Linux CLI Cheatsheet

File & Directory Navigation

Command	Description
pwd	Print current working directory
ls -la	List all files (long format, hidden)
ls -lhS	List sorted by size (human readable)
ls -lt	List sorted by modification time
cd -	Go to previous directory
cd ~	Go to home directory
tree -L 2	Show directory tree (2 levels deep)
find . -name '*.py'	Find files by name pattern
find . -type f -mtime -7	Files modified in last 7 days
find . -size +100M	Find files larger than 100MB
locate filename	Fast file search (uses db)
which / whereis	Find command location

File Operations

Command	Description
cp -r src/ dst/	Copy directory recursively
mv old new	Move / rename file
rm -rf dir/	Force remove directory (CAUTION)
mkdir -p a/b/c	Create nested directories
ln -s target link	Create symbolic link
touch file.txt	Create empty file / update timestamp
stat file	Detailed file info (size, perms, times)
file myfile	Detect file type
basename /path/to/file.txt	Extract filename from path
dirname /path/to/file.txt	Extract directory from path

File Viewing & Editing

Command	Description
cat file	Print entire file
less file	Scrollable file viewer (q to quit)
head -n 20 file	First 20 lines
tail -n 20 file	Last 20 lines
tail -f logfile	Follow log in real-time
wc -l file	Count lines in file
diff file1 file2	Compare two files
sort file | uniq -c	Sort and count unique lines
cut -d',' -f1,3 file.csv	Extract columns 1 and 3
column -t -s',' file.csv	Display CSV as aligned table
nano / vim / vi	Terminal text editors

Text Processing (grep / sed / awk)

Command	Description
grep -rn 'pattern' .	Recursive search with line numbers
grep -i 'pattern' file	Case-insensitive search
grep -v 'exclude' file	Invert match (exclude lines)
grep -c 'pattern' file	Count matching lines
grep -E 'a|b' file	Extended regex (OR)
sed 's/old/new/g' file	Replace all occurrences
sed -i 's/old/new/g' file	In-place replacement
sed -n '5,10p' file	Print lines 5–10
awk '{print $1, $3}' file	Print columns 1 and 3
awk -F',' '{sum+=$2} END{print sum}'	Sum column 2 (CSV)
awk '/pattern/ {print}' file	Print matching lines

Permissions & Ownership

Command	Description
chmod 755 file	rwxr-xr-x (owner rwx, others rx)
chmod +x script.sh	Add execute permission
chmod -R 644 dir/	Recursive permission change
chown user:group file	Change owner and group
chown -R user dir/	Recursive ownership change
umask 022	Set default permissions for new files

Process Management

Command	Description
ps aux	List all running processes
ps aux | grep name	Find process by name
top / htop	Interactive process monitor
kill PID	Terminate process (graceful)
kill -9 PID	Force kill process
killall name	Kill all processes by name
jobs	List background jobs
bg / fg	Move job to background / foreground
nohup cmd &	Run command immune to hangups
cmd & disown	Run and detach from terminal
lsof -i :8080	Find process using port 8080
pgrep -f pattern	Find PID by pattern

Networking

Command	Description
ip addr / ifconfig	Show network interfaces
curl -s url	HTTP request (silent mode)
curl -o file url	Download file from URL
wget url	Download file
wget -r -l 2 url	Recursive download (2 levels)
ss -tlnp / netstat -tlnp	Show listening ports
ping -c 4 host	Ping host (4 packets)
traceroute host	Trace network route
dig domain	DNS lookup
ssh user@host	SSH into remote server
scp file user@host:/path	Copy file over SSH
rsync -avz src/ user@host:/dst/	Sync directories over SSH

Disk & Storage

Command	Description
df -h	Disk usage (human-readable)
du -sh dir/	Directory size
du -h --max-depth=1	Size of each subdirectory
ncdu /path	Interactive disk usage explorer
mount / umount	Mount / unmount filesystems
fdisk -l	List disk partitions
lsblk	List block devices

Compression & Archives

Command	Description
tar czf archive.tar.gz dir/	Create gzipped tarball
tar xzf archive.tar.gz	Extract gzipped tarball
tar xzf archive.tar.gz -C /dst	Extract to specific directory
tar tf archive.tar.gz	List tarball contents
zip -r archive.zip dir/	Create zip archive
unzip archive.zip	Extract zip archive
gzip / gunzip	Compress / decompress .gz
zcat file.gz	View compressed file

System Info & Monitoring

Command	Description
uname -a	System info (kernel, arch)
cat /etc/os-release	OS distribution info
uptime	System uptime and load
free -h	Memory usage
nproc	Number of CPU cores
lscpu	CPU architecture info
dmesg | tail	Kernel messages (recent)
journalctl -u service -f	Follow systemd service logs
systemctl status service	Check service status
systemctl restart service	Restart a service

Redirection & Pipes

Command	Description
cmd > file	Redirect stdout to file (overwrite)
cmd >> file	Append stdout to file
cmd 2>&1	Redirect stderr to stdout
cmd &> file	Redirect all output to file
cmd1 | cmd2	Pipe stdout of cmd1 to cmd2
cmd1 | tee file | cmd2	Pipe + save to file
cmd | xargs -I{} echo {}	Pass piped input as arguments

Handy Shortcuts & One-Liners

Command	Description
!!	Repeat last command
!$	Last argument of previous command
Ctrl+R	Reverse search command history
Ctrl+Z → bg	Suspend and background a process
Ctrl+A / Ctrl+E	Jump to start / end of line
history | grep cmd	Search command history
watch -n 2 cmd	Run command every 2 seconds
time cmd	Measure execution time
alias ll='ls -la'	Create command alias
echo $?	Exit code of last command
date +%Y-%m-%d	Current date (formatted)
env / printenv	Show environment variables
export VAR=value	Set environment variable