📜 Linux Commands Cheat Sheet – From Beginner to Pro

This cheat sheet covers the essential Linux commands every IT professional should know. Whether you're preparing for a sysadmin job, studying for a certification, or managing your own VPS, these commands are your daily toolkit. Bookmark this page and practice on a real server – we've included free VPS credits below.

1. File & Directory Basics

Command	Description
pwd	Print current working directory
ls -la	List all files (including hidden) with details
cd /path	Change directory to /path
mkdir newdir	Create a new directory
touch file.txt	Create an empty file
cp source dest	Copy file or directory (use -r for recursive)
mv oldname newname	Move or rename a file
rm file	Delete a file (use -rf for directories with caution)
cat file	Display file contents
less file	View file page by page (q to quit)

2. Permissions & Ownership

Command	Description
chmod 755 file	Set permissions (rwx for owner, rx for group/others)
chmod +x script.sh	Make a script executable
chown user:group file	Change file owner and group
ls -l	View permissions in list format

3. System Information & Management

Command	Description
uname -a	Show system and kernel info
df -h	Disk usage of file systems (human‑readable)
free -m	Memory usage (MB)
top	Task manager (CPU/RAM usage, running processes)
ps aux	List all running processes
kill PID	Kill process by ID
systemctl status service	Check status of a systemd service (e.g., nginx)
journalctl -xe	View recent system logs

4. Networking

Command	Description
ip addr	Show IP addresses
ping host	Check connectivity to host
curl url	Transfer data from/to a server (HTTP requests)
wget url	Download files from the internet
ss -tulpn	List listening ports
ufw allow 22	Allow SSH through firewall (Ubuntu)

5. Package Management (Ubuntu/Debian)

Command	Description
sudo apt update	Refresh package lists
sudo apt upgrade	Upgrade all installed packages
sudo apt install pkg	Install a package
sudo apt remove pkg	Uninstall a package
dpkg -l	List all installed packages

6. Text Processing & Searching

Command	Description
grep "text" file	Search for text inside a file
find / -name "file.txt"	Find a file by name
wc -l file	Count lines in a file
sort file	Sort lines alphabetically
uniq	Remove duplicate lines (often used with sort)
sed 's/old/new/g' file	Replace text in a file

Next Steps for Your IT Career

Memorising commands is just the start. To turn Linux into a career:

• Practice daily: Set up a VPS (use our free credits) and break things – that's how you learn.
• Learn scripting: Automate tasks with Bash. Our Ubuntu Beginner Guide can help.
• Offer your skills: Once comfortable, freelance as a Linux sysadmin on Fiverr or Upwork.
• Certify: Consider Linux+ or LPIC certifications for a resume boost.

Questions? Reach out – I'm happy to help.