 12

rm -rf

Answer 12

Remove directory with content

Question 13

mv

Answer 13

Move or rename files and directories

Move:
mv source_file destination_folder/

Rename:
mv old_file_name.txt new_file_name.txt

Question 14

mkdir

Answer 14

Create folders

Question 15

mkdir -p

Answer 15

Create subdirectories

Ex:
mkdir -p movies/2004/

Question 16

man

Answer 16

Displays manual page of any other command

Ex:
man mkdir

Question 17

touch

Answer 17

Create new empty file

Ex:
touch new_file_name

Question 18

chmod

Answer 18

Change the file permissions or mode

Question 19

chmod +r

Answer 19

read

Question 20

chmod +w

Answer 20

Write

Question 21

chmod +x

Answer 21

Execute

Question 22

./

Answer 22

Flag that lets your shell run an executable file

For example you can run a python script.

Ex:
chmod +x script
./script

Question 23

Exit

Answer 23

Closes the terminal

Question 24

sudo

Answer 24

“Superuser do”
Basically run as admin

Ex:
sudo apt install gimp

Question 25

shutdown

Answer 25

Powers off your machine in one minute but you can change the time to

shutdown now

Or

shutdown 20:40

Question 26

shutdown -c

Answer 26

Cancels shutdown

Question 27

htop

Answer 27

Interactive process viewer

Question 28

unzip

Answer 28

Extract .zip files

Question 29

apt, yum, pacman

Answer 29

Access package managers (basically software manager)

Example installing gimp:
sudo apt install gimp
sudo yum install gimp
sudo pacman -S gimp

Question 30

echo

Answer 30

Displays defined text

echo “cool message”

Question 31

cat

Answer 31

Concatenate, lets you create, view, and concatenate files

Mainly used to preview a file without opening a text editor

Question 32

ps

Answer 32

Look at the processes your current shell is running

Tells you process ID (PID), TellTYpewriter (TTY), time, and command name

Question 33

htop

Answer 33

More interactive ps

Question 34

kill

Answer 34

Stop a process. Use process ID or the programs binary name

Question 35

ping

Answer 35

Test network connectivity
ping google.com
ping 8.8.8.8

Question 36

vim

Answer 36

Free open source terminal text editor

Question 37

history

Answer 37

Command history

Question 38

passwd

Answer 38

Change the password of user accounts

Question 39

which

Answer 39

Outputs the full path of shell commands

Ex:
which python

Output:
# /usr/bin/python

Question 40

shred

Answer 40

Makes a file almost unrecoverable

Question 41

less

Answer 41

Inspect files backward and forward

More interactive than cat

Question 42

tail

Answer 42

Prints the contents of a file but only last ten lines

Question 43

tail -n

Answer 43

Lets you change the number of lines

Ex:
tail -n 4 long.text

You’ll only see the last four lines

Question 44

head

Answer 44

Outputs first ten lines of a text file

Can use -n with it as well

Question 45

grep

Answer 45

Searches for lines in a text file that match a regular expression and print them

Ex:
grep “linux”

Question 46

grep -c

Answer 46

Counts the number of times the pattern repeats

Question 47

whoami

Answer 47

Displays username currently in use

Can also use echo $USER

Question 48

whatis

Answer 48

Prints a single line description of any other command

Ex:
whatis python

Question 49

wc

Answer 49

Word count

Lines, words, byte-size, name of the file

Question 50

wc -w

Answer 50

Only word count

Question 51

uname -a

Answer 51

Unix name.

operative system information.

Question 52

neofetch

Answer 52

Displays system info

CLI tool that displays information about your system like kernel version, shell, and hardware

Question 53

find

Answer 53

Searches for files in a directory hierarchy based on regex expression

Syntax:
find [flags] [path] -name [expression]

Question 54

wget

Answer 54

World Wide Web get.

Retrieve content from the internet