Decoding the Linux Command Line: 75 Indispensable Utilities Explained

Top 75 Linux Commands Every Regular User Must Know

As a regular Linux user, mastering these essential commands can greatly enhance your productivity and efficiency. Let's dive into the top 75 Linux commands with practical examples.

1. ls (List)

   • ls - List files and directories in the current directory.
   • ls -a - List all files, including hidden ones.
   • ls -l - List files with detailed information (permissions, owner, size, etc.).
   • ls -h - List files with detailed information in human readable format.

2. pwd (Print Working Directory)

   • pwd - Display the current working directory.

3. cd (Change Directory)

   • cd /path/to/directory - Navigate to the specified directory.
   • cd .. - Move up one directory level.
   • cd ~ - Navigate to your home directory.
   • cd - - Go back to the last directory.

4. mkdir (Make Directory)

   • mkdir new_directory - Create a new directory.
   • mkdir -p /path/to/nested/directories - Create nested directories.

5. touch (Create File)

   • touch new_file.txt - Create a new, empty file.

6. mv (Move)

   • mv file.txt /path/to/directory - Move a file to a different directory.
   • mv old_name.txt new_name.txt - Rename a file.

7. cp (Copy)

   • cp file.txt /path/to/directory - Copy a file to a different directory.
   • cp -r directory1 /path/to/directory2 - Copy a directory and its contents.

8. rm (Remove)

   • rm file.txt - Delete a file.
   • rm -r directory - Delete a directory and its contents (use with caution!).

9. cat (Concatenate)

   • cat file.txt - Display the contents of a file.
   • cat file1.txt file2.txt > combined.txt - Combine two files into one.

10. echo (Print)

    • echo "Hello, World!" - Print a string.
    • echo $PATH - Print the value of an environment variable.

11. clear

    • clear - Clear the terminal screen.

12. man (Manual)

    • man ls - Display the manual page for the ls command.

13. uname (System Information)

    • uname -a - Display detailed information about the system.

14. whoami (User Information)

    • whoami - Print the current user's username.

15. head (Show Top Lines)

    • head -n 10 file.txt - Display the first 10 lines of a file.

16. tail (Show Bottom Lines)

    • tail -n 20 log.txt - Display the last 20 lines of a file.

17. diff (Compare Files)

    • diff file1.txt file2.txt - Compare the contents of two files.

18. cmp (Compare Files)

    • cmp file1.txt file2.txt - Check if two files are identical byte-by-byte.

19. comm (Compare Files)

    • comm -13 file1.txt file2.txt - Show lines unique to each file and common lines.

20. sort (Sort)

    • sort file.txt - Sort the lines of a file in alphabetical order.
    • sort -n file.txt - Sort the lines of a file numerically.

21. tar (Archive)

    • tar -czf archive.tar.gz directory - Create a compressed tar archive of a directory.
    • tar -xzf archive.tar.gz - Extract files from a compressed tar archive.

22. grep (Search)

    • grep "pattern" file.txt - Search for a pattern in a file.
    • ps aux | grep process_name - Find processes containing a specific name.

23. ln (Create Link)

    • ln -s /path/to/file link_name - Create a symbolic link to a file.

24. export (Set Environment Variables)

    • export PATH=$PATH:/new/path - Add a new path to the PATH environment variable.

25. zip (Compress Files)

    • zip archive.zip file1.txt file2.txt - Create a ZIP archive with multiple files.

26. unzip (Extract Files)

    • unzip archive.zip - Extract files from a ZIP archive.

27. ssh (Secure Shell)

    • ssh user@remote_host - Connect to a remote system via SSH.

28. service (Manage Services)

    • service apache2 start - Start the Apache web server service.
    • service mysql status - Check the status of the MySQL service.

29. ps (Process Status)

    • ps aux - Display detailed information about running processes.

30. kill and killall (Terminate Processes)

    • kill 1234 - Terminate a process with the specified PID (1234).
    • killall process_name - Terminate all processes with a specific name.

31. df (Disk Usage)

    • df -h - Display disk usage in a human-readable format.

32. mount (Mount File Systems)

    • mount /dev/sdb1 /mnt/usb - Mount a USB drive to the /mnt/usb directory.

33. chmod (Change Permissions)

    • chmod 755 file.sh - Grant read, write, and execute permissions to the owner, and read and execute permissions to group and others.

34. chown (Change Ownership)

    • chown user:group file.txt - Change the owner and group of a file.

35. ifconfig (Network Configuration)

    • ifconfig - Display information about network interfaces and IP addresses.

36. traceroute (Trace Network Route)

    • traceroute example.com - Trace the network path to a remote host.

37. wget (Web Get)

    • wget https://example.com/file.zip - Download a file from a web server.

38. ufw (Uncomplicated Firewall)

    • ufw enable - Enable the firewall.
    • ufw allow 22 - Allow incoming connections on port 22 (SSH).

39. iptables (Firewall)

    • iptables -L - List current firewall rules.
    • iptables -A INPUT -p tcp --dport 80 -j ACCEPT - Allow incoming TCP connections on port 80 (HTTP).

40. apt, pacman, yum, rpm (Package Managers)

    • apt update && apt upgrade (Ubuntu/Debian) - Update package lists and upgrade installed packages.
    • pacman -Syu (Arch Linux) - Synchronize package databases and upgrade installed packages.
    • yum update (CentOS/RHEL) - Update installed packages.
    • rpm -ivh package.rpm - Install an RPM package.

41. sudo (Escalate Privileges)

    • sudo command - Run a command with superuser (root) privileges.

42. cal (Calendar)

    • cal - Display the current month's calendar.
    • cal 2024 - Display the entire year's calendar for 2024.

43. alias (Create Command Shortcuts)

    • alias ll='ls -l' - Create an alias for the ls -l command.

44. dd (Data Duplicator)

    • dd if=/dev/zero of=/path/to/file bs=1M count=1024 - Create a 1GB file filled with zeros.
    • dd if=/path/to/iso of=/dev/sdx - Write an ISO image to a USB drive.

45. whereis (Locate Command)

    • whereis ls - Find the binary, source, and manual page files for the ls command.

46. whatis (Command Description)

    • whatis ls - Display a brief description of the ls command.

47. top (Process Monitor)

    • top - Display real-time information about running processes and system resource usage.

48. useradd and usermod (User Management)

    • useradd new_user - Create a new user account.
    • usermod -aG sudo new_user - Add an existing user to the sudo group.

49. passwd (Change Password)

    • passwd - Change the password for the current user.
    • passwd user_name (as root) - Change the password for a specific user.

50. curl (Transfer Data)

    • curl https://example.com - Fetch the contents of a URL.
    • curl ifconfig.me - Display your public IP address.

51. ping (Test Network Connectivity)

    • ping google.com - Test connectivity to a remote host.
    • ping -c 2 google.com - Send 2 ping packets and stop.

52. netstat (Network Statistics)

netstat -tunlp - Display listening network ports and associated processes.

1. rsync (Remote Sync)

   • rsync -avz /path/to/source /path/to/destination - Sync files between directories locally or remotely.

2. scp (Secure Copy)

   • scp file.txt user@remote_host:/path/to/destination - Copy files between hosts on a network.

3. find (Find Files)

   • find /path -name filename - Search for files in a directory hierarchy.

4. locate (Locate Files)

   • locate filename - Find the location of a file quickly.

5. chmod (Change File Permissions)

   • chmod 755 file.sh - Change the permission of a file or directory.

6. chown (Change File Owner)

   • chown user:group file.txt - Change the owner and group of a file.

7. su (Switch User)

   • su - - Switch to the root user.
   • su - username - Switch to another user.

8. usermod (Modify User)

   • usermod -aG groupname username - Add a user to a group.

9. groupadd (Add Group)

   • groupadd groupname - Create a new group.

10. groups (List Groups)

    • groups username - Display groups for a user.

11. last (Last Logins)

    • last - Show a listing of last logged in users.

12. hostname (Show or Set Hostname)

    • hostname - Show the system's hostname.
    • hostname new_hostname - Set the system's hostname.

13. history (Command History)

    • history - Display the command history.
    • !n - Execute command number n from history.

14. crontab (Cron Jobs)

    • crontab -e - Edit the cron jobs.
    • crontab -l - List the cron jobs.

15. bg (Background Jobs)

    • bg - Resume a suspended job in the background.

16. fg (Foreground Jobs)

    • fg - Bring a background job to the foreground.

17. jobs (List Jobs)

    • jobs - List all jobs.

18. at (Schedule Tasks)

    • at 10:00 - Schedule a command to run at 10:00 AM.
    • atq - List the pending jobs of users.

19. basename (File Name)

    • basename /path/to/file - Display file name without the directory path.

20. dirname (Directory Name)

    • dirname /path/to/file - Display the directory path of a file.

21. file (File Type)

    • file filename - Determine the file type.

22. watch (Execute/Watch Command)

    • watch -n 5 df -h - Execute a program periodically, showing output fullscreen.

23. shutdown (Shutdown System)

    • shutdown -h now - Shutdown the system immediately.
    • shutdown -r now - Reboot the system immediately.

With these 75 essential Linux commands under your belt, you'll be well-equipped to navigate the command line, manage files and processes, customize your system, and supercharge your productivity on the Linux operating system.
Happy Coding!!