LINUX COMMANDS

Question 1

LS

Answer 1

lists files and folders in a directory

Question 2

GREP

Answer 2

SEARCHES TEXT FILES OR COMMAND OUTPUT

EX: Use grep on “access.log” to find the flag that has a prefix of “THM”. What is the flag?

tryhackme@linux1:~$ grep “THM” access.log
13.127.130.212 - - [04/May/2021:08:35:26 +0000] “GET THM{ACCESS} lang=en HTTP/
1.1” 404 360 “-“ “Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36
(KHTML, like Gecko) Chrome/77.0.3865.120 Safari/537.36”

Question 3

CD

Answer 3

cd command in linux known as change directory command. It is used to change current working directory.

Question 4

SHUTDOWN

Answer 4

BRINGS DOWN SYSTEM

Question 5

PWD

Answer 5

This stands for Print Working Directory

DISPLAYS FULL PATH OR WORKING DIRECTORY

EX: /HOME/MARK

Question 6

PASSWD

Answer 6

UPDATES CURRENT USER’S PASSWORD

Question 7

MV

Answer 7

MOVES OR RENAMES FILES

Question 8

CP

Answer 8

COPY FILES

Question 9

RM

Answer 9

PERMANENTLY DELETES FILES
You can simply remove files by using rm. However, you need to provide the -R switch alongside the name of the directory you wish to remove.

ex:
tryhackme@linux2:~$ rm note
tryhackme@linux2:~$ ls
folder1 mydirectory

using -R switch:
tryhackme@linux2:~$ rm -R mydirectory
tryhackme@linux2:~$ ls
folder1

Question 10

CHMOD

Answer 10

CHANGES PERMISSIONS FOR SPECIFIED FILES

Question 11

CHOWN

Answer 11

CHANGES OWNERSHIP

Question 12

IWCONFIG

Answer 12

DISPLAYS AND CONFIGURES WIRELESS NETWORK SETTINGS

Question 13

IFCONFIG

Answer 13

DISPLAYS AND CONFIGURES NETWORK SETTINGS

Question 14

PS

Answer 14

LISTS PROCESSES

Question 15

SU

Answer 15

SWITCHES USER TO SPECIFIED USER ACCOUNT

Question 16

SUDO

Answer 16

RUNS COMMANDS USING ROOT USER ACCESS

Question 17

APT-GET

Answer 17

UPDATES AND MAINTAINS LIST OF SOFTWARE PACKAGES

Question 18

VI

Answer 18

STANDARD LINUX TEXT EDITOR

Question 19

DD

Answer 19

CREATES AN EXACT(BIT-BY-BIT) COPY OF A STORAGE VOLUME

Question 20

KILL

Answer 20

STOPS A SPECIFIED PROCESS

Question 21

echo

Answer 21

Output any text that we provide

ex:
tryhackme@linux1:~$ echo “hello Friend!”
hello Friend!

Question 22

whoami

Answer 22

Find out what user we’re currently logged in as!

ex:
tryhackme@linux1:~$ whoami
tryhackme

Question 23

cat (concatenate)

Answer 23

Outputting the Contents of a File
“Cat” is short for concatenating & is a fantastic way us to output the contents of files (not just text files!)

ex:
tryhackme@linux1:~/Documents$ ls
todo.txt
tryhackme@linux1:~/Documents$ cat todo.txt
Here’s something important for me to do later!

Question 24

touch

Answer 24

The touch command takes exactly one argument – the name we want to give the file we create. For example, we can create the file “note” by using touch note. It’s worth noting that touch simply creates a blank file. You would need to use commands like echo or text editors such as nano to add content to the blank file.

ex:
tryhackme@linux2:~$ touch note
tryhackme@linux2:~$ ls
folder1 note

Question 25

mkdir

Answer 25

making a folder, which just involves using the mkdir command and again providing the name that we want to assign to the directory. For example, creating the directory “mydirectory” using mkdir mydirectory.

ex:
tryhackme@linux2:~$ mkdir mydirectory
tryhackme@linux2:~$ ls
folder1 mydirectory note

Question 26

file

Answer 26

Determining File Type

ex:
tryhackme@linux2:~$ file note
note: ASCII text

Question 27

nano

Answer 27

To create or edit a file using nano, we simply use nano filename – replacing “filename” with the name of the file you wish to edit.

ex:
tryhackme@linux3:/tmp# nano myfile

Once we press enter to execute the command, nano will launch! Where we can just begin to start entering or modifying our text. You can navigate each line using the “up” and “down” arrow keys or start a new line using the “Enter” key on your keyboard.

Nano has a few features that are easy to remember & covers the most general things you would want out of a text editor, including:

Searching for text
Copying and Pasting
Jumping to a line number
Finding out what line number you are on

You can use these features of nano by pressing the “Ctrl” key (which is represented as an ^ on Linux) and a corresponding letter. For example, to exit, we would want to press “Ctrl” and “X” to exit Nano.

Question 28

wget

Answer 28

This command allows us to download files from the web via HTTP – as if you were accessing the file in your browser. We simply need to provide the address of the resource that we wish to download. For example, if I wanted to download a file named “myfile.txt” onto my machine, assuming I knew the web address it – it would look something like this:
ex:
wget https://assets.tryhackme.com/additional/linux-fundamentals/part3/myfile.txt

Question 29

scp(secure copy)

Answer 29

Secure copy, or SCP, is just that – a means of securely copying files. Unlike the regular cp command, this command allows you to transfer files between two computers using the SSH protocol to provide both authentication and encryption

ex: Copy files & directories from your current system to a remote system

Variable Value
The IP address of the remote system 192.168.1.30
User on the remote system ubuntu
Name of the file on the local system important.txt
Name that we wish to store the file as on the remote system transferred.txt

-With this information, let’s craft our scp command (remembering that the format of SCP is just SOURCE and DESTINATION)

And now let’s reverse this and layout the syntax for using scp to copy a file from a remote computer that we’re not logged into:

ex:
Variable Value
IP address of the remote system 192.168.1.30
User on the remote system ubuntu
Name of the file on the remote system documents.txt
Name that we wish to store the file as on our system notes.txt

The command will now look like the following:
command: scp ubuntu@192.168.1.30:/home/ubuntu/documents.txt notes.txt

Question 30

ip address

Answer 30

shows IP address information for linux devices