Desktop

Display Managers

Introduction

The display manager (DM) is responsible for authenticating a user and launching a desktop environment. Here are a few popular DMs available on Linux distributions [6][7]:

  • GNOME Display Manager (GDM) = Specific to the GNOME desktop environment.

  • Light Display Manager (LightDM) = Generic DM used to launch any desktop environment (including GNOME).

Automatically Login User

Here is how to automatically login a user after a given timeout. A reboot is required for these changes to take affect.

  • GDM [5]:

    $ sudo -E ${EDITOR} /etc/gdm/custom.conf

    [daemon]
AutomaticLoginEnbable=true
AutomaticLogin=<USER>
TimedLoginEnable=true
TimedLogin=<USER>
TimedLoginDelay=<SECONDS>

  • LightDM [6]:

    $ sudo groupadd --system autologin
$ gpasswd -a <USER> autologin
$ sudo -E ${EDITOR} /etc/lightdm/lightdm.conf

    [SeatDefaults]
autologin-guest = false
autlogin-user = <USER>
autologin-user-timeout = <SECONDS>

Default Session

List available desktop environment sessions:

# Xorg
$ ls -1 /usr/share/xsessions/
# Wayland
$ ls -1 /usr/share/wayland-sessions/

Set one of the sessions (use the name without the .desktop extension) to be the default session for a specified user by creating the file /var/lib/AccountsService/users/${USER}. [13][14]

[User]
Language=
# Xorg
#XSession=<XORG_SESSION>
# Wayland
Session=<WAYLAND_SESSION>

Window Managers

Window managers (WMs) control the look and feel of windows.

  • Compiz

  • FluxBox

  • Kwin

  • Muffin

  • Mutter

  • Openbox

  • Xfwm

Tiled window managers specialize in splitting up windows into tiles/boxes that can be modified with keyboard shortcuts.

  • Awesome

  • Dwm

  • i3

  • Wmii

[1]

Desktop Environments

Introduction

Desktop environments (DEs) are built on top of windows managers. They provide the full functionality of a graphical desktop by bundling applications for managing media, files, and network connections. Some DEs have created their own custom window managers as well. [1]

DE Name

Graphical Toolkit

WM

Resource Usage

Cinnamon

GTK

Muffin

Medium

GNOME

GTK

Mutter

Medium

KDE

Qt

Kwin

High

Xfce

GTK

Xfwm

Low

Cinnamon

Installation:

  • Arch Linux: $ sudo pacman -S cinnamon

  • Debian (manual): $ sudo apt-get install cinnamon

  • Debian (automatic): $ sudo apt-get install task-cinnamon-desktop

  • Fedora: $ sudo dnf groupinstall "Cinnamon Desktop"

GNOME

Installation:

  • Arch Linux: $ sudo pacman -S gnome gnome-extras

  • Debian (manual): $ sudo apt-get install gnome

  • Debian (automatic): $ sudo apt-get install task-gnome-desktop

  • Fedora: $ sudo dnf groupinstall "GNOME Desktop Environment"

The gnome-tweaks package provides access to useful advanced settings of the GNOME desktop environment via the Tweaks application.

Suggested tweaks:

  • Extensions > Applications menu > On

  • Keyboard & Mouse > Mouse > Pointer Location > On

  • Top Bar > Battery Percentage > On

  • Window Titlebars > Titlebar Buttons > [Maximize|Minimize] > On

KDE

Installation:

  • Arch Linux: $ sudo pacman -S plasma kde-applications

  • Debian (manual): $ sudo apt-get install kde-standard

  • Debian (automatic): $ sudo apt-get install task-kde-desktop

  • Fedora: $ sudo dnf groupinstall "KDE Plasma Workspaces"

Xfce

Installation:

  • Arch Linux: $ sudo pacman -S xfce4 xfce4-goodies

  • Debian (manual): $ sudo apt-get install xfce4

  • Debian (automatic): $ sudo apt-get install task-xfce-desktop

  • Fedora: $ sudo dnf groupinstall "Xfce Desktop"

Display Usage

Rotate Screen

When using Xorg, xrandr can rotate the screen. This needs to use a graphics driver that supports modesetting. Legacy drivers such as xf86-video-amdgpu, xf86-video-intel, xf86-video-nouveau, or xf86-video-vmware will not work.

  • View the list of displays. Rotate it in a specified direction.

    $ xrandr
$ xrandr --output <DISPLAY> --rotate [left|right|normal|inverted]

  • If this error occurs, then a legacy Xorg driver is installed that does not support modesetting. [4]

    xrandr: output eDP1 cannot use rotation "right" reflection "none"

For the TTY, configure the fbcon. The Linux kernel must be compiled with CONFIG_FRAMEBUFFER_CONSOLE_ROTATION=y. Verify that it is by running:

$ zgrep CONFIG_FRAMEBUFFER_CONSOLE_ROTATION /proc/config.gz

All of the available options are:

  • 0 = Default orientation.

  • 1 = Clockwise.

  • 2 = Inverted.

  • 3 = Counter-clockwise.

Temporary change:

$ echo <ROTATION_OPTION> | sudo tee /sys/class/graphics/fbcon/rotate_all

Permanent change [12]:

$ sudo -E ${EDITOR} /etc/default/grub
GRUB_CMDLINE_LINUX="fbcon=rotate:<ROTATION_OPTION>"
$ sudo grub-mkconfig -o /boot/grub/grub.cfg

Remote Access

Comparison

Use case:

  • AnyDesk = Free and no account required.

  • Parsec = Best desktop streaming service for gaming but requires a free account.

AnyDesk

AnyDesk is proprietary, does not require an account, and offers online remote desktop sharing with essential features such as copy and paste.

Benefits of a paid account:

  • Privacy mode to disable the physical remote monitor. [8]

  • Support for more than on monitor. [9]

  • Ability to connect to more than 3 devices.

  • Recording.

  • Tech support.

  • User management.

  • Wake-on-LAN. [10]

Installation:

$ flatpak install com.anydesk.Anydesk

Usage:

  • Open “AnyDesk” on two different computers.

    $ flatpak run com.anydesk.Anydesk

  • Select the “New Session” tab.

  • Note the “Your Address” from the remote computer. Enter that unique AnyDesk address on the client computer in the “Remote Desk” field and then select “Connect”.

Parsec

Parsec is a tool that can be used to remotely access macOS and Windows hosts. It supports Linux, macOS, and Windows as clients. Hosting support for Linux is not currently in development but may come in 2024 or 2025. [11]

Virtual Monitors

Parsec requires a physical monitor to be plugged into the computer and turned on. There are a few ways to create virtual monitors so that a physical monitor is no longer required. [2]

  • Paid versions of Parsec Teams and Enterprise provide support for creating virtual monitors.

  • Hardware HDMI dummy plugs exist to fake having a monitor plugged in.

  • On Windows hosts, use the Amyuni Virtual Display Driver (usbmmid).

    • This virtual display is not persistent on reboots. Create a scheduled task to start it as the Administrator on boot.

      Task Scheduler (taskschd.msc) > Create Basic Task... > Name: Virtual Monitor > Next > When do you want the task to start? When the computer starts > Next > Start a program > Next > Program/script: (select the "usbmidd.bat" file) > Next > Finish
Task Scheduler (taskschd.msc) > Task Scheduler (Local) > Task Scheduler Library > Virtual Monitor > Properties > (select "Run whether user is logged in or not" and "Run with highest privileges") > OK

Virtual Audio

Parsec does not create any virtual audio devices. Instead, it forwards connected hardware audio from the Parsec host to the client. There are a few ways around this for a headless setup.

Image Processing

  • Remove all metadata from an image.

    $ mogrify -strip <IMAGE_FILE_NAME>

  • Compress an image to a specified size.

    $ [jpegoptim|optipng] --size=500K <IMAGE_FILE_NAME>

  • Resize an image.

    $ convert <IMAGE_ORIGINAL> -resize <PERCENTAGE>% <IMAGE_NEW>
$ convert <IMAGE_ORIGINAL> -resize <PIXELS_LENGTH>x<PIXELS_WIDTH> <IMAGE_NEW>

  • Rotate an image.

    $ convert <IMAGE_ORIGINAL> -rotate <DEGRESS> <IMAGE_NEW>

History

Bibliography

  1. “DesktopEnvironment.” Debian Wiki. June 7, 2018. Accessed November 26, 2018. https://wiki.debian.org/DesktopEnvironment

  2. “Remote Streaming Without a Display.” r/ParsecGaming. June 29, 2022. Accessed August 27, 2022. https://www.reddit.com/r/ParsecGaming/comments/kbzbhg/remote_streaming_without_a_display/

  3. “Unable To Hear The Game You’re Playing.” Parsec. Accessed September 6, 2022. https://support.parsec.app/hc/en-us/articles/115002700892-Unable-To-Hear-The-Game-You-re-Playing

  4. “xrandr cannot use rotation “normal” reflection “none”.” Unix & Linux Stack Exchange. August 16, 2021. Accessed February 16, 2023. https://unix.stackexchange.com/questions/636886/xrandr-cannot-use-rotation-normal-reflection-none

  5. “Configure automatic login.” GNOME Library. Accessed April 9, 2023. https://help.gnome.org/admin/system-admin-guide/stable/login-automatic.html.en

  6. “How to Login Automatically to Linux [most distros support].” FOSTips. September 2, 2022. Accessed April 9, 2023. https://fostips.com/login-automatically-linux/

  7. “Display manager.” ArchWiki. April 7, 2023. Accessed April 9, 2023. https://wiki.archlinux.org/title/display_manager

  8. “Screen Privacy.” AnyDesk Help Center. Accessed October 4, 2023. https://support.anydesk.com/knowledge/screen-privacy

  9. “what is the deal with free vs paid.” Reddit r/AnyDesk. March 24, 2020. Accessed October 4, 2023. https://www.reddit.com/r/AnyDesk/comments/fo51wn/what_is_the_deal_with_free_vs_paid/?rdt=50890

  10. “AnyDesk Free vs Paid - How They Compare.” Splashtop. September 12, 2023. Accessed October 4, 2023. https://www.splashtop.com/blog/anydesk-free-vs-paid

  11. “Hosting on Linux.” Reddit r/ParsecGaming. January 4, 2023. Accessed October 4, 2023. https://www.reddit.com/r/ParsecGaming/comments/102svaf/hosting_on_linux/

  12. “How do I rotate my display when not using an X Server?” Ask Ubuntu. June 6, 2014. Accessed March 5, 2024. https://askubuntu.com/questions/237963/how-do-i-rotate-my-display-when-not-using-an-x-server

  13. “Configure a user default session.” GNOME Library. Accessed March 30, 2024. https://help.gnome.org/admin/system-admin-guide/stable/session-user.html.en

  14. “Chapter 8. Setting a default desktop session for all users.” Red Hat Customer Portal. Accessed March 30, 2024. https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/9/html/administering_the_system_using_the_gnome_desktop_environment/proc_setting-a-default-desktop-session-for-all-users_administering-the-system-using-the-gnome-desktop-environment