Dr. Mark Humphrys

School of Computing. Dublin City University.

Online coding site: Ancient Brain

coders   JavaScript worlds


Free AI exercises

Lab - Intro to UNIX / Linux


GUI notes

Last time I looked, the DCU lab machines' GUI was as follows.
This may change over time. Hopefully you will work it out.
We will not dwell on the GUI anyway. GUIs are easy to use.

GNOME on Ubuntu on the DCU lab PCs.

  1. The GUI used is GNOME.
  2. There are many different GUIs. What you see in the GUI here may not be the same on other Linux/Unix.

  3. LHS sidebar with Favourite applications, Recycle bin
  4. Settings in top RHS
  5. Boxes at bottom LHS - All applications

  6. Click "Activities" (or press Windows key) to get:
    • Currently running applications
    • Search box

  7. Keyboard shortcuts
    • Keyboard shortcuts on different OSes and GUIs
    • Alt-Tab - switch between applications
    • Windows key + L - lock

  8. Show desktop:
    • Ctrl-Alt-D (actually toggle raise/lower all windows)
    • You can define your own shortcuts:
      Settings - Keyboard - Shortcuts - Navigation

  9. RHS edge - may have multiple desktops

  10. Favourites list - Right click - Remove from Favourites
  11. All applications - Right click - Add to Favourites
  12. File Browser

  13. Top RHS
    • Power
    • Lock - Swipe up to unlock (on normal login)

Text editors


GUI editors


Command-line editors

More GUI

  1. File Browser
    • dirs = directories (folders)
    • [cryptic View icon] - Show Hidden Files
    • Ctrl-L - edit address line directly

  2. More applications

  3. Take Screenshot

  4. Installing and updating applications on Linux is easy (if you have administrator rights):
    • APT package management tool ("apt-get" command)
    • Will need administrator rights to modify system directories. (e.g. Install Linux on your laptop and try it.)
    • winget Package Manager for Windows 10 up. Can use "winget" on the Windows command line.
    • Package managers on different OSes.
    • List of package managers


  1. Terminal - command line - very powerful - similar to all other Linux/UNIX
    • Search for "GNOME Terminal" - Add to Favourites
    • Increase font is Ctrl + which on your keyboard may translate to Ctrl Shift +
    • Decrease font is Ctrl -
    • Default shell here is bash. Other shells are installed.
    • Unix shell
    • List of Unix utilities
    • Shell script
    • In GNOME Terminal, if a URL appears in the text on the command-line, you can right-click on it to open it in browser.

  2. Command-line keys:

  3. ls
    • ls
    • ls -l
    • echo * (all normal, non-hidden files and dirs)
    • ls -l * (if dir, will display contents)
    • ls -ld * (if dir, display name not contents)

  4. hidden files
    • ls -a
    • ls -al
    • echo .* (all hidden files)
    • echo .* * (all files)
    • ls -l .* (don't need -a if going to actually name the hidden files)
    • ls -ld .*

  5. environment variables
    • set
    • set > file.txt
    • env
    • env | sort
    • echo HOME - the string "HOME"
    • echo $HOME - the global (environment) variable HOME
    • PATH = list of dirs searched for command when you type a command, separated by colons (:)
    • SHELL = shell we are using (default here is bash)

  6. Shared, multi-user, file system:
    • HOME = something like:

    • My test account is here:

  7. current and parent dirs
    • . (current dir)
    • Example: When was the last change to the current dir:
       ls -ld . 
    • .. (parent dir)

  8. cd
    • go home: cd
    • go up to parent dir: cd ..
    • go back to last dir: cd -

  9. command history
    • up/down arrows
    • history
    • h (alias)
    • !n - repeat command n
    • !string - repeat last command that began with string
    • !c - repeat last command that began with character c
    • !! - last command

Disk quota

To see your disk quota, type:
 quota -s  

If you get "Disk quota exceeded"

Installed at DCU - Works of Shakespeare

For testing manipulation of data with Linux commands, it helps if we have some data to manipulate. So I have installed the works of Shakespeare to use for testing.


Core information you need


More on the Shakespeare files

These Shakespeare files use relative HTML links, not absolute HTML links, so can download to any location and the links still work ok.

ancientbrain.com      w2mind.org      humphrysfamilytree.com

On the Internet since 1987.      New 250 G VPS server.

Note: Links on this site to user-generated content like Wikipedia are highlighted in red as possibly unreliable. My view is that such links are highly useful but flawed.