LINUX Commands You need to Know

Introduction:

For those new to Linux, mastering its commands is crucial for effective system management. Here’s a succinct yet comprehensive cheatsheet encompassing the top 60 essential Linux commands, including their syntax. This guide provides a foundational overview, helping beginners quickly familiarize themselves with key operations and functions. From file manipulation to system monitoring, these commands are pivotal for navigating and controlling the Linux environment with precision and efficiency.

1. ls

• Description: Lists the contents of a directory, providing an overview of files and directories.
• Syntax: ls [options] [directory]
• Example:

  ls -l /home
  

2. cd

• Description: Changes the current directory to a specified directory.
• Syntax: cd [directory]
• Example:

  cd /var/log
  

3. sudo

• Description: Executes a command with elevated (superuser) privileges.
• Syntax: sudo [command]
• Example:

  sudo apt-get update
  

4. pwd

• Description: Prints the current working directory.
• Syntax: pwd
• Example:

  pwd
  

5. mkdir

• Description: Creates a new directory.
• Syntax: mkdir [directory name]
• Example:

  mkdir my_folder
  

6. rm

• Description: Removes files or directories.
• Syntax: rm [options] [file/directory]
• Example:

  rm -rf my_folder
  

7. cp

• Description: Copies files or directories from one location to another.
• Syntax: cp [options] [source] [destination]
• Example:

  cp file.txt /backup/file.txt
  

8. mv

• Description: Moves or renames files or directories.
• Syntax: mv [options] [source] [destination]
• Example:

  mv file.txt /backup/newfile.txt
  

9. chmod

• Description: Changes the file mode (permissions) of a file or directory.
• Syntax: chmod [options] [permissions] [file/directory]
• Example:

  chmod 755 script.sh
  

10. chown

• Description: Changes the ownership of a file or directory.
• Syntax: chown [options] [owner][:group] [file/directory]
• Example:

  chown root:root file.txt
  

11. touch

• Description: Creates an empty file or updates the timestamp of an existing file.
• Syntax: touch [file name]
• Example:

  touch newfile.txt
  

12. cat

• Description: Concatenates and displays the content of files.
• Syntax: cat [options] [file(s)]
• Example:

  cat file.txt
  

13. echo

• Description: Outputs the provided string to the terminal or redirects it to a file.
• Syntax: echo [options] [string]
• Example:

  echo "Hello, World!" > hello.txt
  

14. grep

• Description: Searches for patterns within files using regular expressions.
• Syntax: grep [options] [pattern] [file(s)]
• Example:

  grep "error" /var/log/syslog
  

15. find

• Description: Searches for files and directories within a directory hierarchy based on various criteria.
• Syntax: find [path] [options] [expression]
• Example:

  find /home -name "*.txt"
  

16. df

• Description: Reports file system disk space usage.
• Syntax: df [options] [file]
• Example:

  df -h
  

17. du

• Description: Estimates file space usage, showing the amount of disk space used by files and directories.
• Syntax: du [options] [file]
• Example:

  du -sh /home
  

18. top

• Description: Displays dynamic real-time information about running processes, including CPU and memory usage.
• Syntax: top
• Example:

  top
  

19. ps

• Description: Reports a snapshot of the current processes.
• Syntax: ps [options]
• Example:

  ps aux
  

20. kill

• Description: Terminates a process using its PID (Process ID).
• Syntax: kill [PID]
• Example:

  kill 1234
  

21. ping

• Description: Sends ICMP ECHO_REQUEST packets to network hosts to check connectivity.
• Syntax: ping [options] [destination]
• Example:

  ping google.com
  

22. ifconfig

• Description: Configures or displays network interface parameters.
• Syntax: ifconfig [interface] [options]
• Example:

  ifconfig eth0
  

23. ip

• Description: Manages network interfaces, routing tables, and IP addresses.
• Syntax: ip [options] [object] [command]
• Example:

  ip addr show
  

24. netstat

• Description: Displays network connections, routing tables, interface statistics, and more.
• Syntax: netstat [options]
• Example:

  netstat -tuln
  

25. ss

• Description: Displays detailed information about network socket connections.
• Syntax: ss [options]
• Example:

  ss -tuln
  

26. iptables

• Description: Configures the IP packet filter rules of the Linux kernel firewall.
• Syntax: iptables [options] [command]
• Example:

  iptables -L
  

27. sudo

• Description: Executes commands with elevated privileges.
• Syntax: sudo [command]
• Example:

  sudo apt update
  

28. apt

• Description: Manages packages on Debian-based systems.
• Syntax: apt [options] [command]
• Example:

  sudo apt install vim
  

29. uname

• Description: Displays system information, including the operating system, kernel version, and hardware details.
• Syntax: uname [options]
• Example:

  uname -a
  

30. htop

• Description: An interactive process viewer similar to top, but with more features and a better user interface.
• Syntax: htop
• Example:

  htop
  

31. history

• Description: Displays the command history of the current terminal session.
• Syntax: history [options]
• Example:

  history
  

32. shutdown

• Description: Powers off or reboots the system.
• Syntax: shutdown [options] [time]
• Example:

  sudo shutdown -h now
  

33. reboot

• Description: Reboots the system.
• Syntax: reboot [options]
• Example:

  sudo reboot
  

34. man

• Description: Displays the manual page for a command, providing detailed usage information.
• Syntax: man [command]
• Example:

  man ls
  

35. whatis

• Description: Provides a brief description of a command.
• Syntax: whatis [command]
• Example:

  whatis grep
  

36. curl

• Description: Transfers data from or to a server using various protocols like HTTP, FTP, and more.
• Syntax: curl [options] [URL]
• Example:

  curl https://example.com
  

37. zip

• Description: Compresses files into a zip archive.
• Syntax: zip [options] [archive name] [file(s)]
• Example:

  zip archive.zip file1.txt file2.txt
  

38. unzip

• Description: Extracts files from a zip archive.
• Syntax: unzip [options] [archive name]
• Example:

  unzip archive.zip
  

39. less

• Description: Views file content one page at a time, allowing backward

• Description: Views file content one page at a time, allowing backward and forward navigation.
• Syntax: less [options] [file]
• Example:

  less file.txt
  

40. head

• Description: Outputs the first part of files, by default the first 10 lines.
• Syntax: head [options] [file]
• Example:

  head -n 5 file.txt
  

41. tail

• Description: Outputs the last part of files, by default the last 10 lines.
• Syntax: tail [options] [file]
• Example:

  tail -n 5 file.txt
  

42. diff

• Description: Compares files line by line.
• Syntax: diff [options] [file1] [file2]
• Example:

  diff file1.txt file2.txt
  

43. sort

• Description: Sorts lines of text files.
• Syntax: sort [options] [file]
• Example:

  sort file.txt
  

44. awk

• Description: A powerful text-processing language used for pattern scanning and processing.
• Syntax: awk 'pattern {action}' [file]
• Example:

  awk '{print $1}' file.txt
  

45. resolvectl

• Description: Resolves domain names, queries DNS information, and changes DNS settings.
• Syntax: resolvectl [options]
• Example:

  resolvectl status
  

46. cal

• Description: Displays a calendar in the terminal.
• Syntax: cal [options] [month] [year]
• Example:

  cal 08 2024
  

47. whoami

• Description: Prints the current logged-in user name.
• Syntax: whoami
• Example:

  whoami
  

48. finger

• Description: Displays information about system users.
• Syntax: finger [options] [user]
• Example:

  finger root
  

49. shred

• Description: Securely deletes files by overwriting their data.
• Syntax: shred [options] [file]
• Example:

  shred -u file.txt
  

50. ln

• Description: Creates hard and symbolic links to files.
• Syntax: ln [options] [target] [link name]
• Example:

  ln -s /path/to/file linkname
  

51. nano

• Description: A simple and easy-to-use text editor for terminal-based editing.
• Syntax: nano [file]
• Example:

  nano file.txt
  

52. vim

• Description: A highly configurable text editor that is built to enable efficient text editing.
• Syntax: vim [file]
• Example:

  vim file.txt
  

53. exit

• Description: Exits the current shell session.
• Syntax: exit [exit code]
• Example:

  exit 0
  

54. passwd

• Description: Changes the user password.
• Syntax: passwd [options] [username]
• Example:

  passwd
  

55. adduser

• Description: Adds a new user to the system.
• Syntax: adduser [username]
• Example:

  sudo adduser newuser
  

56. useradd

• Description: A low-level command to add a new user.
• Syntax: useradd [options] [username]
• Example:

  sudo useradd -m newuser
  

57. su

• Description: Switches to another user account.
• Syntax: su [options] [username]
• Example:

  su - root
  

58. clear

• Description: Clears the terminal screen.
• Syntax: clear
• Example:

  clear
  

59. ufw

• Description: Uncomplicated Firewall (UFW) provides an easy interface for managing firewall rules.
• Syntax: ufw [options] [command]
• Example:

  sudo ufw enable
  

60. neofetch

• Description: Displays system information in a visually appealing format.
• Syntax: neofetch [options]
• Example:

  neofetch