Essential Linux Command Cheat Sheet for Beginners

This guide provides a quick-reference list of essential Linux commands and their typical usage, organized by functional groups.

Path and Directory Operations

Absolute path example: /etc/init.d Current and parent directories: ./ and ../ Home directory: ~/ Change directory: cd <path> Create directory: mkdir <dir> Create file: touch <file> or vi <file> Copy file: cp <src> <dest> Copy recursively: cp -r <src_dir> <dest_dir> Move/rename: mv <src> <dest> Remove file: rm <file> Remove directory recursively: rm -r <dir> or rmdir <empty_dir> Clear screen: clear Exit shell: exit or Ctrl+C Background execution: append & to a command

Process Management

List processes: ps Show all processes: ps -ef (System V style) or ps -aux (BSD style)

Filter by PID: ps -ef | grep <pid> Show background jobs: jobs -l Bring job to foreground: fg %<job_id> Resume stopped job in background: bg %<job_id> Terminate process: kill [-s SIGNAL] <pid> or kill -9 <pid> List all supported signals: kill -l Disown all running jobs:

disown -r

File Inspection

View file content: cat <file>, more <file>, less <file>, head <file>, tail <file>, vi <file> Paginated view: cat <file> | more Count lines/words/bytes: wc -l <file>, wc -w <file>, wc -c <file> Search text: grep [options] pattern file (use -i to ignore case, -v to invert match)

Search for files: find <dir> -name "pattern", whereis <cmd>, locate pattern List command location:

which <cmd>

Permissions

Change mode: chmod u+x file, chmod 751 file, chmod a-wx,a+r file,

chmod -R u+r dir

Shell Customization

Alias creation: alias la='ls -a' Prompt variables: \u (user), \h (host), \w (full path), \W (basename), \$ (prompt char), \# (command number), \d (date), \t (24‑hour time), \T (12‑hour time), \A (HH:MM), \v (bash version)

View command hash table: hash Arithmetic with built‑in let command

Key bindings: use bind after obtaining the key sequence (e.g., Ctrl+V F12 yields ^[[24~)

System Information

Current terminal: /dev/tty Null device: /dev/null List logged‑in users: who or who am i Network status: netstat IP and interface info: ifconfig Environment variables: env (all) or env VAR (specific)

Disk usage: df -hl (human‑readable), du (directory/file size)

Quota information: repquota (requires root for other users)

Shell Utilities

History of commands: history List all available commands: compgen -c Directory stack: dirs, manipulate with pushd / popd Search for command description: whatis <cmd> The cheat sheet concludes with a reminder that these commands form the foundation for everyday Linux usage and system administration.