Ubuntu Linux Commands

FolSec Linux Disk Enlargement

The disk size of the linux machine on VMware is increased.

“reboot” The machine is restarted with the command.

“cfdisk” command is typed.

“dev/sda3” Click the Resize button.

The new dimension appears and click enter.

You will see the Write option.

“yes” Written.

Hit the Quit button and log out.

On a Linux machine, go to “cd /folsec/bin”

“bash extend_disk_space.sh” The command is executed.

Changing rope

“cd /folse/bin” Written.

“bash ip_setup.sh” Written.

DNS Change Command

sudo nano /etc/resolv.conf

# nameserver 8.8.8.8

# nameserver 8.8.4.4

sudo systemctl restart systemd-resolved

Linux Machine Name Change Command

sudo hostnamectl set-hostname yeni-isim

sudo nano /etc/hosts

# 127.0.0.1 localhost yeni-isim

Docker Update Command

“docker compose down” Closes services.

“docker compose pull backend” backend update command.

“docker compose pull client” client update command.

“docker compose up --build -d” Command to uninstall services.

“docker logs folsec-backend -f” If the control command says Application Start up, you can leave the command line and switch to the interface by doing ctrl + z within 15 – 20 seconds.

Disk Size Learning Command

“df -h”

Command to Learn RAM Usage

“free -m”

IP Address Learning Command

ip addr show

System / File Management Commands
Command	Description	Example Usage
pwd	Shows the current directory	pwd → /home/tevfik
ls	Lists files and folders in the directory	ls -l
cd	Change directory	cd Documents
mkdir	Create a new folder	mkdir NewFolder
rmdir	Remove an empty folder	rmdir OldFolder
touch	Create a new file	touch file.txt
cp	Copy file/folder	cp file.txt copy.txt
mv	Move or rename file/folder	mv file.txt NewFile.txt
rm	Delete file or folder	rm file.txt / rm -r FolderName
cat	View file content	cat file.txt
nano	Edit file in terminal	nano file.txt
chmod	Change file/folder permissions	chmod 755 script.sh
chown	Change file/folder ownership	chown tevfik:tevfik file.txt
grep	Search inside files	grep "searched_word" file.txt


System / Process and Service Management
Command	Description	Example Usage
top	Shows system and process status	top
ps	Lists running processes	ps aux
sudo	Run commands with administrative privileges	sudo apt update
apt	Package management (install/update/remove)	sudo apt install git / sudo apt remove git
dpkg	Query package status	dpkg -l
systemctl	Start, stop, check status of services	sudo systemctl start apache2
service	Alternative service management command	sudo service apache2 restart
df	Show disk usage	df -h
du	Show file/folder size	du -sh Documents/


Network / Networking Commands
Command	Description	Example Usage
ifconfig / ip a	Show network interfaces	ifconfig / ip a
ping	Test connectivity to another computer	ping 8.8.8.8
netstat	Show network connections and ports	netstat -tulnp
ss	Show active connections and port status	ss -tuln
ufw	Firewall enable/disable and management	sudo ufw enable / sudo ufw disable
wget	Download a file	wget https://example.com/file.zip
curl	Fetch data from web	curl https://example.com
netplan apply	Apply Netplan configuration files	sudo netplan apply
netplan generate	Check Netplan configuration	sudo netplan generate
netplan try	Test Netplan changes	sudo netplan try
netplan --debug apply	Apply Netplan with detailed output	sudo netplan --debug apply


Docker Commands
#	Command	Description	Example Usage
1	docker --version	Shows Docker version	docker --version
2	docker info	Provides detailed info about Docker	docker info
3	docker pull	Download image from Docker Hub	docker pull ubuntu:22.04
4	docker images	List local Docker images	docker images
5	docker rmi	Remove Docker image	docker rmi ubuntu:22.04
6	docker run	Create and run a new container	docker run -it ubuntu:22.04 bash
7	docker ps	List running containers	docker ps
8	docker ps -a	List all containers (including stopped)	docker ps -a
9	docker stop	Stop a container	docker stop container_id
10	docker start	Start a container	docker start container_id
11	docker restart	Restart a container	docker restart container_id
12	docker rm	Remove a container	docker rm container_id
13	docker exec	Run command inside a running container	docker exec -it container_id bash
14	docker logs	View container logs	docker logs container_id
15	docker build	Build image from Dockerfile	docker build -t myimage:latest .
16	docker tag	Add a new tag to image	docker tag myimage:latest myrepo/myimage:v1
17	docker push	Push image to Docker Hub	docker push myrepo/myimage:v1
18	docker inspect	Detailed info about container or image	docker inspect container_id
19	docker network ls	List Docker networks	docker network ls
20	docker volume ls	List Docker volumes	docker volume ls