Tag: ubuntu users

Ubuntu Server CLI Cheatsheet

The world’s most popular server OS – CLI essentials for daily administration
Ubuntu Server 25.10 (Questing Quokka) released October 2025: Kernel 6.17, OpenJDK 25, Python 3.14 RC3, Golang 1.25, Rust 1.85. LTS: 24.04 (Noble Numbat) with 12 years support via Ubuntu Pro.
Debian-based with apt package manager. All privileged commands require sudo. Access via SSH (port 22) or console.

1. Installation & Initial Setup

Task	Command / Action
Download ISO	ubuntu.com/download/server → 25.10 (latest) or 24.04 LTS
Boot & Install	USB boot → Language → Install Ubuntu Server → Set hostname, user, SSH key (recommended)
Enable SSH	During install: Check Install OpenSSH server Post-install: sudo apt install openssh-server
Update system	sudo apt update && sudo apt upgrade -y
Set timezone	sudo timedatectl set-timezone America/New_York (or your region)
Configure firewall (UFW)	sudo ufw allow OpenSSH sudo ufw enable
Add user to sudo	sudo usermod -aG sudo username

Cloud Images: For AWS/GCP/Azure: Use official AMIs. Minimal install: ~300MB RAM. Pro Tip: Enable unattended upgrades: sudo apt install unattended-upgrades → sudo dpkg-reconfigure unattended-upgrades.

2. Navigation & File Management

Task	Command
Show current directory	pwd
List files (detailed)	ls -la
List by time (newest first)	ls -lht
List with human-readable sizes	ls -lh
Change directory	cd /var/www
Go home	cd ~
Go up one level	cd ..
Go to previous directory	cd –
Show directory tree	tree -L 2 (install: sudo apt install tree)

3. Create, Copy, Move & Delete

Action	Command
Create directory	mkdir foldername
Create nested directories	mkdir -p /path/to/nested/folder
Create empty file	touch filename.txt
Create multiple files	touch file1.txt file2.txt file3.txt
Edit/create with nano	nano filename.txt (Ctrl+O save, Ctrl+X exit)
Copy file	cp file.txt /backup/
Copy directory recursively	cp -r folder /backup/
Move/rename file	mv old.txt new.txt
Move file	mv file.txt /new/location/
Delete file	rm file.txt
Delete directory	rm -r folder (empty) rm -rf folder (with contents, dangerous!) rm -ri folder (with prompts)

4. Disk & Storage

Task	Command
Disk usage (human-readable)	df -h
Detailed disk output	df -h –output=source,fstype,size,used,avail,pcentused,target
Folder size	du -sh /path
Current directory sizes (largest first)	du -sh * \| sort -hr
List block devices	lsblk
List all disks	sudo fdisk -l
Interactive disk explorer	ncdu / (install: sudo apt install ncdu)

5. Search & Find

Task	Command
Find files by name	find /var/www -name “*.log”
Find large files (>100MB)	find / -type f -size +100M 2>/dev/null
Search text in files	grep -r “search term” /var/www
Case-insensitive filenames only	grep -ril “text” /etc

6. Permissions & Ownership

Action	Command
Set file permissions (644)	chmod 644 file.txt
Make executable (755)	chmod 755 script.sh
Recursive permissions	chmod -R 755 folder
Change owner	chown www-data:www-data file.txt
Recursive ownership	chown -R www-data:www-data /var/www
Take ownership	chown -R $USER:$USER folder

7. System Monitoring & Info

Task	Command
Kernel & system info	uname -a
Ubuntu version	lsb_release -a
Uptime & load	uptime
Memory usage	free -h
Process monitor	top or htop (install: sudo apt install htop)
Recent logs	journalctl -xe
Kernel messages	dmesg \| tail

8. Package Management (APT)

Action	Command
Update package list	sudo apt update
Upgrade packages	sudo apt upgrade -y
Full upgrade (with deps)	sudo apt full-upgrade -y
Remove unused	sudo apt autoremove
Clean cache	sudo apt clean
Install tools	sudo apt install tree htop ncdu
Search package	apt search keyword
Show package info	apt show package

9. Networking & Users

Networking

Task	Command
Show IP addresses	ip a
Listening ports	ss -tulnp
Public IP	curl ifconfig.me
Test connectivity	ping -c 4 google.com
Firewall status	sudo ufw status
Allow SSH	sudo ufw allow 22/tcp

Users

Action	Command
Add user	sudo adduser username
Add to sudo group	sudo usermod -aG sudo username
Change password	sudo passwd username
Edit sudoers	sudo visudo

10. Troubleshooting

Issue	Command
Fix broken packages	sudo apt install -f
Check services	sudo systemctl status service
View full logs	journalctl -u service -f
Boot to recovery	GRUB → Advanced → Recovery Mode
Clear old logs	sudo journalctl –vacuum-time=30d
Reinstall package	sudo apt install –reinstall package

11. One-Liners

# Full update + clean

sudo apt update && sudo apt full-upgrade -y && sudo apt autoremove && sudo apt clean

# Clean disk view (hide snaps)

df -h | grep -v snap

# 10 largest items in current dir

du -sh * | sort -hr | head -10

# Delete logs older than 30 days

find /var/log -type f -mtime +30 -delete

# Newest files in /var/log

ls -lht /var/log | head

# Quick web server (Python)

cd /var/www && python3 -m http.server 8000

12. Useful Tools to Install

sudo apt install htop tree ncdu curl wget vim git ufw unattended-upgrades

13. Ubuntu Resources

Official Docs: https://ubuntu.com/server/docs
Ask Ubuntu: https://askubuntu.com
Cloud/Server Guide: https://ubuntu.com/server

# Check for updates offline

apt list –upgradable

November 23, 2025

Ubuntu Linux Cheatsheet

The world’s most popular desktop & server Linux
Uses apt (Debian-based). All privileged commands require sudo.
Covers Ubuntu Desktop, Server, LTS, and Snaps.

1. Installation (Live USB / Server ISO)

Task	Command / Action
Boot Live USB	Try Ubuntu → Install Ubuntu
Disk setup	Use Eraser or Something Else (manual: `/`, `/boot`, `swap`)
Server install	Boot ISO → Language → Minimal or Standard
Enable SSH (server)	`sudo apt install openssh-server`
Update on first boot	`sudo apt update && sudo apt upgrade -y`

2. APT (Package Management)

Action	Command
Update package lists	`sudo apt update`
Upgrade all packages	`sudo apt upgrade -y`
Full upgrade (new deps)	`sudo apt full-upgrade -y`
Install package	`sudo apt install package`
Remove package	`sudo apt remove package`
Purge (with config)	`sudo apt purge package`
Autoremove unused	`sudo apt autoremove`
Clean cache	`sudo apt clean`
Search package	`apt search keyword`
List installed	`dpkg -l \| grep ^ii`
Show info	`apt show package`
Fix broken installs	`sudo apt install -f`
Which package owns file	`dpkg -S /path/to/file`

3. Snaps (Universal Packages)

Action	Command
Install snap	`sudo snap install package`
Update all snaps	`sudo snap refresh`
List installed	`snap list`
Remove snap	`sudo snap remove package`
Classic confinement	`sudo snap install --classic code`
Find in store	`snap find keyword`

Common Snaps: code, discord, spotify, slack, postman, chromium

4. System Administration

Task	Command
List services	`systemctl list-unit-files --type=service`
Enable service	`sudo systemctl enable service`
Start service	`sudo systemctl start service`
Status	`systemctl status service`
View logs	`journalctl -u service`
Reboot	`sudo reboot`
Shutdown	`sudo poweroff`
Disk usage	`df -h`
Memory	`free -h`
Processes	`htop` or `top`
Kill process	`kill PID` or `pkill name`
Check Ubuntu version	`lsb_release -a` or `cat /etc/os-release`

5. Users & Permissions

Action	Command
Add user	`sudo adduser username`
Add to sudo group	`sudo usermod -aG sudo username`
Change password	`sudo passwd username`
Change owner	`sudo chown user:group file`
Change permissions	`chmod 755 file`
Switch user	`su - username`

6. Networking

Task	Command
Check IP	`ip a` or `nmcli device show`
List Wi-Fi	`nmcli device wifi list`
Connect Wi-Fi	`nmcli device wifi connect SSID password "pass"`
Restart NetworkManager	`sudo systemctl restart NetworkManager`
Check DNS	`cat /etc/resolv.conf`
Test connection	`ping -c 4 google.com`
Firewall (UFW)	`sudo ufw status` `sudo ufw allow 22/tcp` `sudo ufw enable`

7. Filesystem & Storage

Task	Command
Mount USB	`sudo mount /dev/sdb1 /mnt/usb`
Unmount	`sudo umount /mnt/usb`
Format ext4	`sudo mkfs.ext4 /dev/sdX1`
Check disk	`sudo fsck /dev/sdX1`
Find large files	`du -ah / \| sort -rh \| head -n 20`
Search files	`find / -name "filename" 2>/dev/null`
Disk analyzer (GUI)	`baobab`

8. Server-Specific

Service	Install & Enable
LAMP Stack	`sudo apt install apache2 mysql-server php libapache2-mod-php`
Nginx + PHP	`sudo apt install nginx php-fpm`
Docker	`sudo apt install docker.io` `sudo usermod -aG docker $USER`
Node.js	`curl -fsSL https://deb.nodesource.com/setup_lts.x \| sudo -E bash -` `sudo apt install nodejs`
PostgreSQL	`sudo apt install postgresql`

9. Troubleshooting

Issue	Command
Boot to recovery	GRUB → Advanced → Recovery Mode
Fix broken packages	`sudo dpkg --configure -a` `sudo apt install -f`
Reinstall GRUB (UEFI)	`sudo grub-install /dev/sdX` `sudo update-grub`
Clear journal logs	`sudo journalctl --vacuum-time=2weeks`
Boot errors	`journalctl -b -p err`
Regenerate initramfs	`sudo update-initramfs -u`
Check hardware	`lscpu`, `lsblk`, `lspci`, `lsusb`

10. Useful Tools to Install

sudo apt install \
    vim htop git curl wget unzip tree \
    net-tools ufw gnome-tweaks \
    build-essential dkms linux-headers-$(uname -r)

11. One-Liners

# Full system update + clean
sudo apt update && sudo apt full-upgrade -y && sudo apt autoremove && sudo apt clean

# Enable UFW with SSH allowed
sudo ufw allow OpenSSH && sudo ufw enable

# Show Ubuntu version
lsb_release -a

# Update snaps
sudo snap refresh

# Backup apt sources
cp /etc/apt/sources.list ~/sources.list.bak

# List all PPAs
grep ^deb /etc/apt/sources.list /etc/apt/sources.list.d/*

# Reboot into recovery
sudo systemctl reboot --firmware-setup  # (UEFI)

12. Ubuntu Flavors & Resources

Flavor	Command / Note
Ubuntu Server	Minimal CLI install
Ubuntu Desktop	Full GNOME experience
Kubuntu	KDE Plasma
Xubuntu	XFCE (lightweight)
Lubuntu	LXQt
Ubuntu MATE	Classic desktop

Official Docs: https://ubuntu.com/tutorials
Ask Ubuntu: https://askubuntu.com

13. Pro Tips

Use ubuntu-drivers autoinstall for NVIDIA/AMD drivers
Enable Minimized Updates in Software & Updates
Use apt-mark hold package to prevent updates
Backup with deja-dup (GUI) or rsync
Enable Firewall: sudo ufw enable

# Auto-accept reboots after updates (server)
sudo needrestart -a

November 8, 2025