Linux Commands Practice – Kali Linux 🐉

Overview

A beginner-friendly Linux commands practice repository created while learning Kali Linux using VirtualBox.

This repository contains Linux commands along with:

meaning
syntax
examples
outputs
screenshots

The purpose of this repository is to document Linux command practice and improve terminal usage skills.

Basic Navigation Commands

pwd
ls
ls -l
ls -a
ls -la
cd
cd ..
clear

File Management Commands

mkdir
touch
cp
mv
rm
rm -r
cat

User Management Commands

whoami
passwd
sudo
id

Networking Commands

ip a
ping google.com
ifconfig
netstat -tulnp
traceroute google.com
nslookup google.com

Package Management Commands

sudo apt update
sudo apt upgrade
sudo apt install
sudo apt remove

Permissions Commands

chmod +x
chmod 777
chown

Process Commands

top
ps aux
kill

Cybersecurity Tools Commands

whois domain.com
nmap target_ip
wireshark

1. pwd

Meaning

pwd stands for Print Working Directory.

It is used to display the current folder/location where the user is present.

Syntax

pwd

Example

pwd

Output

/home/kali

Screenshot

2. ls

Meaning

ls is used to list the files and folders present in the current directory.

Syntax

ls

Example

ls

Output Example

Desktop Documents Downloads Pictures Videos

Screenshot

3. ls -l

Meaning

ls -l displays files and folders in detailed list format.

It shows:

file permissions
owner
file size
timestamps

Syntax

ls -l

Example

ls -l

Output Example

drwxr-xr-x 2 kali kali 4096 Desktop
-rw-r--r-- 1 kali kali 220 file.txt

Screenshot

4. ls -a

Meaning

ls -a is used to display all files including hidden files and folders.

Hidden files usually start with a dot (.).

Syntax

ls -a

Example

ls -a

Output Example

.  ..  .bashrc  .profile  Desktop

Screenshot

5. ls -la

Meaning

ls -la combines:

ls -l → detailed list format
ls -a → hidden files

It displays:

hidden files
permissions
owners
timestamps
detailed file information

Syntax

ls -la

Example

ls -la

Output Example

drwxr-xr-x kali kali Desktop
-rw-r--r-- kali kali .bashrc

Screenshot

6. cd foldername

Meaning

cd stands for Change Directory.

It is used to move into a specific folder.

Syntax

cd foldername

Example

cd Documents
pwd

Output

/home/kali/Documents

Screenshot

7. cd ..

Meaning

cd .. is used to move back one directory/folder.

Syntax

cd ..

Example

cd ..
pwd

Output

/home/kali

Screenshot

8. clear

Meaning

clear is used to clear the terminal screen.

After executing the command, the terminal becomes empty and clean.

Syntax

clear

Example

clear

Screenshot

9. mkdir

Meaning

mkdir stands for Make Directory.

It is used to create a new folder/directory.

Syntax

mkdir foldername

Example

mkdir test

Verification

ls

Output Example

Desktop Documents Downloads test

Screenshot

10. touch

Meaning

touch is used to create a new empty file.

Syntax

touch filename

Example

touch file.txt

Verification

ls

Output Example

file.txt

Screenshot

11. cp

Meaning

cp stands for Copy.

It is used to copy files from one location to another.

Syntax

cp sourcefile destinationfile

Example

cp file.txt copy.txt

Verification

ls

Output Example

file.txt copy.txt

Screenshot

12. mv

Meaning

mv stands for Move.

It is used to move or rename files and folders.

Syntax

mv oldname newname

Example

mv copy.txt newfile.txt

Verification

ls

Output Example

file.txt newfile.txt

Screenshot

13. rm

Meaning

rm stands for Remove.

It is used to delete files.

Syntax

rm filename

Example

rm newfile.txt

Verification

ls

Output Example

file.txt

Screenshot

14. rm -r

Meaning

rm -r is used to delete folders/directories recursively along with their contents.

Syntax

rm -r foldername

Example

rm -r test

Verification

ls

Output Example

Desktop Documents Downloads

Screenshot

15. cat

Meaning

cat stands for Concatenate.

It is used to view the contents of a file.

Syntax

cat filename

Example

echo "Hello Linux" > file.txt
cat file.txt

Output

Hello Linux

Screenshot

16. whoami

Meaning

whoami is used to display the current logged-in username.

Syntax

whoami

Example

whoami

Output

kali

Screenshot

17. passwd

Meaning

passwd is used to change the password of the current user account.

Syntax

passwd

Example

passwd

Output Example

Changing password for kali
Current password:
New password:
Retype new password:

Screenshot

18. sudo

Meaning

sudo stands for Super User Do.

It is used to run commands with administrator/root privileges.

Syntax

sudo command

Example

sudo apt update

Output Example

[sudo] password for kali:

Screenshot

19. id

Meaning

id is used to display detailed information about the current user such as:

User ID (UID)
Group ID (GID)
Groups

Syntax

id

Example

id

Output Example

uid=1000(kali) gid=1000(kali) groups=1000(kali)

Screenshot

20. ip a

Meaning

ip a is used to display IP addresses and network interface information.

Syntax

ip a

Example

ip a

Output Example

inet 192.168.1.5/24

Screenshot

21. ping google.com

Meaning

ping is used to check internet connectivity and test communication with another server.

Syntax

ping google.com

Example

ping google.com

Output Example

64 bytes from google.com

Press Ctrl + C to stop the ping command.

Screenshot

22. ifconfig

Meaning

ifconfig is used to display network interface configuration details.

Syntax

ifconfig

Example

ifconfig

Output Example

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>

Screenshot

23. netstat -tulnp

Meaning

netstat -tulnp is used to display:

open ports
active services
listening connections
process IDs

Syntax

netstat -tulnp

Example

netstat -tulnp

Output Example

tcp LISTEN 0 128 0.0.0.0:22

Some details may require sudo privileges.

Screenshot

24. traceroute google.com

Meaning

traceroute is used to display the path packets take from your system to a destination server.

Syntax

traceroute google.com

Example

traceroute google.com

Output Example

1 192.168.1.1
2 * * *

Screenshot

25. nslookup google.com

Meaning

nslookup is used for DNS lookup and finding the IP address of a domain.

Syntax

nslookup google.com

Example

nslookup google.com

Output Example

Address: 142.250.xxx.xxx

Screenshot

26. sudo apt update

Meaning

sudo apt update updates the package list from repositories.

It checks:

newest package versions
available updates
security updates

This command does not install updates.

Think of it as:

"Check what updates are available."

Syntax

sudo apt update

Example

sudo apt update

Output Example

Fetched 5 MB in 3s
Reading package lists... Done

Screenshot

27. sudo apt upgrade

Meaning

sudo apt upgrade upgrades installed packages to their latest available versions.

Syntax

sudo apt upgrade

Example

sudo apt upgrade

Output Example

Do you want to continue? [Y/n]

Screenshot

28. sudo apt install nmap

Meaning

sudo apt install is used to install software packages from repositories.

Syntax

sudo apt install package-name

Example

sudo apt install nmap

Output Example

The following NEW packages will be installed:
nmap

Screenshot

29. sudo apt remove nmap

Meaning

sudo apt remove is used to uninstall software packages.

Syntax

sudo apt remove package-name

Example

sudo apt remove nmap

Output Example

The following packages will be REMOVED:
nmap

Screenshot

30. chmod +x file.sh

Meaning

chmod stands for Change Mode.

It is used to change file permissions.

The +x option adds execute permission to a file.

Syntax

chmod +x filename

Example

Create a script:

touch script.sh

Make it executable:

chmod +x script.sh

Verify permissions:

ls -l script.sh

Output Example

-rwxr-xr-x 1 kali kali 25 May 31 script.sh

Screenshot

31. chmod 777 file.txt

Meaning

chmod 777 gives full permissions to everyone.

Owner: Read, Write, Execute
Group: Read, Write, Execute
Others: Read, Write, Execute

Syntax

chmod 777 filename

Example

chmod 777 file.txt

Check permissions:

ls -l file.txt

Output Example

-rwxrwxrwx 1 kali kali 25 May 31 file.txt

Permission Breakdown

Number	Permission
7	Read + Write + Execute
7	Read + Write + Execute
7	Read + Write + Execute

Result:

Owner  = rwx
Group  = rwx
Others = rwx

Important

⚠️ 777 is not recommended for sensitive files because everyone gets full access.

Use only for learning and testing purposes.

Screenshot

32. chown user:group file

Meaning

chown stands for Change Owner.

It is used to change the ownership of a file or directory.

Syntax

sudo chown user:group filename

Example

sudo chown kali:kali script.sh

Check ownership:

ls -l script.sh

Output Example

-rwxr-xr-x 1 kali kali 25 May 31 script.sh

Note: If the file already belongs to kali:kali, the ownership may appear unchanged.

Screenshot

33. top

Meaning

top displays live system activity and running processes.

Think of it as:

Linux Task Manager

Syntax

top

Example

top

Output Example

top - 03:14:53 up 41 min, 1 user, load average: 0.15, 0.19, 0.16

Tasks: 250 total, 1 running, 249 sleeping

%Cpu(s): 2.0 us, 1.0 sy, 97.0 id

PID USER      %CPU %MEM COMMAND
1234 kali      1.0  0.5 firefox

Exit

Press:

to quit the top screen.

Screenshot

34. ps aux

Meaning

ps aux displays all currently running processes on the system.

It shows:

Process owner
Process ID (PID)
CPU usage
Memory usage
Command name

Syntax

ps aux

Example

ps aux

Output Example

USER       PID %CPU %MEM COMMAND
root         1  0.0  0.7 /sbin/init
root         2  0.0  0.0 [kthreadd]
kali      2540  1.2  2.1 firefox

Important Columns

Column	Meaning
USER	Process Owner
PID	Process ID
%CPU	CPU Usage
%MEM	Memory Usage
COMMAND	Program Name

Screenshot

35. kill PID

Meaning

kill is used to stop a running process.

A process is identified using its Process ID (PID).

Syntax

kill PID

Example

Find a process:

ps aux | grep sleep

Output:

kali 2500 0.0 0.0 sleep 300

Kill the process:

kill 2500

Verification

ps aux | grep sleep

The process should no longer appear in the process list.

Note

PID stands for Process ID.

Every running process in Linux has a unique PID.

Screenshot

36. whois domain.com

Meaning

whois is used to retrieve information about a domain name.

It can provide details such as:

Registrar
Creation date
Expiry date
Name servers

Think of it as:

"Who owns this website?"

Syntax

whois domain.com

Example

whois google.com

Output Example

Domain Name: GOOGLE.COM
Registrar: MarkMonitor
Creation Date: 1997

Screenshot

37. nmap target_ip

Meaning

nmap stands for Network Mapper.

It is used to discover:

Open ports
Running services
Devices on a network

Think of it as:

"Checking which doors are open."

Syntax

nmap target_ip

Example

nmap scanme.nmap.org

Output Example

PORT     STATE SERVICE
22/tcp   open  ssh
80/tcp   open  http
443/tcp  open  https

Screenshot

38. wireshark

Meaning

Wireshark is a packet analysis tool used to capture and inspect network traffic.

Think of it as:

"A microscope for network communication."

Launch

wireshark

What You Can See

DNS requests
HTTP traffic
TCP packets
IP addresses

Output Example

192.168.1.5 → google.com
DNS Query

Screenshot

Quick Memory Table

Tool	Purpose
`whois`	Domain information lookup
`nmap`	Network and port discovery
`wireshark`	Packet analysis

Tools Used

Kali Linux
Oracle VirtualBox
GitHub

Skills Learned

Linux terminal navigation
File and directory management
User management commands
Linux networking basics
Linux command usage
Understanding hidden files and permissions
Command-line interface practice
Documentation using GitHub

Repository Structure

Linux-Commands-Practice
│
├── Navigation Commands (1-8)
│   ├── pwd
│   ├── ls
│   ├── ls -l
│   ├── ls -a
│   ├── ls -la
│   ├── cd
│   ├── cd ..
│   └── clear
│
├── File Management Commands (9-15)
│   ├── mkdir
│   ├── touch
│   ├── cp
│   ├── mv
│   ├── rm
│   ├── rm -r
│   └── cat
│
├── User Management Commands (16-19)
│   ├── whoami
│   ├── passwd
│   ├── sudo
│   └── id
│
├── Networking Commands (20-25)
│   ├── ip a
│   ├── ping google.com
│   ├── ifconfig
│   ├── netstat -tulnp
│   ├── traceroute google.com
│   └── nslookup google.com
│
├── Package Management Commands (26-29)
│   ├── sudo apt update
│   ├── sudo apt upgrade
│   ├── sudo apt install <package-name>
│   └── sudo apt remove <package-name>
│
├── Permissions Commands (30-32)
│   ├── chmod +x file.sh
│   ├── chmod 777 file.txt
│   └── chown user:group file
│
├── Process Management Commands (33-35)
│   ├── top
│   ├── ps aux
│   └── kill PID
│
└── Cybersecurity Tools Commands (36-38)
    ├── whois domain.com
    ├── nmap
    └── wireshark

Future Improvements

Add more Linux commands
Practice file permissions
Learn networking commands
Explore shell scripting basics
Document advanced Linux usage

Author

Tejaswani Animireddy

Name		Name	Last commit message	Last commit date
Latest commit History 30 Commits
README.md		README.md
apt-install-command.png		apt-install-command.png
apt-remove-command.png		apt-remove-command.png
apt-update-command.png		apt-update-command.png
apt-upgrade-command.png		apt-upgrade-command.png
cat-command.png		cat-command.png
cd-back-command.png		cd-back-command.png
cd-documents-command.png		cd-documents-command.png
chmod-777-command.png		chmod-777-command.png
chmod-x-command.png		chmod-x-command.png
chown-command.png		chown-command.png
clear-command-1.png		clear-command-1.png
clear-command-2.png		clear-command-2.png
cp-command.png		cp-command.png
id-command.png		id-command.png
ifconfig-command.png		ifconfig-command.png
ip-a-command.png		ip-a-command.png
kill-command-1.png		kill-command-1.png
kill-command-2.png		kill-command-2.png
ls-a-command.png		ls-a-command.png
ls-command.png		ls-command.png
ls-l-command.png		ls-l-command.png
ls-la-command-1.png		ls-la-command-1.png
ls-la-command-2.png		ls-la-command-2.png
mkdir-command.png		mkdir-command.png
mv-command.png		mv-command.png
netstat-command.png		netstat-command.png
nmap-command.png		nmap-command.png
nslookup-command.png		nslookup-command.png
passwd-command.png		passwd-command.png
ping-command.png		ping-command.png
ps-aux-command.png		ps-aux-command.png
pwd-command.png		pwd-command.png
rm-command.png		rm-command.png
rm-r-command.png		rm-r-command.png
sudo-command.png		sudo-command.png
top-command.png		top-command.png
touch-command.png		touch-command.png
traceroute-command.png		traceroute-command.png
whoami-command.png		whoami-command.png
whois-command.png		whois-command.png
wireshark-command.png		wireshark-command.png

Folders and files

Latest commit

History

Repository files navigation

Linux Commands Practice – Kali Linux 🐉

Overview

Basic Navigation Commands

File Management Commands

User Management Commands

Networking Commands

Package Management Commands

Permissions Commands

Process Commands

Cybersecurity Tools Commands

1. pwd

Meaning

Syntax

Example

Output

Screenshot

2. ls

Meaning

Syntax

Example

Output Example

Screenshot

3. ls -l

Meaning

Syntax

Example

Output Example

Screenshot

4. ls -a

Meaning

Syntax

Example

Output Example

Screenshot

5. ls -la

Meaning

Syntax

Example

Output Example

Screenshot

6. cd foldername

Meaning

Syntax

Example

Output

Screenshot

7. cd ..

Meaning

Syntax

Example

Output

Screenshot

8. clear

Meaning

Syntax

Example

Screenshot

9. mkdir

Meaning

Syntax

Example

Verification

Output Example

Screenshot

10. touch

Meaning

Syntax

Example

Verification

Output Example

Screenshot

11. cp

Meaning

Syntax

Example

Verification