Navigation & Filesystem pwd Print current working directory ls List directory contents cd [dir] Change directory tree Visualize directory structure find [path] -name "[file]" Find files by name
File Operations touch [file] Create empty file rm [file] Remove file rm -r [dir] Remove directory recursively cp [src] [dest] Copy files/directories mv [src] [dest] Move/rename files
File Viewing cat [file] Print file contents less [file] Scrollable file viewer head -n 10 [file] First 10 lines tail -n 10 [file] Last 10 lines tail -f [file] Follow live updates
File Permissions umask Default permission mask stat [file] Display file info chmod [mode] [file] Change permissions chown [user]:[group] [file] Change owner/group
Process Management ps aux List all processes top Real-time monitor htop Interactive process viewer kill [PID] Kill by ID killall [name] Kill all by name
Networking ip a Show IP addresses ping [host] Check connectivity curl [url] Fetch URL content wget [url] Download files netstat -tuln List open ports
Disk & Storage df -h Disk usage (human readable) du -sh [dir] Directory size lsblk List block devices fdisk -l Show disk partitions mount / umount Mount / Unmount filesystem
User Management whoami Show current user id Show user ID & groups adduser [name] Add new user passwd [user] Change password groups [user] List user’s groups
System Info uname -a Show system info uptime Show load & uptime free -h Show RAM usage dmesg Boot and kernel logs
Search & Text grep '[pattern]' [file] Search in files awk '{print $1}' Text processing sed 's/old/new/g' Edit text in stream cut -d':' -f1 Split by delimiter sort, uniq, wc -l Count / sort / filter