Linux Cheatsheet

Linux Basic Command Line Cheatsheet

This is a cheatsheet of some basic linux commands.

Basic commands

1. Navigating, go back, list directories, print working directory.

   cd /Users/Hello/Documents/
   cd ..
   ls
   pwd
   

2. Create a file. If already exists, then select that file or directory.

   touch example.txt
   

3. Create a directory.

   mkdir example_folder
   

4. Move file to directory.

   mv example.txt ./example_folder/example.txt
   

5. Remove file, remove directory.

   rm example.txt
   rmdir example_folder
   

6. List User. cat /etc/passwd

7. Permissioning: change ownership of a folder.

   sudo chown stephen ./example_folder
   

8. Grant permission to execute a file.

   chmod 700 example.ch
   

9. Editing a file using Vim.

   vim example.txt
   

10. Basic Vim commands:

    Press i to enter insert mode.
    Press esc to go back to command mode.
    Type :w followed by enter to save.
    Type :q followed by enter to quit.
    Type :q! followed by enter to force quit.
    Type gg dG to delete all.
    

11. Delete Swap Files:

    find . -type f -name "*.sw[klmnop]" -delete
    

12. Check if a process is still running:

    ps aux | grep <script_name>
    

    Here are the different states:

    • R: Running
    • S: Sleeping
    • T: Stopped
    • Z: Zombie (terminated but not fully cleaned up)
    • D: Uninterruptible sleep (usually related to I/O operations)
13. To kill a process use the following. Note, in general, you don’t want to kill a process in the S+ state because it is waiting for an event to complete.

    kill <Process ID>
    

    To force kill all events associated with your script:

    pkill -f <script_name>
    

Ubuntu

1. Updating Ubuntu.

   sudo apt update
   sudo apt full-upgrade
   sudo apt-get dist-upgrade
   

2. Auto-installing critical updates.

   sudo apt-get install unattended-upgrades -y
   sudo dpkg-reconfigure -plow unattended-upgrades
   

3. Clean system:

   su -
   apt autoremove -y && apt autoclean && apt clean