Linux Bash Cheatsheet for Beginners

Navigation

Command	What it does	Example
pwd	Print working directory (where am I?)	pwd
ls	List files and folders	ls
ls -la	List ALL files (including hidden) with details	ls -la
cd folder	Change directory (go into folder)	cd Documents
cd ..	Go up one level (parent folder)	cd ..
cd ~	Go to home directory	cd ~
cd -	Go back to previous directory	cd -

Files & Folders

Command	What it does	Example
mkdir name	Make a new directory	mkdir my-project
touch file	Create empty file	touch notes.txt
cp source dest	Copy file	cp file.txt backup.txt
cp -r src dest	Copy folder (recursive)	cp -r folder1 folder2
mv old new	Move or rename	mv old.txt new.txt
rm file	Delete file (careful!)	rm unwanted.txt
rm -r folder	Delete folder and contents	rm -r old-folder
rm -rf folder	Force delete (DANGEROUS!)	rm -rf folder

Viewing Files

Command	What it does	Example
cat file	Print entire file	cat notes.txt
head file	Show first 10 lines	head log.txt
head -n 20 file	Show first 20 lines	head -n 20 log.txt
tail file	Show last 10 lines	tail log.txt
tail -f file	Follow file (live updates)	tail -f server.log
less file	Scrollable viewer (q to quit)	less bigfile.txt

Searching

Command	What it does	Example
grep "text" file	Find text in file	grep "error" log.txt
grep -r "text" .	Search recursively in folder	grep -r "TODO" .
grep -i "text" file	Case-insensitive search	grep -i "Error" log.txt
find . -name "*.txt"	Find files by name	find . -name "*.md"

Permissions

Command	What it does	Example
chmod +x file	Make file executable	chmod +x script.sh
chmod 755 file	rwx for owner, rx for others	chmod 755 script.sh
chown user file	Change file owner	chown john file.txt

Useful Shortcuts

Shortcut	What it does
Tab	Auto-complete file/folder names
Ctrl + C	Cancel current command
Ctrl + L	Clear screen
Ctrl + R	Search command history
↑ / ↓	Navigate command history
!!	Repeat last command
sudo !!	Repeat last command as admin

Pipes & Redirection

Symbol	What it does	Example
\|	Send output to another command	ls \| grep ".txt"
>	Write output to file (overwrite)	echo "hi" > file.txt
>>	Append output to file	echo "more" >> file.txt
<	Read input from file	sort < names.txt

System Info

Command	What it does
whoami	Show current username
hostname	Show computer name
df -h	Disk space (human readable)
du -sh folder	Folder size
free -h	Memory usage
top	Running processes (q to quit)
htop	Better process viewer (if installed)

Package Management (Ubuntu/Debian)

Command	What it does
sudo apt update	Update package lists
sudo apt upgrade	Upgrade installed packages
sudo apt install name	Install a package
sudo apt remove name	Remove a package

Networking

Command	What it does
ping google.com	Test connection
curl url	Fetch URL content
wget url	Download file from URL
ip addr	Show IP addresses

Pro Tips

1. Use Tab completion - Type first few letters, press Tab
2. Use man command - Read the manual for any command
3. Use command --help - Quick help for most commands
4. Start with ls - Always know what's in your folder
5. Be careful with rm - There's no recycle bin!
6. Use sudo sparingly - Only when you need admin rights

Common Patterns

# Find and delete all .tmp files
find . -name "*.tmp" -delete

# Count lines in a file
wc -l filename.txt

# Sort and show unique lines
sort file.txt | uniq

# Download and extract tar.gz
wget url.tar.gz && tar -xzf file.tar.gz

# Watch a command run every 2 seconds
watch -n 2 "command"

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Remember: When in doubt, use man command or command --help!