How to Install KDE Plasma 5.4 in (K)Ubuntu 15.04

The KDE Community finally announced the release of Plasma Desktop 5.4.0 yesterday morning.

Plasma 5.4 brings much improved high DPI support, a new fullscreen launcher, a new Audio Volume applet, over 1400 new icons, KRunner auto-completion and search history support.

With Plasma 5.4 the first technology preview of a Wayland session is released. On systems with free graphics drivers it is possible to run Plasma using KWin, Plasma’s Wayland compositor and X11 window manager, through kernel mode settings.

For more details, read the official announcement.

Install / Upgrade Plasma 5.4 in (K)Ubuntu 15.04/(K)Ubuntu 15.10:

KDE Plasma 5.4 now is available in Kubuntu CI PPA for both KUbuntu 15.04 and Kubuntu 15.10. To install it, open a terminal emulator from launcher and run below commands one by one:

1. Add Kubuntu CI Stable PPA:

sudo add-apt-repository ppa:kubuntu-ci/stable

If you’ve added Kubuntu backports PPA, and it does not yet update with Plasma 5.4. You may remove it via:

sudo add-apt-repository -r ppa:kubuntu-ppa/backports

2. Update system cache and upgrade your system:

sudo apt-get update

sudo apt-get dist-upgrade

If you’re not in Kubuntu, you may run below command to install KDE:

sudo apt-get install plasma-desktop

If everything goes well, restart your computer to apply changes.

To revert back your (K)ubuntu to previous status, install ppa-purge and purge the PPA as well as downgrade installed packages:

sudo apt-get install ppa-purge && sudo ppa-purge ppa:kubuntu-ci/stable


Turn Off Bluetooth By Default In Ubuntu 14.04

Open a terminal and use the following command to install gksu, if you dot have it installed it already.

sudo apt-get install gksu

gksu is used to enter password while running a program as root. Once you have gksu installed, use the command below:

gksudo gedit /etc/rc.local

It will open the rc.local file. Just add the following line just before exit 0.

rfkill block bluetooth

Altogether, your rc.local file look like this:

That would be it. Restart the computer and you should see that Bluetooth has been disabled. Of course you can turn it on when required by the Bluetooth indicator on the top panel.


This little section is just to give a brief explanation of what we did here. It’s not obligatory to read this section. You can skip to comment section for your suggestions or thanks :)

rc.local file is used to run various shell commands at start up time. These commands are user defined. In a clean install, rc.local has no commands to run. What we did here was to add rfkill block bluetooth. rfkill is a tool to query the state of various switches, buttons and subsytem interfaces. With this command in rc.localm we are basically soft blocking Bluetooth at each start up time. I hope this explains the things a bit.

Install MySql from source on CentOS

Ở bài này sử dụng mysql-5.6.14.tar.gz trên CentOS 6.4 (64bit).
Các gói cần thiết để cài mysql-5.6.14:

  • cmake 2.8.12
  • gcc-c++
  • ncurses-devel
  • bison-devel

Cài hết các gói trên thì đến bước cài mysql:

# Preconfiguration setup
shell> groupadd mysql
shell> useradd -r -g mysql mysql
# Beginning of source-build specific instructions
shell> tar zxvf mysql-VERSION.tar.gz
shell> cd mysql-VERSION
shell> cmake .
shell> make
shell> make install
# End of source-build specific instructions
# Postinstallation setup
shell> cd /usr/local/mysql
shell> chown -R mysql .
shell> chgrp -R mysql .
shell> scripts/mysql_install_db --user=mysql
shell> chown -R root .
shell> chown -R mysql data
shell> bin/mysqld_safe --user=mysql &
# Next command is optional
shell> cp support-files/mysql.server /etc/init.d/mysql.server