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Ubuntu 17.10 Tip: Graphical Apps Doesn’t Launch via Root, Sudo, Gksu

Last updated: October 11, 2017

Ubuntu 17.10 uses Wayland in the default session and Xorg for optional. However, many graphical applications need to run as root so far does not launch in Wayland.

You’ll get following similar errors while running graphical applications via root:

For some applications, e.g., Synaptic Package Manager, Grub Customizer, Gparted, and Ubuntu Tweak, they does not launch in Wayland.
Or you may get following error when trying to launch them via gksu command:

Failed to run *** as user root. Unable to copy the user’s Xauthorization file.
Starting graphical application via sudo in terminal window will get error:
No protocol specified. Gtk-WARNING **: Cannot open display: :0

The most straightforward workaround is to use xhost to temporarily allow the root user to access the local user’s X session.

To do so, run command:

xhost si:localuser:root

After running the command, these graphical applications can be launched from app launcher or via sudo, gksu, pkexec commands until you log out.

To make this work automatically at login, search for and launch Startup Applications utility, click the “Add” button to run the command at startup:

name: whatever
command: xhost si:localuser:root
comment: whatever

In Howtos wayland

QupZilla 2.2.0 released as ‘Final Series’ of the Qt browser

Last updated: October 10, 2017

QupZilla 2.2, the final release series of the cross-platform Qt web browser, is now available.

QupZilla will now get only bug-fix releases, and next major release will be named Falkon as a KDE project.

QupZilla 2.2.0 release highlights:

added back print element background option
added back print preview dialog
added session manager
tab icon is now hidden when page has no icon
improved locationbar completer with search suggestions
improved handling of downloading dependencies in GreaseMonkey scripts
various improvements in TabManager extension
Linux: PulseAudio streams now have QupZilla app name and icon

Install QupZilla 2.2.0 in Ubuntu:

QupZilla 2.2.0 requires Qt 5.9.2. It can’t be built with default Qt libraries in all current Ubuntu releases.

At the moment, you can only download the Appimage, non-install single executable file, from the link below:

Then make it executable via its Properties window, and run the file to launch QupZilla:

Don’t see the “Run” option even after made the appimage executable? Go to file manage menu Edit -> Preferences -> Behavior -> Choose the option says ‘Run executable text files when they are opened’.

In Howtos, News Qupzilla web browser

Rhythmbox 3.4.2 Released, How to Install it via PPA

Last updated: October 9, 2017

Rhythmbox, Ubuntu’s default music playing application, got a new release update after a year of development.

Besides removing visualization plugin, Rhythmbox 3.4.2 features responsiveness improvements during media player sync, better network buffering when crossfading is enabled, and various bug-fixes (or feature request) including:

Critical Assertion Errors
Add --version command option.
Rhythmbox crashed with SIGSEGV during import
Expand playing icon column in entry view
Import hangs for special file
Playqueue UI improvements
Memory leak in error handling of utimes on podcast-timestamp
Open settings crashes the app
build failure with gcc 7.1.1
Keyboard navigation with tab is broken by search entry widget

How to Install Rhythmbox 3.4.2 in Ubuntu:

The project leader for Ubuntu Budgie, fossfreedom, was maintaining PPA with Rhythmbox package and its plugins, though they are not updated for a period of time.

So I uploaded Rhythmbox 3.4.2 into the PPA, available for Ubuntu 16.04, Ubuntu 17.04, and Ubuntu 17.10.

1. Open terminal via Ctrl+Alt+T and run command to add the PPA:

sudo add-apt-repository ppa:ubuntuhandbook1/apps

Input your password (no visual feedback while typing) when it prompts and hit Enter.

2. Then upgrade the music playing application via Software Updater:

or upgrade your system via command:

sudo apt-get update && sudo apt-get upgrade

How to remove:

To revert back to stock version of Rhythmbox in your Ubuntu, purge the PPA as well as downgrade the player via command:

sudo apt-get install ppa-purge && sudo ppa-purge ppa:ubuntuhandbook1/apps

If it’s working good, you may still remove the PPA repository via Software & Updates utility under Other Software tab.

In Howtos, News music player, rhythmbox

Yarock 1.2.0 Released! How to Install it via PPA

Last updated: October 8, 2017

Yarock, a Qt music player designed to provide a clean music collection based on album cover art, reached 1.2.0 release a few hours ago.

It has been one year since the last update of Yarock music player. And Yarock 1.2.0 features:

Configurable custom cover art size
Redesign player tool bar with expanded tool bar mode
Replace Echonest with Spotify web service for artist image.
Add option to prevent downloading artist image from internet.
Change & fix many lyrics provider services
Changes: Many minors ui changes and improvments

How to install yarock 1.2.0 in Ubuntu:

There are a few third-party PPAs contain yarock packages for Ubuntu. At the moment, you can install the 1.2.0 release via this PPA in Ubuntu 14.04, Ubuntu 16.04, Ubuntu 17.04, Ubuntu 17.10, and derivatives.

1. Open terminal either via Ctrl+Alt+T or by searching for “terminal” from app launcher. When it opens, run command to add the PPA:

sudo add-apt-repository ppa:ubuntuhandbook1/apps

Input your password (no visual feedback while typing) when it prompts and hit Enter.

2. Then install the player either via Synaptic Package Manager (after clicking refresh), or by running commands:

sudo apt-get update

sudo apt-get install yarock

Once installed, launch the music player from your application launcher and enjoy!

How to Remove:

To remove the software, use Synaptic Package Manager or run command:

sudo apt-get remove --autoremove yarock

And remove the PPA by launching Software & Updates utility and navigating to Other Software tab.

In Howtos, News qt music player, yarock music player

Visual Studio Code 1.17 Adds Mac OS Touch Bar Support

Last updated: October 7, 2017

Visual studio code reached the 1.17 release a day ago with Mac OS touch bar support, and some performance improvements.

VS Code 1.17 features:

Mac OS Touch Bar actions for navigation and debugging.
Folding now supports region markers.
Terminal rendering is up to 45 times faster with new canvas-based rendering engine
Automatically show module and path import suggestions while coding
Debug Console messages show source location (optionally)
Built-in Dark+ and Light+ themes now highlight regular expression components
new SOURCE CONTROL PROVIDERS section to view changes in multiple source control repositories.

See the video about VS Code 1.17:

How to Install VS Code 1.17 in Ubuntu:

The official .deb package for Debian/Ubuntu is available for download at the link below:

Then install it via either Gdebi package manager or command (Ctrl+Alt+T):

sudo dpkg -i ~/Downloads/code_*.deb; sudo apt -f install

For those who want to receive updates for VS Code via Software Updater utility, add the Microsoft repository via following steps (64bit only):

1. Open terminal (Ctrl+Alt+T) and run command to add the repository:

sudo sh -c 'echo "deb [arch=amd64] https://packages.microsoft.com/repos/vscode stable main" > /etc/apt/sources.list.d/vscode.list'

2. Download and install the repository key via commands:

curl https://packages.microsoft.com/keys/microsoft.asc | gpg --dearmor > microsoft.gpg

sudo mv microsoft.gpg /etc/apt/trusted.gpg.d/microsoft.gpg

Uninstall Visual Studio Code:

To remove the code editor, either use Synaptic Package Manager or run command:

sudo apt-get remove --autoremove code

And remove the Microsoft repository by launching Software & Updates utility and navigating to Other Software tab.

In Howtos, News Visual Studio Code

How to Change Login Screen Background in Ubuntu 18.04

Last updated: May 6, 2024

Boring with the default purple login screen background in Ubuntu 18.04? Well, here’s how to make a change by hacking the css file.

UPDATE 2024: This tutorial is outdated and only work for old Ubuntu 18.04!! For most recent Ubuntu versions, see this tutorial instead!

Ubuntu since 17.10 switches to Gnome 3 Desktop and GDM display manager. Although there are options to change desktop wallpaper and lock screen background (it’s actually screen saver with date & time displayed), the login screen is always purple.

In the picture above, I’ve changed the login background to the image “Aardvark_Wallpaper_Grey_4096x2304.png” locate in /usr/share/backgrounds.

1. Move your favorite image to /usr/share/backgrounds:

It’s better to move the image you want to set as login background to system pictures folder: /usr/share/backgrounds.

To do so, open terminal via Ctrl+Alt+T, then either run command:

sudo cp PATH/TO/YOUR/IMAGE /usr/share/backgrounds/

or run command to open file browser via root and then do copy and paste in that window:

xhost +local: && sudo nautilus /usr/share/backgrounds/

2. Edit the css file that define GDM login background:

Open terminal (Ctrl+Alt+T) and run command to edit file /etc/alternatives/gdm3.css, which is linked to /usr/share/gnome-shell/theme/gdm3.css:

xhost +local: && sudo gedit /etc/alternatives/gdm3.css

Input your password (no visual feedback while typing) when it prompts and hit Enter. And of course back up the file before editing.

3. When the file opens, go to menu (right after ‘Save’ button) -> find and find out following section:

#lockDialogGroup {
  background: #2c001e url(resource:///org/gnome/shell/theme/noise-texture.png);
  background-repeat: repeat; }

change the lines into:

#lockDialogGroup {
  background: #2c001e url(file:///usr/share/backgrounds/Aardvark_Wallpaper_Grey_4096x2304.png);
  background-repeat: no-repeat;
  background-size: cover;
  background-position: center; }

Replace Aardvark_Wallpaper_Grey_4096x2304.png with your picture file name.

Finally save the file and restart your computer to apply changes.

NOTE: these changes may be overwritten in case of an system update with GDM packages. Please let me know if you find a good way to change the GDM3 login background in Ubuntu 17.10.

In Howtos GDM, Ubuntu 17.10

Enable ‘Tap to click’ in Ubuntu (22.04 Updated) GDM Login Screen

Last updated: November 19, 2023

For notebook or PC with a touchpad, you’ll find that tap clicking function does not work in the GNOME login screen out-of-the-box, either in Ubuntu or other Linux.

You may hit Enter on keyboard to login after typing password. It will however more convenient if tap to click works when trying to select another user, session, or upper right corner menu. And here’s how to enable this function in Ubuntu 22.04 and Ubuntu 20.04.

UPDATE: There’s now graphical GDM-Settings configuration tool, can do the job as easy as few mouse clicks.

Enable Tap Clicking in GDM Login Screen.

Both the System Settings and ‘Dconf Editor’ configuration tool have option to toggle ‘Tap to Click’ in Ubuntu. However, none works for the login screen due to permission issue. You need the gdm system user privilege to do the setting.

1.) Firstly, open terminal by either searching from the overview screen or pressing Ctrl+Alt+T on keyboard.

2.) For Ubuntu 22.04, you have to first install the dbus-x11 package for dbus-launch command:

sudo apt install dbus-x11

3.) When terminal opens, run command to add user gdm to the control list:

xhost SI:localuser:gdm

It will indicate that ‘localuser:gdm being added to access control list’.

4.) Finally run gsettings command to enable ‘tap to click’ using gdm user privilege:

sudo -u gdm gsettings set org.gnome.desktop.peripherals.touchpad tap-to-click true

For Ubuntu 22.04, add dbus-launch flag in command, so it will be:

sudo -u gdm dbus-launch gsettings set org.gnome.desktop.peripherals.touchpad tap-to-click true

If you want to do more settings about the GNOME login screen, you may first install “Dconf Editor” and launch the tool via gdm system user. To do so, paste the command below into terminal and hit run:

xhost SI:localuser:gdm && sudo -u gdm dconf-editor

When it opens, navigate to “org/gnome/login-screen“. There you may toggle settings for disable user list, enable fingerprint, smartcard authentications, and more.

That’s all. Enjoy!

In Howtos tap to click, Ubuntu 17.10

Raw image processor RawTherapee 5.3 released (How-to install)

Last updated: September 11, 2019

RawTherapee, an open-source cross-platform raw image processing program, reached the 5.3 release a few days ago with new features, performance improvements and numerous bug-fixes.

RawTherapee 5.3 release highlights:

CIECAM02 enhanced with control over the scene and viewing conditions.
CIECAM02-friendly “Average Surround” color theme and L* middle gray preview background color, takes into account human vision and color appearance with regard to the surrounding color.
Manually save the collapsed/expanded state of tools.
Lensfun support, for automatic (and manual) profiled lens correction.
ACES, DCI-P3 Theater and DCI-P3 D65 output color profiles.
Numerous speed optimizations and bug fixes.

How to Install RawTherapee 5.3 in Ubuntu:

Dariusz Duma’s PPA contains the latest RawTherapee packages for Ubuntu 16.04, Ubuntu 17.04, Ubuntu 17.10, and their derivatives.

1. Open terminal either via Ctrl+Alt+T or by searching for “Terminal” from app launcher. When it opens, run command:

sudo add-apt-repository ppa:dhor/myway

Input your password (no visual feedback when typing) when it prompts and hit Enter to add the PPA.

2. After that, upgrade the software via Software Updater from an existing release:

The upgrading process may be kept back if you were installing it from Ubuntu Software App.

A workaround is simply running following commands instead to install or upgrade RawTherapee:

sudo apt-get update

sudo apt-get install rawtherapee

How to Remove:

To uninstall the free raw developer, run command in terminal:

sudo apt-get remove --autoremove rawtherapee

And remove the PPA via “Software & Updates” utility under Other Software tab, by removing the line says “http://ppa.launchpad.net/dhor/myway/ubuntu”.

In Howtos RAW processor, RawTherapee

How to Install SMPlayer 17.10 via PPA in Ubuntu 17.10

Last updated: November 2, 2017

A new monthly update of SMPlayer media player was released earlier today. Here’s how to install it in Ubuntu via PPA.

SMPlayer 17.10 following two changes:

Replace the deprecated video and audio filters in mpv with new ones.
The karaoke filter is available again.

Note that due to the first change, Linux users may need to update MPV (see how to install the latest MPV) in order to use SMPlayer 17.10.

A workaround is to turn off all video and audio filters. Another workaround is to switch to mplayer by selecting mplayer as multimedia engine in Preferences -> General.

How to Install SMPlayer 17.10 in Ubuntu via PPA:

The new release has made into the official PPA, available for Ubuntu 17.10, Ubuntu 17.04, Ubuntu 16.04, Ubuntu 14.04, Ubuntu 12.04, and their derivatives.

1. Open terminal and run the following command to add the PPA:

sudo add-apt-repository ppa:rvm/smplayer

For those who prefer Qt4 version, use the new PPA instead:

sudo add-apt-repository ppa:rvm/smplayer-qt4

2. Then you can upgrade SMPlayer from a previous release via Software Updater (Update Manager) after checking for updates:

Or you can run the commands below in terminal to do install or upgrade SMPlayer:

sudo apt-get update 

sudo apt-get install smplayer smtube smplayer-themes

How to Restore:

For any reason, you can easily restore the installation to the stock version via the ppa-purge tool:

sudo apt-get install ppa-purge && sudo ppa-purge ppa:rvm/smplayer

For the qt4 ppa, replace ppa:rvm/smplayer with ppa:rvm/smplayer-qt4 in the code.

In Howtos, News mpv, SMPlayer

Final Beta of Ubuntu 17.10 Artful Aardvark Available for Download

Last updated: September 29, 2017

Ubuntu 17.10 Artful Aardvark reached its final beta release earlier today. Ubuntu 17.10 Desktop, Server, and Cloud images, and flavors images of Kubuntu 17.10, Lubuntu 17.10, Ubuntu Budgie 17.10, Ubuntu Kylin 17.10, Ubuntu MATE 17.10, Ubuntu Studio 17.10, and Xubuntu 17.10 are available for download.

The beta release of Ubuntu 17.10 includes 4.13 kernel and updated version of core applications.

Ubuntu 17.10 desktop and server images: http://releases.ubuntu.com/17.10/

Kubuntu 17.10: cdimage.ubuntu.com/kubuntu/releases/17.10/

use VLC as default media player.
Muon package manager shipped by default, as an alternative to Plasma Discover.
Cantata Qt5 music player replaces the unmaintained KDE4 based Amarok as default.
Telepathy instant messaging client has been dropped from defaults.

Lubuntu 17.10: cdimage.ubuntu.com/lubuntu/releases/17.10/

Ubuntu Budgie 17.10: cdimage.ubuntu.com/ubuntu-budgie/releases/17.10/