Unix/Linux Common Commands Cheat Sheet

Unix/Linux systems have a powerful set of command-line tools that allow efficient management of file systems, processing of text data, and monitoring of system states.

File and Directory Management

Command	Description	Example
ls	List directory contents	ls -lh
cd	Change working directory	cd /var/log
pwd	Print working directory	pwd
mkdir	Create a new directory	mkdir -p /path/to/dir
rm	Remove files or directories	rm -rf tmp/
cp	Copy files or directories	cp -r src/ dest/
mv	Move or rename	mv oldname newname
touch	Create empty file or update timestamp	touch file.txt
find	Find files in directory tree	find . -name "*.log"

File Viewing and Text Processing

Command	Description	Example
cat	Concatenate and display file content	cat file.txt
less	View file page by page (scrollable)	less largefile.log
head	Display start of file	head -n 20 file.txt
tail	Display end of file	tail -f access.log
grep	Output lines matching a pattern	grep "error" sys.log
sed	Stream editor for filtering/transforming text	sed 's/old/new/g' file.txt
awk	Text processing and pattern matching language	awk '{print $1}' data.txt
wc	Count words, lines, bytes	wc -l file.txt

Permissions and Identity Management

Command	Description	Example
chmod	Modify file/directory permissions	chmod 755 script.sh
chown	Modify file owner and group	chown user:group file.txt
sudo	Execute command with admin privileges	sudo apt update
whoami	Display current user	whoami
groups	Display user groups	groups username

System Monitoring and Network

Command	Description	Example
top	Display real-time system processes	top
ps	Display snapshot of current processes	ps aux
df	Display disk space usage	df -h
du	Estimate file/directory disk usage	du -sh *
free	Display memory usage	free -m
ping	Test network connectivity	ping google.com
curl	Command-line tool for transferring data	curl -I https://google.com

Compression and Archiving

Command	Description	Example
tar	Archiving tool (packet/extract)	tar -czvf archive.tar.gz dir/
gzip	Compress files	gzip file.txt
gunzip	Decompress files	gunzip file.txt.gz
zip/unzip	Package and compress to ZIP	zip -r data.zip docs/