Ubuntu cheat sheet

ubuntu-cheat-sheet.txt

# Ubuntu CLI Cheat Sheet 🚀

## 📂 File & Directory Management  
```bash
ls -la                 # List all files, including hidden ones
pwd                    # Show current directory
cd /path/to/dir        # Change directory
mkdir folder_name      # Create a new folder
rm -rf folder_name     # Remove a folder and its contents
cp file1 file2         # Copy a file
cp -r dir1 dir2        # Copy a directory
mv file1 file2         # Move or rename a file
find /path -name "filename"  # Find a file by name
locate filename        # Find file (faster but needs `sudo updatedb`)


## 📄 File Operations
cat file.txt         # Show file contents
less file.txt        # View large files page by page
nano file.txt        # Edit file in Nano
vim file.txt         # Edit file in Vim
echo "text" > file.txt   # Create a file with text
echo "text" >> file.txt  # Append text to a file
touch file.txt       # Create an empty file
wc -l file.txt       # Count lines in a file


## 🔍 Process & Resource Management
ps aux               # Show all running processes
top                  # Monitor system processes
kill PID             # Kill a process by ID
kill -9 PID          # Force kill a process
pkill -9 processname # Kill a process by name

## 🔥 Kill Process on a Port
sudo lsof -i :PORT         # Find process using a port
sudo fuser -k PORT/tcp     # Kill process using a port
sudo netstat -tulnp | grep :PORT  # Find process (alternative)
sudo kill -9 $(sudo lsof -t -i :PORT)  # Kill process directly


## 🔗 Network Commands
ifconfig or ip a      # Show network interfaces
ping example.com      # Ping a website
wget URL              # Download a file
curl -O URL          # Download with curl
netstat -tulnp       # List active network connections
ss -tulnp           # Modern alternative to netstat
traceroute example.com  # Trace the route packets take
host example.com      # Get DNS information


## 🔑 User Management
whoami               # Show current user
id username         # Show user ID and group
sudo adduser username  # Add a new user
sudo userdel -r username # Delete a user
passwd               # Change user password
who                  # Show logged-in users
sudo visudo         # Edit sudoers file


## 📦 Package Management
sudo apt update            # Refresh package list
sudo apt upgrade           # Upgrade installed packages
sudo apt install package   # Install a package
sudo apt remove package    # Remove a package
dpkg -l | grep package     # Check if a package is installed
apt-cache search keyword   # Search for a package

## 🛠 System Control
uname -a             # Show system information
df -h               # Check disk usage
du -sh folder/      # Check folder size
history             # Show command history
sudo reboot         # Restart the system
sudo shutdown -h now # Shutdown immediately
uptime              # Show system uptime


## 💾 File Permissions
chmod 777 file       # Full permissions for everyone
chmod +x script.sh   # Make a script executable
chown user:group file # Change file ownership