List of Essential Ubuntu Terminal Commands with Examples

The Ubuntu terminal (Bash shell) is a powerful tool for managing files, installing software, and controlling system processes. Below is a comprehensive list of commonly used commands with practical examples.

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1. File & Directory Operations

Command	Description	Example
ls	List directory contents	ls -l (detailed list)
cd	Change directory	cd /home/user/Documents
pwd	Print working directory	pwd → /home/user
mkdir	Create a directory	mkdir new_folder
rmdir	Remove empty directory	rmdir empty_folder
rm	Remove files/directories	rm file.txt (file) rm -r folder (recursive)
cp	Copy files/directories	cp file.txt /backup/
mv	Move/rename files	mv old.txt new.txt (rename) mv file.txt /target/ (move)
touch	Create empty file	touch newfile.txt
cat	Display file content	cat notes.txt
nano	Text editor	nano file.txt
chmod	Change file permissions	chmod +x script.sh (make executable)
chown	Change file owner	sudo chown user:group file.txt

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2. System Information & Monitoring

Command	Description	Example
uname -a	Show system info	uname -a (kernel details)
df -h	Disk space usage	df -h (human-readable)
free -h	Memory usage	free -h (RAM info)
top	Real-time process monitor	top (press q to quit)
htop	Interactive process viewer	sudo apt install htop then htop
neofetch	Display system specs	sudo apt install neofetch then neofetch
uptime	System uptime	uptime

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3. Package Management (APT)

Command	Description	Example
sudo apt update	Update package list	sudo apt update
sudo apt upgrade	Upgrade installed packages	sudo apt upgrade
sudo apt install	Install a package	sudo apt install git
sudo apt remove	Remove a package	sudo apt remove vim
sudo apt autoremove	Remove unused packages	sudo apt autoremove
apt search	Search for packages	apt search python
apt show	Show package details	apt show firefox

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4. User & Permission Management

Command	Description	Example
sudo	Run as superuser	sudo nano /etc/hosts
su	Switch user	su root
passwd	Change password	passwd (current user) sudo passwd username (another user)
whoami	Show current user	whoami
adduser	Add a new user	sudo adduser bob
deluser	Delete a user	sudo deluser bob
usermod	Modify user (e.g., add to group)	sudo usermod -aG sudo bob

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5. Network & Connectivity

Command	Description	Example
ping	Test network connection	ping google.com
ifconfig	Network interfaces (deprecated, use ip)	ifconfig
ip a	Show IP addresses	ip a
wget	Download files	wget https://example.com/file.zip
curl	Fetch web content	curl -O https://example.com/file.zip
ssh	Remote login	ssh user@192.168.1.100
scp	Secure file copy	scp file.txt user@192.168.1.100:/home/user/
netstat	Network statistics	netstat -tuln (open ports)

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6. Process Management

Command	Description	Example
ps	List running processes	ps aux (all processes)
kill	Terminate a process	kill 1234 (PID) kill -9 1234 (force kill)
pkill	Kill by process name	pkill firefox
bg / fg	Background/Foreground process	bg %1 (resume job #1 in background)
jobs	List background jobs	jobs

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7. File Compression & Archiving

Command	Description	Example
tar	Archive files	tar -cvf archive.tar /folder (create) tar -xvf archive.tar (extract)
gzip	Compress files	gzip file.txt → file.txt.gz
gunzip	Decompress .gz files	gunzip file.txt.gz
zip / unzip	ZIP compression	zip archive.zip file.txt unzip archive.zip

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8. Miscellaneous Useful Commands

Command	Description	Example
history	Show command history	history
grep	Search text in files	grep "error" log.txt
find	Search for files	find /home -name "*.txt"
alias	Create command shortcuts	alias ll='ls -la'
shutdown	Power off/restart	sudo shutdown now (power off) sudo reboot (restart)

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Conclusion

These commands cover file management, system monitoring, networking, package control, and more.

Pro Tips:

• Use man for help (e.g., man ls).

• Press Tab for auto-completion.

• Ctrl+C cancels a running command.