Archives For jimingkui

Linux Kernel

Linus Torvalds announced the released of Kernel 5.0 yesterday afternoon. He wrote on lkml.org:

Ok, so the last week of the 5.0 release wasn’t entirely quiet, but it’s a lot smaller than rc8 was, and on the whole I’m happy that I delayed a week and did an rc8.

It turns out that the actual patch that I talked about in the rc8 release wasn’t the worrisome bug I had thought: yes, we had an uninitialized variable, but the reason we hadn’t immediately noticed it due to a warning was that the way gcc works, the compiler had basically initialized it for us to the right value. So the same thing that caused not the lack of warning, also effectively meant that the fix was a no-op in practice.

But hey, we had other bug fixes come in that actually did matter, and the uninitialized variable _could_ have been a problem with another compiler.

Regardless – all is well that ends well. We have more than a handful of real fixes in the last week, but not enough to make me go “Hmm, things are really unstable”. In fact, at least two thirds of the patches are marked as being fixes for previous releases, so it’s not like 5.0 itself looks bad.

Changes in Linux Kernel 5.0 include:

  • AMD Radeon FreeSync support
  • Logitech High Resolution Scrolling support
  • Raspberry Pi Touchscreen support out of the box.
  • New console font for HiDPI and retina screens.
  • Initial support for NVIDIA Turing GPUs
  • And numerous other changes

How to Install Linux Kernel 5.0 in Ubuntu:

The mainline kernel packages for Linux 5.0 are available for download at the link below:

Depends on your OS type, download and install the packages in turns:

  1. linux-headers-5.0.0-xxxxxx_all.deb
  2. linux-headers-5.0.0-xxx-generic(/lowlatency)_xxx_amd64(/i386).deb
  3. linux-modules-5.0.0-xxx-generic(/lowlatency)_xxx_amd64(/i386).deb
  4. linux-image-xxx-5.0.0-xxx-generic(/lowlatency)_xxx_amd64(/i386).deb

Select generic for common system, and lowlatency for a low latency system (e.g. for recording audio), amd64 for 64bit system, i386 for 32bit system, or armhf, arm64, etc for other OS types.

Alternatively you can download and install the kernel binaries via terminal commands (Ctrl+Alt+T):

For 64-bit OS:

cd /tmp/

wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.0/linux-headers-5.0.0-050000_5.0.0-050000.201903032031_all.deb

wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.0/linux-headers-5.0.0-050000-generic_5.0.0-050000.201903032031_amd64.deb

wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.0/linux-image-unsigned-5.0.0-050000-generic_5.0.0-050000.201903032031_amd64.deb

wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.0/linux-modules-5.0.0-050000-generic_5.0.0-050000.201903032031_amd64.deb

sudo dpkg -i *.deb

for 32-bit OS:

cd /tmp/

wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.0/linux-headers-5.0.0-050000_5.0.0-050000.201903032031_all.deb

wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.0/linux-headers-5.0.0-050000-generic_5.0.0-050000.201903032031_i386.deb

wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.0/linux-image-5.0.0-050000-generic_5.0.0-050000.201903032031_i386.deb

wget -c https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.0/linux-modules-5.0.0-050000-generic_5.0.0-050000.201903032031_i386.deb

sudo dpkg -i *.deb

Once installed, restart your computer and enjoy!

Uninstall Linux Kernel 5.0:

Restart your machine and select boot with the previous kernel in boot menu ‘Grub2 -> Advanced Option for Ubuntu’. Then run command to remove Linux Kernel 5.0:

sudo dpkg --purge linux-image-5.0.0-050000-generic linux-image-unsigned-5.0.0-050000-generic

Ubuntu will play a simple alert sound for certain types of messages and events, e.g., error input in terminal and usb plugged in or removed.

For some reason, you may want to disable or mute the alert sounds. And this quick tutorial will show you how to do it in Ubuntu 18.04 Gnome desktop.

1. Open Settings utility from the left panel, and navigate to Sound settings from its left pane.

2. Then navigate to Sound Effects tab, and either mute or turn off “Alert volume”.

3. (Optional) Instead of playing alert sounds, you can have visual flashes for the events.

Go to Univeral Access settings, choose enable “Visual Alerts”, and set flash window title or entire screen.

That’s it. Enjoy!

Pragha music player 1.3.4 was released few days ago. Here’s how to install it in Ubuntu 16.04, Ubuntu 18.04, Ubuntu 18.10.

While Pragha 1.4 is being close to the final release, Pragha 1.3.4 was released a few days ago as a new maintenance that features:

  • Fixes some border, spacing and margin in all gui.
  • Various improvements to the tag editor dialog.
  • Implement emit CanNext/Prev/Play/Pause/Seek.
  • Use Alt+Return shortcut to edit the selected song.
  • Some backport of improvents to MTP plugin
  • Set user-agent and ssl strict ssl to gstreamer on internet music.
  • Fix second sidebar dont show with accel.
  • Allow apply a custom css. Related to Issue
  • Allows to customize the styles to the distro packagers.

How to install Pragha 1.3.4 in Ubuntu:

There’s an unofficial PPA that contains the latest Pragha packages for Ubuntu 16.04, Ubuntu 18.04, Ubuntu 18.10, and Linux Mint 18.x/19.

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/pragha

Type user password (no asterisk feedback due to security reason) when it prompts and hit Enter.

2. Then install the music player either via Synaptic Package Manager or by running commands:

sudo apt-get update

sudo apt-get install pragha

Uninstall Pragha:

To remove the music player, either use Synaptic Package Manager or run command in terminal:

sudo apt-get remove --autoremove pragha

And you can remove the PPA via Software & Updates utility under ‘Other Software’ tab.

Free score writer MuseScore 3 was released a few months ago. Finally the official PPA for MuseScore 3 is available for Ubuntu 18.04, Ubuntu 18.10, and higher.

MuseScore 3 is a new major release that features automatic placement, brand new Mixer and Piano Roll, dark theme, notation improvements, and many other changes.

MuseScore 3 and MuseScore 2.3 can co-exist on one machine. Installation of the MuseScore 3 will create the association with .mscz/.mscx files, but you can keep using both versions of MuseScore on one machine.

How to Install MuseScore 3 via PPA in Ubuntu:

While MuseScore PPA contains the latest 2.3.x packages, a new official PPA for MuseScore 3 was created. You can do following steps to add the PPA and install the score writer.

1. Open terminal either via Ctrl+Alt+T keyboard shortcut or by searching for ‘terminal’ from application menu. When it opens, run command to add the PPA:

sudo add-apt-repository ppa:mscore-ubuntu/mscore3-stable

Type user password (no asterisk feedback due to security reason) when it asks and hit Enter.

2. Then install MuseScore 3 via command:

sudo apt install musescore3

Linux Mint 19 needs to refresh package cache by running command apt update first.

Once installed, launch the software from application menu and enjoy!

Uninstall:

To remove the software, run command in terminal:

sudo apt remove --autoremove musescore3

To remove the PPA, go to Software & Updates -> Other Software tab.

OBS Studio, free live streaming and screen recording software, released version 23.0 recently with many new features. Here’s how to install it in Ubuntu 16.04, Ubuntu 18.04, Ubuntu 18.10.

OBS Studio 23.0 release highlights:

  • Add Limiter audio filter, Expander audio filter.
  • Add VAAPI video encoder on Linux.
  • Add batch remuxing support to the Remux Recordings dialog.
  • Option to automatically remux recordings to MP4 in Advanced settings.
  • Add Decklink output tool to the tools menu.
  • Add an optional Stats dock (disabled by default).
  • Add multi-track audio support to FFmpeg output in advanced output settings.
  • Add an Invert Polarity audio filter.
  • Add VLC source support to the Instant Replay script.
  • Some other enhancements, and many bug-fixes.

How to Install OBS Studio 23 in Ubuntu:

For the official PPA packages, all current Ubuntu releases can do following steps to install the latest OBS Studio.

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

sudo add-apt-repository ppa:obsproject/obs-studio

Type user password (no asterisk feedback) when it prompts and hit Enter.

2. For Ubuntu 14.04 you also need to run command to add another PPA for FFmpeg library:

sudo add-apt-repository ppa:kirillshkrogalev/ffmpeg-next

3. Now you can install OBS-Studio via Synaptic package manager, upgrade the software from an existing release via Software Updater, or simply run commands one by one:

sudo apt-get update

sudo apt-get install obs-studio

Once installed, launch the software from Unity Launcher, Gnome Launcher, or other app launcher and enjoy!

Uninstall:

To remove the software, either use Synaptic package manager or run command in terminal:

sudo apt-get remove --autoremove obs-studio

To remove PPA repositories, launch Software & Updates and navigate to ‘Other Software’ tab.

Battle for Wesnoth released a new regular update for the 1.14 series. Here’s how to install it in Ubuntu 16.04, Ubuntu 18.04, and higher.

Wesnoth 1.14.6 release highlights:

  • Fixed some AI crashes.
  • New parameter default_ai_algorithm for setting the default AI
  • New parameter mp_rank for setting the order in which AIs appear in the MP computer player selection menu
  • New option “Keep saved AI” when reloading games from the MP Create Game screen.
  • Fix Lua AIs using the ai.stopunit_*() functions potentially creating infinite candidate action loops
  • Many fixes and improvements to campaigns.
  • Miscellaneous and bug fixes

How to Install Battle for Wesnoth 1.14.6 in Ubuntu:

The new release package has been made into Flatpak package, available to install via the Flathub repository.

1. (For Ubuntu 16.04 only), open terminal either via Ctrl+Alt+T keyboard shortcut or by searching for ‘terminal’ from app launcher. When it opens, run command:

sudo add-apt-repository ppa:alexlarsson/flatpak

sudo apt-get update

2. Install flatpak framework via command:

sudo apt-get install flatpak

3. Add flathub repository:

flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo

4. Finally install the flatpak package of Battle for Wesnoth:

flatpak install flathub org.wesnoth.Wesnoth

Once installed, launch the game either from software launcher, or by running command flatpak run org.wesnoth.Wesnoth

(Optional) 5. To remove the game, run command:

flatpak uninstall org.wesnoth.Wesnoth

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After testing for a period of time, OnlyOffice Desktop Editors snap package goes stable for Ubuntu and other Linux desktops.

ONLYOFFICE Desktop Editors is a free office suite that combines text, spreadsheet and presentation editors allowing to create, view and edit documents stored on your Windows/Linux PC or Mac without an Internet connection. It is fully compatible with Office Open XML formats: .docx, .xlsx, .pptx.

The snap is a containerized software package (runs in sandbox) runs in most Linux desktops. It bundles most required libraries and auto-updates itself.

For Ubuntu 18.04 and higher, simply open Ubuntu Software, search for and install onlyoffice:

For Ubuntu 16.04, first install snapd daemon by opening terminal (Ctrl+Alt+T) and then running command:

sudo apt install snapd

Then install OnlyOffice Desktop Editors via command:

sudo snap install onlyoffice-desktopeditors

Like normal software, open OnlyOffice from your system app launcher.

Uninstall:

To remove the software, either use Ubuntu Software, or run command in terminal:

snap remove onlyoffice-desktopeditors

This quick tutorial is for those who want to install the latest Python 3.7.2 in Ubuntu 18.04 LTS, Linux Mint 19.x, and Ubuntu 18.10.

Ubuntu 18.04 comes with Python 2.7 and Python 3.6 out-of-the-box, and later includes Python 3.7.1 in its updates (universe) repository.

For the updated Python 3.7.2, you can do following steps to use the ToolChain PPA packages.

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

sudo add-apt-repository ppa:ubuntu-toolchain-r/ppa

Type user password (no visual feedback) when it asks and hit Enter to continue.

2. Then run command to install Python3.7:

sudo apt install python3.7

For Linux Mint 19.x, run command sudo apt update to check updates first.

3. As the PPA contains other updates toolchain packages, e.g., gcc-7.4.0, gcc-8.2.0, and python-3.6.8, you may remove the PPA afterwards via Software & Updates -> Other Software tab.

4. To make python3 use the new installed python 3.7.2 instead of the default 3.6.7, run commands to add python3.7 as choice:

sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.6 1

sudo update-alternatives --install /usr/bin/python3 python3 /usr/bin/python3.7 2

Then switch between the two versions via command:

sudo update-alternatives --config python3

That’s it. Enjoy!

How to Enable and Set Compose Key in Ubuntu 18.04

Last updated: February 21, 2019

This quick tutorial is going to show you how to enable compose key to allow entering a wide variety of special characters in Ubuntu 18.04 Gnome desktop.

As an alternative to the Character Map tool, use Compose Key sequences can be the most effective way to type often used special characters. For example, compose key followed by C and o will enter ©, a followed by will enter á.

1. To enable compose key in Ubuntu 18.04 and higher Gnome desktop, first open Ubuntu Software, search for and install Gnome Tweaks

2. Then open Gnome Tweaks and navigate to Keyboard & Mouse settings in left pane.

Click the ‘Compose Key’ button to bring up its settings dialog.

3. Turn on the switch and choose a compose key in next window:

That’s it. For compose key sequences, see GtkComposeTable and GtkDeadKeyTable.