Linux Basics commands - Part 1

Part 1: Introduction to Basic Linux Commands

Setting Up Your Workspace

1. Create a new directory named "devops":

    mkdir devops
   

2. Navigate into the "devops" directory:

    cd devops
   

3. Create a new file named "demofile.txt":

    touch demofile.txt
   

4. List the contents of the directory to ensure "demofile.txt" is created:

    ls
   

   Output:

    demofile.txt
   

5. Display the contents of "demofile.txt" (it should be empty):

    cat demofile.txt
   

Adding Text to a File

6. Print a message to the terminal:

    echo "Hello Dosto"
   

7. Write the message "Hello Dosto" to "demofile.txt":

    echo "Hello Dosto" > demofile.txt
   

8. Verify the content of "demofile.txt":

    cat demofile.txt
   

   Output:

    Hello Dosto
   

Creating and Viewing Additional Files

9. Create another file and add text:

    echo "Hello Dosto" > one.txt
   

10. Display the contents of "one.txt":

    cat one.txt
    

    Output:

    Hello Dosto
    

11. View the beginning of "one.txt":

    head one.txt
    

12. View the end of "one.txt":

    tail one.txt
    

13. Continuously monitor the end of "one.txt":

    tail -f one.txt
    

Using less and more Commands

14. View "one.txt" with less:

    less one.txt
    

15. View "one.txt" with more:

    more one.txt
    

Current Directory and File Management

16. Display the current directory path:

    pwd
    

Copying Files and Directories

17. Copy "one.txt" to the "devops" directory:

    cp one.txt devops/
    

18. Copy "one.txt" within the main directory:

    cp devops/one.txt devops/copy/
    

19. Copy a directory and its contents recursively:

    cp -r copy/ devops/
    

Moving and Renaming Files and Directories

20. Move "demofile.txt" to the "copy" directory:

    mv demofile.txt copy/
    

21. Rename the "Devops" directory to "linuxfordevops":

    mv Devops/ linuxfordevops
    

Listing and Counting

22. List files in the current directory:

    ls
    

23. Display the content of "one.txt":

    cat one.txt
    

    Output:

    Hello Dosto
    

24. Word count of "one.txt":

    wc one.txt
    

Creating Soft Links

25. Create and add text to a new file:

    echo "hello this is softlink example." > devops-file.txt
    

26. Display the content of "devops-file.txt":

    cat devops-file.txt
    

27. Display the current directory path and copy it:

    pwd
    

28. Create a soft link to "devops-file.txt":

    ln -s /home/dhruv/Devops/linuxfordevops/devops-file.txt softlink-file1
    

29. List files in long format:

    ls -ltr
    

30. Display the content of the soft link:

    cat softlink-file1
    

Creating Hard Links

31. Create and add text to another file:

    echo "this is harlink example" > devopsfile.txt
    

32. List files to verify the creation:

    ls
    

33. Display the content of "devopsfile.txt":

    cat devopsfile.txt
    

34. Create a hard link to "devopsfile.txt":

    ln /home/dhruv/Devops/linuxfordevops/devopsfile.txt hardlink-file
    

35. List files again to see the hard link:

    ls
    

36. Display the content of the hard link:

    cat hardlink-file
    

Cutting and Sorting Content

37. Cut and display the first character of "one.txt":

    cut -b 1 one.txt
    

    Output:

    H
    

38. Cut and display the first four characters of "one.txt":

    cut -b 1-4 one.txt
    

    Output:

    Hell
    

Using tee

39. Echo text and use tee to display and write to a file:

    echo "hey" | tee
    

    Output:

    hey
    

40. Echo text and write to "hey.txt" using tee:

    echo "hey" | tee hey.txt
    

    Output:

    hey
    

41. Display the content of "hey.txt":

    cat hey.txt
    

    Output:

    hey
    

Differences and Editing with vi

42. Compare two files:

    diff one.txt hardlink-file
    

43. Edit "one.txt" using vi:

    vi one.txt
    

    • Press i for insert mode.

    • Press Esc to exit insert mode.

    • Type :wq to write changes and quit.

44. Sort the content of "one.txt":

    sort one.txt
    

Connecting to Remote Servers and System Monitoring

45. Check disk space:

    df
    df -h
    

46. Navigate to the parent directory and check disk usage:

    cd ..
    du .
    

47. List all files, including hidden ones:

    ls -a
    

Managing Processes

48. View active processes:

    ps
    top
    

49. Find which process is using a file:

    fuser filename
    

50. Kill a process by ID:

    kill -9 process_id
    

Memory and System Performance

51. Check free memory:

    free
    free -h
    

52. Run a command in the background and view the output later:

    nohup free -h
    ls
    cat nohup.out
    

53. Display the first five lines of "nohup.out":

    head -n 5 nohup.out
    

54. Check system performance with vmstat:

    vmstat
    vmstat -a
    

This guide covers essential Linux commands for beginners, offering practical examples and outputs to help you get started with basic file operations, linking, system monitoring, and process management.